New LS1 Owners - Newbie Tech - Are Flowmasters really horrible?

Besides not being the highest flowing, max quality setup on the market, are Flowmasters really as bad as they're made out to be? I'm not going to spend anymore than $550 (shipping included) on a cat-back. And while that opens me up to SLP LMs, I'm not a fan of the sound. Flowmasters IMO carry the best sound, plus I like the way the American Thunder cat-back looks.

And at about $350 shipped, it's an especially attractive piece.

A friend of mine was in a similar situation. I advised him to get Magnaflow. He loves it, even more so after his Kooks and ORY.

Magnaflow catback system 98-02 LS1 (http://www.ws6project.com/user_stor/catalog/98-02-ls1-magnaflow-cat-back-system/)

Price has gone up a little since I told him to order it, but WS6Store is running a special on it right now. Plus its stainless so it won't rust. If my car didn't come with Borla I would have got Magnaflow myself.

I agree Flowmasters sound good but that's all they are. They do little to nothing for performance, some people have actually seen lower numbers than stock with it.

Yes, the Flowmaster Thunder series is not very good because it's their crossflow design. Most likely will not flow as well as the other aftermarket catbacks out there.

I have never truly seen flowmaster in person, only read they are bad so I cannot comment on that... but if price is the issue... Magnaflow makes a great cat-back for our cars in your price range.

Dont know how well the flowmaster flows but if I were you I would just buy a used Borla or something else. Should be able to get one for atleast $550 shipped. There is a bunch of good used exhaust floating around the parts section. Just my opinion tho.

I will definitely hit the classifieds come time to buy. But right now I'm waiting for the bottom end in my, what's supposed to be anyway, DD to get rebuilt.

I also am a huge fan of the way the Flowmasters (http://www.flowmastermufflers.com/shop/index.php?main_page=product_info&cPath=9_176&products_id=4382) exit. Note: the $597.12 listed on their site isn't even close to what I'm gonna pay for them, still brand new, elsewhere (if I do go the Flowmaster route).

I have flowmaster and like the sound, it came on my car. If I were to buy I'd get Hooker Aerochamber. In fact, if extra money comes around I'll probably replace it with that. It's also fairly inexpensive, so should work great for you.

They do little to nothing for performance, some people have actually seen lower numbers than stock with it.

I have to disagree with this, based on personal experience. About 12 years ago, I put their AT catback on my WS6 and I remember picking up about .5 mph on average over the stock WS6 catback (which already has a marginally better muffler than a base LS1 car). It's one thing to say that there are other mufflers that flow better (this is true), but to claim that their system flows worse than stock is just not correct. Remember, getting the full catback means that you're getting mandrel bent pipes, a 3" I-pipe, a muffler with a true 3" inlet, and dual 3" outlets (stock, base muffers only have 2.25" outlets [2.5" for SS/WS6], and all the stock systems have only a 2.75" I-pipe plus are necked down a bit at the muffler inlet).

Lots of people like to push Magnaflow, but I've had this one too and personally I think it's too quiet with cats, but it sounds decent without cats.

IMO, I prefer to pick an exhaust system based on sound, and if maximum flow is desired for the track, just add a cutout. The 5-7hp difference between various catbacks on bolt-on cars isn't going to make any difference for ~99% of the driving that you do with a street car. On the other hand, you have to listen to the exhaust every second that the car is running, so it's very important to pick a system that sounds good to you. For the other 1% of the time, a cutout can ensure maximum flow and HP.

I agree with you about choosing based primarily on sound, but I also wouldn't spend that much money on something that is purely for sound.

I would buy something that sounds good AND flows well without needing a cutout.

I agree with you about choosing based primarily on sound, but I also wouldn't spend that much money on something that is purely for sound.

I would buy something that sounds good AND flows well without needing a cutout.

I don't think I'm gonna come out any better with anything else at $350 shipped. At that price I can have a cutout done and still be sitting better financially than if I went with a great flowing, top quality $600+ cat-back.

I'm having a hard time willingly throwing money at this car as it's got pretty high miles and is only worth about $4K. I plan on buying another car this coming summer too, to have on top of my current Z28. Probably a low miles WS6 or SS.

I have to disagree with this, based on personal experience. About 12 years ago, I put their AT catback on my WS6 and I remember picking up about .5 mph on average over the stock WS6 catback (which already has a marginally better muffler than a base LS1 car). It's one thing to say that there are other mufflers that flow better (this is true), but to claim that their system flows worse than stock is just not correct. Remember, getting the full catback means that you're getting mandrel bent pipes, a 3" I-pipe, a muffler with a true 3" inlet, and dual 3" outlets (stock, base muffers only have 2.25" outlets [2.5" for SS/WS6], and all the stock systems have only a 2.75" I-pipe plus are necked down a bit at the muffler inlet).

