A buddy of mine has a 4" Mufflex on his LT1 T/A, and I love how deep it sounds. How would a 4" exhaust perform w/ the LS1? I've heard of some car guys running dual 3.5's. I'm guessing the hardest part might be finding the pipe?

 

I wondered how a 4 in exhaust - say HD Duramax would sound on a LS1 based trucks ?
Wondered if you would lose too much low end ?
and then how to hook it to the y pipe - is the connection the same ? at the y

 

magnaflow HD catback is 4"

 

These are the ones that I'm looking at right now...

Dynomax Round Mufflers
p/n 17537: 22" case, 27" overall, 4" inlet/outlet, 6" OD
p/n 17225: 16" case, 21" overall, 4" inlet/outlet, 6" OD

Would there be much difference in sound based on the length? Would either one be raspier than the other? Deeper? I've always just thrown a muffler on the truck without much thought and am trying to make a good decision on a single exhaust.

 

I bought my Dynomax cat back system from Jegs for $246. shipped to my door.
Welded muffler with 3" pipe sounds good. I wish I would have gotten the round
muffler as they have a deeper tone.

 

well, i'm not sure how well 4" exhaust would perform. The flow area is pi*r^2. where r = 2". therefore, the flow area is 12.56" compared to 7.068" for single 3" pipe, or roughly the same as dual 3" pipe. In most cases, running dual 3" is foolish and causes a loss in power. The other factor is resonance!

 

Most people run the Mufflex on the LS1s when they plan on making well over 400rwhp and don't wanna go dual. Unless you have a 6.0L or plan on making gobs of power I personally wouldn't do it but I doubt it would hurt much.

 

You can go with the 3" from the cat back with a 4" tip. Thats what my Magnaflow system has. They claim their single exhaust makes a little more power than their dual exhaust setup. that is on the 5.3.

 

a loss of back presure is an increase in horse power, dyno's have proven it again and again. i keep hearing this loss of low end and it is starting to drive me nuts. people report feeling a loss of low end but i say it is just all the noise causing them to not push the pedal as far. dyno's dont lie.

 

Dosen't Basanni (sp) have a 4" cat-back? I think I saw some Silverado SS guys using them.