Exhaust

[Southern_Pride]

How much HP would I gain If I put 2 inch duals on my car and busted the cats out? Dont really wanna put headers and 2.5 inch pipes on it now since Im thinking of keeping it stock and making the capri the hot rod and Keeping this as a DD. I know the factory rating was 10 HP more but it had cats.

[gadget73]

If you're keeping stock manifolds and having essentially a stock catless dual, I'd say maybe 15 hp with the extra flow from no cats. If you can get ahold of a set of 90 Towncar tubular manifolds, it might be a little better. They aren't muchbetter than the iron, but they should be at least marginally better flowing. They're also lighter and will perfectly mate to stock exhaust.

[mrltd]

Not much..I basically did that, and also took the mufflers off and ran straightpipes, had only 2 cats and headers...Didn't do much. Went to 2.5" duals with the same headers and gained 30HP...Knock the cats and put on 2.25"..

[Southern_Pride]

Mrltd are you saying 2.25 from the mainfolds back or the end of the cat pipe back? I dont think itd do much good from the cat pipe back so im asuuming your saying from the manifold back. I think Ill do 2 inch cause Id like to keep it looking stock. Ill be running glasspacks

[Grand Marquis GT]

You live in FL.

I would run the headers, 2.5" offroad H-pipe, and glasspacks, with full tails.

It would sound good, and flow great!

I run the same setup, but without full tails, on a carb motor.

I know you want to keep this as the DD, but I would seriously consider that route...

[mrltd]

Cat back...the cats are 2.25" Not too bad. The biggest restriction is the mufflers and tails....

[Southern_Pride]

I cant run full 2.5 inch tails. Theyll fit the back tires. Stock one barely fits. Id have to dump it. Ill take a pic to show you. Im busting the cats out this weekend. Itll probably wind up with headers though.

[Southern_Pride]

Pic of exhaust and tire.

[mrltd]

Don't need 2.5, 2.25 will owrk OK, and the exhuast guy should be able to snug it to the frame better than stock..

[89GrandMarquis]

When I put on my duals, I went with factory stock sizes (2"), and installed pipe where the mufflers would go.

Since the factory rating boost was 10HP just for duals, I would expect you would get a few more horses with your two cats knocked out.

In my application, the cats serve to quiet to car down real nice. I did it as an experiment - cost $30 to have two pipes bent up, using a new muffler as a pattern (measured a new muffler at the parts place - didn't buy it). It sounds good and IS NOT too loud at all. In fact, it is pretty quiet. Certainly quieter that a cat-less system with glasspacks.

Before you knock out your cats - and after you've taken off the exhaust system - start her up - it won't be near as loud and you might think.

I'll take a pic when I get home.

[Pimp Hard Or Bust]

i drove my towncar with nothing after the ypipe for a year. it was quiet at idle but when you got on it, sounded like this PHLBPHLBPHPBHLPBHPLBHPHLPBLPHHPLBPPLHBHPLBPHLBHPBL PHHPLBBPLHHPLHLPBBHPLLHPLPHHB :P :P :P :P !!!!!!!!!!

my gf at the time said it was "ghetto"

[Southern_Pride]

I know about how loud it will be. My capri has an open offroad h for almost a year now. I have some 2.5 inch tailpipes in the shed Ill test fit on there for clearances.

[89GrandMarquis]

It is surprising though, how much it quiets down when the rest of the pipes connected - and your dumping ten feet behind you.

My exhaust pics:





Those are "truck clamps". I used them so I could live with the pipes for a while without welding or crimping, and the car is quiet enough that they've just found a permanent home.