Lots of people like to push Magnaflow, but I've had this one too and personally I think it's too quiet with cats, but it sounds decent without cats.

IMO, I prefer to pick an exhaust system based on sound, and if maximum flow is desired for the track, just add a cutout. The 5-7hp difference between various catbacks on bolt-on cars isn't going to make any difference for ~99% of the driving that you do with a street car. On the other hand, you have to listen to the exhaust every second that the car is running, so it's very important to pick a system that sounds good to you. For the other 1% of the time, a cutout can ensure maximum flow and HP.

The Magnaflow is quiet with cats for a while, if you keep it on there for years it loudens up for some reason. This is based off experience from when I was looking at getting an F-body. I test drove a ladies 2002 Z28, only mod was a Magnaflow catback, stock manifolds and cats, and everything else and it was surprisingly loud for having cats.

As far as the Flowmaster goes, I know I've seen people say it can lower performance from stock, but no I'm not sure how accurate that is. I found this older thread about it that you responded too - http://ls1tech.com/forums/new-ls1-owners-newbie-tech/1202169-does-f-body-flowmaster-muffler-flow-better-then-stock-ss-muffler.html

OP, definitely look at the classifieds if you don't want to buy a "more expensive" new system.

I don't think I'm gonna come out any better with anything else at $350 shipped. At that price I can have a cutout done and still be sitting better financially than if I went with a great flowing, top quality $600+ cat-back.

I'm having a hard time willingly throwing money at this car as it's got pretty high miles and is only worth about $4K. I plan on buying another car this coming summer too, to have on top of my current Z28. Probably a low miles WS6 or SS.

One thing to note about a catback that cheap though is that it will be aluminized steel, not stainless. That means it will eventually rust. I'm wired to do it once do it right, I went full stainless off the bat to not have to worry about it in the future. You can get a stainless used catback for $250-$500

It says the AT system is stainless steel though. And as far as audible difference, yeah, I'll also be going with LTs and a ORY so I'll definitely be heard! :)

But as you provided with that other thread about the flow of Flowmasters, I'm not going from a stock muffler to a 80 Series muffler. I'm going from a completely stock exhaust to LTs, ORY, and Flowmaster AT cat-back.

I put a flowmaster cat back on my car back in 03, I love the way it sounds. As far as it chocking out performance. Just put an eletrice cut out in. Thats what I did,couldn't be happier.

I don't think I'm gonna come out any better with anything else at $350 shipped. At that price I can have a cutout done and still be sitting better financially than if I went with a great flowing, top quality $600+ cat-back.

I'm having a hard time willingly throwing money at this car as it's got pretty high miles and is only worth about $4K. I plan on buying another car this coming summer too, to have on top of my current Z28. Probably a low miles WS6 or SS.

Hooker Cat-Back from Ws6Store (http://www.ws6project.com/user_stor/catalog/98-02-ls1-hooker-catback-exhaust-system/)

This is a great cat-back, and unless you live near salt water (or in places that snows) aluminized should be fine.

It says the AT system is stainless steel though. And as far as audible difference, yeah, I'll also be going with LTs and a ORY so I'll definitely be heard! :)

But as you provided with that other thread about the flow of Flowmasters, I'm not going from a stock muffler to a 80 Series muffler. I'm going from a completely stock exhaust to LTs, ORY, and Flowmaster AT cat-back.

Make sure you get the right part number. I just looked and they make a stainless version and an aluminized version so just make sure you're getting what you want if you didn't know there was more than one version.

Flowmaster stainless part # 817199
Flowmaster alumized part # 17199

I put longtubes, deleted the cats, and put magnaflow on my car and absolutely love it! It screams when I get on it and has a fairly loud idle. All in all from longtubes to the tips I think I spent around $300. Flowmasters do sound pretty good though lol!

I have flowmaster and like the sound, it came on my car. If I were to buy I'd get Hooker Aerochamber. In fact, if extra money comes around I'll probably replace it with that. It's also fairly inexpensive, so should work great for you.

I've got the Hooker Aerochamber catback and it is very quiet. You can't even tell my car has a MS4 in it until you open up the cutout. But if your looking for that killer sound then this isn't it. Its more like a stealth system for cops that hate loud mufflers. And I usually open the cutout till it sounds like I like it and if you hit a check point you can go silent running for awhile. When I got my car somebody had cutout the factory muffler and replaced it with a Flowmaster. It sounded like crap. A single in/out Flowmasters are ok but the single in/double out are the ones to avoid. Have you gone to www.ls1sounds.com and checked out the site?

Well, when I was shopping for an exhaust, I considered Flowmaster, but I do not like cut-outs. So I asked myself a question: "Do you want to make noise, or do you want to make power?" I chose the power.

