Ok guys, I have an N/A and I uses the air pump to actuate my 6 port so I don't really need the back pressure from the cat to do this. So I went ahead and bought a pre-silencer for the turbo (the ones without a back pressure tube). My question now is, how do I block off the split air pipe that connects to the intake manifold?

 

It is an outlet, so unless the hissing noise bothers you, you can leave it open.

 

Yep, just leave it. I did it, and no problems (but I of course wired the ports open....which I won't do on my next Rex)

 

hmmmm.... just an outlet? i thought it is also an inlet because that's where the backpressure goes in. please correct me if im wrong.

 

HENRX7.....You're wrong. There. I did it.

 

ok, i'll just leave it open then

 

Yup. The backpressure on the '86-'88 comes from a small line (bout the size of a vacume line) that tees off the split air pipe. The large dia pipe has a check valve in it. Air goes in but not back out.

 

I got my pre-silencer installed this morning. Oh man, is it loud or what!!! I thought the pre-silencer was supposed to tone it down a little but it got louder. But on the other hand, I am satisfied with the performance gain. I get a better acceleration and the high pitch metal sound is now gone (i hate that ).

One thing I noticed was my exhaust is now spitting white smoke. I never had this before. Any idea guys?

 

Like a lot of white smoke? Does it do it after it warms up? More details please.

 

no not a lot but it smokes when it accelerates. At idle, its fine. Has it something to do with the newly installed pre-silencer?