I've got a GT28RS on a 1600cc clubman. I originally had a GT25 which had too much mid range and tapered off at the top end. The GT28RS is a really good unit. The hard boost starts at 4000rpm and it revs cleanly to 8000rpm like a naturally aspirated motor. We have 350hp from a 1600 so it should spool up earlier for a 2000cc motor and have an even better top end.

The cars at the clubman factory if you want to drop over and look at the installation this weekend. Could even take you for a ride Aus.

Chris.

 

That was a great read! Pfff..... disco is dead my @$$

 

I will definitely take you up on that offer Chris. Saturday is the S2ki drive but if you're there Sunday I'll pop over.

 

Aus,

I'll be there Sunday, got a clubman to finish building.

Chris.

 

Ultimate Racing is Garrett t3/t4 60-1 .82 A/R

 

How does the UR turbo drive? Is it a drag racing set up or very streetable? Where does boost come in?

 

If you want quick spooling and max power, definitely opt for the Garret GT series turbos. We've tuned a number of cars running the 30R and 35R GT's and they kick ass. One car, at only 6 psi, picked up over 60 hp on the top end simply by switching from a T3/T4 60-1 to a GT35R and the spool up rpm was unchanged.

Personally, I think the GT28R is a little small for S2000 purposes, but if you don't mind a cap on the top end potential, it'll work fine. I'd choose a 30R myself.

UL

 

[QUOTE=ultimate lurker,Dec 2 2004, 02:57 PM]If you want quick spooling and max power, definitely opt for the Garret GT series turbos.

 

It sounds like a lower turbine A/R is good for minimising lag. Somewhere down to about .60 but a larger compressor size because of the free breathing nature or the F20C. Hence the popularity of the T3/T4 hybrids.

UL- when you say the GT28R is a bit small what sort of power limits are you thinking about? I'm not looking for anything stratospheric. An absolute max of 400hp but more likely 350.

 

he needs a smaller turbo. always go with the smallest turbo that will fit your hp requirements. if your hp requirements change, than so should your turbo. putting a GT35R on a car with goals of only 350 hp is overkill.

the GT28RS is a little small for making 350 rwhp. but you didn't specify rwhp or crank hp. from garrett's turbo info they give, the turbo is good for a max of 325 hp. the only problem is that the gap between the gt28 and the gt30 is a decent sized one. the GT28RS is rated for 175-325 hp. the GT30R is rated for 350-500 hp.

looks like the best match for you would be the GT3071R with a .50 A/R compressor housing and a .63 A/R turbine housing. if you want the quickest spool possible while still being able to reach a 350hp goal, this is the turbo for you. it is rated at 300-460hp by garrett, so it fits perfectly within your goals and can even be altered to make more hp by changing compressor/turbine housings.

sorry if this post is a little long, but choosing the correct turbo depends on a lot of different variables. the best way to pick a turbo would be to make dyno runs with different turbos and plot the hp against the boost you are running to see how efficient the turbo is, then once you've narrowed it down to a specific compressor and turbine wheel you could try different housings to alter the A/R ratio. since you don't have that luxury then going by garrett's compressor maps and hp predictions is going to have to do.

on a final note however, chris_barry says he was able to make 350hp with the GT28RS. if this is in fact true, then this would be the PERFECT turbo for you. like i said, my predictions were based on garrett's info on their turbos, real world results are always better than theoretical predictions.