# G30-770 or G25-660



## leeroygibbano (Nov 9, 2019)

I'm having a bit of a (re)think regarding turbos. The existing 3582s are OK but too slow coming on the spool. I've seen some good information about the G25-660 turbos and I've decided to go that route, but before the engine goes back in, I've got to consider if I'm likely to want to go further later on.

With Built box, Quaife billet LSD, casings and all of the supporting fuelling, I could fairly easily go for a larger engine (maybe 4.1litres) in future and make 1300-1400hp at the crank, but I don't know whether the driveability at 1000/1100 would be that much worse with G30-770's versus G25-660's.

I know both Turbos are fairly new to the market, but if anyone has any practical experience with either of these on VR38DETT engines, I'd be interested to hear about it. I guess I'll make the same power at 1.8 bar on G30s with a slightly later spool as I would at 2bar on G25s. I just don't want to be buying turbos again when I go large on the engine, the question is if the G30 will be any less driveable / will the difference be noticeable?

Cheers in advance!


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## leeroygibbano (Nov 9, 2019)

Also, does anyone have any advice about "no brainer" bits to change whilst the engine is out - I'm consdering uprated throttle bodies, as an example.


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## PhilEvans64 (Oct 30, 2018)

I have some SVM 70mm TB's that I may have fitted next year; though one respected tuner warned there could be idle issues whereas another said no problem. It seems there are lots of US and Japanese cars with larger TB's but you also see standard TB's on big builds. King bearings, ARP bolts and Supertech valve guides could be done with the engine. As well as various braces. The gearbox and clutch will presumably be upgraded too?


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## leeroygibbano (Nov 9, 2019)

Gearbox and clutch are both good for 1500hp +, I'm focusing on the engine bay now.


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## TABZ (Apr 30, 2003)

Is engine being built?

I had/have the linney Garret GT32’s fitted and found them to be an excellent medium between fast road spool and good torque curve further up.

Graph for comparison on 2 different cars but same turbo set up.


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## scoooby slayer (Jun 13, 2009)

Totally off topic but I thought srd had a Dyno dynamics Dyno ?


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## dudersvr (May 7, 2003)

scoooby slayer said:


> Totally off topic but I thought srd had a Dyno dynamics Dyno ?


Nope Dynojet


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## dudersvr (May 7, 2003)

leeroygibbano said:


> I'm having a bit of a (re)think regarding turbos. The existing 3582's are OK but too slow coming on spool. I've seen some good information around the G25-660 turbos and I've decided to go that route, but before the engine goes back in I've got to consider if I'm likely to want to go further, later on.
> 
> With Built box, Quaife billet LSD, casings and all of the supporting fuelling I could fairly easily go for a larger engine (maybe 4.1litres) in future and make 1300-1400hp at the crank, but I really don't know whether the driveability at 1000/1100 would be that much worse with G30-770's versus G25-660's.
> 
> ...


Dude 4.1 with 3582 would not be laggy, we expected no lag with my GT3584RS (which are for sale and will do over 1500whp)


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## scoooby slayer (Jun 13, 2009)

dudersvr said:


> Nope Dynojet


I've had a brain fart just realised I was thinking of Surrey rolling road lol


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## scoooby slayer (Jun 13, 2009)

TABZ said:


> Is engine being built?
> 
> I had/have the linney Garret GT32’s fitted and found them to be an excellent medium between fast road spool and good torque curve further up.
> 
> Graph for comparison on 2 different cars but same turbo set up.


I can't make sense of the srd plot it's just a smooth torque curve like an na engine, I've just checked mine and the race fuel plot looks like this aswell where torque just keeps on climbing into higher rpms 


But the JM run shows clearly full boost hit at 4500 rpm when motor hits peak torque first, I assume that one is a pump fuel run, and srd is race fuel run


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## Black_Supra (Aug 18, 2015)

Some Dynoplots Linney posted on Facebook a few days before.

All Plots on the same Dyno

G25_660

G30_770

G30_770_vs_EFR_6758


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## leeroygibbano (Nov 9, 2019)

I'm epected full boost at 3k rpm, just trying to see how later it would be on G30 vs G25


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## scoooby slayer (Jun 13, 2009)

leeroygibbano said:


> I'm epected full boost at 3k rpm, just trying to see how later it would be on G30 vs G25



I can't see over 1000 hp and full boost by 3000 rpm being possible, unless your talking about full boost by 3000 rpm in higher gears only ?


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## TABZ (Apr 30, 2003)

I’ve no idea ScoobySlayer tbh as the Jm graph is from my car and the SRD is from another car (courtesy of Dudesvr)

Think they’re the ideal fast road turbo imo and I was delighted with them, just need to sell them now


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## leeroygibbano (Nov 9, 2019)

So do i keep these 35xx's or what?


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## scoooby slayer (Jun 13, 2009)

leeroygibbano said:


> So do i keep these 35xx's or what?


I would be 100% keeping the gt35s if it was me future proof for big power


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## scoooby slayer (Jun 13, 2009)

TABZ said:


> I’ve no idea ScoobySlayer tbh as the Jm graph is from my car and the SRD is from another car (courtesy of Dudesvr)
> 
> Think they’re the ideal fast road turbo imo and I was delighted with them, just need to sell them now


They look good mate with full boost at 4500 rpm, my green one is full boost around 5400 rpm like gt37s I think garret equivelant, and my road car gt30s full boost by 3500 rpm is real responsive for upto around 960 hp


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## gtr mart (Mar 29, 2004)

You need to be clear on what you want tbh. If big power the 35s are great. But totally wasted at 1000bhp. If you want better response and to be able to run at 1000 ish with better response then the g25 660 will deliver the goods. But you'll never breach 1200/1400 bhp.

Whilst 1000bhp is a great number to quote, it's just a common power number nowadays. If you want to be really special then you need 1600 to 2000bhp.

So be clear on what you want and shoot for it. If it's sub 1200 on pump with good spool then those g25/ maybe g30s look sweet and will likely out spool most other turbos. I have the full efr 7673 kit which will do similar power on pump fuel so would be interested in the results if you pic a different turbo.

But you need the fuel system to match anything beyond 1050 bhp imo.


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## leeroygibbano (Nov 9, 2019)

I'm not chasing numbers per se but a reliable 850-900lb ft and 1100hp preferably under 2 bar would be nice.


