# Which is the best twin turbo choice for around 650hp at the wheels



## manzy47 (Apr 6, 2008)

I believe a similar thread was posted a while ago (2012), but with turbo technology improving somewhat since then, I thought I'd see what is currently the turbo to go for. Engine wise I'm running a 2.8 HKS step 2 stroker engine and want to keep to the twin turbo setup. I have the 2530's at the moment, but they are limited in terms of how much power I can get from them. Plus with ceramic ball bearing billet internal options I'm sure there are quicker spooling turbos that can handle bigger power on the market.


Any suggestions welcome?


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## zimmersquirt (Aug 30, 2014)

Nice talking to your earlier mate

this is something more modern , possibly to new to have much feedback though , there are various turbo sizing options avail on this setup , HTH 

https://www.full-race.com/store/borg-warner-efr/efr-turbo-kits/nissan-rb26dett-efr-twin-turbo-kit-1/


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## manzy47 (Apr 6, 2008)

zimmersquirt said:


> Nice talking to your earlier mate
> 
> this is something more modern , possibly to new to have much feedback though , there are various turbo sizing options avail on this setup , HTH
> 
> https://www.full-race.com/store/borg-warner-efr/efr-turbo-kits/nissan-rb26dett-efr-twin-turbo-kit-1/


Cheers Ant. 

Some great advice and useful info going forward :thumbsup:


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## Spiidfriik (Sep 9, 2015)

Take a look at Garretts new G series. I think two G25-550 would be pretty nice!
https://www.garrettmotion.com/racing-and-performance/performance-catalog/turbo/g-series-g25-550/


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## FRRACER (Jun 23, 2013)

None of those are standard fit and need new manifolds and downpipes. ATP Turbo sells GT2867 in Gen 2 GTX format. Uses standard manifolds outlets etc. Couple this with HPI outlets and new Tomei cast Manifolds. Should work well on a 2.8


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## CT17 (Mar 25, 2011)

zimmersquirt said:


> Nice talking to your earlier mate
> this is something more modern , possibly to new to have much feedback though , there are various turbo sizing options avail on this setup , HTH
> https://www.full-race.com/store/borg-warner-efr/efr-turbo-kits/nissan-rb26dett-efr-twin-turbo-kit-1/





manzy47 said:


> Cheers Ant.
> Some great advice and useful info going forward :thumbsup:


I have this turbo kit, it was fitted about 2 years ago IIRC.
TBH I am not sure there are that many people running this in the UK.

There are positives and negatives to any set up so this is my opinion of the Full Race kit. These are my personal opinions.

First off, it's a very tight fit in the engine bay on an R32 GT-R. You would have more space on a 33 or 34, but on the 32 one turbo is around 3mm from the NS suspension strut and in terms of height it's above the level of the wings. It only fits under the bonnet due ot the bonnet bracing not being where the turbo is.
However, all that aside I;ve had the car very hot several times and not had any heat issues regards paint etc...

Secondly, you have to get the fitment right.
When it was first installed it was better than my previous set up but not as mind boggling as I expected. After six months we took all the pipework apart and got a motorsport team to refit it all and make a few small changes to maximise flow. We instantly got even better response and the car made more power.

Thirdly, the response when set up right is brilliant. My 32 now spools like a modern OEM car, is very flexible in gear and you are really shifting way before 4,000rpm. It comes in around 3200-3500rpm which for a car revving to almost 8000rpm gives you a large powerband.

Lastly, due to the amount of parts required to fit it, it's not cheap!
A good modern big single would be lighter, use less space and be cheaper/easier to fit.

The car is an RB28 with the stroker kit built by RK tuning.
It makes 780bhp and full boost very early so is more responsive than I expected was possible.


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## manzy47 (Apr 6, 2008)

CT17 said:


> I have this turbo kit, it was fitted about 2 years ago IIRC.
> TBH I am not sure there are that many people running this in the UK.
> 
> There are positives and negatives to any set up so this is my opinion of the Full Race kit. These are my personal opinions.
> ...


