Final Turbo Decision

[ICER33]

alright for a long time now i have been tossing up with the idea of upgrading the turbo on my rb25det. now the options were:

1 - hi flow (possibly in the gcg group buy)

2 - garret gt30r or gt3071r

now it looks more financially viable to opt for the high flow option as this seems that there will be less hidden expenses and that it wil come relatively close to my desired power level.

the goal for my car is to run mid to low 12's, whilst i dont want a lag monster rather a quick streeter. ultimatley i have read that these high flows are capable of around 260rwkw with supporting mods. which will be:

-power fc

-avcr

-fmic

- turbo back 3inch exhaust

- pod

- injectors (hi-flow the standard ones or opt for aftermarkets around 550cc?)

- fuel pump, fpr

- clutch

- suspension will be coil-overs for street and standard for the strip

- decent tyres (currently potenza's)

-also a larger afm (z32 or q45)

what injector choice should i go for...high flow standards or get some new after market ones??

would it be worthwhile to include cams and cam gears or one or the other to get to my goal?? what benefit is sought installing these??

is this achievable or not?? and with a good tune and a good run will i get into the mid to low 12's???

thanks

Edited June 14, 2006 by ICER33

[JaFF]

I think if you want mid 12s then without cams should do the job, low 12s you'll need more average power so cams would be better. I think to get to 260rwkw with a high flow you'll definately need the cams too.

[James_03]

I would be going the gt30r over the hi-flow, but obviously the GCG is going to hit boost somewhat faster the the gt30 will.

Edited June 14, 2006 by James_03

[Sydneykid]

the goal for my car is to run mid to low 12's, whilst i dont want a lag monster rather a quick streeter.

R34GTT with GCG ball bearing high flow and Tomei Poncams 11.9 at 120 mph.

And I am not the only one to do it, Ben (HPI editor) in his R34GTT did it as well.

cheers

Edited June 14, 2006 by Sydneykid

[The Dan]

The GCG highflow will still hit full boost at around the same time as a GT30R with the 0.6 rear. If you want anything over 240rwkw then you will need cams.

The highflow is ok but I would like to hear from anyone who has actually got one to 260rwkw. The most I have seen is 240rwkw and running 20psi boost. The GT30R will make the same power on 14psi. Sure you have to spend more money but what's the use of doing a half arsed job. The only thing I regretted about the upgrades on my cars was not doing them the way I wanted from the start. Always went for the cheaper option to save a buck then ended up having to spend even more later on as I wasn't completely happy.

[The Dan]

R34GTT with GCG ball bearing high flow and Tomei Poncams 11.9 at 120 mph.

And I am not the only one to do it, Ben (HPI editor) in his R34GTT did it as well.

cheers

What other mods do you have to do a time like that? Obviously we're not talking about an unopened engine.

[Sydneykid]

The highflow is ok but I would like to hear from anyone who has actually got one to 260rwkw. .

Me = 265 rwkw

Ian, Bullant 47 = 275 rwkw (different dyno)

Peter, Bass Junky 250 rwkw (on another different dyno)

Yet to checked after he fixed the wastegate problem

And probably 10 more if I looked up the dyno charts

cheers

[Sydneykid]

What other mods do you have to do a time like that? Obviously we're not talking about an unopened engine.

Depends on what you mean by “unopened”. The bottom end was certainly untouched. I am not a fan of decompressing engines using thick head gaskets. So I pulled the head off and had our machinist port it slightly and match the combustion chamber volumes and then polish them. We o’ringed the head at the same time, just for safety and used a standard head gasket. No real drop in the compression ratio, but no detonation problems on 98 ron. If I had access to 100 ron then, like I do to Shell Optimax Extreme now, I wouldn’t have bothered doing the head.

Ben’s R34GTT on the other hand had a thick head gasket to decompress it.

