What power increase, if any, would you expect by removing silencers from a standard valver exhaust. By this I mean removing the 2 boxes in the middle, so you have a straight through exhaust with just a back box?
Am I right in thinking this would releave back pressure therefore increase power, or would it risk releaving to much back pressure.
This is the only mod I have to my engine so am just curious as to whether it would be doing just as good a job as an aftermarket system?
Yes, reducing the back pressure will gain you power and torque. Not massive amounts though, a few percent sayt. A decent aftermarket system will have pretty reasonable silencers.
Plus, although we all like some noise, a permanent headache in your left side isn't fun. That's what the Peco system did on my 1.3 Astra.
Until i fitted the sportex that now addorns my battered gte, it had the original factory GM exhaust on it. Yes you read that right. The factory exhaust lasted 10 years, it was a company car for those years and did 100,000 miles on the queens highways. Anyway, i digress, even though the carcass was in tip top shape, the wire whool type baffles in the second centre section and the back box were burnt away completely. It was louder than the sportex, but performance was brill. The first exhaust box after the downpipe is just a straight through pipe anyway, it is in effect a factory decat pipe, they must have planned catalytic converters for the future cause my car had neither a cat or lambda probe or affiliated ecu.
I did it about 6 months ago, it does sound brilliant, like a rally car. I am very pleased with the sound, just wondered if it would have caused any performance gains. And you've answered my question so cheers guys.