Different exhaust systems for TBI engines?

[94_C/1500]

Once you start looking at performance mufflers, they are all usually close on power levels. And dyno numbers vary from one run to next. The vehicle won't always do the exact same, and the dyno isn't that accurate to compare a 1 or 2 HP difference.

 

[94_C/1500]

http://www.9c1.net/forum/index.php?showtopic=172419&pid=200257&mode=threaded&show=&st=0

yep, flowmasters not the best, but clearly still better than straight pipes. perhaps if i were running a race car i would choose something else to run.

I really like this link, everytime I see it I laugh. Look at the Warlocks opened compared to no mufflers. Those numbers should be pretty close, but they aren't.

 

[90'rado]

Yeah most aftermarket mufflers are pretty close in terms of power to be gained. Flowmasters just don't flow as well as the name implies, still an improvement from stock. The main thing is stock mufflers are usually very restrictive, so getting rid of that for anything else is usually a big improvement.

These are just a few cases in which having mufflers produces more power output than not having them. Exhaust theory is pretty crazy and highly theoretical, my hypothesis is that most engines require a certain amount of backpressure to help with the pulses and scavenging effect of exhaust gases. For the vast majority of engines on the street, this probably means running mufflers to create the 'magical' amount of backpressure, not to much, not too little. When you get into more radical engine combinations, (one's which come alive from 4,500-,8 or 9 K RPM), the benefit of running straight pipes becomes clear, the engine will be moving a ton of air at that RPM range, and even more so if it's a radical engine. So, in that case, you want the absolute least restrictive path for the exhaust gas to be expelled from the engine.

On a side note, 99% of people I've known personally that run straight pipes have that setup on a stock engine, so there is no point or advantage to it there, probably the inverse actually, they just like to be obnoxiously loud I suppose.

 

[6chevy9]

yes i agree. but i posted that because we arent driving top fuel drag cars lol. im pretty sure in most stock and mild builds mufflers are best to have. i dont want to sound like im trying to defend flowmaster just because i run them on my truck, and this may sound like a bs excuse. but they were using 3 chamber 50 series flowmasters and comparing them to more or less race mufflers. i think the flowmaster 40s or even the 10 series would have out performed the 50s for sure. they said they could not get anything else from flowmaster in a hurry for their test. but hey stomp all over that excuse if youd like to...i agree that flowmaster did not do the best in this test and proof is proof i cant argue with that. but i would have really liked to see a comparison with a more performance style flowmaster myself. i dont want to try to push my beliefs on anyone i just like flowmaster. if i was going all out for horse power i think id take the hooker max flow i belive it was.

 

[1badgmc]

It didn't take long for me to get really burnt out on the Flowmaster sound. Everybody wants 'em. Everybody has 'em. Some vehicles sound pretty good with them, but for me, I wanted something other than that tinny Flowmaster sound. I guess it was '98 when I had the exhaust done on my '91. Man...That sounds like ages ago! I went with a pair of Borla mufflers, a pair of Summit brand hi-flo cats and had true duals ran. When I first had it done, I had it run out the back with a pair of the rectangular Z28 tips coming out from under the rollpan. It looked good and sounded even better. A nice, deep, mellow rumble that was really very quiet on the highway. Before long, I had the rear steps shaved. The new rollpan that came with that kit was different than what I had and I didn't like how the tips fit with it, so I had the exhaust dumped after the axle. This didn't make much difference in the sound. When I had the truck bagged in '01, there was no more room for the exhaust to go over, so I had it dumped before the axle. This made the biggest difference in the sound. It's still nice and mellow, but it's even deeper and louder. I love the way it sounds. If it was a daily driver, it would get old, but for as little as I drive it, I like it.

 

[6chevy9]

yeah when they dump under the bed like that the echo alot. i like it too just not on a dd. im really interested to hear a hooker muffler myself. i love the flows sound but who knows what ill put pipes on next.

 

[94_C/1500]

yes i agree. but i posted that because we arent driving top fuel drag cars lol. im pretty sure in most stock and mild builds mufflers are best to have. i dont want to sound like im trying to defend flowmaster just because i run them on my truck, and this may sound like a bs excuse. but they were using 3 chamber 50 series flowmasters and comparing them to more or less race mufflers. i think the flowmaster 40s or even the 10 series would have out performed the 50s for sure. they said they could not get anything else from flowmaster in a hurry for their test. but hey stomp all over that excuse if youd like to...i agree that flowmaster did not do the best in this test and proof is proof i cant argue with that. but i would have really liked to see a comparison with a more performance style flowmaster myself. i dont want to try to push my beliefs on anyone i just like flowmaster. if i was going all out for horse power i think id take the hooker max flow i belive it was.

I forgot about that part of the test, they only used one kind of Flowmaster. I'd bet the 40, super 40, super 44, 10, and especially the outlaw would outflow the 50.

 

[90'rado]

yes i agree. but i posted that because we arent driving top fuel drag cars lol. im pretty sure in most stock and mild builds mufflers are best to have. i dont want to sound like im trying to defend flowmaster just because i run them on my truck, and this may sound like a bs excuse. but they were using 3 chamber 50 series flowmasters and comparing them to more or less race mufflers. i think the flowmaster 40s or even the 10 series would have out performed the 50s for sure. they said they could not get anything else from flowmaster in a hurry for their test. but hey stomp all over that excuse if youd like to...i agree that flowmaster did not do the best in this test and proof is proof i cant argue with that. but i would have really liked to see a comparison with a more performance style flowmaster myself. i dont want to try to push my beliefs on anyone i just like flowmaster. if i was going all out for horse power i think id take the hooker max flow i belive it was.

