i had true duals on my car and it was WAY to loud for me and the local cops. i switched to a stock catback and custom ypipe (with cutouts) and it felt like i lost 75 RWHP. my heads/cam LT1 felt as "slower than my stock 02 LS1. i then put a flowmaster muffler on it. no improvement in power, at all !!!!

the car felt just as slow with the flowmaster muffler

so i go back to the exhaust shop have a bullet put in the I-pipe and straight pipes where the muffler goes. now the car is fast again a little loud but not as loud as the true duals....

jesse

 

but it sounds fast right

 

actually the flowmaster was just a tad louder than the stock mufler, it was an 80 series.....

 

I'm ordering a hooker aerochamber muffler for my car to replace the flowmaster catback I already have on it.

 

Yes it does suck ***. It was on my car when i got it but its coming off soon

 

Sounds like you have a cobbled up mess causing the problems, not the Flowmaster.

 

Was it a Flowmaster 80's series? I switched from one of them to true dual Bullets, and I suppose it felt a little better, but nothing like you described. Everyone bashes Flowmaster all the time, but I don't think they are as restrictive as most people exaggerate. True, probably not the best flowing muffler on the market, but I still stand by my word saying it is one of the best sounding.

 

i diisagree with you about it being restrictive we put one on a buddys car after he put the 230 236 in and it blew the mufller apart. it blew a hole big enough to put a football in. then we put a bullet on there and no more prblems.

now far as i sounding yes. but sound doesnt move you down the track does it.

 

The only thing I can add is...My car runs 12.2 THROUGH a Flowmaster with a stock bottom end/stock suspensuion/and full weight...With mid length headers. Does anybody really think the Flowmaster is holding me back that much?...LOL

Frank

 

well was that with the cutout open or close. that would make a little difference.

 

I also have a flowmaster 80 series. I didn't feel one bit of improvement when I took off the stock muffler and bolted on the 80 series. But now with the cut-out I do feel a slight difference between open and shut....

 

I will by at the dyno again with my car soon to see the
difference between the Flowmaster 10 series race
mufflers and a Dynomax Ultraflow. I expect the Dynomax
to show a slight reduction in rwhp. I'll post the results,
probably in the next couple of weeks.

 

That was before I put the cut-out on the car...

Frank

 

Whats funny is everyone that puts on a flowmaster catback and says "I didnt feel a bit of difference." What catback does make the SOTP difference? None. You're not going to feel 7-8 hp, which is about what you're gonna get on a stockish car. It may seem faster, due to the amount of sound coming from the car, but c'mon....no one is gonna be able to tell the difference in power feel between a Flowmaster and Borla or anything else. I have duals on my car, and I have two flowmasters. My junk must be really restrictive then.....

 

I had my stock exhaust with a flowmaster muffler bolted to my lts after i put them on. I then changed that to an xpipe and dual bullets. I felt no difference though i know the car is faster since we lessened the resistance on the exhuast. Now there is no way that you can tell the difference by simply putting on a new muffler.