Would the RB pre-silencer for a FC bolt up in between my RB street headers and OEM connecting pipes? Can i just plug up the hole for the back pressure sensing tube?

 

Nobody knows?

 

I'm not sure on the fitment of the piece, might be one of those things you have to measure, or do a little bit of fab work on. And if you just plug up that tube your secondaries won't work, so you better do mechanical secondaries.

 

i was just at seven stock and RB did a tour of thier shop...all the presilencers i saw in the works were packed with fiberglass and not steel wool, i thought that was wierd...i have a long magnaflow presilencer that works beautifully but i cant say i know exactly what you were asking, sorry...its not difficult for a shop to weld it in..

 

Yes, you can make a block off plate for the auxiliary air tube, or cut it down to where it's an inch or so long, pinch it flat, fold it over, weld it. As far as fitment length, no idea.

 

fiberglass? really? I thought that doesn't last for a rotary's exhaust. Their website says steel wool.

 

Just called RB... They said that they will not bolt up

 

Just to clarify, however your header is connected wont effect your carburators secondaries. They are controlled by vacuum created by your engine, regardless of what kind of exhaust manifold you are running, and wont be affected by this.

The only time you have to worry about such a problem is in a GSL-SE, or later model 6 port engine. In this case, the 5th and 6th ports are operated by the exhaust backpressure.