Make sure you get the right part number. I just looked and they make a stainless version and an aluminized version so just make sure you're getting what you want if you didn't know there was more than one version.

Flowmaster stainless part # 817199
Flowmaster alumized part # 17199

I didn't know there were two versions, so thanks for that! Fortunately the one I found for $335 IS the stainless steel (409S) version!

Now it's a waiting game. Hopefully it'll still be readily available and for that price or close to come time to buy.

I've got the Hooker Aerochamber catback and it is very quiet. You can't even tell my car has a MS4 in it until you open up the cutout. But if your looking for that killer sound then this isn't it. Its more like a stealth system for cops that hate loud mufflers. And I usually open the cutout till it sounds like I like it and if you hit a check point you can go silent running for awhile. When I got my car somebody had cutout the factory muffler and replaced it with a Flowmaster. It sounded like crap. A single in/out Flowmasters are ok but the single in/double out are the ones to avoid. Have you gone to www.ls1sounds.com and checked out the site?

Yeah, I've checked out the website. A lot of good clips there. The Flowmaster ATs sound really good IMO.

As far as the Flowmaster goes, I know I've seen people say it can lower performance from stock, but no I'm not sure how accurate that is. I found this older thread about it that you responded too - http://ls1tech.com/forums/new-ls1-owners-newbie-tech/1202169-does-f-body-flowmaster-muffler-flow-better-then-stock-ss-muffler.html

Looks like that thread was about muffler replacement only. That's not the same as getting the full catback. The 80-series replacement muffler is only a 3" in, dual 2.5" out muffler - the AT catback uses a 3" in/dual 3" out muffler (or at least it did when I bought mine many years ago). Also, by getting the full catback you're getting a bigger I-pipe and improved bends. I absolutely can't believe that anyone has ever installed the entire AT catback and *lost* power over their stock LS1 catback (dual/dual excluded).

So I asked myself a question: "Do you want to make noise, or do you want to make power?" I chose the power.

The other way to look at this is, "Do you want an exhaust note that you're happy with 100% of the time on a street car, or do you want to make marginally more power for the 1% of the time you're at WOT?" :D

I've got the Hooker Aerochamber catback and it is very quiet. You can't even tell my car has a MS4 in it until you open up the cutout. But if your looking for that killer sound then this isn't it. Its more like a stealth system for cops that hate loud mufflers. And I usually open the cutout till it sounds like I like it and if you hit a check point you can go silent running for awhile. When I got my car somebody had cutout the factory muffler and replaced it with a Flowmaster. It sounded like crap. A single in/out Flowmasters are ok but the single in/double out are the ones to avoid. Have you gone to www.ls1sounds.com and checked out the site?

You're the first person I've heard say this. I always new magnaflow was quiet but I thought the aerochamber was louder than the flowmaster. Sound is very opinionated. I have the same exhaust as you speak of (weld-in flowmaster) that sounds like crap and I think it sounds fine. Then again most seem to like borla, which I can't stand.

I liked my exhaust on my old 98 cammed formula, it's just that it was too loud. Dumped true duals with sweet thunder 3" mufflers.

Sound is very opinionated. I have the same exhaust as you speak of (weld-in flowmaster) that sounds like crap and I think it sounds fine. Then again most seem to like borla, which I can't stand.

Agreed on all counts. :nod:

Go with magnaflow. Great system for the money. Mods are in sig.

The other way to look at this is, "Do you want an exhaust note that you're happy with 100% of the time on a street car, or do you want to make marginally more power for the 1% of the time you're at WOT?" :D

Exactly. It all comes down to what you want/prefer. A few years ago, I bought a Fox Body 5.0 that had Flowmasters. Inside of a week, the Flowmasters were gone, and replaced with Borlas. To some, the sound of Flowmasters is pleasing. To me, they are simply noisy. With both the Magnaflows now, and the Borlas then, I had both the power AND a sound I like.
The point I was attempting to make for the OP, was that liking or disliking a particular system's exhaust note is a matter of personal preference. But, barring cutouts, he will be sacrificing power by going with the Flowmasters over many of the other popular brands. It's basically a decision he's going to have to weigh for himself. For me, I'm glad that I found an exhaust that allows me to have my cake and eat it, too!:)

Personal preference will obviously be the deciding factor, but for some reason the LS world isnt fond of the "Flows" like old school guys... It think that our rumbler cat back offers a sound similar to that old school sound, but we definitely dont use a flowmaster.

