# What would you do single/ twin decision?



## David (Apr 25, 2003)

Background:-

5 years ago I owned a stage 1 R33 GTR, which I started buying parts to bring it up to 600 bhp (flywheel) with 2860-5's . Unfortunately I needed to buy a house which involved selling the GTR before the parts got fitted. It has been the car I have missed the most, so I recently bought another black nice stage 1 R33 GTR.



















I have already bought a set of used HK2530's but things have moved on considerably since these were cutting edge and I am considerering going single instead (which could give better responce and also give more power later on).
I am also considering a 2nd stage 12 months after the 1st,which the single option suits better, but if I am happy with 600 bhp unless I have a failure I may not go down this route.


To simplify things I am leaving out clutch/ fuel pump as I understand them, but they just over complicate the options. I also already have downpipe exhaust filters to suit twins


*Option 1 2530's*
Fit the used 2530's I have
Keep stock cams
Tomie turbo elbows
Fit Injector dynamics 1000cc injectors
Syvecs s6 ecu

*Option 1b Single*
Precision 6262 / BW EFR ect
Keep stock cams
WhifBitz single manifold / Twin tials, or none with EFR
Fit Injector dynamics 1000cc injectors
Syvecs s6 ecu
Tune for 600 flywheel bhp

*Stage 2 (1 year later opening engine)*
1b +
272 or 282 10+mm lift cams, uprated springs % followers, 
CP or similar Forged pistons
Argo Rods
Tomie oil pump + assosiated oil modification restrictors/baffled sump or Dry sump
Steel head gasket
Remap with max boost 700+ flywheel bhp

OS/ getrag box when my gearbox breaks

The reason to not change the cams with the turbos is that building the rb30, shimming the cams was one of the worst jobs I have done on an RB and i wouldn't want to do it in car. If I were to change cams I would want high lift 272's that would mean replacing springs followers i.e removing the head for machining, I also dont think the standard piston can be used with high lift cams maybe someone can prove me wrong. Also would I get close to 600 bhp at the flywheel with stock cams?

Let me know your thoughts


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## Brains (Jul 6, 2010)

I just made That decision. 
Twins are history! I have a precision 6266 on it's way home. 

Less cludder, less things that can break, less stuff to buy, atleast the same performance and 0 shuffle issues. 

Easy choice


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## David (Apr 25, 2003)

Brains said:


> I just made That decision.
> Twins are history! I have a precision 6266 on it's way home.
> 
> Less cludder, less things that can break, less stuff to buy, atleast the same performance and 0 shuffle issues.
> ...


Thats another big reason to choose a single my Supra is converted to single and I can remove the turbo in about an hour.

The only reason I think to stick with twins is I already have the 2530's and potentially slightly cheaper.


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## Wade (Jul 31, 2008)

Go for the single mate. Just be careful with some of the borgs as I cross referenced one of my turbo's with the borg equivalent and it wasnt as expected :thumbsup:


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## drewzer (Jun 22, 2009)

Looking good David, so this is what you ended up getting, looks awesome!! I have the same dilemma, single or twin. The only thing that puts me of a single is finding a manifold that wont need welded every year, that don't cos £2k!!! e.g "full race"


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## David (Apr 25, 2003)

drewzer said:


> Looking good David, so this is what you ended up getting, looks awesome!! I have the same dilemma, single or twin. The only thing that puts me of a single is finding a manifold that wont need welded every year, that don't cos £2k!!! e.g "full race"


Thanks, I have been doing some reading and have found some interesting results. It seems the FR manifold volume is does not actually sut 600-800 bhp turbos (its even not recomended by FR) and better responce is achieve with a single gate HKS style manifold. So a full race manifold is at the bottom of my list

The whiffbitz manifold is proven for 2Jz's and very well respected. It also has half the cost and a 5 year anticrack warrenty

Garage Whifbitz

The other option I am considering is Sinco, which subboy have used an got great results from. These are even cheaper especially without wastegate ports to suit an EFR turbo.


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## Rarche2002 (Jun 19, 2012)

I personally love the sound of twin I'm trying to get my hands on a 33 Gtr at the moment just to have a twin turbo sound in my life.


