i know that the 86-88 tII make around 180 and that the 89-91 make around 200. What makes the 89-91 faster? which one would be better in the long run if both were modded? I noticed the that 86-88 have lower compression, wouldnt that be better for higher boost? which TII would be better to buy?



Sorry guys im a newbie with a lot of ?s https://www.nopistons.com/forums/pub...R#>/unsure.png

Feel free to ask as many questions as you have, you won't get flamed here for asking a dumb question.



The S5 (89-91) have higher compression (like you said) the rotors are lighter weight too. The turbo is much better on a S5, it has a larger wastegate. Also, I'm not too sure, but I think that mazda may have made some changes with the intake manifold (I know they did with the NAs).



The S5 would be better in the long run, the housings are a little stronger (can handle more hp), but the S5s are hard to find. S4 TIIs are pretty easy to find, and are pretty damn cheap.



The lower compression could come in handy if you are like me, and can't tune worth a damn, but if the car is tuned well, the higher compression will just help you net more power with a given mod.



Hope that helps. https://www.nopistons.com/forums/pub...#>/biggrin.png

No, it doesn't help at all! It makes me wish my '88 was made a few months later as an '89. :P



I'm not complaining though. It's a sweet ride.