Mods list;

GCG ball bearing high flow

Standard R33GTR intercooler

Pipework made by our race team fabricator

Performance Metalcraft split dump

3.25” no name Jasma exhaust

High flow cat

Tomei 260 Poncams

Nismo FPR

Nismo Injectors

Bosch 044 fuel pump

R32GTR BOVs’

Power FC with Boost Control Kit

Tuning by Dyno Dave

Steve Thompson “special”, sprung paddle clutch

Lightened flywheel

MT drag slicks

11.99 at 119.8 mph with 1.8 for 60’

265 rwkw on Shell Optimax 98 ron and 287 rwkw on Elf Turbo Max

I am currently doing an R33GTST with pretty much the same set of mods as above. I want to get to 270 rwkw without touching the cylinder head on Shell Optimax Extreme 100 ron.

cheers

[rb26s13]

HKS GTRS

[Muffa180]

My last car was a R33 GTST series 1. It made 254 kws at the wheels on 14 psi mods were.

Power FC

high flow injectors by APC

GCG high flow turbo rated at 500 hp internal gate.

GCG intercooler kit

o44 fuel pump

mesh removed from AFM

3 inch exhaust and dump

pod filter.

The car was tuned at APC. I had problems with the flapper valve in the turbo not being big enough. On cold evenings the car would boost to 17 psi even with the bleed valve disconnected. I removed the turbo and ported the waste gate hole slightly larger but this didnt make much diff. From what im told they dont make this size high flow now. Other wise it was a great turbo.

Hope that helps.

Thanx Michael...

[ICER33]

whats the difference between r34gtt and r33 gtst turbos?

how much difference is there between the two and would it be worth cahsing one up to complete the hi-flow as i am pretty sure this is the path i will be taking

[wolverine]

ICE the R34 turbine housing is larger than the R33.

at the right price it is worth it. i believe it might be worth around 15kw.

[R31Nismoid]

GCG for mid 12's. It will do it easily.

You dont need a butchered GT30... ie an externally gated turbo using machined int. gated housings. Its just not cricket.

The R34 turbo is the one you wanna hi-flow if you have access to it.

As stated the rear housing is larger.

They generally cost $150 more second hand than an R33 turbo

[Sydneykid]

ICE the R34 turbine housing is larger than the R33.

at the right price it is worth it. i believe it might be worth around 15kw.

Back to back, same car, same dyno, 10 rwkw, that's all we could get and we tried real hard.

cheers

[wolverine]

Back to back, same car, same dyno, 10 rwkw, that's all we could get and we tried real hard.

cheers

SK you say you tried real hard, so did you use anodised fittings, polish the compressor housing and use flashing LED's to light it??

humbly, i stand corrected.

[jazza08]

But with the GCG hi-flow the rear housing's dont make a difference as they are both machined out to the same size???

Curious does anyone think that a GCG on an rb20 r32 could do mid 12's?

I understand they won't make near the power they can on rb25s (ie 30rwkw even..) but obviously the 32 weighs abit less too!

Personally i will be happy with 280rwhp (210rwkw) with supporting mods (afm, injectors etc) which is probably only good for a low 13 but aim low and anything i get above that (hp wise) will be a bonus!

I can only recommend the GCG hi-flow for rb25, makes the car a very quick street car which seems to be what ur looking for

Thoughts on the 32 situation?

Edited June 14, 2006 by jazza08

[ICER33]

whilst we are talking of hi-flowing whats are ppl's stances on hi-flowing the original injectors???

also where would i pick up an r34 turbo and how much should i be looking at??

[R31Nismoid]

original injectors, IMO i wouldnt. I have concerns about spray patterns etc

Being new ones cost $900, thats my pick

[Abo Bob]

I've got 255rwkw at only 0.9 bar so 260 not out of the question. I have the GCG highflow btw.

I've run 12.7's

Car is an auto.

$500 for a second hand R34 turbo.

GCG state on their website that they don't do group buys.

[R31Nismoid]

Check the group buy section Adam