I currently have a Ravin Z55 with stock 2.5" pipes (SI/SO). I really like the muffler -- no perceived loss in low end torque and a much better sound. However, I would ideally like to have a little more sound while ensuring that I am maximizing my potential power gains. I have both a K&N FIPK and a Superchip and, therefore, want to know if I am losing any amount of potential gain (especially with the intake free up) by only having stock diameter. While I was toying with going SI/DO, I have heard too many people comment on low-end loss. Therefore, I was thinking about staying with the SI/SO setup and swapping the muffler for a 3" outlet with new pipes. Any help would be greatly appreciated.

 

I've got the Gibson Swept Side, and it has the 3" mandrel bent tail pipe. Since it came with the muffler too, I don't know what just the muffler would have done by itself. But, just by looking at the two tail pipes, the 3" one has less bends and of course, smoother bends compared to the stock 2.5" one. While you are not really "flowing" more exhaust, because of the restricted Y and 2.5" headpipe, I think what is flowing is getting out of the muffler easier, so that would help keep the engine from having to "push" the exhaust as hard. Just my own thoughts..... No proof on any of it. Besides, the 3" pipe and 3.5" tip looks cool!!

 

From what I have read pipe diameters should be decided by peak horse power (and therefore air flow) potential. I don't have all the numbers but 2.5 inch is supposed to good up to 300 hp.

 

Mitch150 and SCAdien,

Thanks for your replies. Very cool truck Mitch150, by the way! The exhaust tip looks great.