Ok, so the current exhaust on my 86 NA is terrible. It rattles badly and i can almost feel it restricting my power. So i was thinking about replacing it.
First: Any ideas of what sort of a setup i should use?
Second: My friend said i should leave my cat. and pre-cats on because N/a cars use the pressure built by the cats to their advantage... is this true and should i replace the cats (if so what type of cat should i buy?)
thanks
_sam

 

The pressure on S4 cars is to open your 5th/6th ports i believe. Without enough pressure they will not open which means lost power up top.

 

On my 86GXL I have a Racing Beat cat replacement pipe and presilencer. It has a tube that connects to the line going to the intake manifold to provide the pressure you need to open the auxilary ports.

 

so with the racing beat replacements you dont have either a cat or precat and you havent noticed a loss in power? (or gain in power for that matter?)

 

This is the one project84 has (Im pretty sure)http://www.racingbeat.com/resultset....rtNumber=16206


Anyway thats a nice piece, it says it will give you about 18HP increase. I'm pretty sure that bolts up to the stock exhaust system. I think you should go with that. Good luck man!

 

thanks man, appreciate the help you guys.