Power Upgrade Time For The Gtr.. Where Should I Spend Money Next

[GTRNUR]

Hi everyone,

Well my Vspec R33 GTR has been a lot of fun in its current tune but I am after a little more power and as much response as is possible. The car is a daily driver for the most part so I dont want to loose that smooth drivability of a fairly stock system, and would like to really keep the response of the engine as close to stock or even improve on it if thats possible.

I am thinking of getting a pair of GTSS's but I have found little comparing the drivability of these with stock turbo's with regards to response and development of torque in the 3000-6000 rpm range. For the most part I never rev the engine past 7000.

I figure i'd also add HKS dumps to the shopping list along with some ported stock manifolds or agian hks or tomei manifolds.

Also with regards to chamshaft timing, where is the direction to go in if chasing more response and low to mid range torque torque?

Im adding a PWR 40mm radiator this week as the current one is beginning to look a little sad. The car compression tested at 185 on all cylidners so i know everything is in top shape. Ive put about 8000k's on the car since getting it and spare no expense with regards to maintenance and upkeep.

Here is the current mod list:

ARC Super Cold air induction box

Hi Octane custom baffeled breather box/washer bottle tank

HKS 100mm Intercooler

Gates radiator hoses

Gates timing belt

N1 water pump

Nismo front pipe

HKS 100mm exhaust

Greddy adjustable intake and exhaust cam gears

Apexi Power FC tuned to 1 bar by some tuner on the gold coast, but i have it dialed back to 10lb for reliability.

Apexi AVCR

All Redline Synthetic fluids and oils.

Ive had the big single lag monster skyline prior to this one and frankly power is over-rated. I do miss the nimbleness of the R32 though, and am hoping that with the right mods will gain some of that back for the R33.

Any suggestions?

[R31Nismoid]

GT-SS for a street car.

LOADS of threads on them now, results, other parts and so on

[GTRNUR]

GT-SS for a street car.

LOADS of threads on them now, results, other parts and so on

Believe me I have spent hours using search and browsing the dyno thread but its hard to gauge whats really what when the responsiveness I am after is more of a perception thing. Everyone talks about the power for sure but thats not what I am after.

I dont want a mega powerful GTR and most of the GTSS thread talk about power ranging from 280-400kw (race fuel) but ive seen few actually talk about at what rpm a certain boost level is achieved, expecially in the lower gears where it counts. I want one that pulls like a train midrange, and makes boost just off idle. I'd be happy if it had the power level it already has, and just widened the power band a lot more.

Of course a little more power would be great too. The current tune doesnt really get up and go till around 5000 rpm or so. Lowering that 1k RPM would be a great start. Maybe something from the trust catalogue might prove more responsive but I have no idea about that stuff.

Edited January 13, 2008 by Vspec R33

[paulr33]

The GTSS's will do exactly that, widen the powerband more with same wind up response of the stock turbos

they are i think 0.60a/r the stockers are 0.48/ar so its only a tiny step up. they are known to be the best turbo's cloest to stock

and they will max out around 300kw - definetly not 400kw

no twin setup on the 2.6 will make boost off idle - you would need stroker setup, 3 litre etc

[R31Nismoid]

For what your asking, its only GT-SS/-7's that will fix your requirements

[GTRNUR]

So turbo's need to be first on the list. After that how about exhaust system changes and cams or anything else to improve response?

[a20089]

There's no substitute for testing what a car performes like in the real word, but getting even a passenger ride can be very hard. No two cars are exactly the same but I went the Garret 2860-5's (like the HKS 2530's) and my car runs the same (as in pick up) as when I had the stock turbo's except with much more power around 4500-5000rpm. Saying that they are now running 18psi and I'm not sure if my original turbo's were in the best condition.

If I were to do it again I'd try the GTSS HKS turbo's. But i'm considering the 2.8 stroker unit + cams to bring boost on earlier.

[GTRNUR]

Yeah I saw the 2.8 kit that someone has for sale in the parts section too, but thats a can of worms I dont want to open.... just yet.

Was the HKS 2510 supposed to be a simular replacement to the stock turbo but plain bearing, that was then superseeded by the GTSS?

The best price ive found so far on a new GTSS kit is $2700.

Is it worth replacing the manifolds at the same time, or only if your going to match port to the head, and turbine housing..? Every thread on front end exhaust ive read says get rid of the stock dump pipes ASAP, but not much of a mention is made of the primary manifolds.

[rockabilly]

hi vspecr33.

here in the uk they seem to favour gt-ss turbos, with tomei poncams 260,s 9.15mm lift seems goods. cars seem to produce 500-550bhp @ the fly and boost from 3000rpm onwards..bernie

Edited January 13, 2008 by rockabilly

[Risking]

GT-ss all the way for what you want. If your prepared to go further latter on then the 2530's would also be a good choice.

Cams are always extremely good and nothing can be taken away for a good tune.

If your happy with the car being at full tilt by 4 grand then the SS/2530's are the only two you should be considering.

[SLIPPERY]

i honestly feel that my GT-SS twins come on slightly earlier than the stockers did thanks to cam gears and a decent tune. These definitely sound like the turbos you want that have a phat midrange and pull early.

Thanks to the exchange rate they really arent the expensive option they used to be

[GTRNUR]

Im pretty much sold on SS's and perhaps some Jun 260 or poncams. I found a dyno sheet that showed full boost of 15psi by about 105km/h in 4th, so thats pretty good. I doubt I want to run more than 1 bar anyway, I just want a tiny bit more without worrying about that ceramic wheels issue.

Thanks for the input everyone.

[GTRNUR]

Dam double post!!

Edited January 13, 2008 by Vspec R33

[ferni]

GTSS come on the same as my stock turbos, but just produce more power/run more boost.

Stock cams are fine. Just get adjustable cam gears and a good tuner! Ohh and a good exaust, gotta flow nice.