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## Brains (Jul 6, 2010)

Turbobandit here in Sweden has a manifold that costs around 600-700£ if i recall correct.


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## David (Apr 25, 2003)

Brains said:


> Turbobandit here in Sweden has a manifold that costs around 600-700£ if i recall correct.


Thanks for that they look good, I am also in Sweden every other week at the moment. Are they rated well on the Swedish forums?


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## Brains (Jul 6, 2010)

Oh Yes they are. I've never heard anything negative about them. 

I've got that manifold myself. Haven't tried it yet though.


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## gts-tom (Jun 14, 2010)

I changed from 2 different sets of twins to a single and would never go back to twins again. Single if anything is so much easier and in terms of lag theres not a lot of difference


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## pupsi (Aug 29, 2006)

Nice looking car you've got there David, very nice. Go single, its the best choice, you know it makes sense.


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## Sub Boy (Jan 28, 2008)

After just getting my car tuned, I'm glad I went for EFR single, I still have to really get the most out of the turbo yet, but it makes more power everywhere compared to the -5's I had.
Cams would help, but a EFR7670 or what I have the EFR8374 would do the trick.


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## David (Apr 25, 2003)

pupsi said:


> Nice looking car you've got there David, very nice. Go single, its the best choice, you know it makes sense.


Thankyou, it has polished up quite nicely . Which turbo did you end up with finally on your Ripz engine?


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## davew (Apr 28, 2003)

we have a complete TO4Z kit on clearance here for £2000!!!!


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## cossie0_4 (Dec 25, 2008)

i also gone single with precision 6266 and andy at amt is doing manifold with twin wastegates m8


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## Jakobsen (Dec 19, 2007)

You might wanna check this car and setup out 
http://www.gtr.co.uk/forum/164123-garage-whifbitz-singleturbo-build.html

Very responsive and very good power !


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## David (Apr 25, 2003)

Jakobsen said:


> You might wanna check this car and setup out
> http://www.gtr.co.uk/forum/164123-garage-whifbitz-singleturbo-build.html
> 
> Very responsive and very good power !


Hello, I saw that one and TBH wasn't all that impressed, the responce seems worze than a T04z and certainly no where near the responce of subboys EFR.


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## pupsi (Aug 29, 2006)

David said:


> Thankyou, it has polished up quite nicely . Which turbo did you end up with finally on your Ripz engine?


I ended up going for the TO4z, plenty of power and the best choice for a street car, wicked response, so far nothing has beat me on the roads, except the big bikes but I catch up with them pretty quick.


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## asiasi (Dec 22, 2007)

David said:


> It seems the FR manifold volume is does not actually suit 600-800 bhp turbos (its even not recomended by FR) and better responce is achieve with a single gate HKS style manifold. So a full race manifold is at the bottom of my list


Really ? No mention to me about this when i inquired about full FR kit with 9180 and 900hp target.


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## David (Apr 25, 2003)

asiasi said:


> Really ? No mention to me about this when i inquired about full FR kit with 9180 and 900hp target.


If you read the link in the link you posted on the supra turbo/manifold test there is a quote from full race stating there manifolds are aimed at 800 bhp+ and below this you may be better off with a smaller diameter header manifold. When I get to a proper computer I'll quote it for you.


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## scoooby slayer (Jun 13, 2009)

if i was paying and building myself i would single 100%.


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## R322 (Mar 21, 2012)

I'd say twins are better, response is very important afterall, also you already having the 2530s means, you'll save money on manifold etc. Are your 2530s still in good nick?


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## Sub Boy (Jan 28, 2008)

R322 said:


> I'd say twins are better, response is very important afterall, also you already having the 2530s means, you'll save money on manifold etc. Are your 2530s still in good nick?


I've got more response and more HP with my single than I did with my twin -5's:flame:


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## .::TopSky::. (Nov 4, 2010)

The response talk is old. Today many good 650hp+ single setups crush similar twin setups in terms of performance. I´m sure many will sacrifice a couple of hundred RPMs later boost for overall better performance.

To4Zs work very nice with higher displacement engines (Stroker/RB30) but if you are going too keep stock displacement I suggest choosing another turbo.

For your manifold, try talking to some locals or some known shops abroad for custom manifolds. They are cheaper than most people think, in some cases.

