Exhaust replacement on a 1990 LE..suggestions?
 

Ok, here's the skinny. (Please actually read the details to avoid any confusion/arguments.)

Car is a 1990 Bonneville LE. Current exhaust system is stock with a single exit in the rear facia. What I would like to do is up the diameter of the entire system and replace the muffler and cat with less restrictive ones. (also change the exhaust note to something a little throatier.) The goal is to accomadate a higher flow through the entire system. Not even thinking of one of those silly resonator coffee cans on the tip.

My understanding thus far is the stock 2.25" pipes can be replaced with stock 2.5" pipes off a later model H-Body and the muffler can be replaced with an 4th gen F-body V6 muffler. Is this correct? If not, Plan B is to get the muffler dejur and have the pipes made up at a local shop.

How about muffler choices. I'm thinking along the lines of a Flowmaster, but not sure which series would sound nice on the V6. Sandrock's 80 Series on his Malibu sounded rather nice.

The best sounding LN3 we've ever heard was Jim W's Red Light District with a Magnaflow on it. He may still have a vid for you.

Yes, the 2.5" will benefit you more, especially with a power-adder. Without the power-adder, you may lose low-end.

Thanx,

I also have considered replacing my stock exaust system.

Our cars are basically the same, so I could use the advice too. :D

CD

I'll take a look and see what I have. I had a Autosound high flow cat welded to the stock piping and a Magnaflow muffler for F-Body 3800's (ie Firebird and Camaro)..works on many GM cars though. I also had a GMC Yukon Denali chrome tip. Gave the car a great look and great sound.

Here ya go! Only vid I have of the exhaust...sorry man. Good luck with whatever you end up doing.

https://img.photobucket.com/albums/v...h_MOV00019.jpg

https://img.photobucket.com/albums/v...lacej/0032.jpg

Whichever muffler you choose (flowmaster 80 or magnaflow f-body) remember it is going to be loud, because you do not have a resonator.

I did the flowmaster 80 and a high flow cat on my '89. It sounds like a beast at idle, but had alot of drone at travelling speed.

Curt, I like the sounds from brads car.... But as much as I liked the sound, the drone was a little more than I'd ever want...

I have been wondering for a while what my 95 would sound like with a Magnaflow keeping the Res...

Not sure what the size of the downpipe is on the 90-91...I'm thinking 2.5 for the DP and 2.25 for the rest... I do believe that a newer exahust should fit, but its a bit questionable... Not 100% on the length...

On another note I found a restriction on my old rear manifold from my 91....

* runs to find Manifold, Takes Picture *

https://img.photobucket.com/albums/v...C/CurtMani.jpg

Not sure if yours has this restriction... After I found a clean cut manifold from an 89 Buick I noticed a deeper tone.... The 92+ had a better rear manifold...


But a 2.5" exahust would be interesting

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I'm thinking all the LN3 manifolds have that restriction. Hacking it out has been found to make a worthy performance difference.

My '95 L67 manifold does not have it, if it helps at all

i say put cherry bombs on it :D

Thanks, I remember that from earlier and it's on my list of things to check when the pipes get dropped. I figure if it's like that, a die grinder will make short work of it.

Eh, I gotten used to it...but I think at the start of next year I am going to resonate it. Flowmaster actually makes a resonator that should match with the 80 series perfectly. Agreed that it sounds nice at idle-3k, anything after that starts sounding...ricey.

Also Curt, remember exhaust velocity...my 3500 puts out less velocity now than it did with the factory exhaust (I did the full exhaust swap and not just a muffler swap), and puts out less than a 3800 for obvious reasons. The tone will sound deeper than what you heard from mine. *Scratches head for a second or two*...didn't you say you were gonna keep this a sleeper? Maybe go with a stock F-body muffler...you will get your flow w/o the noise that way.

Oh no... I liked it on the drive..... But if it were to be a long drive the Drone would bug me after a while... H*** I hit it a few times just to hear it...LMAO

Curt, Have you thought about a 2.50" in and 2 2.25" Outs( on the pasenger side ) like the 92-93 N10( Single side-Dual Outlet ) Optioned Bonnevilles... This way it will retain a stock apperance but a nice new sound? And I believe that both Flowmaster and Magnaflow have that configuration... ;)

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Yup...had one on my SLE ;)

http://memimage.cardomain.net/member...088_2_full.jpg

http://memimage.cardomain.net/member...088_1_full.jpg

http://memimage.cardomain.net/member...88_13_full.jpg

Thats exactly what I was thinking of.... I was thinking Malibu and forgot about the SLE :oops:

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Hmmm.. thats a thought. My '87 Camaro V6 started life with a single inlet, dual outlet on the same side. I think I'll start with just a single in/single out and see what it sounds like.

The constant drone doesn't bother me much...My hearing is pretty much shot, so things sound different to me to start with (I can't hear high frequency stuff) It's kinda like having the bass turned way up and the treble turned way down on everything.

As to sleeper...It has to *look* like a stocker. Doesn't have to sound like a stocker (most of the victims have the stereo turned way up anyways ;)

Interested to see what you do Curt ;)

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Well, did it yesterday. went with a Flowmaster knock-off made by IMCO (no packing, just chevron shaped baffles in the muffler body). single inlet, single outlet, no resonator.

Sounds pretty good, not much louder than the stock muffler, with a little bit of burble to it.

I haven't dropped the center pipe to look up inside the exhaust manifold. Picked up the exhaust gaskets this weekend and figure on dropping the manifold over the Christmas holliday long-weekend.

Curt I'd be interested to see what you mani looks like... I have seen a few that were like mine...

If it is, and you clean it up you may get a deeper nicer tone out of it ;)

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