aoc_pilsener

I am in the process of building a exhaust system from 85 gsl se(stock). The car came with a racing beat header and presilencer. When I look in the presilencer the pipe (5/8Od) inside the presilencer that should be bent at a 90 , pointing to the front of the car ,to control the Aux port is burnt off. I want the ports to work like they were intended to work and I dont know what to do.

I have been searching and all I seem to read is people talking about a compressor mod, Air pump Mod, Or the fourms go in to a debate about wiring them open or close. I have searched things like, Air pump mod, Aux air pump mod, compressor mod, ports compressor mod, ect ect and and cant seem to find what I'm looking for. Can somebody point me in the right direction.

I have came up with a couple ideas.
A) take peace of the exhaust, Bend a peace of stainless steel tubing at a 90, Weld it into a the exhaust pipe. And run a resonator and hope it works.

B) Or get a rpm activated switch and electric vacume solenoids, wire it up to work.
But then i run into 2 problems with that, like
What rpms should the ports be opening or closing?
All the rpm trigger switches that I have seen are for piston engines, will these still work with a rotary.

The exhaust I'am building is 2 1/2 od mandral bend. With a magnaflow muffler at the end.

Thank you

aoc_pilsener

ok I hate when i find post something and then find it on my own half hour later
http://www.rotaryresurrection.com/2n...elec6port.html

patmac6075

iTrader: (26)

Perhaps the simplest solutions are the best....it seems as if you're willing to go to all the trouble rigging some sort of vacuum contraption....which could very well not work...why not just order a new presilencer from Racing Beat?
Short of that....find a competent shop to re-weld the 90 degree tube back on our original.

aoc_pilsener

just trying to look at all my options, what would be better for my wallet? car? performance? future mods?

trochoid

iTrader: (6)

Simplest solution is what I did on my FC. 1 brass 90* elbow, 3/8" NPT on one end, 1/8" compression fitting on the other and 8-12" of 1/8" copper tubing. Tap the header for the elbow, screw elbow in, screw the tubing into the compression side, connect the tubing to the rubber line coming off of the Aux ports. Works like a charm, costs about 10 bucks if you have the 3/8" NPT tap.

I've had this set up on the FC for nearly 9 years. The nice part about it is there's nothing to fail and no maintenance.

aoc_pilsener

trochoid thats what i was thinking about doing but just putting it in the exhust pipe. suprised that 1/8" tubing works because the one In the RB pre silencer is at least 5/8 -1/2 tubing. I dont know what size the factory one is. What are you running for exh?

trochoid

iTrader: (6)

I had to dig to find this pic but this is what I did with the FC to actuate the AUX ports. It works surprisingly well, sort of like a the secondaries opening up on a mechanical 4 barrel carb. AUX ports open around 3800 rpm. Don't be put off by the small size of the tube. It only take few psi to open the ports. I wouldn't tap any farther back in the exhaust system as one might see a pressure drop.

Pic is in the following thread: Post #7:

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/custom-exhaust-5th-6th-ports-399198/

aoc_pilsener

Thank you thats awsome I will definitely be giving that a try. And now I can finish my exhaust with in the week =)

aoc_pilsener

So I finished My exhuast. Over all I think it turned out good. I wasnt to impressed with my welds but eh I guess thats where experience comes in.

Glazedham42

iTrader: (4)

This is pretty much what I have planned for my 12A powered '85 GS. Do you have any sound clips of this? If you could post some I would REALLY appreciate it. Also, any feedback you could provide would be awesome. How loud is it? Anything you'd change a second time around?

Thanks,
Jamie