Dual exhaust with stock crossmember

[85 Cutlass Brougham]

It's late at night and I have an idea.... Why not run dual exhaust snaking under the single crossmember back to the exhaust pipes at the rear? GM did a dual cat setup in 350 TPI F bodies that then Y'd down to the single pipe, but is there enough space to put a set of 2 1/4 in pipes and dual cats in the space currently occupied by the single setup? I have a Dynomax Exhaust for a Monte SS and a Edelbrock TES system for the headers to the cat which puts 2 2 1/4 in pipes down to the oval cat inlet that GM used for a high flow setup, and I think it may fit. It's not the best solution, but it may be cheaper than an aftermarket crossmember setup.

 

[87MonteSS]

I have true dual exhaust with the stock crossmember. But I don't have the cats anymore. If you want I can try to take a few pics tonight.

 

[GP403]

I've got the same deal. 2 1/4", the drivers side crosses under the trans and both run through the stock c-member "hump" then it crosses back over w/ the mufflers just in front of the axle. from the mufflers I'm running stock '69 grand prix tailpipes. I've got the mufflers and tailpipes off ATM (*that* was not fun BTW, 17+ yrs they were on there) while I wait for new mufflers and tailpipes, so its up in the air and I could get some pics...

My downpipes were custom bent (a looong time ago) to the mufflers, but I'm sure there's something out there to do the trick.

Dunno how much clearance you'd have to cross under the trans w/ an automatic though. My 4-spd is a good bit smaller and of course doesn't have a big pan hanging down.... I'm surprised nobody's come up with a way to cross under the oil pan like the stock crossover pipe did and then come down....

will try and get some pics tonight.

 

[87MonteSS]

So much for the pics idea. The pipes are so close together and the way they cross over each other up front you can't tell waht's what in a pic. If I had access to a hoist it would work, but I don't.

 

[GP403]

Here ya go. They're hanging lower than usual due to mufflers/tailpipes being off, normally the one going under the trans is right up there.

like I said though I don't know how much room you'd have w/ an auto-trans pan hanging down lower....

 

[maliburacinfreak]

if you run long tube headers, forget that idea. the headers come back almost all the way to the crossmember. a good crossmember is just a lil over $100 and makes it sooooooo much easier. or you can use some 6" C-channel and notch your stock one.

 

[crappycutlass]

i have duals with the stock cross.. it hangs low but i have yet to hear it rub on anything.. when the car gets back form paint i'll get a underbody shot

 

[87MonteSS]

if you run long tube headers, forget that idea. the headers come back almost all the way to the crossmember. a good crossmember is just a lil over $100 and makes it sooooooo much easier. or you can use some 6" C-channel and notch your stock one.

The OP said he had the Edelbrock TES headers, so kind of a useless point.

 

[85 Cutlass Brougham]

Yeah, the Edelbrock TES setup uses shorty headers and includes the downpipe, and the car has a 355 Chevy with a TH200-4R transmission. The downpipe crosses between the front suspension crossmember and the oil pan and then the tow sides join into one pipe to go to the cat. It looks like there may be enough room for duals in there, I have to borrow one from a friend who has a 2 1/4 in cat lying around and see how it fits. I just don't want huge ground clearance issues ( like my AMC Spirit with long tubes has) as the car is mildly lowered ( Eibach Pro Kit springs) and sometimes smacks the mufflers on raised manhole covers that exist around here on older roads that have settled funny.

 

[Alanco]

Duals w/stock crossmember

I took off the cat, made a cut in the crossmember and welded a half circle piece of mild steel in the crossmember. The Hooker headers were too close to the brake line going to the right side, so that was re-routed around the front of the car to the right brake. Plenty of room for the headpipes and glasspacks. The only problem was that the upgrade of the rear end to an 8.5 fit ok, but a Ford 9" would not have left room for the tailpipes.

It sounds great with glasspacks. Out here in Central Nevada there are no smog checks.