Impressive! Getting the fitment right has paid off massively. Your final output and the way it runs sounds just what I'm looking for in regards to performance and behavior. Certainly doesn't look like a cheap setup with all the extra items required. I've bought all the pipework recently (nismo pipes, arc box, mines Ti downpipe) with my mindset on keeping things stock looking but adding drop in turbos that would get me where I need to be without having to lose all those parts, otherwise, I was thinking single.


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## manzy47 (Apr 6, 2008)

I'll take a look at the above options. Value the feedback :thumbsup:


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## GTRNICK (Apr 29, 2005)

I would advise a single at this power level. Borg warner efr 8374 or precision 6266 as a minimum Less plumbing and complication.


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## Spiidfriik (Sep 9, 2015)

Stock location is a very limiting factor, i wouldnt throw any big money there. 
I have a 614hp stock location set up on my BCNR33. Big money spent long ago, built by Tweenie Rob (allegedly). Works fine, pulls hard, a lot of fun! But hardly worth the money today i think, considering new turbo technology. 
I have no boost under 3,5k, feels lazy. 
Full boost (1,4) at 4,5k, feels decent. 
Real power comes at just under 5k (280 cams) and goes on past the 8,5k limiter, feels awesome!

Custom single can be more responsive and make more power for the same money.

Custom twins can be even more responsive and make even more power, but will cost a lot more, be a lot more complex and can have heat issues.

Im still aiming for custom twins myself since two is more then one.


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## CT17 (Mar 25, 2011)

Can I just add (mainly because of my twin EFR R32 and my big single R34 that both make similar power) that I don't really see a big difference.
It's all about spec and set up.

My R32 GT-R with the twin EFRs does drive amazingly, but the R34 that runs a big single has an equally impressive engine build. So on the big single response is almost as good.
I'd esitimate boost builds around 300rpm later.
In the real world, with the cost savings and simplicity, I don't see two being that more than one.

2 turbos being pushed round by the gas from 3cyl each.
1 turbo being pushed round by the gas from 6cyl.

Not a huge difference, if the engine is built to a good specification and everything is set up to be as responsive as it can be.


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## manzy47 (Apr 6, 2008)

CT17 said:


> Can I just add (mainly because of my twin EFR R32 and my big single R34 that both make similar power) that I don't really see a big difference.
> It's all about spec and set up.
> 
> My R32 GT-R with the twin EFRs does drive amazingly, but the R34 that runs a big single has an equally impressive engine build. So on the big single response is almost as good.
> ...


Totally agree. If I didn't want to keep my current setup, I'd have gone down the single route or even something like the twin EFR's which looks a good kit, however, I want to keep my car OEM (twin stock location) looking and not having to lose my ARC box, Nismo pipes, Mines Ti Downpipe etc. 

Just want to look at upgrading from the 2530's to something superior and drop them in and make use of the extra power the engine build will give me. Might not be the best way in relation to complexity and heat issues but that's the way I want to keep it for now anyway. 

I'm sure someone on here is running decent power on stock location twins and I'm just curious to see if there's anything that can get decent top end power. Then a lot of work getting it mapped just right.


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## manzy47 (Apr 6, 2008)

CT17 said:


> Can I just add (mainly because of my twin EFR R32 and my big single R34 that both make similar power) that I don't really see a big difference.
> It's all about spec and set up.
> 
> My R32 GT-R with the twin EFRs does drive amazingly, but the R34 that runs a big single has an equally impressive engine build. So on the big single response is almost as good.
> ...


Are these the turbos on your r23?

https://www.full-race.com/store/efr-turbo-kit/nissan-rb26dett-efr-twin-turbo-kit-1/


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## FRRACER (Jun 23, 2013)

Having such high duration cams all you are doing is pushing the power band further up the Rev range so no surprise you have no boost at 3500. 



Spiidfriik said:


> Stock location is a very limiting factor, i wouldnt throw any big money there.
> I have a 614hp stock location set up on my BCNR33. Big money spent long ago, built by Tweenie Rob (allegedly). Works fine, pulls hard, a lot of fun! But hardly worth the money today i think, considering new turbo technology.
> I have no boost under 3,5k, feels lazy.
> Full boost (1,4) at 4,5k, feels decent.
> ...


