Seriously thinking about sizing up my current 3.00" exhaust for a Mufflex 3.50". Here is my reasoning. My two 2.5 inch pipes going into the Y-Pipe have a total area of 9.812 square inches. My current 3 inch pipe after the Y-Pipe has an area of 7.065 square inches. That is knocking down the size of the pipes 25% at the Y-Pipe and looks like a potential restriction to me.

A 3.50" pipe has an area of 9.616 square inches which is very close to the total area of my two 2.5 inch pipes at 9.812 square inches. Of course I will need a custom Y-Pipe that goes from the two 2.5 inch pipes to the 3.5 inch pipe. Also looking at either the Magnaflow or Dynomax muffler with the single 3.5" outlet.

I'm currently around 380HP at the flywheel and need all the help I can get to achieve 400HP with my TPI. Also will be mounting a Holley 58MM throttle body to help on the other end. Remember every CFM and HP count. Allen

 

I have the 3.5" Mufflex on my Camaro with the Flowpuppy 3 bafle muffler - a freind had the same exact exhaust with the Magnaflow muffler - his sounded like crahp compared to the FM. Both cars had the 1 outlet tailpipe and the same size engine with an auto (mine has 125 more HP though). According to Mufflex, the pipe should be worth about 20hp at the 400hp level over the 3" - I haven't verified this yet, but it does seem to have a tad more top end over 5000rpm.

Downside is the pipes and muffler are a lot heavier than the 3".

 

Hi Paul

Thank you for the information and nice web site. From my searching a ton of posts on the web most say that either the Magnaflow or Dynomax give the best performance and lowest noise levels. I'm not into noise only the best flow and quietest.

If I got around 20HP that would be icing on the cake. If I got 10HP that would be great. I was thinking along the lines of maybe 5HP. At this point I'm looking for HP where I can find it without going to extreme and with a 212 degree cam. Not that easy to get a TPI 350 to the 400HP level NA and on the motor. Allen