Good Luck!


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## R322 (Mar 21, 2012)

What turbo are you using Subboy?


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## R322 (Mar 21, 2012)

Topsky any ideas on turbos? Do you mean things like Gt35r? What sort of turbos can produce in excess of 650 and have similar setup to -5s?


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## Sub Boy (Jan 28, 2008)

R322 said:


> What turbo are you using Subboy?


Borg Warner EFR 8374


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## Fuel Performance (Aug 31, 2010)

.::TopSky::. said:


> The response talk is old. Today many good 650hp+ single setups crush similar twin setups


+++++++1


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## R322 (Mar 21, 2012)

I had no idea Single Turbos had advanced that much, I was referring to the old T51rs and T04zs etc, didn't realise they have moved the game on so much. I do love the aggression of a Single Turbo (screamer pipe), but worry about manifolds cracking etc. Maybe custom manifold is the way to go? Would you say there are Single Turbos out there (like the BW EFR) that can be even run on stock engines/headwork with minimal lag like twins?


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## David (Apr 25, 2003)

R322 said:


> I had no idea Single Turbos had advanced that much, I was referring to the old T51rs and T04zs etc, didn't realise they have moved the game on so much. I do love the aggression of a Single Turbo (screamer pipe), but worry about manifolds cracking etc. Maybe custom manifold is the way to go? Would you say there are Single Turbos out there (like the BW EFR) that can be even run on stock engines/headwork with minimal lag like twins?


The whiffbitz manifold has an anti crack garrentee so that shouldn't be an issue. I am now sold on a single so watch this space for stock bloc with 600 bhp and better response than -5's.


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## Fuel Performance (Aug 31, 2010)

David said:


> The whiffbitz manifold has an anti crack garrentee so that shouldn't be an issue. I am now sold on a single so watch this space for stock bloc with 600 bhp and better response than -5's.


Amen!


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## freak4speed (Feb 9, 2007)

I like the big singles. I know theres more lag, but when it kicks in WHAAAAAA HOOOO. hold on to yer man purse cos warp speed hits with a bang lol and the anticipation of the revs building to 5,000rpm when the fun starts cant be beaten. Its akin to being on a roller coaster when your going up, up up to the top and you know when you get there your gonna get butterfles in your stomach then go shooting off hanging on for dear life lol or is that just me and my driving experiences.


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## R322 (Mar 21, 2012)

They look impressive the manifolds. Must be more exciting the all or nothing characteristics of a Single Tubby


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## David (Apr 25, 2003)

R322 said:


> They look impressive the manifolds. Must be more exciting the all or nothing characteristics of a Single Tubby


T78, T88 would give you that impact, but have a look at subboys dyno plot with the bw EFR turbo the responce is significantly better than with a pair of 2860-5's. I honestly believe it will be possible to get better responce with a modern single than twins with more power than 600 bhp.


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## R322 (Mar 21, 2012)

It seems the response is to do with the manifold too? Although the BW EFR is very different to the t04zs etc. Only one turbo so less hassle that way too.


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## .::TopSky::. (Nov 4, 2010)

R322 said:


> I had no idea Single Turbos had advanced that much, I was referring to the old T51rs and T04zs etc, didn't realise they have moved the game on so much. I do love the aggression of a Single Turbo (screamer pipe), but worry about manifolds cracking etc. Maybe custom manifold is the way to go? Would you say there are Single Turbos out there (like the BW EFR) that can be even run on stock engines/headwork with minimal lag like twins?


People have more knowledge now than before, people are now using custom manifolds instead of poor design kit-manifolds, the turbos are getting more advanced, we have better tuners, better cooling solutions, people are paying more attention to the intake side, more people understand that the head plays a big role etc

We have examples in the OEM-industry aswell, one is the BMW 335i. The earlier models used a twin turbo setup, later on BMW realized a twin scroll singel is more efficent and they changed.

There are many good turbos but one good choice would be, BorgWarner EFR 7064 wich is a turbo I´d go with if I was in your position.

One bad thing with the EFRs though is that spare parts are hard to find.


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## R322 (Mar 21, 2012)

Thanks bud, seems that custom manifolds and a newer Single turbo like BW is a good option for response.


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