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## dudersvr (May 7, 2003)

Black_Supra said:


> Some Dynoplots Linney posted on Facebook a few days before.
> 
> All Plots on the same Dyno
> 
> ...


Well you wont make head nor tail of those as they are not scaled correctly, torque crosses hp at 5250 rpm they dont touch


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## gtr mart (Mar 29, 2004)

I couldn't really zoom in very well on the plots but it's possible they aren't crossing because the torque line is not in lbft


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## krozna (Sep 1, 2019)

leeroygibbano said:


> I'm having a bit of a (re)think regarding turbos. The existing 3582's are OK but too slow coming on spool. I've seen some good information around the G25-660 turbos and I've decided to go that route, but before the engine goes back in I've got to consider if I'm likely to want to go further, later on.
> 
> With Built box, Quaife billet LSD, casings and all of the supporting fuelling I could fairly easily go for a larger engine (maybe 4.1litres) in future and make 1300-1400hp at the crank, but I really don't know whether the driveability at 1000/1100 would be that much worse with G30-770's versus G25-660's.
> 
> ...


Hi! You said you have changed your OEM differential to Quaife LSD and no need to limit torque anymore, so can you tell me how much OEM front differential can handle power/torque? If the casing is already changed to billet.

I have heard that the cast casing is the biggest problem but parts inside of it should handle well even bigger horsepowers, +1000bhp.

Or am I wrong?


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## leeroygibbano (Nov 9, 2019)

I'm going by the advice I've received that the Quaife LSD will be "enough" with the other drivetrain components I have to do mid 800lb ft's, but anything else is "unknown". I think that was to cover said person, so no complaints. The front casing does seem to be the thing that holds together most of the standard diffs and of course, less flex is less stress on the internals. I guess it's horses for courses as there will be many out there with standard internals and uprated casings, too.

I don't have any definitive markers here but I'm quite confident that this setup will hold a 850lb/ft (or maybe more) setup with 1000-1100hp and in my style of driving.

If something breaks I'll be going up towards the 2000hp mark with a billet race engine and might even be confident enough to drag the car, that's the summer target but I'd like to see how it drives at 1000hp, first.


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## gtr mart (Mar 29, 2004)

I have the quaife. Make a nice difference to the drive. I also went billet front diff housing as I wasn't prepared for the oem housing to break as on rare occasions it can take the block out. I run the Litchfield sport engine and needed to protect it. 

The issue is often the big gear (pinion gear?) that breaks. I'm pretty sure this is reused, even when you go for a quaife. 

If you opt to go 2000bhp, you'll pretty much be starting from scratch. I'd also say it will be terrible to drive on the road.


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## leeroygibbano (Nov 9, 2019)

Been in today to collect the RS6 and had a chat. I'm sticking with the G25's for this engine; we'll replace them if / when we need to go further - I think the spool will be worth it and there's not much point going to G30 (T3) for now.

Thanks for the advice on the diff, will be looking to do the casing and ask about the pinion gear, although I saw what they removed today and it's a complete unit that's been taken out...


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## krozna (Sep 1, 2019)

I have those G25’s also going in soon, so was thinking just to replace the billet casing and keeping oem internals. Was thinking that you get more benefits from Quaife if you are driving on the track and I’m planning only doing some 400m/half mile challenges. But do you guys think I still should go with Quaife?
Yes the pinion gear is the weak point and I haven’t found any stronger part with oem ratio. Linney said while ago that they are currently designing that.


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## leeroygibbano (Nov 9, 2019)

Re: " But do you guys think I still should go with Quaife? " I'll let you know once I've driven the car, hopefully this weekend.


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## krozna (Sep 1, 2019)

leeroygibbano said:


> Re: " But do you guys think I still should go with Quaife? " I'll let you know once I've driven the car, hopefully this weekend.


Ok, looking forward ??


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## Lith (Oct 5, 2006)

Black_Supra said:


> Some Dynoplots Linney posted on Facebook a few days before.
> 
> All Plots on the same Dyno
> 
> ...


These are really interesting, I'm very surprised to see the G30s appear to match the EFR6758s - I haven't been able to find this post ANYWHERE, or really any results or comparisons for G30s. Do you have a link to the post, or any other info about the testing? The comments I've heard through the GT-R world so far indicate the G30-770s are a little disappointing response wise, yet matching EFR6758s seems too good to be true.


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## leeroygibbano (Nov 9, 2019)

Looks like we're going to find out what the G30-770's can do. Does anyone have any graphs from these in stock location (with spacer bracket) on a 3.8 engine?


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## gtr mart (Mar 29, 2004)

I've not seen anything on those so far but certainly look interesting. I notice Litchfield will be running the 900s on a 4.6 build shortly, albeit on the LM manifolds. 

I've just had my Efrs checked over and serviced by LM/tuebo dynamics but was wondering if the G30s might have been nice. Efrs got a clean bill of health though and drive so nice I thought I'd stick with them.


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## leeroygibbano (Nov 9, 2019)

I'll have some results to report in about a week. The G25's just didn't hit the spot.


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## Chronos (Dec 2, 2013)

leeroygibbano said:


> I'll have some results to report in about a week. The G25's just didn't hit the spot.


didn't hit the spot? how so? arn't they supposed to be 1000bhp capable super spoolers?


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## leeroygibbano (Nov 9, 2019)

Hit a brick wall at 980hp - probably needs other supporting mods like manifold, inlet, maybe cams etc. to go the rated figures. Gonna try some G30's and give my self some more initial power with headroom to go higher later on. Car is having a few little breathing oddities and these may well go away with more flow through the turbo and little bit less boost.


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## Chronos (Dec 2, 2013)

leeroygibbano said:


> Hit a brick wall at 980hp - probably needs other supporting mods like manifold, inlet, maybe cams etc. to go the rated figures. Gonna try some G30's and give my self some more initial power with headroom to go higher later on. Car is having a few little breathing oddities and these may well go away with more flow through the turbo and little bit less boost.


maybe lose a bit of spool with the G30s tho?


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## gtr mart (Mar 29, 2004)

leeroygibbano said:


> Hit a brick wall at 980hp - probably needs other supporting mods like manifold, inlet, maybe cams etc. to go the rated figures. Gonna try some G30's and give my self some more initial power with headroom to go higher later on. Car is having a few little breathing oddities and these may well go away with more flow through the turbo and little bit less boost.


