what does the split air pipe do, i was driving and mine fell off. i intend on putting it back on, but i want to know what it is and what it's used for.

 

Helps if you put what model you have...

But for Turbos and on 89+ coupes it feeds air into the cat converter to keeop it from burning out.

On non turbo S4 models it also feeds the cats, but also feeds the aux port solenoids to activate the aux ports.

 

i have the 87 base non turbo. sorry.

 

i have gutted cats and the airpipe is off too...its gone....stock exhuast too...no air pump wat effects should i be seeing because of it?

 

if you have a series4 non turbo, you will see a decrease in power from 3800rpm up. The split pipe helps the actuators for the auxilary ports open, via backpressure from the exhuast.

Jahan

 

thank you very much. i am not too great with welding, so i took it to tuffy and the douch bag there said it didnt do anything, so i will go to him with this knowledge and prove him wrong. thanks guys. this is just one way this site has made my life easier, and made my knowledge of the 7 grow dramaticly.