thebart455

i have a flowmaster on my car and cutouts and i like em both. but i dont see it giving me 25 hp maybe 5-10

ChocoTaco369

Yes, I read your post and it's full of holes.

I'd like to see the A/F ratios in order to see what is really going on here, and it would also help to see the entire power curve and a picture of the exhaust itself, showing all bends and such after the cutout.

I'd also like to see that same muffler run, only with a 4" inlet on a 4" exhaust system since that muffler in a 3" was not designed to be run behind a 600bhp+ motor. Any 3" crossflow muffler will choke down some horsepower at that power level. It's not even remotely fair to stick a muffler designed for a car rated at 305 horsepower behind a car making literally twice that, then to call that muffler a restriction. No **** it's a restriction, it's a 3" crossflow muffler stuck behind a damn race car motor that would NEVER be found on a production car stock.

ChocoTaco369

Right, so...

He lost a measly 24rwhp on a 513rwhp car.

That equates to a power loss of 4.68% due to the muffler. Significantly under 5% on a car making 200rwhp more than stock. Nevermind the muffler was not designed to flow that kind of air, it's only costing him LESS THAN 5 PERCENT OF THE TOTAL HORSEPOWER OF THE CAR.

Now, on the OP's car, it's only costing him 8rwhp on a 406rwhp car. That equates to a measly 1.97% of the car's horsepower through the muffler. That isn't much at all.

So, obviously the muffler has reached its breaking point on a well over 500rwhp car. How is that bad when the muffler was designed for a car making 300rwhp from the factory? Nearly ANY 3" single-in/dual-out muffler will be a restriction on that kind of car. Even oxidizr himself said the 3" straight-through Magnaflow single-in/dual-out muffler found on their F-body catback becomes a restriction on a car making over 400rwhp, which is why they were developing a race catback that sadly never saw the light of day.

24rwhp horsepower is NOT much power on a 600bhp motor, you asshat. It's a drop in the bucket, and considering that muffler was designed to be run behind motors making literally HALF that horsepower, that is NOT bad.

But I guess you didn't think your brainless comment through, did you?



Your lack of thinking has yourself, brother. Bandwagon-hopping nutswingers like you are the reason why forums are filled with so much bad information.

JerseyLS1TA

iTrader: (2)

Man choco you get to butt hurt over **** but seriously I have always heard that the Flowmaster, 80 seriers at least, dont flow all that well..but I did like the sound of it on my 94 T/A, but not better than my Magnaflow

RevGTO

iTrader: (12)

I've posted this numerous times in these kinds of threads, but ...

I was at the track with a friend who had the FM catback and cutouts. He ran back to back: 12.94 closed, 12.97 open. MPH was within a couple of tenths. This is a bolt-on car. In effect, no difference.

That settled the FM debate for good for us.

Colin91Z

iTrader: (9)

After reading your rambling, It's quite obvious to me that you did not read my first post, or at least you didn't read all of it.

I don't know how to make this any more clear...maybe this will help...

I AM NOT KNOCKING FLOWMASTER

The whole reason that this car has twin cut-outs is because the owner and I felt that a single 3" catback would be a restriction on a big-inch motor like that....guess what...it was!!! Yet he wanted to keep the cat-back in order to keep the car civil being as it is his daily transportation.

I never said that it was any more restrictive than any other 3" cat-back would have been. I feel that the restriction was the single 3" pipe. Period. Not the muffler. Otherwise I wouldn't be running a Flowmaster on my personal vehicle as I stated in my first post. Not to mention my sig.

For the record though there are no bends in the exhaust before the cut-outs. They are in the y-pipe right where the pipes bend towards each other (obviously for the least restriction possible)

And full of holes? Get a life dude, you don't get any better real-world test of an exhaust system than back to back pulls....

Once again, if you don't believe the facts that I have shown you, feel free to give Ed Wright a call. I already gave you the car owners name, there is nothing for me to hide. Nor a reason for me to hide anything.

'99bluez

iTrader: (6)

I wouldn't consider 5% loss small. 24rwhp is a lot, even when on a 600hp car. And lighten up on the guy he wasn't bashing flowmaster - why do you have to get into arguements in every damn thread?

ChocoTaco369

5% is not a big loss when you're using a muffler that was never designed to support a 600 horsepower motor. If you had, say, a 4" or 5" 80 series on there, then it would make more sense, but you can't knock a muffler designed to support a 300 horsepower motor for not being able to support a 600 horsepower motor as well. Even a straight through muffler like a 3" single-in/single-out Magnaflow would show significant horsepower restrictions with that kind of motor. It's not a fair comparison. 24rwhp worth of restriction on a 600hp motor would be more like a 5-8rwhp restriction on a 300rwhp motor when you factor in restriction gets exponentially worse as horsepower increases. That's not too bad for the bad wrap Flowmaster gets on this site. It's not the best, but it's not the devil, either.

