# Twin Garrett G25-660 - performance?



## krozna (Sep 1, 2019)

Hi guys!

Would be very nice to hear UK/Europe experiences from these new Garrett G25-660 in R35.

Have anyone here installed those yet?
Dynosheets? 1/4 mile?

Have been reading of those from the US, but how about here in UK/Europe.

Thanks,
-Kroz


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## archan (Apr 25, 2019)

I am also interested. Considering a Winter upgrade. Which I had promised myself to not do lol.


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## Skint (Oct 11, 2014)

Just go with the efr***8217;s, proven for many years now, others are playing catch-up.


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## archan (Apr 25, 2019)

Question would then be, which EFRs to get? I am essentially maxing out my 6958s at slightly above 1000 PS.
Would like minimal changes, e.g. keep manifold and downpipes if possible.


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## Chronos (Dec 2, 2013)

Skint said:


> Just go with the efr’s, proven for many years now, others are playing catch-up.


playing catchup or bypassing?


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## krozna (Sep 1, 2019)

EFR***8217;s are nice and reliable.

But if those results from US are real, G25***8217;s are spooling quicker and making more power than any others at this point when looking about the same size turbos.

Want to hear some real results from UK/EU.


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## Skint (Oct 11, 2014)

What application are they wanted for?


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## krozna (Sep 1, 2019)

https://www.amsperformance.com/the-new-omega-12-r35-gtr-turbo-kit/

That is. I just want to see real results from UK/EU. What kind of performance people here have found with these.

Those dynosheets and 1/4 mile numbers, sounds too good to be true. Unbeatable street car with oem like spool etc.

Hope someone here has installed these already and wants to share the experience with us.


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## archan (Apr 25, 2019)

Very interesting. Claims to spool faster than the EFR 6758s. That's impressive to say the least.


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## Chronos (Dec 2, 2013)

archan said:


> Very interesting. Claims to spool faster than the EFR 6758s. That's impressive to say the least.


certainly is IF legit! Omega 12 kit AMS

" Way more impressive than the peak power numbers though, is the fact that starting a run at 2000RPM in 4th gear, the car will hit 500ft-lbs torque at the wheels by 2750RPM, and 800ft-lbs before 3500! I have never seen a turbo kit spool this fast, and that includes the extremely high tech Borg Warner EFR 6758s I was running before; the previous fastest spooling turbos on the market; the Omega 12s blow them completely out of the water, outspooling them by 500-600RPM! Compared to any other turbo I have tuned that has similar power potential, you are looking at peak torque coming, on average, 1000+ RPM later!"


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## archan (Apr 25, 2019)

Drool! God damnit, this winter is going to get expensive real fast LOL.
I almost pray that my G/F finds my credit card and shreds it before I go all-in haha.


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## krozna (Sep 1, 2019)

Exactly. Hopefully someone in UK/EU would like to share their own experience. Yanks often has different powerbands than what we get here with same setups...


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## leeroygibbano (Nov 9, 2019)

Getting mine fitted as we speak. Car is on Litchfield 3.8 forged engine, 1050cc 14 hole injectors and Ecutek. Should be a good benchmark and no need to limit torque as I'm having a quaife LSD fitted at the same time. I'll post the graphs once it's dyno'd later this week.


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## Chronos (Dec 2, 2013)

leeroygibbano said:


> Getting mine fitted as we speak. Car is on Litchfield 3.8 forged engine, 1050cc 14 hole injectors and Ecutek. Should be a good benchmark and no need to limit torque as I'm having a quaife LSD fitted at the same time. I'll post the graphs once it's dyno'd later this week.


Forged gearbox to? as that'll be needed to let the torque loose....


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## leeroygibbano (Nov 9, 2019)

Dodston 1-6, billet baskets, the whole shooting match and quaife diff at the front, for now


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## turboDean (Sep 29, 2018)

Check out Litchfields Instagram or Facebook, about 5 days ago they posted Dyno graph of G25 660s...
Standard manifold on standard engine and LM manifold on there 3.8 Sport engine.


