GEN II/3rd CAT

ROCKYTOP

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Hi All!
Anybody know if the third cat combines both exhausts or are they completely separate going through it? Thanks in advance! :)
 
RE: GEN II/3rd CAT

Thank's Ray! That's what I thought! Thought my '98 LSC was supposed to have true dual exhaust. This third CAT sure doesn't make it a true dual exhaust system being that it combines both exhausts. Comments anyone?? :-(
 
RE: GEN II/3rd CAT

SMOOTH8 If the third cat combines, is that similar to the (X) pipe?, balancing exhaust pressure from both heads?.
 
RE: GEN II/3rd CAT

cut it off, take an air hammer to the other two cats, then have two x-pipes and 2.5" duals run all the way back. The second x helps kill the drone. Oh, yeah, don't forget mufflers. I have magnaflows, and i like them. BTW, you won't pass emissions.
 
RE: GEN II/3rd CAT

Dynamax or Magnaflows? Million $$ question!!

I am ready to do my muffler ASAP so I need to decide and pull the trigger on which one's to purchase.

The Magnaflows carry a lifetime warranty how bout the Dynamax??

BTW the Dynamax web-site claims the the Ultraflow welded outflows the SS by 133 cfm's..............True?

"Any help would be hot"...Jar Jar Binks-Star Wars Ep. I

Thanks, Joe
1997 Mark VIII LSC (Blk/Blk) "Blacker"
http://www.hostmysig.com/data/slowjoe/LODSigPic1.jpg
 
RE: GEN II/3rd CAT

cut it off, take an air hammer to the other two cats, then have two x-pipes and 2.5" duals run all the way back. The second x helps kill the drone. Oh, yeah, don't forget mufflers. I have magnaflows, and i like them. BTW, you won't pass emissions.

In Maryland now, if your have a 1996 or newer and have the plug-in for the computer, so long as it hasn't thrown any emmission codes, they won't even run your car on the E.G. Analyser. So as long as you have a code reader before you go for the emmisions check, you'll pass.
 
RE: GEN II/3rd CAT

Dave,
I don't have to worry about the emissions here. I've replaced the two stock mufflers with Smitty's 18" glasspacks (they've been around at least since the fifties) and the exhaust sounds way better than stock, although you can tell by the sound that the exhausts are coupled through the third CAT. There's sort of a restrictive muffled groan at higher RPM's. I'm going to hack off the third CAT and install two more Smitty's in place of it to provide enough back pressure and give it a true dual exhaust system without the expense of the X pipes. It should also improve the sound more dramatically as well as eliminate any droning sounds. These two sets of 18" mufflers will total 36" of muffler per side. I have two 40" Smitty's on my 64 Ford F100 with a 312 "Y" block and it sounds awesome, but not loud enough to knock your socks off. Also, the 40 inchers would never fit under my Mark. I know that there are after-market companies out there that sell exhaust components for our Mark's, but after listening to all of the sound files (companies and members) I've found on both of the Mark VIII sites, I not a happy camper. They just don't sound like V8's to me. If I'm not happy after this MOD, I'll try something else.
 
RE: GEN II/3rd CAT

I can vouch for Bud. I'm in Maryland with a '96 and all they did was the eec hookup then kicked me out the door after taking my money.
 
RE: GEN II/3rd CAT

Jack - The exhausts on these cars sound a lot better in person than they do over the computer. Trust me I have a single-X exhaust with Magnaflows and I am very happy with this set-up. I have heard many combinations of cat back exhausts on this car and most sound great. I have even heard Johnny's FULL exhaust on his Mark and that was awesome! (he has long tube headers, high flow cats, single-x 2 1/2 exhaust and dynomax mufflers).

If you are near anybody on this board or the 'other' board that has an aftermarket exhaust you should drive over and hear it in person and you will be sold!!!

Ken
 
RE: GEN II/3rd CAT

Have any of you considered cutting out the 3rd cat - and welding in a dual in/dual out muffler such as Flowmasters 50 series SUV in its place and then cutting out the 2 oem mufflers and having 18" of straight pipe in each of their places? This seems like a good idea for a few reasons.

1. Saves weight by only having one muffler
2. Saves $$$ as the one is about 90$
3. You still have exhaust equilization within the one muffler
4. It seems that cars with lots of pipe AFTER the mufflers sound
throatier than cars with tips right after the mufflers do.
5. The dimensions of the 50 series SUV muffler are a 5X10 oval - 17"
long - similar to the 3rd cat - so fitment/ground clearance
should not be a big issue

What do you think?
 
RE: GEN II/3rd CAT

Ken,
I'm still a beleiver in people. Will take your advise and use the "X". There's nobody (as far as I know) that has an aftermarket exhaust within a reasonable distance from me. I'm in Mountain View, Arkansas. Thanks for your thoughts and advise. Will post after the work is done. :)
 
RE: GEN II/3rd CAT

Next question: If anyone has done this and read the emission codes, does it throw up that it's okay (?) or does it say that it will fail??? If it doesn't tell the ECC system that it will fail emissions test, I'll get rid of MY rear cats!
 
RE: GEN II/3rd CAT

I have my 3rd cat cut out and I just passed NJ emissions inspection with no problems, not even close, she runs clean as a whistle.
 
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