APR

After many months and many iterations we have completed our S4 cat back system. It uses the latest SRT (side resonance technology) to produce a system that gives you the most performance for your dollor. All info has been released on our web site (www.goapr.com) including pictures and pricing. Also stay tuned for a turbo back system with high flow cats to be released late June. This will have a program mod as well. Feel free to give us a ring.

Thanks

Stephen/APR
1-800-680-7921<ul><li><a href="http://www.goapr.com">http://www.goapr.com</a</li></ul>

WickdS4GoByeBye

I assume this is the SRT, but WHAT is it and how is this better... etc....

APR

In the past when trying to muffle exhaust sound the exhaust gas had to flow through a resonator or muffler etc. Although this worked, the exhaust gas inevitably lost velocity. In other words this added restriction. With SRT you are able to muffle sound without slowing down the flow. The resonator sits off a manderal bend and muffles sound very efficiently. We tried many types of designs in the R&D stage and found this to offer the best of both worlds. Great performance, great sound and good quality. I hope this helps.

Thanks

Stephen/APR
1-800-680-7921

Paul C

<p><a href="http://registry.audiworld.com/audi/registry/details.asp?car=4098"><img SRC="http://pictureposter.audiworld.com/AudiWorldPics/2000/random151.jpg" BORDER=0></a>

lomel

Does it exhaust fumes/gases? Could the fumes/gases possibly enter the cabin with this "resonator" exhausting under the car like this?

silvertip

little low - is that correct? - also can we get a pic of the undercarriage? - and finally, do I have to send you my ECU (that I bought from you) to get it reprogramed for the exhaust?

Thanks

ultrafreak

APR probably mucked with the length of the SRT so that it produces a cancelling wave for certain frequencies produced by the exhaust. Quieter exhaust without the backpressure of a muffler or resonator. A semi-informed guess.

s4burner

<p>00 s4 Silver/Silver
MTM Stage 1

Sander

Dude, if it was open it would be super noisy! Of course it's closed!

Mark Dean 2

Pluses - can cancel pressure pulses with little restriction/disturbance to flow

Minuses - works only at a specific frequency, added expense of fabricating.