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## leeroygibbano (Nov 9, 2019)

turboDean said:


> Check out Litchfields Instagram or Facebook, about 5 days ago they posted Dyno graph of G25 660s...
> Standard manifold on standard engine and LM manifold on there 3.8 Sport engine.


They have capped the torque on it because it's not on a built transmission.


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## turboDean (Sep 29, 2018)

760ft/lb gotta be pushing the limits of a standard box


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## leeroygibbano (Nov 9, 2019)

Only a single power run ?


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## Chronos (Dec 2, 2013)

turboDean said:


> Check out Litchfields Instagram or Facebook, about 5 days ago they posted Dyno graph of G25 660s...
> Standard manifold on standard engine and LM manifold on there 3.8 Sport engine.


can you upload it here? taa


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## scoooby slayer (Jun 13, 2009)

Dyno plot from Litchfield Instagram 










Full boost is after 4000 rpm looking at those plots


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## Chronos (Dec 2, 2013)

200+ bhp difference?


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## gtr mart (Mar 29, 2004)

That graph and the test was (IMO) to show the versatility of these turbos. Not actually the difference between the stock turbofold version and the LM manifold version. it shows that these turbos can be fitter to a stock engine with capped torque and still run very well. But with further engine and gearbox upgrades can be 'turned up' to deliver even more fun.

I'm interested to see what the native G30s run. I currently have the LM1200 kit with EFR 7663 which is great and shortly fitting a better intercooler which should help with inlet temps, tuning and ultimately happy power production. 

From what I've seen so far, the G25s run very well and can produce around 1000bhp when provoked. A nice turbo set up well worth considering.


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## krozna (Sep 1, 2019)

Nice! Thanks guys, I’m sure that many people are interested about these turbos. Also G30’s.

Looking for more shared results!


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## Chronos (Dec 2, 2013)

Whats price difference G25/G30? and spool?


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## krozna (Sep 1, 2019)

Chronos said:


> Whats price difference G25/G30? and spool?


What I’ve seen, few hundred rpm difference in spool and few hundred £ pricing difference, I think because with G30’s you need the custom mounting plates.


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## leeroygibbano (Nov 9, 2019)

Here's your answer  

Torque had to be limited to make sure the rods don't implode (remember this engine was built for circa 750lb ft originally). Very very happy with the spool, early torque and flat torque curve...

The difference between these and the GT3584's is simply staggering. We have another issue this time with tyre size which needs fixing, but the remit was to get the car 100% right, which is exactly what's happening.


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## scoooby slayer (Jun 13, 2009)

leeroygibbano said:


> Here's your answer
> 
> Torque had to be limited to make sure the rods don't implode (remember this engine was built for circa 750lb ft originally). Very very happy with the spool, early torque and flat torque curve...
> 
> ...


What was the boost pressure for each setup ?


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## Chronos (Dec 2, 2013)

leeroygibbano said:


> Here's your answer
> 
> Torque had to be limited to make sure the rods don't implode (remember this engine was built for circa 750lb ft originally). Very very happy with the spool, early torque and flat torque curve...
> 
> ...


987bhp, thats such a tease!!!! 1000 we want! haha

so you've got 3.8 forged engine and dodson gearset.. so why's it being limited?? What aftermarket rods are limited to 750lbft?


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## leeroygibbano (Nov 9, 2019)

I'll quote the words of the tuner .... "We tried it at 2 bar, 2.1 bar and 2.4 bar but increasing the boost didn't make any difference, not even marginal." I gather Iain spent a lot of last night and some of the early hours on the dyno with my car and was as impressed as I am with the spool and torque.

"The most the motor wanted to do due to other restricting things like standard cams, manifold etc. was reached at 2/2.1 bar, so the maximum these turbos would blow on this setup". This isn't to mean this is the limit of the turbos, far from it. It simply says this is achievable on fairly run of the mill displacement, forged pistons, rods, and roudn town driveability. 