What breathing oddities?

Initially I wondered if you got beaten by something or someone you shouldn't have ? ?


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## leeroygibbano (Nov 9, 2019)

gtr mart said:


> What breathing oddities?
> 
> Initially I wondered if you got beaten by something or someone you shouldn't have ? ?


I got beaten by a milk float due to some wierd knock sensor issue but we're also seeing a bit of oil around the cylinder walls and want to drive the car gently for a bit after doing a breathing mod. I decided on the couple of decent runs I had that I want a bit more build up on spool and more drama higher up, these are literally pulling in air from bugger all rpm. Will be an interesting comparison between 3584, G25 and G30 no doubt.


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## gtr mart (Mar 29, 2004)

Those 3584 you had looked like junk if I'm remembering you dyno plot correctly. I think your decision to change them was a good one and the results will make for a very drivable car. 

I know what you mean about wanting a bit more drama. I went efr 7663 but capped the torque down a bit and love it when they come on boost. 

I'm looking forward to your results. You should chat to iain about a flex fuel tune too so you can run ethanol as and when you want to. Not sure if your fuel system will be handle it though

Bad news on the oil on the cylinders. Hope that's nothing too serious.


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## leeroygibbano (Nov 9, 2019)

gtr mart said:


> Those 3584 you had looked like junk if I'm remembering you dyno plot correctly. I think your decision to change them was a good one and the results will make for a very drivable car.
> 
> I know what you mean about wanting a bit more drama. I went efr 7663 but capped the torque down a bit and love it when they come on boost.
> 
> ...


Yeah, I wasn't enamoured with the 3584's and they were a bit "all or nothing" although the map was also very generic. I'm not mad on these turbos where the housing is cut and welded at 90 degrees, seems a bit retarded to do that to a brand new turbo, at least to me.

The silly thing is the car had EFR's on it before they were changed to 3584's..... I'm not really interested in Ethanol as I'd end up just buying loads of it to have full power all the time. I do have a set of 1600cc injectors which came out of the car, though! Fuel system will do it fine, just not interested.

They are convinced the oil in the cylinders is due to a breathing issue with the separator that's on it. We'll see I guess - I'm running with the rear crankcase breather into an oil bottle and checkig its contents after every drive. Not seeing a massive amount in there.


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## scoooby slayer (Jun 13, 2009)

If your wanting over 1000 hp imo there is no free lunch where your gonna have stock like spool, gotta loose some at the bottom to gain some at the top it's just physics imo 

My latest gtr is making almost 1100 hp at the wheels so about 1250 crank hp on pump fuel 2 bar of boost, but the turbos are a gt37 size turbo motor pulling strong by 4000 rpm but don't make full boost til approx 5500 rpm


Whereas my road gtr gt30s full boost 3500 rpm 928 hub hp 1.8 bar on e50 and turbos are flat out it just won't make anymore power


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## leeroygibbano (Nov 9, 2019)

scoooby slayer said:


> If your wanting over 1000 hp imo there is no free lunch where your gonna have stock like spool, gotta loose some at the bottom to gain some at the top it's just physics imo
> 
> My latest gtr is making almost 1100 hp at the wheels so about 1250 crank hp on pump fuel 2 bar of boost, but the turbos are a gt37 size turbo motor pulling strong by 4000 rpm but don't make full boost til approx 5500 rpm
> 
> ...


I think the G30's will hit the spot. the 25's spool is no doubt awesome but I don't need it quite that early, 500-700rpm later is fine, just want some more headroom. 

Few other problems to deal with and some logging / driving to do, but I think the G30's will do the trick once everything else is sorted.


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## leeroygibbano (Nov 9, 2019)

scoooby slayer said:


> If your wanting over 1000 hp imo there is no free lunch where your gonna have stock like spool, gotta loose some at the bottom to gain some at the top it's just physics imo
> 
> My latest gtr is making almost 1100 hp at the wheels so about 1250 crank hp on pump fuel 2 bar of boost, but the turbos are a gt37 size turbo motor pulling strong by 4000 rpm but don't make full boost til approx 5500 rpm
> 
> ...


I've never driven a stock GTR so I wouldn't know what stock spool is like 

First one I've ever driven after being nagged by Andy Clarke to get one as a part time toy (mainly because he said I'd break it all the time) was a Litchfield 775hp which they had for sale. I loved the aggressive steering, suspension felt accomplished and tight but not uncomfortable, car went and sounded perfect, but just not quite enough to excite me. 

I bought a "1000hp" car which was "sorted" and ended up with one with multiple problems but a good base configuration. It was still cheaper than doing it myself (or at least that's what I keep saying to myself) but in all truth, you never get exactly what you want unless you build it yourself.

"Stock" I'd imagine would be very boring. If I find a 775hp car capable, but far from exciting there's next to no hope of me buying a Nismo, Track edition or otherwise and finding it fulfilling.

Choices to far have been mainly to "reverse the hooligan elements of the car" with a few mods for strength and abuse capability, but the turbos are really a personal choice. This car has had OEM, EFR, GT3584, G25-660 and will now have G30-770's. It's only done 14k miles so it begs the question "Is there an underlying gremlin which has been chased by many".

So far I'm into the car for £60k (ish) and have a good spec, but need to get to the point it handles and goes like I want. We'll get there and I must add that there's a lot of hours being trousered by the garage now when this isn't their fault, but they also need some R&D and logs for these new generation of turbos, with miles being put on the setup an advantage as they don't have the time.

It's going to end up being an epic car, and certainly I don't want to outstay my welcome and be a moany punter, if what I'm getting at the end is the result of a lot of new kit, development and willing to try things. After all this isn't my only fast car.

Once we're sure about the engine internals and breathing, I have no doubt there'll be willingness to push the G30's reasonably hard, but to make sure no one (including me) gets pissed off we need to see what it'll do at around 1100hp, first.


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## scoooby slayer (Jun 13, 2009)

I've never driven a stock gtr either
But look at this for response just 1.5 bar on pump fuel 840 hp
30-130 mph 6.8 seconds










But limited on power due to relatively small turbos 
Will be interesting to see where the g30s spool and make full boost from a dyno plot, to torque curves will pretty much show the boost curve


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## krozna (Sep 1, 2019)

leeroygibbano said:


> Hit a brick wall at 980hp - probably needs other supporting mods like manifold, inlet, maybe cams etc. to go the rated figures. Gonna try some G30's and give my self some more initial power with headroom to go higher later on. Car is having a few little breathing oddities and these may well go away with more flow through the turbo and little bit less boost.


