Muffler question

[Fullthrottlex02]

Has anyone ever Gained any hp from a muffler, Whats the Upsides and Downsides to running one, Im experimenting with a thrush Turbo muffler, Just wondering about what I can expect, I don't have much in the muffler"freebie" so Just Post Your Opinion, Thanks for all your guys help

[return to dirt]

it can be used as a tuning tool. i usually use flowmasters but i've heard borlas are also good. when used with the correct length pipe between the header and muffler you can see a gain in power.

olin

[millerlt3]

dont know of any hp gain but with a muffler they say it gains a little torque. so my opinion if you run headers run straight pipe off to behind drivers seat and throw the muffler on the self

[Profile]

Has anyone ever Gained any hp from a muffler, Whats the Upsides and Downsides to running one, Im experimenting with a thrush Turbo muffler, Just wondering about what I can expect, I don't have much in the muffler"freebie" so Just Post Your Opinion, Thanks for all your guys help

Lobak, the muffler co that makes the spiral muffler that Moroso sells and one of the lowest, if not the lowest, back pressure muffler, says there is NO SUCH THING AS A MUFFLER THAT DOEN"T COST HP. Plain and simple. If you use a straight tail pipe, no loss. Right???? Well what happens if there is a bend in your tail pipe? I've always heard that one 90 deg turn equals 20 feet of straight pipe in back pressure. True? Who knows, but what is the one thing that matters? Which one is the fastest? 45 degs / 90 degs / muffler / straight pipe???? Only you can answer that and that's the way it should be.

[car62]

i call BS,if you are running a ford 2300 with just a straightpipe,and then you put a muffler on there,i dont care if its a flowmaster,dynamax,borla,whatever,you will see a HP/TQ gain because of the backpressure gained

[Profile]

Guess I'm not stupid enough to understand that. Give me time.

[Profile]

I understand it now. The added back pressure gives you more HP/TQ over even a straight pipe. Got it. Thanks.

[Dirtman29]

Wouldn't a smaller diameter exhaust create the same effect (back pressure) as a muffler?

[Profile]

I don't think Lobak would have said what they did if it was not true. Would have been easy for them to say our mufflers give you more HP, but they said all mufflers cost you HP. Dave in his 50 or so pages of exhaust and intake tech, said that if you could run without a muffler, do so. And that's what racers like NASCAR do. The only engine that makes HP with a muffler is a two stroke. BUT you must understand, this is just an 80 year old gear head own ideas and as stated above, BS.

[stock car driver]

chassis dyno is only way your going to know for sure.........

[car62]

wow,since when do they run the Ford 2300 in nascar? i thought we were discussing the 2300???

[car62]

i can tell you that there was a race last year when my muffler snapped off at the inlet.and i lost so much power...went from running 2nd out of 16 cars(i started last),to almost getting lapped in last place. put a new muffler on(flowmaster 40 series..same that was on it before)and had all my power back

[stock car driver]

wow,since when do they run the Ford 2300 in nascar? i thought we were discussing the 2300???

Looking at the above thread it appears your the only one talking about a 2300...

I haven't seen a 2300 in a race car since I left Spokane, around here all 60 tracks within 6 hours of me run front wheel drive 4 cyl cars.

[84Dave]

As brief as I can make this. If your Rules say you MUST run a muffler, consider a Vizard 'Expansion Chamber' and see if your Tech will allow you to call it a 'muffler'. Expansion Chamber = completely gutted interior + additional TQ/HP. The reason? The engine 'thinks' the exhaust is emptying into the atmosphere. Consequently, the negative wave traveling back up the exhaust toward the head is increased in amplitude. You say......... 'so what?' With the improved negative wave, the combustion chamber is better evacuated of burnt exhaust, less reversion, and the negative pressure aids the beginning of the fuel/air out of the induction and into the combustion chamber on the cam overlap cycle. A win-win in terms of improved power out of the engine. If memory serves, the internal volume of the Expansion Chamber should be about 10x the volume of a single cylinder. They aren't small! And for those not required to run a muffler? A straight pipe exiting the exhaust system into the open atmosphere should have a generous 'flare' at the exit point. A straight/circular pipe with no flare is actually a slight restriction at the exit point. "Vena Contracta"! -Dave-

[Dirtman29]

stock car driver, there are lots of 2300s running in NE Illinois.

[stock car driver]

stock car driver, there are lots of 2300s running in NE Illinois.

ok so? that's not within 6 hours of me or the 60 tracks in that range.

[Profile]

As brief as I can make this. If your Rules say you MUST run a muffler, consider a Vizard 'Expansion Chamber' and see if your Tech will allow you to call it a 'muffler'. Expansion Chamber = completely gutted interior + additional TQ/HP. The reason? The engine 'thinks' the exhaust is emptying into the atmosphere. Consequently, the negative wave traveling back up the exhaust toward the head is increased in amplitude. You say......... 'so what?' With the improved negative wave, the combustion chamber is better evacuated of burnt exhaust, less reversion, and the negative pressure aids the beginning of the fuel/air out of the induction and into the combustion chamber on the cam overlap cycle. A win-win in terms of improved power out of the engine. If memory serves, the internal volume of the Expansion Chamber should be about 10x the volume of a single cylinder. They aren't small! And for those not required to run a muffler? A straight pipe exiting the exhaust system into the open atmosphere should have a generous 'flare' at the exit point. A straight/circular pipe with no flare is actually a slight restriction at the exit point. "Vena Contracta"! -Dave-

DAVE! When are you going to write / print another 50 pages? I've wore out the old ones from use. Looks like there is several guys on here that need to read the old one. Keep up the good work.

[84Dave]

Profile........ would you post the name/title of the Thread here? The one where I blew off some steam about induction(?)/exhaust systems? I remember the Thread but don't remember the name/title. Also the approximate date I posted? Thanks......... -Dave-

[Profile]

Dave! I'll have to find it first, but the last I looked for it, it was gone. At least 5 years ago I think. You went back and forth with a lot of people, so maybe one of them will remember. I sure hope so. Looks like I need a new copy. I remember you told of a book from some really smart guy, who knew it all. Not though he knew, but really knew it all. Wish you luck.

[Profile]

Dave it was called "induction and exhaust tuning". That's all I could find.