I know it's difficult but isn't it possible to fabricate the s4 turbo to except the s5 manifold? For example say I ported my turbo inlet... would that make them fix together?

 

no the bolt patterns are different for the turbine housings not sure though if you can just swap housing or if the turbine wheels are different sizes, but as far as making it fit just get an s5 turbo and manifold, if you need the turbo i know someone selling theres, they upgraded

 

No, it cannt be done. I know. I tried (well, almost tried )

Different bolt pattern. Different sized ports. Different placed ports. Different housings. Different (very small difference) A/R and turbines. Different control method.

Just get a S4 set (turbo + manifold), make the proper adjustments, and you're good to go...

 

Negative. Take a motor apart and you will find out real quick.

 

The '87-88 and '89-91 turbine housings and manifolds are VERY different designs. But, the compressor, center section, turbine wheel, etc. is all the same on the turbo itself.

To upgrade your turbo to an '89-91 turbo, all you need is the manifold, turbo to manifold gasket, turbine housing, and wastegate actuator - that's it. Or, just get the whole turbo and manifold - they go for sale off of Jspec motors very frequently, usually for a good price.

Dale

 

Bringing this one back from the dead guys, sorry..Question though...I have an 88 TII and I am wondering, does the S5 Manifold bolt directly? Can you just get an S5 manifold and S5 Turbo and swap out with no problems?? Just give me a list of what I need to convert s4 to s5 and that would be wonderful.. Thanks!

 

Yes they bolt straight on. Use the S4 oil and water lines, cap the twin-scroll actuator line and cap the tee on the S5 wastegate actuator line.

 

Thanks man for the help! Now another question..how would I go about porting the waste gates on the S5 turbo???

 

Just like you port any other wastegate I would think.

 

with a grinding bits in a rotary tool. or you could drill it out

 

if you drill it, be careful. You could bust a bit. I would use the grinder.

 

Whats the max size on porting an S5 turbo wastegate???

 

you match port it to the flapper

 

Not quite as big as the flap. Leave some area for the flap to seal to, otherwise it'll leak and boost won't rise quite as quick. You can still get the S5 ports quite big.

 

could you show me any diagrams or pictures of this?? that would help me a lot! Thanks.

 

The S5 isn't a twin-scroll turbo? I know it's a better turbo, is it just because the hot side is that much better, that it doesn't need the twin-scroll?

 

the S5 turbo has a divided manifold which acts as a twin scroll so it doenst need the actuator.

 

Yeah, they're both twin-scroll designs, it's just that Mazda refers to the switching system on the S4 (which closes off one scroll at low rpm) as the "twin-scroll turbocharger control system".