I just removed a flowmaster that was on my Formula. My local muffler shop said he had seen f-bodys slow down 2 tenths over the stock muffler with the flowmaster I had.
He said it was mainly the crossflow flowmasters, where you have an inlet and outlet on the same side.
My new exhaust is removed cat, custom 3" pipe to a single 3" big body magnaflow with single inlet/outlet , then one 3.5" out tail pipe. I don't need dual outlets.
This defintley pulls harder in the upper rpms and is not much louder than the flowmaster with a cat. I love it. The magnaflow came from my truck new it was about $100 and it was $175 for the exhaust, for a total of $275. Not bad consider catbacks are are $400+

 

i have a 80 flow on my car its nice for highway crusin but i am going with the magnaflow with my headers and ory i think the magnaflow sound bad ***

 

I get your point about the base RT system, but that same system can be had in stainless. Most places that sell the base system also sell the stainless version.

I know what you mean about the higher end systems though, the overall quality is usually better.

 

Ok, first off, I am not a kid.
Second, why get all hopped up on this? I asked for some proof, thats it. No need to go off and be a jerk. Did you have a bad day? get fired? PMS?
Also, the Flowmaster came on the car when I bought it, it is going to get duals, I just need a few more pieces. So, your wrong, those that use/have a Flowmaster didnt buy into anything, look at some other opinions on it, some just like it.
Again, all I was looking for was proof, not just someones opinion, because thats what they read somewhere else. Which is something that tends to happen a lot on here. I dont see why that is such a hard thing to answer, why do some take my looking for proof hostile or insulting? I didnt tell anyone they were stupid or mindless for not liking Flowmaster. So, how did I offend you?

Thank you to all the others that answered my original post intelligently and with some evidence (ronn25, Blue02Ws6).

 

I also have ran flowmaster's for more then 10 years and also have been pleased with the sound.

I took my car to my friends exaust shop to have a flowmaster installed on my 02 Z-28. I was going to go with the 80 series muffler but he stated that a few other guys that have the same car as mine picked up very little power on the dyno over stock. So they took it back and had him install the 40 series flowmaster with the 3" in 3" out with one single tailpipe and they took it back to the dyno and made much better gains.

So I had him install a flowmaster 40 series muffler 3" in 3" out with the one tailpipe also. Sounded good but didn't like having only one chrome tip coming out the drivers side. Looked like a V-6.

So I decided to take it back and have him make a dummy pipe to have the dual pipes again. When he put it in the air I started to see how it would work and asked if there was any way he could design it to where it could be mounted into the pipe right before it would enter the muffler? He said yes he could do it. Then I said how about cutting a 1 1/2" hole where he was mounting the pipe so it would also flow air before it even entered the muffler.

well 45 minutes later he was done and it looked awsome. He did a great job and when he started it up WOW.

I have no dyno #'s or anything but I liked it and it was a total of $250.00 for everything. I am very pleased with it.

 

Me and a few buddies cut mine off today...Worlds of difference without that choking piece of **** under my car. Louder, more throttle response, and used to only be able to break my tires loose in first anywhere from 0-35 MPH. Now I can break them loose in second, and even get an occasional scratch going into third. Thanks for the help this afternoon guys...

 

1BlownV8 had pretty much the same experiance , as me. My muffler shop said the same thing about the crossflow series (80series?). A flowmaster 40 series single inlet/outlet would work great though.

 

1BLOWNV8, I would love to see pictures of the exhaust and a sound clip of your car!

 

at speed inc, i gained 7 rear wheel horsepower on back to back dyno pulls with the flowmaster. while it may not be as freeflowing as some other exhausts, youre not gonna lose power over stock.

 

Cheap and bad flow

 

Proof that Flowmasters suck? A friend of mine got his 68 Olds 442 rear wheel dynoed. The numbers weren't what he had hoped for, so for the hell of it he dropped his 3 1/2" 40 series Flowmasters and strapped her back on the dyno. The Blowmasters were costing him 29 horse at the wheels. The 1 chambers may be alright, but the rest are disappointing, from both a performance and quality standpoint.

 

I LOVE mine. With stock manifolds it was extremely refined and sounded great. With LT headers and a Catted Y it is one of the top LS1 sounds IMO.

And the Corsa tips are the best looking bar none.

 

WEll i got the 80 series and pacesetter LT's and i am loving the sound also with the 3in ORY form TSP. Freakin loud and like i said before flowmaster in my opinion has the best sound.

 

I like the Magnaflow stainless steel catback systems. They look great, flow great and have a nice sound IMO. They're a great bargain compared to other stainless steel systems such as Corsa, and GMMG. Flowmasters sound good, but other than that they suck.

 

I had a 94 Z28 and put a 3" in/3" out Flowmaster on it and although sounded sweet did not run any faster in the 1/4 than with the stock muffler. I am still a Flowmaster fan but do not like the crossflows- which is why I didnt run one of them.

 

magnaflow

 

hell, gentlemen why even argue? Lets all agree to dump those shitty boxes of crap (mufflers) and get a true dual setup. The world would practically be a better place to live. Children could walk down the street and hear the sweet staisfying sound of true american muscle flowing through longtubes and straight through exhaust.

No cat back can match the gains of a true dual setup, and hell tsp true duals only cost 420 bucks new! you can get that and a pair of pacesetters for less than 700 all together, and then YOU WILL SEE GAINS!!! and not just top end, you'll get useable power under the curve.

No more mufflers!!

TRUE DUALS.

 

You will never see a Dyno sheet from Flowmaster. They claim to test on a dyno, but never publish the numbers. Why because the numbers are just not there. Companies like Magnaflow will not produce an exhaust system unless it produces a significant improvement over stock. Heck, they already have a new system for the 05 mustang, and ford is on record saying that it has an exhaust that cannot be improved on.

 

Honestly, why even argue this anymore?? If you really like the Flowmaster tone a lot (which I do on the right set-up), then just use it! You won't feel the difference on a stock or mostly stockish car, but at least you'll have the tone you like. Now if you're concerned with every last horsepower potentially available to you (or don't want to be chocked up later on as you start modding the car with headers, internal work, FI) go with a much better flowing system available. You could always just throw a cheap $35 cutout on your I-pipe to negate the "flow issues" with the Flowmaster mufflers. Just a simple opening of the dump will allow you to bypass the muffler entirely and I personally guarantee you NO other cat-back is going to outflow an open cutout. A few might be equal, but they'll never out do that.

Anyway, these Flowmaster love/hate threads are getting so old...Everyone already knows the crossflow mufflers don't flow very well...So if that is a problem with you, simply don't get one...But if you're not concerned with giving up a few horses on your ride, they provide a nice sound for those who like it.

The only time I would strongly recommend against running the crossflow set-up is on a car with more than just bolt-ons as dynos have shown you'll start giving up quite a bit at that point. Otherwise, Flowmaster provides a nice, fairly cheap system with a very low rumble that many other mufflers don't produce...

Mike

 

I agree 100% when I took my Flowmaster off and went back to the Dyno I had no horsepower or torque change just an obnoxious exhaust note. I only left it off for the 50 pound weight reduction.