You might have seen from my earlier post, that we just finished work on a piggyback computer for my S.

The next step is a turbo. I want to use a T3/4 for my setup, since it seems like what every other kit is using. Since I don't want to rebuild internals, I am limiting boost to about 7-8psi.

However, when I do the maths for gas flow etc, I come up with a "T28" as my ideal size. Hmm. This is further reinforced by my tuner, who says that T3/4 is too big. I pointed out that every kit uses them, and he said that's because every kit wants to publish large KW numbers, not drivability.

Now... He and I are good friends, and we both enjoy track days more than drag racing, and he said that using a smaller turbo would give me better times on a track, because of a more predictable feel around corners, as well as better daily drivability, because I wouldn't need to drop clutch at 4500rpm, which is where a T3/4 would produce 7psi boost...

What do you guys think? T3/4 or pure T3? (I'm not going T28, I'm sure that's way too small)

 

I don't know much about turbos, but why not consider the T28? Wouldn't the smaller turbo be more efficient and have reduced lag?

 

[QUOTE]Originally posted by gernby
[B]I don't know much about turbos, but why not consider the T28?

 

The t/3 Might make the car a little squirrly and hard to handle at lower rpm's. The s2000 is light and people have trouble maintaining traction with s/c and turbos already. I would suggest a t3/4 and reduce your rear gear and pinion for a little more low rpm grunt

 

what about using a Garrett GT dual ball bearing? That way, you will have awesome spool up (3xxx rpm) due to less friction and the turbo is more efficient and has a higher hp max. Otherwise, a t3/t4 would work well too but if money isnt an object, go for a Garrett GT. There's an awesome turbo company that you can buy them from for $1200. I also know of a guy with a T61 on his S2000 which is freakin huge. Wait for more responses, you'll get plenty of info.

 

t28?
NONONONOOO
Did your tuner factor in the 9k redline on the car? and the 2.0 liter motor??
I dont know what calculator you are using but several turbo specialists can offer you insight on turbo matching to a specific app. This is true when you buy a kit you are getting a generic setup perhaps not suited to your driving style but a t28 by any means will not fit anybody's driving style. That turbo mated with an s2k will be on the extreme border of ineffuciency. The car will surge and stutter in lower rpm driving. It will feel very squirlly and nervous.....verry jumpy at minimal throttle inputs. This is very common with an undersized turbo mated to the wrong application. And the t28 is not just a little undersized but overly undersized. You will have deterimental results.

What do u want the car for primarily track driving.
I would reccommend a garrett t3/t4 hybrid with a t3 stage 1 turbine wheel and .48 turbine housing. And a to4 50 trim housing and comp wheel.
This is the smallest t3/t4 out there and you will have reached full boost onset by 4000 rpm. As you already know when you are on the track you are never under 4k and your power curve will be very linear and predicatble.
Even this turbo I just mentioned is to small for my taste but I like topend driving and that would warrant an entirely different turbo.

Just PLEEASSE do not put a t28 on the car. This will be catastrophic.
And after 6k you will be so inefficient blowing hot air in the motor.
It will feel like a turbo VW 1-3k will have torque and then it will fall flat on its face.

 

The T 28 does look good on paper, but you need 2 of them to make them work.

A T3/T4 hybrid in the Super 60 trim is almost ideal.

Having been down this road over and over for the past 6 months I can say with certainty the GT series of turbos is not available. And even more so, regardless of the ads they are not all ball bearing, twin scroll or new designs.

The only place I have found to get the GT is out of Australia. Try Ray Hall http://www.turbofast.com.au/ he even has some good calculators that will help you make your decision.

 

not available? agpturbo carries them, cheapturbo.com carries them. cjb80 just bought one, he posted pics of it. They are very available. They are made in America too. Contact me, I am in the process of buying a GT turbo over the next few months and know of a few places to get these at better than retail prices. AGP have been very helpful. -Anthony

 

David B, what do you mean they aren't ball bearing. I have read countless times they feature a dual ball bearing cartrige. I hear they have less rotational friction on the crank of the turbine causing much faster spool up time, increased efficiency, and they release less heat. If you could tell me why you think they aren't ball bearing I'd be interested to know. I appreciate it, Anthony

 

here is one that cjb80 bought very recently from cheapturbo.com

It is a GT30/35 hybrid

https://www.s2ki.com/forums/showthread.php?...threadid=103860