Will I loose any horsepower by going to the flowmaster muffler in the stock catback 2.5? I have the 3in. magnaflow and am tired of the popping, plus I like the sound of the flowmonster.

 

Yeah you will

The Flowmaster is the worst flowing crossflow muffler for our cars...it loses power over the stock muffler oftentimes.

 

I just went from a Dynomax Super Turbo wich was to quiet to a 3 inch Flowmaster 2 chamber( 3in in/3 inch single out). Also 3 inch Tailpipe and 4 inch tip. Not only does it sound bad as hell, I think it feels just as fast if not better.

 

I have a Flowmaster muffler on the SLP dual/dual that came from the factory. It sounds good and I didn't feel a power loss.

 

As long as I don't loose any time at the track, I don't care about 2hp.

 

The idea here is to sound better and go faster at the same time ,not change catbacks for the sound and fun of it.

 

n20 it will be alot more than 2hp you will be going from the best(other than going true 2)to the worst . and you will feel it .if you want to try put some type of matal in the airs way before your tips if you want it not to pop and not be as loud add some dynatech thingies (they look kind of like a cork you put in your tips
and Eastern Bowtie:turbo type mufflers suck but they are better than slowmaster
RedLS1 since yours came from the factory you would not know what power you lost
NightHawk hit the nail on its head

 

I'm guessing you will lose around 5 rwhp, and you will probably see a loss in the 1/4 as well...

 

Yeah you're probably right .... the dozens of flow tests that show the flowmasters SUCK are definately wrong ... and your seat of the pants feeling is right.


I agree. If you lose HP on the dyno, you will generally lose time in the quarter ... they're not independant of each other.

I have had the magnaflow for awhile now, and never heard of this Popping noise you are talking about. Why don't you get a dynomax bullet in your I pipe, or the cork thing someone else was talking about. Going to flowmaster = bad idea ...
.

 

I have a friend with a h/c car and his feels as fast as mine, he has the flowmaster, but he hasn't been to the track. I may just wait to see if the tsp x will clear an aftermarket torque arm.

 

LMAO

I actually have a Flowmaster 53083 muffler in my garage right now that never made it onto my car. The reason being that I found not only many people saying that they suck, but dyno numbers that PROVED that they suck (way more than just a couple hp). Their straight mufflers aren't bad from what I've seen. I'll probably end up going with their one chambers when I re-do my duals, but the only way I'd put a blowmaster crossflow on my car is if I had a cutout to go with it.

BTW if any of you FM diehards want to buy one of these monstrosites, I'll sell you mine....cheap

 

Exuse me for having an opinion of my own car. You must be one of the lost retards from LS1.com that jumps on top of you for having your own opinion. If I say my car feels the same with a Flowmaster i think i know. I have had this car since 1998 and the Super Turbo muffler has been the only mod ever since. I drive this car everyday single day and after 91,000 miles I can pretty much tell if it is slower or faster.

Just an FYI for ya...I have an '87 GN that runs 10.70's, an '85 Monte SS that runs 11.0's and and a '85 Mustang that runs 12.40's with a Turbo SVO (4cyl) motor. I'm well aware that Flowmasters are resrtictive (especialy on Turbo cars) but run and sound great on any N/A car. People have been using Flowmasters since the begining of hot rodding. Never once will you hear someone make a comment like "I don't like the way that flowmaster sounds."
All the people on theese LS1 sites rant about how great straight through style exaust is but then every other post is " How can i get rid of the rasp." The answer is put a real muffler on your car!

I don't know where you found the flow numbers for crossflow F-body Mufflers but can you please share them with the rest of the board? The only flow numbers currently are for straight single in and single out muflers. And in those numbers the 2.5 inch Super Turbo flows: 278 CFM and the FM 2 chamber flows: 249 CFM. By switching the FM to a 3 inch and turning the Super Turbo into a Crossflow i'm sure the differnence would be made up.

Here are the dyno #'s from a N/A car. I'd hate to see how the Super Turbo Crossflow would compare if the Ultra Flo is a huge step up!
As you can see the Flowmaster 2 chamber is about equivalent with the Dyno Ultra Flo wich is 5 times the muffler the Super Turbo Crossflow is. If you are looking at some different tests(wich I doubt you are) by all means....share???
If not please move on to the next thread.

 

a friends car, 386 rwhp, flowmaster, 400 magnaflow.

nuff said.

i took my flowmaster off, and put a corsa on, better power, but the flowmaster sounded better, imho

Ryan

 

I'm not the one with 9 posts, and the flowmaster on my car.

"just AN for your information for ya" ....

