I wouldn't rule out a S4 (87-88) turbo II. They have a slight weight advantage over the S5 (89-92). But the S5 has more hp.

 

Who me?

 

The HP advantage is MAINLY due to 2 PSI of boost and a slightly better turbo. If you're going to upgrade the turbo then that stuff doesn't matter. The only other real differences would be the air flow meter and the intake manifolds.

 

i like the S5 better because of updated interior,exterior, everything etc

 

i think the engine of the S5 is also upgraded. the S4 NA only has 146 hp stock, the S5 has 160 hp stock along with a higher red line. I think the engine has lighter rotors and better seals and other upgrades.



The S5 does look better. I especially like the rear tail lights. the rims are also more racey.

 

yeah im diffenitly gonna upgrade the turbo. if thats the main reason for the hp advantage in the S5 then i'll probably look for a S4, they're a lot easier to find and cheaper too. thanks for the help.

 

Yeah, the turbo is the main thing. The compression is a little higher in the 89-91 cars, but not by much. The 89-91 intake manifold is slightly better, but it's not a huge difference.

 

What about N/A version, it's a 15 hp gain? Maybe the new intake has more effect on the N/A's.

 

The S5 NAs have VDI, 9.7 compression ratio vs. 9.4, and lighter weight rotors.



The extra hp a S5 has just makes up for the extra weight.



Here is a link to info on both S4 and S5..... beyondtheredline.fd3s.net