I'll use this opportunity to quote myself since maybe you missed it the first time:

Granted top fuel is full on race car, but even some street driven engines will do better (even if marginally so) with straight pipes.

I'm just saying that in some cases, it could potentially be beneficial to have straight through exhaust, or cutouts. I'm not trying to attack you b/c you have flowmasters, I'm just saying that despite their name, they really aren't "flowmasters".

It's a brandname thing more than anything that's why flowmaster brandname mufflers are on the pricey side. I USED to have what are called 'flomaster clones', ran them for 3 or so years before my current exhaust setup, never had any problems with them, they did sound good, but I just got tired of that drone and wanted something significantly quieter. These flowsclones (as they're called around here) looked, and sounded just like the real deal, but you could buy two of them for still less money than the price of ONE brandname flowmaster muffler. So we have two mufflers made identically to each other, but one comes with a much higher price tag for no difference at all with the sole exception of the 'status' of having the brandname flowmasters.

For those dynos, or really any for that matter, you'd have to have the EXACT same engine, w/ the EXACT same parts in the EXACT same vehicle in order to reasonably expect the same results if you were trying to duplicate anything, theres lot's of variable to consider. Otherwise it would just give you kind of an idea, but a rough one. The name of the game is about experimenting to see what works best, and sometimes that happens to be straight thru exhaust. My close friend has a 66 Nova which has seen various exhaust setups over the years b/c it's been in the family for, ever. The car has some cheapy turbo style mufflers on it now to make it driveable. Last time at the track, we ran the car on multiple passes with open headers, and, with the full exhaust bolted up. The car always ran a little bit faster with open headers.

 

[6chevy9]

i didnt miss what you said. i was just saying the majority of the people with straight pipes have nothing done to the motor. not everyone but most, atleast around here! i have no doubt that there is an exact knock off, but at the same time id still prefer the flows because of the name one, and two because i know that they didnt use some strange material to make them. im not saying thats what was done in this case, but most cases knockoff parts in manufacturing have some kind of difference. hence the saying you get what you pay for. but also being major in the manufaturing world myself, i also know that no two things made are exact. there are always defects and variences. always. weather its the steel chemical properties, the way it was put in the machine that day, whatever there will be something to change. but none the less im not trying to fight either. i do think straight "pipes" will help on big horse power motors yes. but mild i doubt it. open headers i can see making more power than anything, but once again not on a stock motor. i just dont see a stock motor making more power on open headers unless it was using a stock exhaust before the open headers. but hey those are my thoughts and expriences, im not a rocket scientist. all i know for sure is with my application having mufflers will make more power than straight pipes.

 

[90'rado]

i didnt miss what you said. i was just saying the majority of the people with straight pipes have nothing done to the motor. not everyone but most, atleast around here!

Are you sure you didn't miss what I said, b/c it seems like you're still missing some of what I've already said.

On a side note, 99% of people I've known personally that run straight pipes have that setup on a stock engine, so there is no point or advantage to it there, probably the inverse actually, they just like to be obnoxiously loud I suppose.

i have no doubt that there is an exact knock off, but at the same time id still prefer the flows because of the name one,

So you'd rather pay more for something for no actual difference whatsoever??

and two because i know that they didnt use some strange material to make them. im not saying thats what was done in this case, but most cases knockoff parts in manufacturing have some kind of difference.

The "strange" and elusive material they use to make flowclones is sometimes referred to as "steel." Ironically this is also the case for flowmasters®

hence the saying you get what you pay for.

Hence the saying "you don't always get what you pay for" I guarantee it that you wouldn't be able to tell a difference if two identical trucks were running the same exact setup w/ one having flowmasters® and the other flowclones. Another example that comes to mind, I run the house brand of oil from Napa which is the exact same oil, from the exact same refinery as the more expensive Valvoline. I don't give a damn about the name, it's quality stuff, cheap, what's not to like?

i also know that no two things made are exact. there are always defects and variences. always. weather its the steel chemical properties, the way it was put in the machine that day, whatever there will be something to change.

No two things are exact per say, two brand name flomasters® aren't the exact same, there is always some degree of manufacturing difference, hence the concept of "tolerance"; is the part within tolerance?, i.e within the accepted range of deviation. Steel is Steel there are no ""defects in the steel chemical properties"" Flowmasters® are essentially made of sheetmetal, once they're cut and rolled/shaped into the appropriate pieces, in raw material form, there is no more ""putting them in the machine"" they're just welded up.

The bottom line is you're paying MORE for NOTHING. If anything you pay for the increased marketing costs passed along to the consumer. As I've said, you couldn't tell the difference between these flowclones and the real deal, I'VE seen them BOTH, never had a real set myself, but plenty of friends did, and I had the ripoff versions for 3 or so years and they worked just the same, noone knew a difference, not even me unless I got to thinking about it. I'm a rocket scientist, and I'm here to rain on your parade all day long.