Tyblat

hey guys. I've got an 87 Gxl and I'm gonna replace the cat's with a presilencer. just wondering if I have to buy one from a brand like racing beat, or if I could have a shop fab one up.

Also wondering, how much of a gain is this expected to produce? I've heard tons of numbers thrown around so I'm not sure exactly what to believe.

Rx7TyreBurna

iTrader: (1)

Eh, never dyno'd mine. But I felt a difference between my clogged cats and not having them.

I would suggest RB because they won't rust out quick like some other ones you can get. If you have them fab one, make sure it is setup just like the RB one, with all the .... well, can't think of the word now, but all the holes to reduce noise.

Great buy though. Well, worth the money. I would get the headers and the presilencer. I got the downpipe and the presilencer. But if I could buy over I would go for the headers and the presilencer.

mr_vaughn

iTrader: (1)

for a turbo huge increase in horse power... also for NA too . some work better witha bit of back pressure. for lower end torque..

if pre fabbing also use high temp materials since rotaories run hotter than standard cars.

also straight pipe versus pre -silencer is niose .
there are a few out there basically the same but have different sounds.

ROTARYROCKET7

Well RB sells two presilencers. For ours 87 gxl, you need to make sure u get the s4 presilencer wth the lil hose extension for the 5th/6th port actuators.

Racing beat man, catback with clogged up cats and exhaust manifold i felt a difference i cant wait to get the headers and Presilencer

woohooooo

Jason NYC

Jager

iTrader: (10)

Actually when I had my switch from the superflo from bonez to the RB presilencer, I didn't have a noticable difference. My power just seems to be back in the powerband a little bit more with the header. With the Superflo system from Bonez I could still squak 2nd.

rxspeed87

what about using a borla XS muffler as a presilencer?
would almost think it would run quieter on the car if you have enough room to do the mounting of it

n/a-luvr

Why not a straight pipe? Course you need to be prepared to wire your ports too... ~Rich

rxspeed87

uh why would you need to wire your ports if you still put the pressuer tube in the straight pipe?