LS4 Performance - X-Post from GMLS4 - Probably gonna be a little loud...Exhaust Project

3" Catless Hogan downpipe with custom 3" exit flange and rear O2 bung
Custom FULL 3" into dual 3" Catback exhaust

I will have one of these in the resonator position and one for each muffler. They are a total length (including welding stubs) of 6" long. haha:

http://www.summitracing.com/parts/SCH-63030/

Thinking this might liven up the geexxxpee a little bit...add a bit of bark to the bite :nod:

EDIT: Today

Look what the car fairy dropped off for me!

http://a4.sphotos.ak.fbcdn.net/hphotos-ak-ash4/425905_10150603412643988_500488987_8941440_1957972 763_n.jpg

race muffler? more like a single baffle lol

I think unless your making much more power than stock its gonna struggle severley at low and and probably not gain anything up top, just a cam wont put out enough to make that worthwhile. Even if you do run 3inch all the way back after the y you have to make it smaller diameter pipes or the backpressure will be bad.

It will not suffer badly as these cars make an overabundance of low end torque and the exhaust is a known restriction. This will sacrifice a small bit of that low end torque in exchange for very nice gains in the midrange and top end. The loss of low end torque could in theory make the car easier to launch thus further reducing ET at the track.

Single 3" will be good for roughly 350 to 400hp before it needs to be reexamined. there is no rule that says you have to run smaller pipes after the cat or Y and furthermore i'd say the stock manifolds will provide all the backpressure i'd ever need.

Oh and this arrived today!

http://a2.sphotos.ak.fbcdn.net/hphotos-ak-ash4/429128_10150606397598988_500488987_8947133_1497602 549_n.jpg

5 170* bends and 4ft of 3" straight tubing (not pictured). Those 3 little black things are the new resonator/mufflers. pictured below on a 1qt oil jug for reference:

http://sphotos.xx.fbcdn.net/hphotos-ash4/430709_10150606400628988_500488987_8947140_4332792 97_n.jpg

I honestly think you could have saved $45 and not bought those res/mufflers, I dont think they are going to do anything.

I honestly think you could have saved $45 and not bought those res/mufflers, I dont think they are going to do anything.

they still gotta be there...it needs some form of sound control in order to be somewhat legal...

I even have a spare 3" cat for inspection time. of course there will be one on the car since it is operated on public roadways ;)

Oh yeah I forgot this is the 3" catback from Dick Lipps Performance right?

yessir it is! haha...

Maybe i can get some DLP badges made up for the car?

I would run a DLP sticker on my car for sure.

Maybe they will help create some back pressure

RESULTS IN!

HOLY HELL BATMAN is it LOUD! the Schoenfeld "mufflers " do help a TINY TINY bit but might as well be redneck straight pipes. I was surprised the drone wasn't worse so that's how i know they did SOMETHING..but lets be honest...this thing needs a real muffler of some sort. I'm thinking a single bullet muffler in the resonator position will tone it down enough to be tolerable.

PICS:

For anyone that doesn't think the Ubend is that bad...it's still bad...just not AS bad...

http://a1.sphotos.ak.fbcdn.net/hphotos-ak-ash4/420513_10150610135463988_500488987_8957026_1658148 430_n.jpg

Beginnings of custom Y split. The "resonator" actually got welded right to the single 3" inlet because i forgot to include it after the flange. whoops. it actually worked better this way after i figured out how to route tubing around the gas tank and under the rear sway bar...which BTW is a GIANT PITA...

http://a7.sphotos.ak.fbcdn.net/hphotos-ak-snc7/409523_10150610135628988_500488987_8957027_3880095 89_n.jpg

Exhaust is OFF the car!

http://a8.sphotos.ak.fbcdn.net/hphotos-ak-snc7/430927_10150610135778988_500488987_8957028_1631897 872_n.jpg

those tips look nice but neck down to about an inch before the exit. pathetic.

Exhaust in process. This is about hour 10 or so IIRC...long and tedious because all welding was done outside the car and each piece test fit and done individually.

http://a2.sphotos.ak.fbcdn.net/hphotos-ak-snc7/409511_10150610135918988_500488987_8957029_1632930 452_n.jpg

ONE WELD LEFT!!!

http://a5.sphotos.ak.fbcdn.net/hphotos-ak-snc7/422728_10150610136078988_500488987_8957030_1890368 944_n.jpg

don't ask how i maneuvered it in the vice or installed it in one piece by myself after over 14hrs in the garage...i don't know. i honestly dont.

I still have to finish mocking up hangers later today but the car is driveable and YES it was a HUGE improvement!

for future reference Hogan Performance ALSO has a 3" catback piping KIT for these W chassis cars. it saves you all this trouble. If i had to do it again i would've went with their downpipe AND kit all in one shot.

Pics of tips and vid of sound are coming soon. I'll try to get some shots under car. I also need to wrap the section that goes around the tank. i'm probably safe BUT i'd rather be more safe than dead.

In Conclusion...

Difficulty - 7
Time - 10+
Cost - 5
Results: Awesome

Would do again...just with the hogan kit instead!