Interesting to see what kind of difference you will have with G30’s.

You should definitely have more power on G25’s with aftermarket intake manifold, throttle bodies, cams etc...

But didn’t you also say that your connecting rods can’t handle all the torque? That could be even more a problem with G30’s if you really want to find out more power out of them?


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## leeroygibbano (Nov 9, 2019)

Rods are up for debate, Manley Turbo Tuff.


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## leeroygibbano (Nov 9, 2019)

Pistons are 
*625GR3-1*
Rods are
*Manley Pro Series I-Beam Turbo Tuff Connecting Rods 14424-6*


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## gtr mart (Mar 29, 2004)

I thought turbo tuff were OK tbh


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## krozna (Sep 1, 2019)

leeroygibbano said:


> Pistons are
> *625GR3-1*
> Rods are
> *Manley Pro Series I-Beam Turbo Tuff Connecting Rods 14424-6*


Ok, those rods are rated to 1250 flywheel. Should be ok with pump gas without need of limiting torque.


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## leeroygibbano (Nov 9, 2019)

krozna said:


> Ok, those rods are rated to 1250 flywheel. Should be ok with pump gas without need of limiting torque.


Yes, that's what I understand but garage has advised the engine was built for 900 ish so maybe there's some other stuff which isn't uprated and needs to be. Not sure if bearings, head studs etc. need to be aftermarket, maybe that's it as the components of a LM 3.8 are just uprated rods and pistons, most other stuff is OEM.

I think they are comfortable with 1100 ish but not a massive amount more. Torque they were keen to limit to 800lb ft.

I'm of the mind to say screw it, if the breathing issue is sorted let's just turn up the taps.


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## scoooby slayer (Jun 13, 2009)

leeroygibbano said:


> Yes, that's what I understand but garage has advised the engine was built for 900 ish so maybe there's some other stuff which isn't uprated and needs to be. Not sure if bearings, head studs etc. need to be aftermarket, maybe that's it as the components of a LM 3.8 are just uprated rods and pistons, most other stuff is OEM.
> 
> I think they are comfortable with 1100 ish but not a massive amount more. Torque they were keen to limit to 800lb ft.
> 
> I'm of the mind to say screw it, if the breathing issue is sorted let's just turn up the taps.



I don't suppose you have dyno plots for the 3584s and then the g25 660s do you ? 

I'd like to have a look at those if possible bud


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## leeroygibbano (Nov 9, 2019)




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## scoooby slayer (Jun 13, 2009)

leeroygibbano said:


> View attachment 258629



That's incredible they made the same hp above 5000 rpm and the g25s have all that gain in spool down low 

Do you know what boost pressure each tune is running ?


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## leeroygibbano (Nov 9, 2019)

2bar on both mate.


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## leeroygibbano (Nov 9, 2019)

Really struggling to find any neck and neck comparisons on the same GTR engine, in fact hardly any comparisons at all, other than Evo forums (single turbo and much smaller displacement). Really looking forward to seeing what these do and comparing between 3584, G25 and G30, should make for an interesting read.


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## jimbo1234567 (Sep 17, 2018)

I can see you having a 4.6 engine before the month is out...


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## leeroygibbano (Nov 9, 2019)

LOL, you're probably right.


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## Skint (Oct 11, 2014)

That’s a decent improvement, from 2k onwards you should be able to tell the difference.
660’s should have plenty left in them.


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## leeroygibbano (Nov 9, 2019)

Skint said:


> That’s a decent improvement, from 2k onwards you should be able to tell the difference.
> 660’s should have plenty left in them.


Literally nothing left at 2.1 , 2.2 , 2.4 bar.


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## scoooby slayer (Jun 13, 2009)

leeroygibbano said:


> Literally nothing left at 2.1 , 2.2 , 2.4 bar.


My gt30s did the same mate 928 hub power and just flatlined 
I'm really looking forward to these g30 results, if they don't top 1000 hp there's got to be another restriction somewhere


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## HellsSalesman (Apr 12, 2017)

leeroygibbano said:


> Pistons are
> *625GR3-1*
> Rods are
> *Manley Pro Series I-Beam Turbo Tuff Connecting Rods 14424-6*


the first limiting factor here are the small .180" Wall piston pins which are not even good for 1000hp. the pistons and rods themselfes will take a lot more than 1200hp.


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## Tiler (Mar 28, 2014)

4.6 now you are talking. You can take another 800rpm out of that. For more low down grunt.


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## leeroygibbano (Nov 9, 2019)

HellsSalesman said:


> the first limiting factor here are the small .180" Wall piston pins which are not even good for 1000hp. the pistons and rods themselfes will take a lot more than 1200hp.


wrist pins are the first thing we change in high power generating sets


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## krozna (Sep 1, 2019)

leeroygibbano said:


> wrist pins are the first thing we change in high power generating sets


Yes can’t believe it can be like that. I think that’s a totally wrong place to save costs, wrist pins...


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## scoooby slayer (Jun 13, 2009)

Tiler said:


> 4.6 now you are talking. You can take another 800rpm out of that. For more low down grunt.



It will knock of some rpms of spool at the bottom but it will also I'm sure knock off some rpms of the rev limit as the rod angles with a 4.6 must be far from ideal ! 

I'd rather a high revving 3.8 barnstormer, my vr38 on e100 revs to 8500 rpm 
I'd like to know the safe rpm limit of the Manley 4.6 stroker kit ........


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## Black_Supra (Aug 18, 2015)

HellsSalesman said:


> the first limiting factor here are the small .180" Wall piston pins which are not even good for 1000hp. the pistons and rods themselfes will take a lot more than 1200hp.


Got the same pistons with only 0.18" Wall piston pins. My tuner told me 1.100 hp wouldn`t be a problem.

I am pretty sure your limiting factor are the stock camshafts.


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## gtr mart (Mar 29, 2004)

Jamie P runs stock heads and cams (uprated springs) and I'm sure made 1150 whp on ethanol. 

