Does the position of the muffler in the system affect performance?

[sum_weirdo]

Was just mulling over redoing part of the exhaust system on my truck. As it stands the original y-pipe is still intact but some bozo reduced the rest of the system down to 2.25 inch with an ancient glasspack for a muffler. Maybe he thought it would net some kind of benefit, maybe he was just throwing together parts from his backyard. Either way it's going, I'm planning to keep the Y-pipe but step it up to 3 inch with a Flowmaster chambered muffler and I just suddenly wondered if the position of the muffler in the system affects performance. If I put it directly after the Y-pipe the exhaust pulses would hit it sooner...what effect that would have I really have no idea. Anyone want to chime in?

[kens64]

Muffler location doesnt matter for performance, but it does for sound.

[Bear River]

I would image that location could make a subtle difference. But it would be so minor in comparison to other things. Basically if the exhaust is hotter and moving faster, the muffler would have the same effect as being less restrictive and HP and torque would increase, but the difference would be very minor in even the most ideal situations. I would suspect that too close to the engine would sound like crap, or at least sound weird. The sound projection would be terrible. I don't know, it just seems to me that closer to the tailpipe would be better in terms of sound.

[jimdandy]

The muffler is a huge heat sink. Hot Rod magazine did some experimenting with exhausts on a Corvette. They found that the further back the muffler was located, the better the exhaust performed. The exhaust gasses didn't cool as fast and allowed the velocity of the gas to remain higher. Don't know how it would effect your truck.

There is nothing wrong with glasspack mufflers, by the way. They usually will give a slight performance increase over a stock system. jd

[sum_weirdo]

Originally Posted by jimdandy

There is nothing wrong with glasspack mufflers, by the way. They usually will give a slight performance increase over a stock system. jd

Maybe it's just because the one I've got is ancient and all the glass has burned away inside but I think it sounds like a cement mixer full of cats. For arguments sake if I did get another one how does length factor into it?

[ghunt]

If it has louvers in it, you don't want it. Even with the louvers turned around they still create a lot of turbulence and don't flow very well.

If it's got a smooth, perforated core, it probably outflows that Flowmaster you wanna put on there.

Oh and more length=quieter. Just have to think about the fact that you've got more surface area and more packing.

[redneckfarmers]

so if you turn a louverd glasspack around backwards does it muffle anything or is it just like straight pipes and what brand of glasspacks dont have louvers?

[Dave Severson]

Ditto on what Jim Dandy said... The best performance will be with the mufflers as far back in the system as possible.... We've played with it on the chassis dyno with a couple different cars and pickups.... No huge gains, but ya might as well get any "free" gains you can.... You have to have mufflers, so put them in the back and let the pipes maintian the velocity and move the exhaust heat away from the engine as efficiently as possible.....

[ghunt]

Originally Posted by redneckfarmers

so if you turn a louverd glasspack around backwards does it muffle anything or is it just like straight pipes and what brand of glasspacks dont have louvers?

Well most people just turn them around so they'll be louder.

But even with the louvers backwards they still flow like crap.

I don't know glasspacks that well, but Dynomax's race bullets aren't louvered. Summit Racing's glasspacks might not be also, I dunno.

[redneckfarmers]

so a guy would be ahead to just run straight piprs then instead of turnig glasspacks around backwards besides flowing better it would be cheaper

[magusjinx]

So if I am correct, since us diesel burners want our exhaust gases cooler then it would be a good idea to put the muffler as close to the engine as possible?

[Stumpalump]

Exhaust gas flows better when hot. It flows like oil. Hot oil or exhaust gas flows better than cooler exhaust gas or oil. Thats one reason to use header wrap or ceramic coatings. To keep the heat in. I would think on a quet rstrictive muffler than being close to the engine would be best but on a more free flowing how much could that really help. The other consideration is if you can stand to have a hot muffler under the cab. It will heat things up inside a whole lot more than a straight pipe under the cab and summer is comming.

[justin_jkj]

Originally Posted by redneckfarmers

so if you turn a louverd glasspack around backwards does it muffle anything or is it just like straight pipes and what brand of glasspacks dont have louvers?

thrush glass packs dont have louvers and they stay full diamiter the whole way through Glasspack Muffler Spec

[magusjinx]

Originally Posted by Stumpalump

The other consideration is if you can stand to have a hot muffler under the cab. It will heat things up inside a whole lot more than a straight pipe under the cab and summer is comming.

No problems here ... Summer gets up to a balmy 80 for about a week ...

[just-n-time]

one of the most under thought systems in performance response has been in the class 8 trucks, I always had to tinker with that, the best kept secret was to keep the heat in the pipe,remember it is a flue like your chimney by rapping the exhaust system you cause it to run toward the opening in order to exhaust, this creates a drawing effect as well as its forced effect from the turbo. I spent a great deal of time with the boys at diesel injection of Pittsburgh PA. my little truck ran heavy haul and was in the 6to7 hundred hp so heat control was critical, it is amazing what heat wrap will do, along with muffler to the rear and restriction to a minimum, not loud just free flow, lets face it if the power plant has the hp it will sound like it. JNT