No doubt with flow matched this and that, inlet manifold, various other tweaks and race fuel these turbos could go towards their 1200hp (crank) maximum, but under less than ideal supporting parts and at 2 bar (the run pressure) it's a pretty impressive set of results. 

I'd say this heralds the way for a (torque capped at mid 700's) "rod job and piston" upgrade and therefore 1000hp from little more than a pair of turbos and pistons, rods and injectors, fuel pumps. 

So, I ask you this question: If you could pick up a £30k GTR and spend £15k on basic gearbox strengthening, rods, pistons, injectors and ECUtek, see 1000hp essentially and use it daily without it breaking (which remains to be seen but I'm hopeful) for £45k you've basically got a car that will slay a 911 turbo, most supercars and still be civilised on taxed tarmac - Seems pretty good value to me.

I'll let you know how it drives when on the road but, given that I've had them do Quaife front LSD, quite a few other breathing and exhaust changes plus 4 wheel alignment and suspension setup, I'd hope it'll be epic.

Sorry to nick the thread with my reply and I started a thread about the same thing only a few weeks ago but I thought it'd be pertinent to keep this one and reply to it because of the OP being the first one to ask about these turbos, before me.


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## leeroygibbano (Nov 9, 2019)

It wasn't 987, it was 989.7 and that was corrected.... I believe the flywheel power is the 1015hp figure, although I'd have to clarify that with Iain. Anyway I'm not chasing numbers here, the proof is in the pudding and I'll let you know once I've had a drive my self!


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## leeroygibbano (Nov 9, 2019)

I'll l


Chronos said:


> 987bhp, thats such a tease!!!! 1000 we want! haha
> 
> so you've got 3.8 forged engine and dodson gearset.. so why's it being limited?? What aftermarket rods are limited to 750lbft?


I'll leave Iain to reply to that but the basic 3.8L forged engine isn't his idea of "safe and reliable" with a good safety margin much above 800 ft/lb and I know he aires on the side of caution and reliability, which is good by me. I'm sure it could be pushed further but as a daily driver and a low rev throttle "planter" that I am, he's done what I've led him to do, based on my driving style and the fact I don't want to take the chance of being stranded on the way to an emergency call out somewhere in europe with a rod sticking out through my block or a piston embedded in the armco.


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## krozna (Sep 1, 2019)

Nice!

Thanks for sharing this + all the other meaningful info you gave.

You talked about racegas, so was this dynoed with pump gas?


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## leeroygibbano (Nov 9, 2019)

This was on pump gas, not even fresh, it was filled up a couple of weeks ago on normal 98 octane, so these results are exceptional and a credit to the tuner's "safe and reliable" attitude. If you can have 1000hp and this type fo torque curve on pump fuel, these turbos get my vote. If it spools anywhere like my RS6 and makes more power, it'll drive epicly, especially with the lower kerb weight.


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## adz87kc (Jan 8, 2018)

Your result was on the Nissan manifolds?
Did Iain say how his setup with LM manifold and full frame turbos would compare?


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## Chronos (Dec 2, 2013)

leeroygibbano said:


> I'll quote the words of the tuner .... "We tried it at 2 bar, 2.1 bar and 2.4 bar but increasing the boost didn't make any difference, not even marginal." I gather Iain spent a lot of last night and some of the early hours on the dyno with my car and was as impressed as I am with the spool and torque.
> 
> "The most the motor wanted to do due to other restricting things like standard cams, manifold etc. was reached at 2/2.1 bar, so the maximum these turbos would blow on this setup". This isn't to mean this is the limit of the turbos, far from it. It simply says this is achievable on fairly run of the mill displacement, forged pistons, rods, and roudn town driveability.
> 
> ...


cool thanks for the info, it makes sense now! You'll have to tell us how it drives, and what the power/spool is like on the road!!  congrats!

How do the G25's spool compared to stock turbos and EFR's?

