I've been doing tons of research to get a reasonable noise level out of a street-driven P-Port (yes I know, reasonable is a stretch). I was looking at these universals from Racing Beat. Supposedly the same construction as the old style from the streetport setup, just larger for turbo.

I will attempt to fit 2 of these (one version is longer and the other is shorter) pre/at the rear axle.


On a local PP around here once, he ran 1 2.5" round standard rb presilencer and one side of an RB turbo II exhaust. It was nearly as quiet as my SP.

The Larger on the right is the uni-rear muff. I may have to replace the Rotaflo in the rear if I get hassled too much...

 

brother Jaime
If you wanna hear it perform, Im using the RB universal 2.5" in my 73 RX-3 with streetport while the quattro with a TII bridge has a 3". if you wanna check it out, come-by sometime next week. Im waiting for new OC lines for the quattro so i wont be able to start it. And if you're lucky, I may take give you a ride on the 3-rotor.

 

Gotta love summer vacation! I'll hit you up!

 

Have you thought about running 2-1/2" dual pre-silencers off the header, then merging into a 3-4" over the axle pipe. Then you could go with a 3-4" Rotaflow or Borla. I'd use Borlas for the pre-silencers

 

IIRC, blake (may he rest in peace) had a p-port with dual 2" to make it quiet?

I was gonna do a p-port also but I junked that idea as performance will suffer with small pipes. why build one if you cant drive it like you stole it.

 

Jaime, running the 3" pre silencer and then the 3" uni high flow muffler you have pictured is about the best compromise for power and sound. It will still be loud as hell but not as loud as my system without pre silencer. If you go any other route to make it quieter you are going to lose more horsepower than the pport is worth doing. IOW- you'll have a quiet pport with the power of a streetport, so why bother.

 

I have a friend with a pp 13b second gen. I believe he uses Borla with the removable silencer. He says that having the silencer in kills about 20+ hp off the top end. Without the silencer it is loud as hell. My suggestion, follow what I have done. I run 2 presilencers and a magnaflow, very drivable. When I race I click the switch for an electric dump off the header (qtec). So i get the best of both worlds. I do plan on doing a dyno pull in a month or so so I can measure the difference, but the butt dyno says 20+ hp over 6000 rpm as she really pulls better with the exhaust open!

 

That's a good idea too. Could you post pics of your set up?

 

This Aurotary thread has excellent info on building your own muffs.
http://ausrotary.com/viewtopic.php?f...&sd=a&start=80

 

Mines out of service due to a camden failure right now. When it is back in service I'll give a video of open and closed exhaust and pics. maybe video the qtec as well

 

Put a 90* mandrel bent tailpipe on there. Making the exhaust turn nintey degrees quiets it down. Plus adding some pipe does too.

 

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