That's on a switzer r1000 turbo which I think is a modified GT30


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## scoooby slayer (Jun 13, 2009)

gtr mart said:


> Jamie P runs stock heads and cams (uprated springs) and I'm sure made 1150 whp on ethanol.
> 
> That's on a switzer r1000 turbo which I think is a modified GT30


Gt3081s I think he said, 980 whp at 2 bar on pump fuel, and on a dynojet looks like full boost about 4500 rpm, mine only makes an extra 100 hp on pump fuel at 2 bar and I've got worked heads and 272 cams and I'm 1000 rpm later spool at 5500 rpm for max boost !
Jamie's setup is working really well incredible for gt30s minimum lag and upto 1350 hp crank power 
And remember we are talking wheel figures here not the guestimated flywheel figures


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## HellsSalesman (Apr 12, 2017)

Black_Supra said:


> Got the same pistons with only 0.18" Wall piston pins. My tuner told me 1.100 hp wouldn`t be a problem.


well good luck!

should have went with the Manley Extreme Duty Pistons which include the 9310 alloy .210" wall pin:

*PISTON WRIST PINS AND PIN OFFSET*
Manley Nissan GT-R pistons are designed with offset wrist pins to reduce connecting rod angularity. Please note the arrow on the top of each piston. This arrow MUST point to the front of the block. _The Standard Series pistons come with Premium Chrome Moly 0.180" wall (625 Series) _or 0.210" wall (626, 627, 631, 633, 634, and 635 Series) _pins suitable for up to 800WHP_. _The Extreme Duty Series come with 9310 alloy 0.210" wall pins suitable for 800-1600 HP._ Engines up to 2000 HP it is recommended to install our Turbo Tuff/DLC 0.250" wall wrist pins P/N 42745. Engines exceding 2000 HP it is highly recommended to install our Turbo Tuff/DLC .300" wall wrist pins P/N 42746.


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## dudersvr (May 7, 2003)

krozna said:


> Yes can’t believe it can be like that. I think that’s a totally wrong place to save costs, wrist pins...


These are used by ETS for 3500 the one on the right of pic


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## dudersvr (May 7, 2003)

scoooby slayer said:


> It will knock of some rpms of spool at the bottom but it will also I'm sure knock off some rpms of the rev limit as the rod angles with a 4.6 must be far from ideal !
> 
> I'd rather a high revving 3.8 barnstormer, my vr38 on e100 revs to 8500 rpm
> I'd like to know the safe rpm limit of the Manley 4.6 stroker kit ........


Yeah it must be low revving, we asked callies and ets about my max rpm and he said 9000 would be fine ocasionally as it rapidly wears the valve train.


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## scoooby slayer (Jun 13, 2009)

dudersvr said:


> Yeah it must be low revving, we asked callies and ets about my max rpm and he said 9000 would be fine ocasionally as it rapidly wears the valve train.


What cc are you mate ?


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## dudersvr (May 7, 2003)

scoooby slayer said:


> What cc are you mate ?


4.1


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## scoooby slayer (Jun 13, 2009)

dudersvr said:


> 4.1


Perfect that's around where I would go if ever stroking so as not to loose the rpm, imagine the 4.6 at 8500 rpm, boooooooooooom ? lol


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## krozna (Sep 1, 2019)

dudersvr said:


> These are used by ETS for 3500 the one on the right of pic


Those are nice n thick.

I got CP pistons with HD wrist pins myself.

What I meant with my message was that it is hard to see that the engine is assembled so that the pins can take less power than the connecting rods itself. I think it’s the wrong place to save costs.

Or let’s say if 800whp really is enough, there may be cheaper rods and pistons on the market for that power level.


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## Tiler (Mar 28, 2014)

The reason I went for the 4.6 was more low down grunt. The toque comes in much earlier than a 3.8. There is no need to rev the nuts out of it. 7600rpm is fine for me. And you only need 1.7 bar to make 1100bhp with ease.


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## krozna (Sep 1, 2019)

leeroygibbano said:


> Yes, that's what I understand but garage has advised the engine was built for 900 ish so maybe there's some other stuff which isn't uprated and needs to be. Not sure if bearings, head studs etc. need to be aftermarket, maybe that's it as the components of a LM 3.8 are just uprated rods and pistons, most other stuff is OEM.
> 
> I think they are comfortable with 1100 ish but not a massive amount more. Torque they were keen to limit to 800lb ft.
> 
> I'm of the mind to say screw it, if the breathing issue is sorted let's just turn up the taps.


Hi mate,

anything new with G30’s?


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## leeroygibbano (Nov 9, 2019)

Nothing yet I'm afraid, still patiently waiting for a call to drop the car off. I might give them a call tomorrow to see if they can get it in next week as it's just sat locked in my workshop at the moment.


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## archan (Apr 25, 2019)

Any news? I am considering pulling the trigger on a set of g30-770s myself.


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## leeroygibbano (Nov 9, 2019)

Litchfield are still closed. I'm considering asking for the turbos and fitting them myself !


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## archan (Apr 25, 2019)

Just saw a post on a other GT-R forum. He got 1207 AWHP out of his Linney g30-770. 3,6s 60-130 mph. Sounds like solid turbos to me.


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## leeroygibbano (Nov 9, 2019)

You got a link Archan?


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## archan (Apr 25, 2019)

Yes!








New gt25 660 turbo/kits


Hello again guys. I'm wondering anyone has tried the ets kit using the GT25 660 turbos from garett? I was review a few articles that are very recent and lots of good things are being said about this combination, obviously on a built motor and not for the stock setup. I'm wondering how this...




www.gtrlife.com


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## leeroygibbano (Nov 9, 2019)

Cheers!

I've been speaking with Andy Clarke and he's of the same opinion as I am - The G25's are solid for ~900hp (fly) but seem to get very hot after a couple of runs and timing gets pulled once you heat them up a bit. I'm really still completely unimpressed with the rated figures versus realy world figures but the G30's will probably hit the spot. That said I doubt I'll be getting mine any time soon.


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## krozna (Sep 1, 2019)

Are there any differences between oem cover IHI or G25/G30 covers? Any power or spool differences?

Have seen both. Those suction pipes are smaller on IHI covers so sounds like airflow is not the same then.


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## dudersvr (May 7, 2003)

It seems there seems to be an issue with G25's in stock manifolds, they just build back pressure after x amount of boost, so 1.6 bar is your max! However they work really well on E85/98
As for G30's, well on a proper manifold they are a fantastic turbo however the magic is in the housing so once you remove the housing the internals are not that special, why use a turbo thats way more expensive than say a GTX3076 to throw the trick part in the bin? save the best part of 2K and go with a GTX3076 , the stock manifold is always going to be a restriction, yes it can do a glory pull on a dyno or a drag run, but run it on track etc and it will get hot and watch the power fall away!


