BEN WIGHT or LOZ

psi · tinkerer Joined: 17 Apr 2002 Posts: 123

Hey,
I've noticed you guys know a fair bit about turbos and was wondering if you can help me out. I'm after a turbo but am unsure of what type to get. Its for a piazza 4zc1, and can be any type as im getting a custome exhaust manifold made up. I am aiming for 250-260ish bhp. The motor can easily handle 25psi. my limit for the turbo is $1500. One of my choices are a series 5 RX7 turbo hiflowed, but wasnt sure if this was an appropriate size for the boost i was going to run. Thanks for any suggestions!!

rob_w · tinkerer Joined: 19 Feb 2002 Posts: 395

try a garrett gt25 roller bearing turbo @18-25 psi.....
[ask eggy, its his car....]
rob.

Ben Wight · backyard mechanic Joined: 04 Oct 2001 Posts: 946

An S5 or S4 hiflow will do what you want easily, probably on about 16psi intercooled with exhaust.

You can pick them up cheap at Dysons or Daltons in Geelong, about $900.

A standard unit will also do the job and be cheaper, and spool up quicker, but it means more boost, which is more dangerous. If you want to run 25psi, with avgas and a big intercooler, then the hiflowed one should do it, I dont know, I have never ran that much throuh one before.

Ben Wight

psi · tinkerer Joined: 17 Apr 2002 Posts: 123

o.k.
so about a T28 size will be best suited for the 2 litre piazza, and have a good chance at getting 250 bhp on 16psi?? I was told to get T3 to T3/T4 size, but other people said it was too big.
thanks 4 your help peoples

Ben Wight · backyard mechanic Joined: 04 Oct 2001 Posts: 946

No sorry, you misunderstood. An RX7 turbo is based on a T03 bearing housing, a T28 is a smaller unit.

A T3 highflow in particular is quite a bit 'bigger' than a T28.

It will probably take a T28 more boost than 16psi to make 250hp@flywheel. Then again, it really depends on rest of engine and fuel used.

Ben Wight

Loz · backyard mechanic Joined: 05 Oct 2001 Posts: 943

If you can and dont mind spending $1500 then a gt28 would be the way to go. You can get a 300hp unit for about $1350, and a genuine 340hp one for about $1700. These will boost well past 25psi safely, however they will max out at about the 25psi mark. Aside from that the internal wastegate cant really handle that much anyway, so it would probably be best at 20psi.
Ive got a gt28 that made 220kw at the rear. (Not my car though) Sad

A T28 of an s15 can make close to 180rwkw, so long as it doesnt have a ceramic turbine wheel. That is on an sr20 though, so a gem engine would be different.

Ben Wight · backyard mechanic Joined: 04 Oct 2001 Posts: 946

Thats pretty cheap for a new GT28, we are talking brand new ball bearing turbo right?

Where from?

Loz · backyard mechanic Joined: 05 Oct 2001 Posts: 943

Yep thats right. Its from Cooma diesel in Canberra. They would probably be the cheapest for the garrett BB turbos in aus. Coz they are really trying to move alot of them.