So am thinking mine with carrillo rods/cp pistons and HKS Cams would just push the 1000 fly maybe with G25's (gearbox linney HD gearset + dodson gearbox extras)


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## scoooby slayer (Jun 13, 2009)

leeroygibbano said:


> I'll quote the words of the tuner .... "We tried it at 2 bar, 2.1 bar and 2.4 bar but increasing the boost didn't make any difference, not even marginal." I gather Iain spent a lot of last night and some of the early hours on the dyno with my car and was as impressed as I am with the spool and torque.
> 
> "The most the motor wanted to do due to other restricting things like standard cams, manifold etc. was reached at 2/2.1 bar, so the maximum these turbos would blow on this setup". This isn't to mean this is the limit of the turbos, far from it. It simply says this is achievable on fairly run of the mill displacement, forged pistons, rods, and roudn town driveability.
> 
> ...



Were the gt3584s run at 2 bar boost on that dyno plot as well ?


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## leeroygibbano (Nov 9, 2019)

Yes, they were at 2 bar on map 3 and map 4 - both maps gave the exact same dyno plot.


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## scoooby slayer (Jun 13, 2009)

Chronos said:


> certainly is IF legit! Omega 12 kit AMS
> 
> " Way more impressive than the peak power numbers though, is the fact that starting a run at 2000RPM in 4th gear, the car will hit 500ft-lbs torque at the wheels by 2750RPM, and 800ft-lbs before 3500! I have never seen a turbo kit spool this fast, and that includes the extremely high tech Borg Warner EFR 6758s I was running before; the previous fastest spooling turbos on the market; the Omega 12s blow them completely out of the water, outspooling them by 500-600RPM! Compared to any other turbo I have tuned that has similar power potential, you are looking at peak torque coming, on average, 1000+ RPM later!"


Looking at this plot for a start the torque and hps cross over at totally different points and neither are at 5252 rpm which they should be if it's scaled correctly 

And the 800 lbft before 3000 rpm and onto over 1100 hp all seem to good to be true, but if it's on an engine dyno or even on a dynapack on a very slow run then potentially the load could be way above what can actually be achieved in a car on the road and bring boost in alot earlier because of it


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## gtr mart (Mar 29, 2004)

On the 2 graphs I saw above, power and torque do cross at 5252. Bit confusing as there are two plots on each graph. But to my eyes the torque and bhp curves that relate to each other are crossing in the right place. 

Maha dyno is certainly a long pull. Comparatively to other dyno plots from the same dyno the spool looks good considering the power available.


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## scoooby slayer (Jun 13, 2009)

gtr mart said:


> On the 2 graphs I saw above, power and torque do cross at 5252. Bit confusing as there are two plots on each graph. But to my eyes the torque and bhp curves that relate to each other are crossing in the right place.
> 
> Maha dyno is certainly a long pull. Comparatively to other dyno plots from the same dyno the spool looks good considering the power available.


They do not cross at 5252 not sure what your looking at mate but it's not the plot I quoted 

I don't know what dyno there using for the alpha 12 run but the curve looks almost physically impossible to be true road load imo 

I've seen it before on engine dyno plots, huge amounts of load making boost come in 1000 rpm sooner than it can in real life out on the street !


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## scoooby slayer (Jun 13, 2009)

Gtr mart 

Here is a direct comparison of an engine on an engine dyno then onto a dyno dynamics rolling road, same tune and fuel 

Engine dyno 












Then onto dyno dynamics rolling road 










Approx 1500 rpm later spool from engine dyno to rolling road !


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## gtr mart (Mar 29, 2004)




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## gtr mart (Mar 29, 2004)




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## gtr mart (Mar 29, 2004)

What are you looking at?


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## scoooby slayer (Jun 13, 2009)

gtr mart said:


> What are you looking at?



Your still not looking at the plot I quoted 
IL add it below, it's from the start page of this thread 

For some reason it won't let me add an image now


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## gtr mart (Mar 29, 2004)

Just went back and saw the one. Yes that's all over the place. Doesn't make sense.