And I didn't start the argument. Big difference. I was attacked for making a harmless point.

ChocoTaco369

You're not knocking Flowmaster, but you sure do a good job of making pointless insults

You're talking about a 3" single-in muffler designed to work behind a 300bhp motor and you're sticking it behind a 600bhp motor. There will be horsepower loss. ANY 3" single-in/dual-out, even straight through models, will show a significant horsepower loss on a motor like that. The only point I am trying to make is that the Flowmaster muffler is not as bad as people think. Obviously, it's not the best flowing muffler out there, but it's not horrible. It's still better than stock, and the claims against it are usually exaggerated.

Bends in the exhaust before the cutout don't better. It's the bends in the exhaust AFTER the cutout that matter. That's why I asked you if there were bends AFTER the cutout, not before. Maybe it's you who should read my post better

1fastz

iTrader: (16)

this threads great lol

Colin91Z

iTrader: (9)

Look Choco, you said that no one ever really see's a 25rwhp loss running through a flowmaster cat-back vs an open cut-out. All I did was show you proof stating otherwise. And for that, you basicly called me a liar. Not cool in my book. And I'm not one of those sheep that thinks that flowmaster sucks because "the guys on LS1tech said so".

And no ****, I know a cat-back designed for a 300rwhp motor is gonna lose power on a motor with 513rwhp. That is why the friggin car had twin cut-outs in the first place.

Now, you said my story is full of holes and that you want AF and all that other jazz....however this is not my car, merely a good friends car that I helped alot with, so all I have is a copy of the dyno sheet....which I just happened to take another pic of just now to share with you

Now please take note of the file names just in case you'd like to call Ed and have him e-mail you a graph of the AF or any other mumbo-jumbo you wanna see to "verilfy". Also, you'll notice a phone # on there for your convience.

Also, be sure to note the times, which are just to the right of the file names, indicating back-to-back runs



And here's a pic of the underside of my car to show you that I do in fact own flowmaster products for good measure. This is not the car that goes with the dyno sheet above, so don't get them confused.



Thanks folks, I'll be here all week. Be sure to tip your wait staff.

ChocoTaco369

Yea, on a stockish vehicle. Obviously, if you're pushing double the horsepower of a stock vehicle, anything is possible. You're going to see that kind of significant gain with a open cutouts vs. any full-sized 3" single-in/dual-out muffler. That's because of two reasons.

First off, flow restriction is an exponential increase. A muffler that costs nearly 0hp at 300rwhp and 5hp at 400rwhp could cost 25hp at 500rwhp. Your car is a great example of this, and since the argument was never about running a muffler designed for a stock car on a 600+bhp race motor, there's no point in continuing it.

Also, with dual open cutouts, you are turning your car from a single y-pipe setup into a measly 3" muffler into a 3" TD setup with no mufflers. Obviously there will be a significant gain vs. a 3" single-in/dual-out full-sized muffler. Again, since the argument was never about this, there is no point in continuing it.

Now, if you'd like to post information showing a Flowmaster muffler is worth 25rwhp over another catback on a lightly modified vehicle like the thread is actually about, be my guest. If you would like to actually talk about the argument at hand, be my guest. If you want to change the argument to better suit your agenda, there is no point in continuing. The OP's car isn't even close to as highly modified as yours, so the comparison is not even close.

Colin91Z

iTrader: (9)

Dude, seriously, finish reading my post before you respond. I stated in the second paragraph of my last post exactly what you just stated in yours, only in fewer words.

Case closed.

Red99TA

iTrader: (11)

Since when is 500 RWHP double 300 RWHP

BlkBird2000

iTrader: (10)

Your not gonna see a difference in most mufflers unless your on a dyno. Who can feel the great 8rwhp the magnaflow puts over the flowmaster? You might get .05 off your et. I do it all for the sound. Which is why I chose flowmaster. I have a cutout if I want the crazy loud exhaust and the CRAZY 8rwhp or whatever it gives me!!! I would never put flowmaster on a car that is making 500rwhp anyways. A car like that is a weekend warrior that deserves true duals. Buuut that's just my opinion. Sorry for the goofy or weird *** paragraph I just wrote... I just got home from work..midnights.

ChocoTaco369

Because the LS1 was originally rated at ~305bhp, and 513rwhp equates to over 600bhp when you factor in drivetrain losses. The motor is making roughly double the power that the LS1 was rated at.

plaf713

iTrader: (8)

you cant compare cutout numbers to what a catback puts down, i want to see some numbers where people run on a dyno with flowmasters and switch to a different catback, im sure you wouldnt see much of a difference

Nightrydass

i had one on my '90 GTA w/ the L98 engine (Flowmaster 80 series)...it gave me a boner

Red99TA

iTrader: (11)

I'll give you the "roughly" double...I've seen stock LS1's dyno over 300RWHP...we all know 305 is severely underrated.

ryanfx

iTrader: (2)

all I have to say for this thread....