Interesting tests. Not huge differences but that tells you each is capable of flowing enough for the HP. The sound differences are pretty big.....

I installed some 3.5" Pypes mufflers on my car with full exhaust out the back to the bumper and have found that it runs just as well capped up as it used to with open headers and extensions. I was pretty impressed since first pass with them was a 9.94@140+. One less thing to mess with at the track now!

JIM

 

Interesting tests. Not huge differences but that tells you each is capable of flowing enough for the HP. The sound differences are pretty big.....

I installed some 3.5" Pypes mufflers on my car with full exhaust out the back to the bumper and have found that it runs just as well capped up as it used to with open headers and extensions. I was pretty impressed since first pass with them was a 9.94@140+. One less thing to mess with at the track now!

JIM

What was your exhaust before? are you using any kind of crossover?

 

horsepower be damned, nothing like open headers at the track. I'm sure there's all kinds of data about this but I don't care, I love that open sound. If mufflers made more power I'm sure Jimmie Johnson would be whooshing around the track....

 

Nice Post! good info for sure!

 

I had a 3" system with Dynomax race bullets. The new one is faster and quieter.

I don't have a crossover...might add it someday.

At one time with a milder version of this motor I had the same 3" pipes and 2 chamber Flowmasters. At the time it literally picked up 50 RWHP when I uncapped it. From 565 RWHP to 615 RWHP! We were all stunned! Hence the Bullets went on...but I never got a chance to test them to see the improvement...but the SOTP improvement was good.

JIM

 

At one time with a milder version of this motor I had the same 3" pipes and 2 chamber Flowmasters. At the time it literally picked up 50 RWHP when I uncapped it. From 565 RWHP to 615 RWHP! We were all stunned! Hence the Bullets went on...but I never got a chance to test them to see the improvement...but the SOTP improvement was good.

JIM

Jim..I am running 3" back to 40 series 2 chamber flowmasters behind an 8-71 461 bbc.700hp street deal.
In your opinion..am I choking this guy off with the chambered mufflers?Would you recommend a straight thru muffler to enhance exhaust breathing?Sound is not an issue for me and i would like to retain my 3" h-pipe.
George

 

Interesting for sure. I'm curious as to what my dual Flowmasters are doing for my bone stock 396 325 if anything. I bought it with them already installed so I have no comparison. I think my car originally had single exhaust.

 

Thanks for the info. I had a set of 3" magnaflows, the 3 chambered mufflers and picked up .15 and 1 mph at the track. I never put it back on and im cant make up my mind on what mufflers to use and if i should a crossover.

 

I've never considered my flowtech terminators to be loud, I think they seem quiet compared to a lot of aftermarket mufflers.

 

Good read. I think each muffler could do better if the a/f ratio was tuned to each 1.

The welded Ultraflo uses a "3 core on a "2.5 in/outlet...so it might need a tiny bit more fuel to get the same hp #'s as the rest.

That said , 8 hp between the worst to the best on "that" motor isn't that bad.

What would that equate too in the 1/4 ?

 

Hard to say, would really like to see the average horsepower for the mufflers.

 

I've always wondered about jetting changes when uncorking headers. I've had bikes that run like crap if the jetting is optimized for the mufflers, just uncorking them requires rejetting, sometimes major changes. So if you jet for open exhaust, how rich is it when running full exhaust?

 

Flowmaster SUV muffler to comparison test?
Seems that they would have used Super 40's or along those lines instead even if they had to wait a day or two.

 

In the article it said they found it strange when they requested a car performance muffler and Flowmaster submitted an SUV muffler.

What was nice to know, is that if I choose a muffler primarily for sound purposes, it may only cost me a couple horsepower and torque, which is livable.

 

Seems to me that building a exhaust with dumps would be the think to do with a X pipe or H pipe, whatever fits your needs. Maybe even check into a very quick removable exhaust. Then search by ways here or have been posted for the less resective muffler and go from there. Then you can do you on testing to see if full exhaust slow you dont or not.

 

Even if it slows you down on the track, it equals what we do on the street Run them like it's Friday night at A&W and you are looking for a little fun down in the industrial park

 

Alot of why a straight through muffler performs differently than a chambered muffler has more to do with changes in collector length than flow.

 

Even if it's 4' away from the collector or it just maintains the same diameter all the way through the muffler V's having an open box then pipe again?

 

The exhaust see the straight through muffler as added collector length where as a flow master type muffler limits the collector length at the front of the muffler so youre testing exhaust collector length tuning rather than just flow

 

Long case Super Hemi Turbo for me. I think mine are Walker. These are not an expensive muffler at all. Good around the neighborhood, start talking about 3500. These are on a roller cam 406.

Really don't need to tip off every law officer within a couple miles if I decide to let it breathe a little.

 

I had put together some charts on the quoted test in the past and it's in this post. http://www.chevelles.com/forums/showpost.php?p=7131889&postcount=25

Based upon that I'd buy the Borla XS because they made just as much average horsepower and they were the most quiet. They gave up very little on peak HP.