Mufflex W/spintech Dual Outlet
I still love the sound of this system so I might just do it with some cut outs for when I go to the track. I just can't stand the loudness of some other systems for reguar driving.
We have 1 3/4 hvmc QTP headers and 3" to 4" y-pipe. Then we have a 4" cut out before the rear. Then the 4" mufflex exhaust. We run the car with the cut out open so we couldn't give a hoot how restrictive any muffler is. This combo works for us! Good luck to all !!!!
Does the 4" pipe hurt velocity enough to reduce scavenging? I realize that there is a big difference in area of a 3" vs. 4" pipe, maybe some of the ~400hp NA cars can benefit from running 3" rather than 4"?
ps. I have no facts about this, just some stuff I read suggested velocity being important
ps. I have no facts about this, just some stuff I read suggested velocity being important
Originally Posted by Firehawk441
It's 402 cu.ins. 523 RWHP & 497RWTQ. To answer your question, not all engines will benefit from a larger exhaust.
Do you by chance have any dyno #'s with and without the cut out? I was considering going with the mufflex system.
Originally Posted by Bad Habit Bird
Actually I was wrong about the 24rwhp it was actually 29 rwhp and 34ftlbs 
The reason I bought that catback was because of it being 4" and thinking it would flow the best. The exhaust consisted of a 3" y-pipe with a flowmaster 3" into 4" collector and then the 4" Mufflex exhaust. I didn't actually use a cutout though, I had a flange made and put on directly before the muffler so I could take the muffler off at the track. Anyways I have attached my dyno results from going through the muffler vs. taking the muffler off. (sorry about the quality I just took a pic with my phone since I don't have a scanner setup yet.
The reason I bought that catback was because of it being 4" and thinking it would flow the best. The exhaust consisted of a 3" y-pipe with a flowmaster 3" into 4" collector and then the 4" Mufflex exhaust. I didn't actually use a cutout though, I had a flange made and put on directly before the muffler so I could take the muffler off at the track. Anyways I have attached my dyno results from going through the muffler vs. taking the muffler off. (sorry about the quality I just took a pic with my phone since I don't have a scanner setup yet.
