What factors help in keeping exhaust gas velocity up?
Reason I ask is because after installing a Powertech muffler I feel like I've lost a lot of low end punch. Most everything is 2.5" except for headers, which are stock.

 

Pipe sizing. Exhaust design. Smaller the pipe = higher the exhaust gas velocity. In gen terms anyway.

 

Has anyone found that 2.5" exhaust would cause a loss of velocity in an NA setup? It doesn't seem normal to me. I thought that this could only happen if I were to go ~3".

 

I have a BERK/APEX-i and Cattman catback setup.....I do not notice the low end lose....

oh yeah I previously owned a 96 SE 5spd too....and that car had FC/Stillen, warpspeed downpipe, and greddy catback....didn't feel low end lose either...

it's weird becuz I hear alot of people complaining about losing low end as u start to free up the engine....but i don't feel **** in either one of my cars

 

Theoretically the straighter the pipe the fast the exhaust velocity as well as keeping the size in proportion... 2.5 inch piping with a 2.25 tip would create a quicker velocity than one with a 2.5" tip

 

I thought I heard that an exhaust should help in bringing back some of the low/mid range that a short ram intake would take away. (somebody correct me if I'm wrong) In my case, I may have gone too far but I thought that our engines should be able to generate enough exhaust pressure to flow well through a 2.5" piping.

 

I thought i read somewhere that if you use heat rapping in some spots that it helps keep the gas flowing faster since gas moves faster when it is hotter. I dono just my input.

 

You answered your own question...the stock precats are not flowing enough (they are probably melted)...time for headers

 

I used to think that and that's what I run (dyno queen and 14.1sec) but I'm not so sure anymore. 2.5" Y, Cat, b-pipe, to the 2.25" A33 muffler.