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## Skint (Oct 11, 2014)

Are they any better than the efr’s


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## krozna (Sep 1, 2019)

Any news _leeroygibbano_ what kind of difference turbos made?


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## krozna (Sep 1, 2019)

_archan_ did you get your G30-770's yet?


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## Skint (Oct 11, 2014)

Well I am looking at these g series turbine housings and see an open scroll, cast stainless, v band mounting housing, they‘been in production for years by different manufacturers.

Am I missing something obvious?


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## krozna (Sep 1, 2019)

dudersvr said:


> It seems there seems to be an issue with G25's in stock manifolds, they just build back pressure after x amount of boost, so 1.6 bar is your max! However they work really well on E85/98
> As for G30's, well on a proper manifold they are a fantastic turbo however the magic is in the housing so once you remove the housing the internals are not that special, why use a turbo thats way more expensive than say a GTX3076 to throw the trick part in the bin? save the best part of 2K and go with a GTX3076 , the stock manifold is always going to be a restriction, yes it can do a glory pull on a dyno or a drag run, but run it on track etc and it will get hot and watch the power fall away!


Would be nice to know that what other parts are around them if really 1.6 bar is the max, too small downpipes/exhaust? Any head work made etc?


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## Skint (Oct 11, 2014)

I would say the restriction is the oem exhaust manifold/housing, it was never designed for large turbo’s with big flow rates.

They are renound for cracking and you have to hack and weld them up to make into hybrid turbo’s.


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## krozna (Sep 1, 2019)

Yes the exhaust manifold is too small, companies who have their own designed exhaust manifolds they got a lot more power out of them.


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## krozna (Sep 1, 2019)

I think they use the oem exhaust manifold even with the way bigger turbos, like G35’s?


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## krozna (Sep 1, 2019)

Black_Supra said:


> Some Dynoplots Linney posted on Facebook a few days before.
> 
> All Plots on the same Dyno
> 
> ...


Back to these dynoplots, looks interesting.

G25’s can pull almost all the way to the rev limiter, but looks like G30’s are really struggling, they clogging already on 7000rpm and power levels going down fast...for me it looks like those stock exhaust manifolds are already way too small for these G30’s... What you guys think?


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## archan (Apr 25, 2019)

krozna said:


> _archan_ did you get your G30-770's yet?


I ended up selling the car instead. Not a fan of rebuilds as the cost is pretty much the same as new build when more and more parts need to be uppgraded. Also I wanted the EBA model (MY17). However the market here in Sweden is stale as f-k. Interest for the GT-R is dropping like a rock.

On topic: quite interesting info regarding the stock manifolds. I'd consider getting an aftermarket set if targetting 1000+ WHP based on the issue with cracking manifolds. Guessing it's easier to break them if tracking the car and running pump fuel. E85 cools and streetdriving means short pulls.


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## dudersvr (May 7, 2003)

archan said:


> I ended up selling the car instead. Not a fan of rebuilds as the cost is pretty much the same as new build when more and more parts need to be uppgraded. Also I wanted the EBA model (MY17). However the market here in Sweden is stale as f-k. Interest for the GT-R is dropping like a rock.
> 
> On topic: quite interesting info regarding the stock manifolds. I'd consider getting an aftermarket set if targetting 1000+ WHP based on the issue with cracking manifolds. Guessing it's easier to break them if tracking the car and running pump fuel. E85 cools and streetdriving means short pulls.


E85 makes a big difference, the stock manifold is a big restriction and just builds heat so performance drops off, big figure dyno run is easier as just run it when its cool enough, same with 1/4 time, there is opportunity to cool off between runs, do back to back dyno or street pulls and watch the power drop off .


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## Skint (Oct 11, 2014)

The manifolds crack on std cars, I know of a very low mileage car that suffered.


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## dudersvr (May 7, 2003)

All cast turbo exhaust manifolds crack, mostly around the pop valve, not normally an issue if it doesnt get too extreme


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## Skint (Oct 11, 2014)

They crack up at the top near the manifold face as well


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## scoooby slayer (Jun 13, 2009)

dudersvr said:


> It seems there seems to be an issue with G25's in stock manifolds, they just build back pressure after x amount of boost, so 1.6 bar is your max! However they work really well on E85/98
> As for G30's, well on a proper manifold they are a fantastic turbo however the magic is in the housing so once you remove the housing the internals are not that special, why use a turbo thats way more expensive than say a GTX3076 to throw the trick part in the bin? save the best part of 2K and go with a GTX3076 , the stock manifold is always going to be a restriction, yes it can do a glory pull on a dyno or a drag run, but run it on track etc and it will get hot and watch the power fall away!


My svm gt30s are the same 1.7 bar ethanol 928 whp and turbos are flat out 
Super responsive motor though


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## krozna (Sep 1, 2019)

archan said:


> I ended up selling the car instead. Not a fan of rebuilds as the cost is pretty much the same as new build when more and more parts need to be uppgraded. Also I wanted the EBA model (MY17). However the market here in Sweden is stale as f-k. Interest for the GT-R is dropping like a rock.
> 
> On topic: quite interesting info regarding the stock manifolds. I'd consider getting an aftermarket set if targetting 1000+ WHP based on the issue with cracking manifolds. Guessing it's easier to break them if tracking the car and running pump fuel. E85 cools and streetdriving means short pulls.


Oh really! True, cheapest way is to go all out from the stock setup.
I think if they would crack all the time, I think they wouldn’t sell them so much now, but definitely there is a possibility if going too extreme + they are a restriction.


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## krozna (Sep 1, 2019)

scoooby slayer said:


> My svm gt30s are the same 1.7 bar ethanol 928 whp and turbos are flat out
> Super responsive motor though


Stock exhaust manifold as well?


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## Skint (Oct 11, 2014)

If your wanting to use stock manifolds then the 2020 is much better, I am not sure if it’s possible to remove turbo’s in situ, but if the do crack you can buy manifolds and there’s a possibly of turbine housings, if there generic.
I have seen some on a work bench at Litchfields but did’nt want to touch or examine them as they are not mine.