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## scoooby slayer (Jun 13, 2009)

That's the plot I quoted mate, I never whole heartedly believe as much since I saw the plots of the yb engine, they are true comparable plots for my Sierra with previous owner and show just how much extra load can hugely move boost threshold to the left


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## Juhani (Jun 12, 2010)

And did you notive that this plot is against TIME, not rpm, that’s why the crossing points don’t match.


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## ShadyGTR (Aug 20, 2017)

Sounds like money well spent not to mention I have a lot of faith and trust in Iain and his team. Have you given any thought to the suspension with the likes of the dsc sport controller unit, something I’m interested in but have yet to purchase.


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## leeroygibbano (Nov 9, 2019)

ShadyGTR said:


> Sounds like money well spent not to mention I have a lot of faith and trust in Iain and his team. Have you given any thought to the suspension with the likes of the dsc sport controller unit, something I’m interested in but have yet to purchase.


Was this a question for me?


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## leeroygibbano (Nov 9, 2019)

Just drove the car in map 3 and map 4 and all I can say is wow. Throttle response and spool is instant, pulls hard to the redline and can even feel the grip on the front end from the quaife diff. Really worlds apart from the GT3584's. Had what felt like a boost cut under WoT but nothing on the Ecutek apart from suspension error codes as I have KWv3's. Wondering what that could be as there's no trouble codes.

Also have a pretty loud whistle on lift off or partial throttle which doesn't happen under WoT, not sure about that but will ring up tomorrow and ask.

Couldn't be more happy witht he turbos, car picks itself up and goes, awesome point and shoot experience now. I can't see myself needing any more power for the time being, but when I've changed the tyres and the weather turns, who knows


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## gtr mart (Mar 29, 2004)

Time on the bottom axis makes sense although not a common measure I've seen.. Glad you're happy with it. Deffo get some logs on a few pulls and send across to litcho and they will refine the tune. Should make it even better. 

I think I have a bit of a whistle on part throttle, could be the quaife diff.


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## scoooby slayer (Jun 13, 2009)

leeroygibbano said:


> Yes, they were at 2 bar on map 3 and map 4 - both maps gave the exact same dyno plot.



Awesome result then 600 rpm gain in spool with no loss of power nice one


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## Juhani (Jun 12, 2010)

These turbos whistle, nothing strange about it. Addictive sound! I have them as well with a 4.1L stroker engine, some head work, 12 injectors, AMS manifold, big TBs, 2x3.5”->4” exhaust etc. full effort build aiming for fbo (or better) spool with 1200hp (E85) on tap. Only street tuned at 1.8bar for now, but I’m living in Finland and on snow tires (compulsory from December to March), weather is cold, so no grip for further tuning until spring. Even on dry roads spins all four on 4th gear pull

Can barely wait for spring to get street tuning properly done and getting timing / max power tuning done on dyno!


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## leeroygibbano (Nov 9, 2019)

It's not the same whistle as you get through the exhaust and intakes..


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## Juhani (Jun 12, 2010)

Ok, shouldn’t be Quaife though, mine doesn’t make any sound. Unless you have aftermarket ring and pinion, that could possibly explain it.


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## leeroygibbano (Nov 9, 2019)

It's deffo air not mechanical moving.


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## Hugh Keir (Jul 25, 2001)

Changing the way that graphs are presented is just smoke and mirrors.

Early torque is always where it's at and delivers the reduction in time that is being referred to in the above.

As a comparison that is worth looking at, here is my Dyno graph showing wheel power with EFR 7763 turbos with SX-E compressor covers.

Take note that this is Wheel horsepower, so 800ft lbs torque at just over 4000 RPM and 1000BHP from around 5700 RPM to 7600 RPM.

The Litchfield Dyno plot with the G26-660 turbos provided earlier in this thread shows a maximum Wheel horsepower of 832.6 equaling an engine horsepower of 1015.2. It has 800ft lbs torque at 4000 RPM

Using the Litcho conversion on their dyno sheet, that would give me Engine figures of 975ft lbs torque at just over 4000 RPM and 1220 BHP from around 5700 RPM to 7600 RPM.


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