: Brougham dual exhaust conversion.



Strickland
05-07-13, 04:40 AM
Just wondering if anyone has converted to dual exhaust on the RWD Broughams? I want to install duals right from the manifolds back, but the stock manifolds are different ( 1990 Brougham D'elegance with 5.7L). Just wondering which manifolds will fit and what to do about the air injection tubes.

csbuckn
05-07-13, 07:37 AM
You can do dual exhaust using the stock exhaust manifolds. I ran dual exhaust down one side and also had them going down each side of the car with a notched exhaust under the crossmember on another car, notch the crossmember so the exhaust doesnt hang down too low. If you get headers, look for something that will fit a caprice from the 70s or 80s but post a link to what you find before you buy them. I would keep the stock exhaust manifold unless you plan on doing an aftermarket intake manifold and other mods down the road. Really open exhaust without any other mods can kill your exhaust valves in the long run and you'll lose some torque. I personally like mini-turbo mufflers with a decent bark when I hit the gas but quiet-ish at idle. Turbo mufflers/glasspacks will be loud all the time, even at idle.

1980coupe
05-07-13, 01:19 PM
mine has dual exhaust and I kept the stock headers. Didnt have to notch nothing. I have cherry bombs in my caddy. I have a vid but I'll upload it later...

cadillac kevin
05-07-13, 01:43 PM
I have flowtech afterburners on my brougham, along with a pypes cat back dual 2.5" system.

Fleetwood472
05-07-13, 02:00 PM
Here's a link that has some pictures of different examples. If you are running one pipe down each side then the crossmember should be notched otherwise they'll have to dip the pipe down to clear it which will make the exhaust hang kind of low. If you don't want to do that i've seen guys run systems that split into duals after the cat running down the passenger side and then split just behind the transmission into dual exhaust. Heres the link with some examples:

http://www.cadillacforums.com/forums/rwd-19xx-1984-deville-fleetwood-1985/263666-single-dual-exhaust-design.html

Keep in Mind the 77-92 fullsize cadillac fullsize cars are all very similar so the exhaust routing will be the same.

paetional0
05-07-13, 02:15 PM
Hold on I'm uploading pics of my setup with dual magnaflows

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http://youtu.be/vyjYjZwFmFs

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http://youtu.be/7b8mUdhW8vs

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Old stuff but still underway

Strickland
05-07-13, 04:00 PM
Id like to find a set of manifolds that both are the same (instead of the stock caddy ones where both are different from one another) from another GM that had true duals and also used the air injection tubes........ anyone know of anything??

csbuckn
05-07-13, 04:37 PM
The frame and accessories prevent you from running the same manifold. The cadillac has a frame reinforcement and tranny linkage on the drivers side that makes the manifold go down instead of back. Not sure how you would get by that.

Fleetwood472
05-07-13, 05:54 PM
Hey Sam, Did you end up keeping the brace on that runs from the rear of the transmission on the crossmember to the front of the frame? I took mine out but was thinking of making a new piece for that.

csbuckn
05-07-13, 06:34 PM
I'm not using it. Make two :)

cadillac kevin
05-07-13, 07:22 PM
Id like to find a set of manifolds that both are the same (instead of the stock caddy ones where both are different from one another) from another GM that had true duals and also used the air injection tubes........ anyone know of anything??

I'd guess chevy truck....I have a set of those manifolds floating around somewhere....I'll take a look at them.

jayoldschool
05-07-13, 10:58 PM
There is no need to change manifolds, they have nothing to do with running duals.

Strickland
05-08-13, 01:20 AM
There is no need to change manifolds, they have nothing to do with running duals. I realize its not necessary, but Id rather find a set that are the same as one another so the duals can be symmetrical from the heads back......if that's possible.

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I'd guess chevy truck....I have a set of those manifolds floating around somewhere....I'll take a look at them. You think a set from a truck would fit....... any idea which year?

jayoldschool
05-08-13, 01:52 AM
I realize its not necessary, but Id rather find a set that are the same as one another so the duals can be symmetrical from the heads back......if that's possible.

The question is... why? GM cars that were factory equipped with duals didn't have mirror image manifolds. There's just no need for it. There is a reason why the exits of the manifolds are pointing in different directions. Am I missing something?

Strickland
05-08-13, 03:30 AM
The question is... why? GM cars that were factory equipped with duals didn't have mirror image manifolds. There's just no need for it. There is a reason why the exits of the manifolds are pointing in different directions. Am I missing something? Oh whats the reason? My thought is just that if I could make it this way it would be a tidier setup for the duals. Just cosmetics is really the only reason I am wanting to do this.

SafariOne
05-08-13, 04:02 AM
Only the human species will find or make a problem where none exists. Totally baffles the mind it does.

csbuckn
05-25-13, 10:52 PM
You may have to search for one made for a caprice with the same tranny. The bubble caprice had a dual exhaust crossmember.

cadillac kevin
05-25-13, 11:26 PM
You may have to search for one made for a caprice with the same tranny. The bubble caprice had a dual exhaust crossmember.

Depending on your transmission, the crossmember frame bracket is in the wrong spot to use the LT1 crossmember (found this out the hard way...my LT1 crossmember is still lying around somewhere). I just had my factory crossmember notched. Cost me 100 something dollars.