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## FRRACER (Jun 23, 2013)

I***8217;ve already told you few posts up what you need to get. They will fit in your stock location with the parts you have. You need to plan and make sure all works together. Common mistake people throw drag spec 280/290 11.5/11.8 cams and then wonder why they don***8217;t make any low down power. 



manzy47 said:


> Totally agree. If I didn't want to keep my current setup, I'd have gone down the single route or even something like the twin EFR's which looks a good kit, however, I want to keep my car OEM (twin stock location) looking and not having to lose my ARC box, Nismo pipes, Mines Ti Downpipe etc.
> 
> Just want to look at upgrading from the 2530's to something superior and drop them in and make use of the extra power the engine build will give me. Might not be the best way in relation to complexity and heat issues but that's the way I want to keep it for now anyway.
> 
> I'm sure someone on here is running decent power on stock location twins and I'm just curious to see if there's anything that can get decent top end power. Then a lot of work getting it mapped just right.


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## Spiidfriik (Sep 9, 2015)

FRRACER said:


> Having such high duration cams all you are doing is pushing the power band further up the Rev range so no surprise you have no boost at 3500.


I know, im not surprised. Just telling about my setup as a reference. 
I love high rpm, so its right for me. But i still think i would probably get better spool with two modern turbos (like EFR or G25) compared to my current Trust modded Mitsu 16T turbos. Not to mention lots of more power, obviously. Also custom manifolds and less restrictive "elbows" would help both spool and power, I think. With those cams it can never be a low- or even mid range monster, but i think it can be more so than it is today.


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## GTRNICK (Apr 29, 2005)

https://youtu.be/45ZODU3XWlg


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## manzy47 (Apr 6, 2008)

FRRACER said:


> None of those are standard fit and need new manifolds and downpipes. ATP Turbo sells GT2867 in Gen 2 GTX format. Uses standard manifolds outlets etc. Couple this with HPI outlets and new Tomei cast Manifolds. Should work well on a 2.8


What do you think of the GTX2967R? Apparently has a more balanced turbine to compressor ratio than 28:s is what I've read on another post. 

I'm running HKS Elbows at the moment with Tomei cast manifold, but do you think the HPI have an advantage over the HKS?


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## manzy47 (Apr 6, 2008)

FRRACER said:


> I’ve already told you few posts up what you need to get. They will fit in your stock location with the parts you have. You need to plan and make sure all works together. Common mistake people throw drag spec 280/290 11.5/11.8 cams and then wonder why they don’t make any low down power.


Head wise I'll be looking at running the HKS V Cam Pro cam with duration of 264° valve lift 10mm. Exhaust size depending what works with the turbo


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## manzy47 (Apr 6, 2008)

GTRNICK said:


> https://youtu.be/45ZODU3XWlg


Hard to argue with the points mentioned in the video especially with newer turbos with better-designed airflow systems, but it certainly makes you wonder how much difference there would be with newer single and twin technology as compared to Z tune models and other jap tuned engines running low mount twins pushing 550-600 hp around a track and road use. Would be a good comparison for one of Tsuchiya's race videos


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## manzy47 (Apr 6, 2008)

FRRACER said:


> None of those are standard fit and need new manifolds and downpipes. ATP Turbo sells GT2867 in Gen 2 GTX format. Uses standard manifolds outlets etc. Couple this with HPI outlets and new Tomei cast Manifolds. Should work well on a 2.8


https://www.full-race.com/product-category/garrett-turbos/garrett-g-series-turbos/

These look like the replacement to the GTX 2867 turbos


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## RB28 (Jan 14, 2018)

Garrett GTX2863 or GTX2867's should do the trick. Im Also running a HKS Step2 2.8 and Step2 Vcam with GT2860's making just shy of 600whp on 98 pump fuel. A GTX2863 or GTX2867 setup on E85 should see you hit the mark no issues and, as mentioned above, bolt straight up!:thumbsup:


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## CT17 (Mar 25, 2011)

manzy47 said:


> Are these the turbos on your r32?
> 
> https://www.full-race.com/store/efr-turbo-kit/nissan-rb26dett-efr-twin-turbo-kit-1/


That's the kit, yes.


