Hi All,

I was just reminiscing and came up with a thought/question. Back in my 4-wheeler (quad) racing days the exhaust system played a big part in the powerband and peak power the engine would make. Some guys would take the baffles out of the stock pipe and it would be loud as heck but only make a little more power. A good aftermarket unit would be quieter but make alot more power. Most all of them used a perforated tube down the middle of the muffler surrounded by packing material (usually fiberglass or steelwool). They would be the quietest and make the most power when brand new. As the packing material blew out or disintegrated over time the muffler would get alot louder and cause more backpressure. The engine would make less power on a worn out hollow muffler than one with the proper amount of packing material in it. Most mufflers were repackable - one end would come off with screws or rivets, you pack in more fiberglass, and good as new. Full power restored!

Does this apply at all to cars??? Is a car with a 3 year old worn out can going to make less than one with a brand new can?? On the quads it could make a 10% difference. What do you think it would be on cars? Maybe 1%??

Just something to contemplate. . .

EVOlutionary

 

My guess is "no" on anything modern. I don't think there's any packing to wear out on most newer designs. Then again, what do I know...

Since you're reminiscing, i too remember my old honda motorcycle. I went the "remove baffle" route you described and had open megaphones. Man, firing that thing up would make people jump. I loved absolutely drowning out cocky harley riders with my little 550. A dog below 4k but after that she ran like a raped date!

 

On a turbocharged engine you dont want back pressure, hence the 3" exhausts.. Turbos like to flow. Some people go as far as removing the exhaust after the downpipe at the drags to free up a lil more power.. But on a N/A engine not the case.. On my n/a toyota pickup, it had a crack in the downpipe and wouldnt get out of its own way.. fixed the downpipe and couldnt stop the tires from breaking loose..

 

I'm wondering this same thing about mine... it's getting louder with no leaks that I can find

 

Its not very often other quad people pop up on evo forums...

Its gonna be different with a NA engine and a Turbo application, a quad pipe needs the back pressure to make torque where as our evo less is going to be better to an extent.

 

I raced a Raptor in GNCC for a couple years. Also had a MX setup and Dune setup for it. I sold all the MX and sand stuff, and now it's been sitting in corner of my garage for a couple years (ever since I got the EVO). Crazy - I spent as much on the quad as you can get a good used EVO for now !!

EVOlutionary