My car's got 150k miles, and the compression isn't exactly awesome anymore. I want more power anyway. I'm thinking that I'll either rebuild and port mine (the NA path), or buy an old junked TII s4 or s5 and rip the engine and everything out and rebuild it+port it (the turbo path). Obviously the NA path is easier, but which is the better value for the money? Is it difficult to put the TII ecu into an NA? What's the best 1/4 time I could get on a streetable NA?

best value for money is turboII path, presuming you don't blow up the engine and get enough use out of it.

the 89-91 ecus interchange except for 2 wires, basically as long as you do everything 89-91 it will fit



mike

Turbo

You might as well go TII https://www.nopistons.com/forums/pub...#>/biggrin.png

the only problem is that s5 t2's are fairly rare, right? Do you have to rewire your dash if you put in an s4? Oh yeah, what specifically made the s5 t2s have more power?

the easiest path to t2 power is a j spec motor, they come with the turbo, intake, injectors etc. you will prolly want to rebuild the j spec motor though



mike

I do want to pass emissions. Can I put stuff like the ACV on a jspec?

the jspec has all that stuff, so yes you can



mike

If I was in the market for a j-spec S4 TII motor, what would I expect to pay? Mine's fine, but I noticed a bit of what appeared to be oil in the coolant when I changed the antifreeze this fall. Maybe not oil, but some kind of black sludge was left on the bottom of the bucket when I poured out the old coolant at the recycle station at the county landfill.