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## manzy47 (Apr 6, 2008)

RB28 said:


> Garrett GTX2863 or GTX2867's should do the trick. Im Also running a HKS Step2 2.8 and Step2 Vcam with GT2860's making just shy of 600whp on 98 pump fuel. A GTX2863 or GTX2867 setup on E85 should see you hit the mark no issues and, as mentioned above, bolt straight up!:thumbsup:


That's very similar to key components to my set up. That's good to know much appreciated. The new G series is a completely new design but I don't think they do a bolt on for the RB26. The GTX2860 looks like the way forward for me :thumbsup:


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## Ryan_H (Jun 28, 2016)

Can I ask what power you are now? Just wanting to say that you can do a tidy 500hp on stock location turbos for a lot less money than a custom or shelf 650hp set up, and in reality that 150hp won't be something you need most of the time. Worth considering.


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## manzy47 (Apr 6, 2008)

Ryan_H said:


> Can I ask what power you are now? Just wanting to say that you can do a tidy 500hp on stock location turbos for a lot less money than a custom or shelf 650hp set up, and in reality that 150hp won't be something you need most of the time. Worth considering.


Hi Ryan, I'm currently going through a rebuild phase with a number of parts new in boxes as part of the upgrade. Before this it was pretty much a standard 2.6 with stage 1 mods, but for me power wise I felt it's time for some changes. I've been buying trick parts over the years and now is the time to go through with it. Car is undergoing a restoration and as it's a vspec 2 I wanted to keep it low mounts, but with a decent engine build and good quality parts to support. 

Drivability wise, my man goal is response and as you say in the real world a solid 500 bhp setup is ample. But with all the modifications especially moving to a 2.8 hks set up with v cams, I want to be able to unlock the potential and have the response with good power to match. I could go for a big single, but as you say I won't be using that kind of power much. Cost wise, I've already spent silly amounts to get this far. The final piece are the turbos and hopefully that's me done :runaway:


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## Bennyboy1984 (Jul 26, 2009)

Have you considered the Tomei range of bolt on turbos? I don’t think many people used them as most already had -5’s or 2530’s etc but they appear to push out the figures you’re looking for. Would be very interesting having them on a 2.8 with v-cam 

https://www.tomeiusa.com/_2003web-catalogue/000_arms/product_arms_rb26-e.html


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## manzy47 (Apr 6, 2008)

Bennyboy1984 said:


> Have you considered the Tomei range of bolt on turbos? I don’t think many people used them as most already had -5’s or 2530’s etc but they appear to push out the figures you’re looking for. Would be very interesting having them on a 2.8 with v-cam
> 
> https://www.tomeiusa.com/_2003web-catalogue/000_arms/product_arms_rb26-e.html


I've certainly look at those too, but I found thread mentioning negative reviews on them from a number of members. I've discounted them based on what I've read. Can't do it any other way at the moment unless someone has seen the results. I've seen many good things about the GTX28 and so far it's the one I'm going with based on my findings.


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## Bennyboy1984 (Jul 26, 2009)

manzy47 said:


> I've certainly look at those too, but I found thread mentioning negative reviews on them from a number of members. I've discounted them based on what I've read. Can't do it any other way at the moment unless someone has seen the results. I've seen many good things about the GTX28 and so far it's the one I'm going with based on my findings.


That’s fair enough. Shame really as they’re a solid company and usually make good parts, but not turbos it seems.
The GTX28’s are top mounted turbos aren’t they?


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## manzy47 (Apr 6, 2008)

Bennyboy1984 said:


> That’s fair enough. Shame really as they’re a solid company and usually make good parts, but not turbos it seems.
> The GTX28’s are top mounted turbos aren’t they?


Agreed, they do make some real good stuff otherwise. 

