Man, do flowmasters suck...
 

I have the 40 series muffler for my car when Im just cruising and in the winter. Any other time the cutout is usually off. I know I get about 10 rwhp from the cutout but when that thing is capped, my car runs like a dog. What is up? Do flows really suck that bad? I mean I know theyre for sound, but I think my stock muffler did better for performance.

I think my American Thunder which I believe uses the 80 series flows works great. The sound is amazing and I do not notice any dogging in fact I think I am quicker.

everyone gets the 80 series and the 40 series confused. if it fits exactly where the stock muffler is the it's the 80 series flowmaster # 42583 made just for camaros and firebirds. So its really just a 40 series made for camaros and firebirds(trans ams) named the 80

you make 0 more hp by putting on just a flowmaster muffler.

There has to be some type of gain with a muffler. Sure it is not as good as a full exhaust but there must be something. I bought my 98 used and it had k and n and flowmaster muffler on it. I drove it and got used to it. I drove a 02 at work that was bone stock and a got on it. my car seemed to have more kick in it. there was also a guy on a nother board that said he dyno-ed more hp with the muffler. :confused: I can not understand why a "performance" exhaust manufacturer would put a product out that does nothing. :(

The Flowmaster 80 series will give you a little more hp than stock, but it's not that great compared to Magnaflow and such. Flowmaster makes pretty good exhaust systems EXCEPT the 80 series...so go with something else is my advice

I'm not a big fan of flowmaster my friend put flows on his 00 trans am with LTs and no cats and IMO it sounds just not too good and hes not impressed with it either so he just slapped two cutouts on after the headers and it sounds a hella lot better specially when hes got that big ol cam in there :)

Two cutouts after the cats??? Doesnt that rattle the HELL out of the interior?

I'm a big dynomax ultra flow fan. It is completely straight through you can pick it up and see through it. It has a low grumble at idle and sounds bad ass when you really get on it.

USHotRod, FYI... I still have that LM you PM'ed me about. Send me a PM for the new price:cool: If you are still interested

LOL yea its extremely annoying if ya ask me i dont know how he stands it, but he also has 4 12's cramed in the back so i think hes half deaf anyways, hes not the smartest but it sounds cool :)