I do have a chart, but I don't have it with me right now. That's what I was thinking too, because I have a 2.5 inch downpipe, going to a 2 inch pipe back to the muffler where it's 2.5 flowmaster. I am going to change the rest of the piping when I got a little more cash. The storys I read of people making more HP than me said they did it with everything else stock, but I suppose they could have meant with the motor itself, and not the exhaust. I got it tuned at a place called turbo tune here in Greensboro N.C. He seemed to know what he was doing, but I don't know if he gave me a tune that would work, or a real johnny on the spot tune.
Last edited by Rooftop voter; 01-17-2007 at 08:39 AM.