The GTX28's are actually low mount turbos and are direct bolt replacements which is perfect for me as I want to stick with the twin setup and get as much power as possible without a big single giving things away. The GTX is suited to an RB28 capacity over a 26.


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## Ryan_H (Jun 28, 2016)

Don't write off a modern big single like a Borg Warner EFR series unit, you may be surprised! Build sounds fun either way.


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## CT17 (Mar 25, 2011)

Bennyboy1984 said:


> Have you considered the Tomei range of bolt on turbos? I don***8217;t think many people used them as most already had -5***8217;s or 2530***8217;s etc but they appear to push out the figures you***8217;re looking for. Would be very interesting having them on a 2.8 with v-cam
> 
> https://www.tomeiusa.com/_2003web-catalogue/000_arms/product_arms_rb26-e.html


I personally wouldn't worry much about V Cam.
I have it on some of the R34s I have, but the most responsive car doesn't have it...

Modern turbo technology is so good it's rendered V Cam non-cost effective IMO. It probably made more sense on older technology.

Someone told me that the V cam on their RB28 was amazing.
Then I looked at the graph and the powerband came in almost 1000rpm later than mine as was an older build making similar power.


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## FRRACER (Jun 23, 2013)

I***8217;m also not a fan of V cam it***8217;s a half way hack compared to modern systems where you also have the variable cam timing on the exhaust to make the most gains from this technology. However if people want it and makes them feel happy then it***8217;s their choice. 

I***8217;d personally look at extensive head work, intake systems, valve train cam and turbo matching to get the best response and torque. Not to mention the rest of the such a bullet proof bottom end and electronics.


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## Bennyboy1984 (Jul 26, 2009)

CT17 said:


> I personally wouldn't worry much about V Cam.
> I have it on some of the R34s I have, but the most responsive car doesn't have it...
> 
> Modern turbo technology is so good it's rendered V Cam non-cost effective IMO. It probably made more sense on older technology.
> ...


That is strange, i always assumed the V-cam was supposed to have the turbos spooled up sooner by a considerable margin??
I guess it also comes down to who's mapped/set up the build. But as you say the cost of modern turbos now out weigh the cost of a V-cam set up, which was promoted by HKS during their GT turbo 'reign'. Ah the good ol' days lol


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## Cris (Sep 17, 2007)

Bennyboy1984 said:


> That is strange, i always assumed the V-cam was supposed to have the turbos spooled up sooner by a considerable margin??
> I guess it also comes down to who's mapped/set up the build. But as you say the cost of modern turbos now out weigh the cost of a V-cam set up, which was promoted by HKS during their GT turbo 'reign'. Ah the good ol' days lol


I'd say that there's a balance of theory, reality and cost.

In theory a V-cam car will have better pick-up than an otherwise identical car.

In reality maybe the cam profiles on the v-cam suit your set-up and maybe there's a better option out there which makes up for the theoretical advantage.

Finally cost. V-Cam costs money and maybe that money would be better spent elsewhere. If you were building an engine you might want to direct the v-cam money into a stroker crank or whatever.

Nothing against v-cam at all but all things must be taken in context. Sometimes the theoretical best thing isn't the best choice for you.


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## RB28 (Jan 14, 2018)

FRRACER said:


> I’m also not a fan of V cam it’s a half way hack compared to modern systems where you also have the variable cam timing on the exhaust to make the most gains from this technology. However if people want it and makes them feel happy then it’s their choice.
> 
> I’d personally look at extensive head work, intake systems, valve train cam and turbo matching to get the best response and torque. Not to mention the rest of the such a bullet proof bottom end and electronics.


HKS actually did trial a Vcam for the exhaust side but the gains were not enough to justify the cost of the product. They simply didn't believe they would sell.

A friend of mine went a fully built head, E85, Cabon tail shaft and 4.11 diff gears (HKS Step Zero 2.8 with 2530's) and my HKS Step2, -5's and Vcam was still more responsive down low on 98


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## manzy47 (Apr 6, 2008)

https://m.youtube.com/watch?v=JQUlE5Dfg1o

Only thing I could find on youtube in regards to vcam on/off.