I tested a Flowmaster for HP loss. I have a 3" exhaust and a Flowmaster 80, with LTs, Y pile, and an electric cutout under the rear seat. Car is an LT1 383. First run open cutout, 2nd run through the FM80. 12 HP loss out of 417, less than 3%, not too bad. I don't know what a stock system costs for HP. Mustang Dyno BTW.

http://i154.photobucket.com/albums/s253/jp95zm6/Z28/CamaroProject335.jpg

http://i154.photobucket.com/albums/s253/jp95zm6/Z28/CamaroProject339.jpg

Personally I love the sound of the Flowmaster 80. Here's what idle sounds like; this is too high an RPM to hear the cam lope much, 750 sounds a lot cooler, but you can get the idea.

http://s154.photobucket.com/albums/s253/jp95zm6/Z28/?action=view&current=Freshlybuilt1000rpmidle.mp4

Exactly. It all comes down to what you want/prefer.

Agreed.

No matter how many people profess their love for Magnaflow and Borla, there will still be those of us that prefer Flowmaster. Sound is all opinion anyway, so there will never be a wrong answer in this regard.

For a street/strip application I would simply do a cutout for track events.

For a race car I wouldn't even consider a catback; too much extra weight and pipe bends. Headers with duals ending mid-body. Add a couple of race bullets if your track has noise restrictions.

I made the mistake of going 80 series Flowmasters when i first bought my TA, I felt no difference at all other than a bit more rumble vs my stock exsht.

But i do have to agree with Post #8 If you want good flow, add a cut out. I did it to my exhst and always leave it open! Some ppl down the street give me dirty looks all the time, but it sounds awesome IMO. After the cut out, i never bothered replacing the flowmaster, its there for when i close the cutout for long trips or normal sound.


Stay away from Flowmaster, theres alot more options out there that you'll be happy with.

http://m.modmotortech.com/forums/showpost.php?p=7575000&postcount=33

Don't forget, many companies make systems for our cars. MAC and Pypes are two no one ever mentions on here. I've had FM80, LM 1, and Pypes myself.

Saw a muffler comparison a few years back and Flowmaster was right at the bottom.

The crossflow muffler on our cars is what sucks, and the Flowmaster crossflow muffler "seems" to be among the worst.

On a mildly modded car the factory pipe flows VERY well with a single in/out muffler on it.

On my car I only picked up 5rwhp going from the stock pipe with a Magnaflow single in/out muffler turned down under the drivers side bumper to a SLP 2OTL.

This was making 385 to the wheels.


EDIT

On my 1992 Silverado I went from a 70 series Flowmaster with a dual 2.5 inch inlet/single 3 inch outlet to a Magnaflow with a Flowmaster Merge and only picked up 4 to the wheels.

The single in/out Flowmaster mufflers do ok.

....single in/out muffler turned down under the drivers side bumper....

The single in/out Flowmaster mufflers do ok.

This is what I've been thinking about doing lately. A FM Super 44 3" single in/out with a turndown tucked up near the driver's side frame. This should look fine on a Camaro or Formula since they don't have any tail pipe provisions in the bumper anyway. If I use a muffler with offset inlet/offset outlet, it should fit in the stock location and be able to be connected to the stock hangers.

Sound is very opinionated. I have the same exhaust as you speak of (weld-in flowmaster) that sounds like crap and I think it sounds fine. Then again most seem to like borla, which I can't stand.

I liked my exhaust on my old 98 cammed formula, it's just that it was too loud. Dumped true duals with sweet thunder 3" mufflers.

Agreed. 100%

I have used Flowmasters since about 85; met Roy in 87 when nearly no one knew Flowmaster.

I am a diehard fan and the "tests" that I have seen are negligible.

Crossflow sucks whomever makes it.

Flows and cutouts is priceless.

This is what I've been thinking about doing lately. A FM Super 44 3" single in/out with a turndown tucked up near the driver's side frame. This should look fine on a Camaro or Formula since they don't have any tail pipe provisions in the bumper anyway. If I use a muffler with offset inlet/offset outlet, it should fit in the stock location and be able to be connected to the stock hangers.

http://i1122.photobucket.com/albums/l528/FASTFATBOY1/Exhaust.jpg

I had a original 40 single in/ou on my 92 and everyone thought it sounded amazing. It did not sound like and other 3rd gen; of course it was a true L98 and had headers when very few 3rd gens had them, sooooo

Much better setup than a crossflow.....

This is what I've been thinking about doing lately. A FM Super 44 3" single in/out with a turndown tucked up near the driver's side frame. This should look fine on a Camaro or Formula since they don't have any tail pipe provisions in the bumper anyway. If I use a muffler with offset inlet/offset outlet, it should fit in the stock location and be able to be connected to the stock hangers.This is what I run on both my Formulas, except Hooker Maxflow instead of FM 44.

I actually had different mufflers on a flow bench at UTI when I was still in school and the worst flowing aftermarket muffler was a super turbo followed closely by a Flowmaster 40 series. The best brand we tested was a dynomax Ultraflo unsurprising due to its strait through design. I am not saying all flowmasters are bad but if all out power is the name of your game then I would recommend something else.