Well I have been bored after my 4L80E swap so I decided to redo my exhaust. I was running true 2 1/2" dual Moroso spiral flows and dumped them before the axle but it was just too loud and they hit on everything.
To build this 4" system I bought 5-90deg bends and pieced the 2 1/2 pipes to the self made merge pipe with some spare stuff I had laying around. All together with the Dynatech Split Flow muffler I have about $275 into this exhaust. I am very pleased with the fit and sound. Here are the pics.

 

Some more...

 

More...

 

nice work.

 

Looks clean and killer

 

Very nice!!! Can you put a video on You tube with it running? I would like to hear it.

 

Once the weather breaks I can pull it out of the garage and get some video. I will post a link here once I do.

 

what kind of ground clearance do you have at the back of the system before it goes over the axle? it looks really low

 

WOW you do some awesome work. i always see custom exhausts that have blobby crappy welds but this is killer man!

 

I am fortunate enough to have buddy who is an awesome welder. I did all the cutting and fitting and just tacked everything into place.

 

Most "custom" exhaust systems look horrible, however, this looks wonderful. Fantastic fab work. I am very impressed.

I especially noticed how there aren't any crimped bends, and at each bend there is a nice smooth transition. Would you mind itemizing your final parts list? This could be very helpful to those making an exhaust with LSX headers (that don't want to spend another $2k for aftermarket parts to complete the rest). The rear section looks better than aftermarket. Well done.

 

nice, jealousy abounds. dang it.

 

Thanks for all the nice comments.

Here is the parts list for the merge pipe back. It doesn't make too much sense to include anything before that since everyones setup will be different.

About 24" of straight 2-1/2" pipe
2 - collector rings Summit Racing p/n SUM-G4760
5 - 6" radius 4" diameter 90deg. bends Summit Racing p/n ECP-65975
2 - 4" butt joint band clamps Summit Racing p/n WLK-33280
1 - 4" lap joint band clamp Summit Racing p/n WLK-33286
1 - Dynatech Split Flow muffler Summit Racing p/n DTC-776-14402

I made the merge pipe from a straight piece of 4" pipe that I formed in a bench vice and welded in the 2 - pieces of 2-1/2 straight pipe. I welded the collector rings to each piece to allow easy removal.
I used a $50 Harbor Frieght chop saw to cut all the pipe. You will just need some patience and be sure to measure twice and cut once...this pipe can get expensive if you have to fix too many mistakes. I did a lot of research on the mufflex system along with some other members setups to map out the best approach. A lot of people say that you can't fit a 4" pipe over the axle and retain the panhard bar brace, but I assure you that you can. I found if you add just a little bend section in there it clears just fine.

 

Thanks for the list. I am going to have to look into this.

 

I had this muffler on my 383 11 to 1 compression motor on my homemade 4" exhaust and it sounded AWESOME but was ridiculously loud. I went to a dynomax ultraflo round 6" case, and it was alot better. On a turbo motor tho I bet the split flow sounds great. I have the split flow somewhere in the garage still if anyone wants it.

Good job on the system. Looks great. its basically how I had mine done on my turbo motor. I used a flowmaster Y merge and it worked nicely...your pipe looks just like it tho and bet it didnt cost 50-60 bucks.

 

Awesome job!

 

sooooo? any pics on the ground?

 

Damn I almost sent you a PM asking if you still had it before I bought mine

 

a couple vids

http://www.youtube.com/watch?v=s1hT36xEyF0

http://www.youtube.com/watch?v=-gC7BrwfAGw

Sorry for the narrow window I shot this with my ipod touch.

 

Coming soon promise...it actually hangs lower then I thought it would but still better then my original dual setup.

 

Sounds good. Second vid a cold start??

 

Are your downpipes off of the turbos 2.5" or do you have reducers? The system looks amazing for the cost. Sounds good too. $600 for a Mufflex system seems steep to me but I think I'll just copy yours. Your over the axle piece fits better than my Flowmaster 3" system with about the same ground clearance.

 

Yeah, both were pretty cold...idling in 1500-1000 range.

 

The downpipes are 2-1/2 right off the turbos, so no reducing.

Yeah that is a hefty price tag for a cat back system. For those serious about doing this you might want to get those 4" bends ordered through Summit. Right now it appears Edelbrock is blowing out thier exhaust stuff so these bends are $22.50! I am not sure how long they will last.

 

Orr is your muffler 4 inch inlet? I really do not want to put a flowmaster on mine, am dreading it lol

 

Yeah i still have my 4" split flow and my 4" ultraflo but theres a bend of pipe welded to the outlet that I'd have to cut off.

87 TA had a 4" single chamber flowmaster on his car and its one of the best sounding cars I ever heard with the flowmaster single chamber. With open pipe all the way back dumped over axle it sounds incredible It may be the best sound i've heard from an exhaust system and gen I sbc

 

X2

 

very nice work. Clean car man

 

Here is a pic of the lowest hanging section (right before axle). Like I said it is lower then I thought, hard to tell laying on your back with the car in the air.

 

Thats about how low mine was

 

ooh, thats not going to work well. you can get it a lot higher than that.

 

I think it will work just fine...sure I would like it to be up higher, but honestly I don't think I can raise it.

Orr - did you have any problems with yours?

 

That was mine. It hung lower than I wanted but to be honest, it rarely touched the ground at the muffler. It crushed the y pipe which went under the frame rails by the tranny but thats about it. I had a few skuffs on the muffler from very uneven country roads in PA but other than that it worked.
I did have problems getting onto dyno ramps and other steep inclines but those are places you normally dont take a lowered car to.

 

Jonarotz, That work looks good. I notice that its a 91 your working on and that low spot is hard to get any higher unless you cut the cross-member. Mine is a 90 and I have the same problem, I think the sub-frame is made different than other models in that area. I could be wrong, but from the exhaust pictures I have looked at, the sub is different than mine.

 

what area exactly? all 3rd gen floors are the same AFAIK. I cant tell any difference between the floor of my 86 or my 92

 

Yeah I think the floors are all the same. I really don't have an issue up by the frame rails, it is near the back where it goes up to go over the axle. The rear seat pan and rear diff kinda make things difficult.

 

very nice

 

Very nice work with the exhaust but yikes, that exhaust would end up below ground if it were on my car.