Turbo Reasonably Effecient At 16psi

[Roy]

I was looking at running a GT30R, but looking closely at the results there arent many ppl making early 300rwkws with them. Typically 280-290rwkws with a good lung full of boost. So not much headroom for pumping a few extra psi to get anpother 30-40rwkws out if it for ballpar 340rwks.

So from there GT30R, how much difference in driveability is there to a GT35R? Im hoping to get around 290-300rwkws from 16psi, with the occasional adventure to around 22psi where i would hope to net 340-350rwkws on Optimax.

Needs to be a single, and needs to be T3 flanged. Since i already run a Greddy setup was also considering the TD06SH-25G.

Not overly concerned about lag, as long as it makes strong power from 4,500rpm to 8,500rpm. (4,500rpm +200rwkws)

Speaking Garret talk, i suppose im curious to know if the 3240/3540 are good things etc, or can the GT30R be leaned on to credibly give the numbers i want?

[Guilt-Toy]

I hear the 3540 dont start making efficient power till around 20psi

mine made 350rwhp on 15psi

[Busky2k]

16psi on a 2L to make 300rwkw is a hard ask Roy. Its like asking a RB20DE to make 140-150rwkw in naturally aspirated form. The GT35R might do it, but 16psi is not much flow to work with unless you have big cams/porting etc. You are better off leaning on the GT30R to reach your goals rather than oversizing the turbo just for the 'lower boost' mentality. A GT35R is a huge thing for a 2L and the transient response even on boost will be less than desirable. Remember 300rwkw is 300rwkw, no matter what the boost; the strain on the motor is the essentially same really.

EDIT - of course this is assuming you have an RB20DET...

Edited October 30, 2006 by Busky2k

[Roy]

Airflow is airflow...so just wondering what turbos can make reasonable power at 1.1bar, but really sing with 1.5bar in it.

I figure guys are running 3540s etc on SOHC RB30ETs so the RB20 head cant be any worse. I will just need rpm

[R31Nismoid]

Ye, but they are 3ltr man... you are 2ltr.

You need more boost, the SOHC guys have ported heads/cams etc.

So its not something comparable.

And they are using more than 15/16psi for thier 300rwkw, closer to 20

You'll need 20+ psi to get close to 300. I had 270 on ~17psi

[Roy]

Ok you had 270 on 17psi. What sized wheels did your GT30 have?

Anyway, its not an RB20

[R31Nismoid]

The biggest one you could get

So what motor then eh?

[Roy]

The biggest one you could get

So what motor then eh?

A STROKER for a stroker!

So your GT30 was bigger then a GT30R?

[R31Nismoid]

Oh... the latest crack pot idea you had eh? hehe

i cant remember, it had the biggest wheel offering at the time for the 600hp variant.

there were 500 and 550 also... wasnt those though

btw - your weak as p|ss, going home @ 3am

[Roy]

Had work to do...not that i got much done on Sunday

Maybe start with the GT30R and go from there...id rather a bit too small then too big

[discopotato03]

Yes a big ask from a 2L six . How far are you prepared to go/spent to get it there Roy ? Probably needs a really flying head and healthy cams to get there . Its fair to assume that the GTS-R's exhaust manifold is good considering it was designed for the Grp A RB20 .

Does anyone know what spec the GMS R31's ran and what sort of power they made ?

Cheers A .

[Roy]

Ive got a pretty good idea of the Gibson cars since i know a guy that has just restored one and has spare Gibson blocks etc laying around. He is one of the little birdies in my ear saying that the std RB20 is pretty strong...hence me beign pretty comfortable about running 1.5bar for a few laps at Sandown

Its not a 2L either. Will be running 26 crank, Eagle 26 rods, Apexi cams and cleaned up head.

[discopotato03]

Is there any chance of grafting an R32 RB25DE head onto it ? A lot of work on the cooling jackets and not shure it the valves would clout the block . Damn it Roy can't you sleeve the 25DE block back to 78 so you can sleep at night ? LOL ...

[Roy]

Damn it Roy can't you sleeve the 25DE block back to 78 so you can sleep at night ? LOL ...

lol...note that i didnt list the block or head that i will be using

[discopotato03]

Hmmm , well Watson we'd probably have doubts about using a hydraulic head to 8.5k so the evil Moriati may have the gun head in the wings ...

[govich]

HKS 3037?

[Roy]

Hmmm , well Watson we'd probably have doubts about using a hydraulic head to 8.5k so the evil Moriati may have the gun head in the wings ...

Whats with the negative waves....why cant you just dif what a beautiful day it is

And im not that fussed about the std lifters. With the std springs at the moment im pulling 8,500-8,800rpm. I even gave it a hit at 1.5bar and it didnt seem to have any head problems. I hope with better springs and still only mild lift cams i can still get away with the hydraulic lifters. At the end of the day im hoping not to have to rev the new engine as hard as the std RB20...but will if i need to get the drive in the next gear

That said, i am on the lookout for a poor soul that has had dramas with a bottom end letting go and a ruined 26 head. It would be good to get my hands on the valve gear

My understading is 3037 is basically the GT30R

[Young GT-R]

basically, but supposedly spools up quicker.

[shanef]

That said, i am on the lookout for a poor soul that has had dramas with a bottom end letting go and a ruined 26 head. It would be good to get my hands on the valve gear

i've still got my 26 bottom end (minus pistons & rods) which made way for an RB30

[Roy]

Its the head i want, but one wht damaged chambers as all i want is the valves, lifters, springs etc etc