hi, i have a 89 turbo II with a s4 motor/turbo. Im looking for a small ball bearing turbo that will fit on my stock manifold that isnt too pricey. im planning on pushing about 14 pounds of boost. my manifold is a basic t3 flange right? sorry i dont know much about turbos. thank you

 

The Hitachi HT-18 that our cars have do not have as standard T3 bolt pattern or gasket.

A potent turbo you could make with the stock '89 turbo would be to buy a ball bearing T04B 60-1 (T04S) cartridge put on a 60-1 Hi Fi compressor housing (small enough to fit in stock location) and bore the stock turbo housing to fit the T04 exhaust wheel and CHRA.

Bryan at BNR turbos would be a good person to ask about this project.

It would end up costing ~$1,500 when it was done but you would have a nice very quick spooling turbo that looked pretty stock and could support 300-400 RWHP.

I have thought of doing this swap myself. I currently have a modded BNR stage 4 that is the same wheel/ housing specs as my proposed hybrid but plain bearing and I love it.

I get positive manifold pressure off idle and full 15pis boost before 3,500rpm now, and I imagine it would be even better w/ BB center.

 

Saw that you had a S4 turbo and motor in the '89. I wouldn't use a S4 turbo for this hybrid since the manifold design is poor, but a blown S5 turbo and manifold wouldn't break the bank.

 

I find this extremely helpful and educating. Thanks.

 

No such thing...

First, "ball bearing" and "cheap" do not go together.
A BB CHRA retrofit is like $1,000 right there...

Second, no off-the-shelf turbo (BB or non-BB) fits the stock turbo exhaust manifold, as it has been mentioned already.

WTF stuff an S4 turbo onto your Kouki FC3S?!??!?


-Ted

 

well i bought the car with a blown motor. the only motor we could get a hold of was a s4 motor. the motor came in and it was in great condition, and the turbo was in much better condition then the s5 turbo on my blown motor. so thats why.

and i was thinking something along the lines of a t28 from a sr20. you can find those used but in good condition for like 300-400 bucks. how would i be able to make that work? your help is appreciated

 

On our rotary engines the ball bearing feature of a T-28 will not be able to overcome its smaller T-25 exhaust wheel size compared to our large T3 STOCK turbo exhaust wheel.

The overlap of the rotary makes it sensitive to exhaust back pressure, so a smaller exhaust wheel will not help response much on stock ports, hurt response on larger ports and really hurt power, especially at higher boost levels.

Added to this is that the stock exhaust exhaust wheel is of a straight vaned "Impact" design designed especially for the rotaries harsh exhaust pulse by Mazda and Hitachi. This helps response and flow on a rotary.

For these reasons a S5 stock plain bearing turbo/manifold with a compressor upgrade would have better response and power compared to an undersized BB unit.

 

really?....thats interesting. thanks for the info