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## krozna (Sep 1, 2019)

Skint said:


> If your wanting to use stock manifolds then the 2020 is much better, I am not sure if it’s possible to remove turbo’s in situ, but if the do crack you can buy manifolds and there’s a possibly of turbine housings, if there generic.
> I have seen some on a work bench at Litchfields but did’nt want to touch or examine them as they are not mine.


Whats the difference between 2020 and older manifolds?


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## scoooby slayer (Jun 13, 2009)

krozna said:


> Stock exhaust manifold as well?


Yeah there stock but I think made to flow better by svm 
Enough for 100-200kph in 4.3 seconds


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## krozna (Sep 1, 2019)

scoooby slayer said:


> Yeah there stock but I think made to flow better by svm
> Enough for 100-200kph in 4.3 seconds


Ok, maybe some machining done there more then


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## krozna (Sep 1, 2019)

On stock manifold with G25-660 on e85 I’ve seen 100-200kph in 3,57s


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## scoooby slayer (Jun 13, 2009)

krozna said:


> On stock manifold with G25-660 on e85 I’ve seen 100-200kph in 3,57s


Mine only runs e50 max 1.7 bar and power flatlined at 928 whp full boost at 3500 rpm though very responsive set up but lacks the top end grunt of my new one

That seems way to quick for that spec to me 3.57 seconds, mine in old spec at 1105 whp only pulled 3.57 100-200 kph but pulled a 9.7 @ 154 mph iirc


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## Skint (Oct 11, 2014)

Krozna, you asked the difference in manifolds between years,

08/2019 Manifolds are all the same. It’s a cast Iron manifold with the turbine housing built into it making it a single piece.

The pitfall here is that other than using the ihi journal bearing core there’s not much you can change on them, you can bore out the housings to accept bigger wheels but your fixed with a/r not being able to be altered So have a compromise straight away.
From memory you can’t buy the exact turbine and compressor wheels from the nismo to fit into stock housings, only wheels similar to the nismo.

The alternative to the above is to modify the std housings and weld an adaptor plate in to enable the fitment of such things like the efr/g series range of turbo’s but the a/r is still the same and can’t be altered.

The pitfall here is that if the manifold cracks which is very likely, you‘ll need to buy a std set of turbo’s just to get the manifolds off, And then have machined And welded again and now that’s 2 engine in and out jobs.

2020 onwards uses the the old school design where you an exhaust manifold and turbine housing separate. If you were to have a failure with this set up then the parts required will be less And costs involved much cheaper. I don’t know at this stage if you can remove the turbo’s in situ.
Ive seen the stock 2020 turbine units at Litchfields a few weeks ago but they were from a customers car so did’nt want to touch them, so I’m limited at this stage as to wether or not the turbine housing is general fitment or gtr fitment only.

Im sure with the 2020 turbine housing it’s much easier to modify and replace, I possibly think somebody with recast these manifolds with options of different a/r available.

This is just my general assumption, pls feel free to chip in any additional info or correct me where I may have gone wrong.

Thanks


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## krozna (Sep 1, 2019)

scoooby slayer said:


> Mine only runs e50 max 1.7 bar and power flatlined at 928 whp full boost at 3500 rpm though very responsive set up but lacks the top end grunt of my new one
> 
> That seems way to quick for that spec to me 3.57 seconds, mine in old spec at 1105 whp only pulled 3.57 100-200 kph but pulled a 9.7 @ 154 mph iirc


Check out MRT automotive on instagram, there they have first dynoed 1175bhp (Alpha 12/G25-660) and 3,57s with dragy results and videoclip. Nice numbers with stock exhaust manifold 👍🏽


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## krozna (Sep 1, 2019)

Skint said:


> Krozna, you asked the difference in manifolds between years,
> 
> 08/2019 Manifolds are all the same. It’s a cast Iron manifold with the turbine housing built into it making it a single piece.
> 
> ...


This is good info, maybe there will be some more potential for higher power levels.

I only have heard about cracked manifolds, but not seen one. If that would be that big of a problem, I think companies would not make turbo kits with stock exhaust manifolds anymore.


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## scoooby slayer (Jun 13, 2009)

krozna said:


> Check out MRT automotive on instagram, there they have first dynoed 1175bhp (Alpha 12/G25-660) and 3,57s with dragy results and videoclip. Nice numbers with stock exhaust manifold 👍🏽


What fuel are they using ? That is seriously quick for relatively small turbos that's for sure if it's true


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## Skint (Oct 11, 2014)

That car at MRT has a clip somewhere of it doing that pull on the dyno.

Its what I would expect to see on a good set up and confirms what I’ve been saying.

A size smaller turbo making much more power than the bigger framed ones.


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## scoooby slayer (Jun 13, 2009)

Skint said:


> That car at MRT has a clip somewhere of it doing that pull on the dyno.
> 
> Its what I would expect to see on a good set up and confirms what I’ve been saying.
> 
> A size smaller turbo making much more power than the bigger framed ones.


A smaller turbo is not going to make much more power than a bigger one what an odd thing to say 🤣😂 lol
It's just matching the flow of the exhaust and the compressor side to maximise the efficiency for the motor

With comparisons they must be like for like comparisons or your compareing apples to oranges

Fuel used, engine spec, gearing, vehicle weight, either boost pressure or turbo shaft speed are all things that can alter compareing results


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## Skint (Oct 11, 2014)

I believe the bigger turbo is not suited to the manifold, it only shows one dyno pull and I believe it power would drop more in the real world. It also shows nothing in terms of transient response.


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## scoooby slayer (Jun 13, 2009)

Skint said:


> I believe the bigger turbo is not suited to the manifold, it only shows one dyno pull and I believe it power would drop more in the real world. It also shows nothing in terms of transient response.


Yep spot on about the transient response just had the same with my cosworth, dropped down a turbo turbine housing size and only lost 10 hp and gained about 500 rpm max in boost curve on the dyno but out on the road mad instantly noticed a big increase in the response and coming on boost curve out on the road, and data logs verified it

The turbos that impress me the most so far on gtrs from looking at dyno plots are the elite prime r they look to be very good turbos for response and power


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## Skint (Oct 11, 2014)

Looking back at the dyno chart would I correct in saying there pushing more boost the the g series to make it looks like it’s more powerful than the efr?


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## scoooby slayer (Jun 13, 2009)

Skint said:


> Looking back at the dyno chart would I correct in saying there pushing more boost the the g series to make it looks like it’s more powerful than the efr?