Great ... so you agree with me. I am glad you spend all this time argueing then. Why don't you read some of the posts the other people on here have made .... I have not seen 1 person say "I vote for flowmaster" yet .. EVERYONE has said NO.

Dude, you're the reject that ASKED THE QUESTION. Then when you get the answer, you flipout?! Listen buddy, I have HAD A FLOWMASTER, and I NOW HAVE A MAGNAFLOW ... I know what both sound like, I know the power in both, and I gave you nothing but pure fact. If you don't like it when people contradict what you have set in your pathetic little mind, why don't you stop asking stupid questions.
.

 

I never asked any questions you post whoring looser. I don't need false information from clueless people like you. I'm sure your tin can sounds real good. Thank god i'm smart enough to not need advise from internet mechanics like you. As I expected you have no numbers to back up your half *** claims of horsepower.

WHERE????

Please take a few minutes to re-read the "true" facts that i posted for you so maby you will stop steering people away from a pretty good sounding muffler on a stock car.

OH BTW, For the guy who started the post. Yes you will probably loose a few horsepower putting a muffler on your car. But it will sound great (no popping) and you will get compliments...I promise. Also, just a quick note, my girlfirend has a bone stock 2002 Z28 that ran 13.70 @ 103 first time out stock. After a Flowmaster (muffler/tailpipes) and lid it ran 13.33 at 105 like 3 weeks later.

 

ive had neither exhaust but ive never heard anything good about the flowmaster catback for ls1's and ive heard nothing but good things about the magnaflow catback for ls1's. ill stick to my overpriced straight through borla .

 

[QUOTE=Eastern Bowtie]Exuse me...................the begining of hot rodding. Never once will you hear someone make a comment like "I don't like the way that flowmaster sounds."

I HATE the way a Flowmaster, on a Fbody, sounds! Honestly, I haven't heard a Fbody with a Flowmaster that sounds good. I do like them on a big block though, that was on the Hot Rod Power Tour, and the guy had 572ci monster! I think that car would have sounded great with any muffler.

It really is a subjective thing. I don't mean to be difficult, it's almost like buying speakers. You know how controversial "stereo speaker's sound" can be, right? I think it is much the same issue. Different people have different sound perceptions. IT really is that simple.

Personally, I hate the "dreaded drone" that most aftermarket catbacks make on a Fbody car, at about 2150 RPM. My 3.42 geared 2000 Formula makes that drone at 2150 RPM, unfortunately, it's right where I like to drive, around 70-72mph!

That Random Technology cat back on my 2000 Formula, sounds great! I get a lot of compliments on it. It definately sounds different next to a Fbody with a Flowmaster 80 series. Then there is the whole issue of flow rates, which every website states a different thing. I have to rely on what Popular Hotrodding did in a test of cat backs a couple years back. The Flowmaster, regarding actual air moved, was down on the list!

I just bought a Magna Flow for my 2002 Formula Firehawk. I hope it sounds as good as I remember it being on another Firebird. IF it doesn't, I will change it! I like their straight through design, so when you punch it, it will make some noise! But, it also has some sound material packing, for those casual drives to the store, like when my wife drives my Firehawk, it isn't obnoxious.

It's just a personal taste issue, when it comes to the subjective sound thing. And, I respect your opinon, it's just different then my perception.

Isn't it great we live in a country where we can agree to disagree!

 

I have cut off and thrown away more F-body FlowMasters after cutomers hear the MagnaFlow than stock systems. FlowMaster sounds Bad on the F-body keep your MagnaFlow it is one of the best.

Nate

 

Yep ... I do not know where Eastern Bowtie is getting his info from, but flowmasters on F-bods do NOT sound as good as they do on other cars (LT1's, big blocks, stangs) ... and it's just a known fact that they do not make power, period. IMO, anyone who puts a flowmaster on an LS1 is either mentally ill, or has done absolutely no research ... as Eastern Bowtie as shown. I have had both, Magnaflow sounds better, and flows better. Magnaflow definately does not sound like a "tin can" btw ... at idle it is very deep and mean sounding, and at WOT it sounds like an F1 car on steriods. I get more compliments on the magnaflow sound then I ever did with the flowmasters.

Stick with the people who know what they are talking about, and get the magnaflow. Eastern Bowtie is the only reject in this thread that has supported flowmaster, and it is obviously due to lack of knowledge. (he even left out the fact that the magnaflow outperformed the flowmaster in the exhaust test he quoted.)

Eastern Bowtie, please get a clue before you continue running your mouth.

.

 

Magnaflow Vs SLP LM

Which is louder at idle? Which is louder at WOT? And which flows better?