Ok I have an 87 N/A I have taken out the cats and replaced with pipe. Now what do I do with That pipe that runs to the air pump? Or can I just remove the Air pump? I heard this affects my 5th and 6th port actualtion? Thanks in advance.

 

somebody correct me if i am wrong.....
air pump only controls aux ports on S5 89-91's
exhaust backpressure controls S4 86-88's

so, you should be able to remove the airpump now without any issues

 

ok thanks but i would like to know for sure before i f-up my car :p no offence

 

Yeah but with a straight pipe wont the ports be slower to activate, or not activate due to the lack of back pressure?

You may have to go to an eletric port activation, read the sticky thread at the top of this forum if this is the case....

 

Bump ^

 

no offence taken but i am sure that is the case on the ports.

drox is correct, it is possible that your exhuast will not have enough back pressure.

i would highly recommend that ya do the electronic port activation.

have you driven it since you put the straight pipe on? if so, how does the throttle feel after 3500?

good luck

 

Doesn't it take 3 1/2 psi to open the ports? Someone on here said before that it should still open at the correct time, but we know how that stuff works. One car will do one thing and another car another thing.

 

i dont have straight pipes i still have the cans. and after about 3300 rpms it sounds mean as hell so they are opening. but I dunno if its the air pump or the exhoust back pressure.