Where's the dyno plots mate I can't see any ?


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## Skint (Oct 11, 2014)

It’s on SKellz thread.


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## krozna (Sep 1, 2019)

scoooby slayer said:


> What fuel are they using ? That is seriously quick for relatively small turbos that's for sure if it's true


They were on E51 ethanol, with stock intake manifold + stock throttle bodies. So there is definitely potential +1200bhp.

And they have a videoclip on their instagram of that 100-200 pull.

You should also check out these, that turbo kit is G25-660 with stock exhaust manifold:


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## krozna (Sep 1, 2019)

Skint said:


> Looking back at the dyno chart would I correct in saying there pushing more boost the the g series to make it looks like it’s more powerful than the efr?


Don’t know what dyno plot you are looking for but it’s been said that G25’s can’t handle more than 34psi (~2.35bar) of boost


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## Skint (Oct 11, 2014)

Whats your desired spec?


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## krozna (Sep 1, 2019)

Skint said:


> Whats your desired spec?


Mine? Exactly what those G25-660’s are giving.

1200bhp (w/ e85) with stock like spool, 8sec 1/4 mile, 3,5sec 100-200kmh.

Just amazing numbers with stock drivability!


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## scoooby slayer (Jun 13, 2009)

161 mph in the 1/4 mile is incredible for such small turbos 😮
Almost seems impossible in the 8s all the cars in the 8s I've seen are alot higher spec makes me think there's more to it either lightened or gearing altered or something


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## Skint (Oct 11, 2014)

whats it make on std pump fuel


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## scoooby slayer (Jun 13, 2009)

Skint said:


> whats it make on std pump fuel


I think he said in the video 988 hp on pump 😮


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## UKPAISLEY (Jan 17, 2003)

Alpha 12x 10K usd turbo kit ? inc new manifolds ?


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## krozna (Sep 1, 2019)

scoooby slayer said:


> 161 mph in the 1/4 mile is incredible for such small turbos 😮
> Almost seems impossible in the 8s all the cars in the 8s I've seen are alot higher spec makes me think there's more to it either lightened or gearing altered or something


No, it is a full weight car (3950lbs w/ driver, full interior) and those dynonumbers are AWHP. You can find Sam and his times on dragy too, example you can see there 60-130mph 3,79sec.


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## krozna (Sep 1, 2019)

UKPAISLEY said:


> Alpha 12x 10K usd turbo kit ? inc new manifolds ?


Yes it’s a stock manifold turbo kit. Just need to send your core there, otherwise paying the core fee for extra.


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## scoooby slayer (Jun 13, 2009)

krozna said:


> No, it is a full weight car (3950lbs w/ driver, full interior) and those dynonumbers are AWHP. You can find Sam and his times on dragy too, example you can see there 60-130mph 3,79sec.


It must be the ethanol making alot of difference, there's a g25 660 run on gtr cartel on pump fuel 4.6 100-200 kph


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## dudersvr (May 7, 2003)

Ask Lee Gibbins his experience on G25 stock manifolds! In fact im pretty sure a certain tuner will neither supply nor fit them anymore!


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## Reano (Oct 1, 2015)

dudersvr said:


> Ask Lee Gibbins his experience on G25 stock manifolds! In fact im pretty sure a certain tuner will neither supply nor fit them anymore!


 Tell us more? Why?


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## scoooby slayer (Jun 13, 2009)

Reano said:


> Tell us more? Why?


I would hazard a guess to small and get to hot


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## UKPAISLEY (Jan 17, 2003)

scoooby slayer said:


> I would hazard a guess to small and get to hot


when going over a given boost level? 1.6 or 1.7 bar ?


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## scoooby slayer (Jun 13, 2009)

UKPAISLEY said:


> when going over a given boost level? 1.6 or 1.7 bar ?


It's just a semi educated guess mate ? They are small turbos whatever anyone says, I have a gtr with gt30s on it, it needs alot of fuel in it to keep the temps down which Ryan did when he mapped it


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## Skint (Oct 11, 2014)

Where did this SVM project go to? Any updates?


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## Reano (Oct 1, 2015)

Will be soon just bedding in but you can see some progress here Facebook

Then gotta go back for mapping, etc


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## Reano (Oct 1, 2015)

__ https://www.facebook.com/SevernvalleyMotorsport/posts/3622737564454755



I can discuss some of the details but probably better I create a new page later.


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## Skint (Oct 11, 2014)

Hi, it would be great if you can do a full spec write up now your finalised.

Any dyno charts would be nice too👍

Thanks


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## Reano (Oct 1, 2015)

Skint said:


> Hi, it would be great if you can do a full spec write up now your finalised.
> 
> Any dyno charts would be nice too👍
> 
> Thanks


Yep will do. I’m looking at making a video per area as I think this will be my last full petrol car so going to the max for a street/track car.
was gonna go motec m150 and just tweak myself later (using high performance academy already used to do some on Subaru ages ago after doing the EFI 101 training) but for now will be ecutek with Linney tuning.
should also have the dyno’s too but cFeb 😮 when fully complete as might change plastic catch can to a black one as just sticking out at mo


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## Terryc82 (Aug 13, 2021)

Hi guys,
Any further updates from guys running g30-770 over g25-660?

I’m currently about to pull the trigger on either Linney version and can’t decide…


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## Reano (Oct 1, 2015)

Terryc82 said:


> Hi guys,
> Any further updates from guys running g30-770 over g25-660?
> 
> I’m currently about to pull the trigger on either Linney version and can’t decide…


Linney version or Linney advertised one (should just be the standard one) unless he said he polished it a bit to make it Linney 'version', anyway. From what I understand (I have the G30-770) that the g25-660 has had some back pressure issues but I dont know speak to one of the tuning shops. Mine has easily made over 1000bhp and over 800 torque with room and drives really well on road for spool. Depends on your spec I guess.

What are your supporting mods I have been documenting mine in the projects page HulkPanther.


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## Skint (Oct 11, 2014)

There's just one person who had issues with back pressureto my knowledge, there may be more but I'm not aware of anything.

The turbo's are clearly comprised by not using the correct housings. That does'nt mean they don't work in just means they would be more efficient in the correct housings.

Look at Garret motion site and you can see there efficiency reduce when there housing sizes are reduced.


----------