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## Bennyboy1984 (Jul 26, 2009)

Cris said:


> Finally cost. V-Cam costs money and maybe that money would be better spent elsewhere. If you were building an engine you might want to direct the v-cam money into a stroker crank or whatever .


Exactly what I did. Back in 2010 when I was having my engine built I remember being torn between getting V-cam or a stroker kit as I wasn’t able to do both. I ended up going for the Tomei 2.8 kit as it was a few hundred pound extra (crank + rods) in comparison to the Vcam set, and thought the gains would be more noticeable. Always loved the idea of Vcam as I used to be a bit of a Honda fanboy, and the thought of having a ‘reversed vtec’ system on an RB was quite appealing :chuckle:


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## FRRACER (Jun 23, 2013)

manzy47 said:


> https://m.youtube.com/watch?v=JQUlE5Dfg1o
> 
> Only thing I could find on youtube in regards to vcam on/off.


The Mines car still has better response through other mods.


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## FRRACER (Jun 23, 2013)

Further more people are not talking about static CR. This has a huge impact on response and also off boost performance. Here in the UK I***8217;d go at least 9:1 or even 9.2:1 via custom pistons. Most offer this service, Wossner, CP, Wiseco etc.


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## RB28 (Jan 14, 2018)

Here's a before and after with Vcam Step1 on a RB28 with GTX2860-5's and E85:thumbsup:

The car is a R34 GTR that had stock cams. Dyno run in 5th gear. Can see on the same boost it picked up 100kw mid range!


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## Cris (Sep 17, 2007)

RB28 said:


> HKS actually did trial a Vcam for the exhaust side but the gains were not enough to justify the cost of the product. They simply didn't believe they would sell.
> 
> A friend of mine went a fully built head, E85, Cabon tail shaft and 4.11 diff gears (HKS Step Zero 2.8 with 2530's) and my HKS Step2, -5's and Vcam was still more responsive down low on 98


This is from my oft times foggy memory so...

I read a discussion about the SR20VE/T many moons ago. In short there are a couple of varients of SR20 with variable timing and lift. AFAIK only one car used the SR20VET and thus only one version of the VE had a turbo.

The NA versions of the VEs had NeoVVL on both intake and exhaust and the switch over points were played with by various types. There were people hanging turbos off them to 'make' SR20VETs.

One of the guys had laid their hands on a 'real' SR20VET and if I remember correctly the inlet side of things was pretty much the same as the NA engine but the exhaust side of things was always in 'high' mode. The theory for this was that on an NA engine you can do pulse tuning etc by fiddling with the exhaust valve. On a turbo engine you always wanted the maximum exhaust flow to get the turbo moving as much as possible.

Whether the theory is correct or not Nissan choose not to use different profiles on the exhaust cam. The VET engine came a fair few years after the VE versions were released so it was purposefully not included.


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## Gav.Diamond (Jul 26, 2003)

I spoke with Herman at platinum racing products and he is developing a double v-cam system that should hopefully be released this year


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## paul450 (Jul 4, 2006)

my car is at abbey motorsport just now after a turbo failure, its fitted with the hks2835 top mount kit.
I was looking at getting the new garret g25-550 turbos fitted,but mark said it would cost a bit to get it changed over( turbos,manifold,wastegates etc) so my turbos are currently away getting rebuilt with modern internals.
once back and fitted along with the other little jobs (trigger kit, getting the ecu to control the boost instead of the boost controller), car will make over 700bhp at the hubs, 800 at the fly  hopefully with slightly better spool.
getting launch control activated and new suspension fitted while its there also.

car has been off the road since july last year, cant wait to get it back so I can drive it.


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## RB28 (Jan 14, 2018)

Gav.Diamond said:


> I spoke with Herman at platinum racing products and he is developing a double v-cam system that should hopefully be released this year


Did he give a rough cost of what it will cost? cheers


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## Gav.Diamond (Jul 26, 2003)

RB28 said:


> Did he give a rough cost of what it will cost? cheers


No, not as yet


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