exhaust project next, a few ?'s

[Nick52284]

my next project after the rims and tires get put on (hopefully tomorrow) is the exhaust i have a question tho, i only glanced at the stock system, i know they have 4 cats but what would happen if i took the lower 2 off and just kept the upper 2 for emissions or won't it pass with just two? i'm gonna run the patriot sidepipes 60" and i want them to sound like sidepipes! what the best thing i can do and still be emissions legal?

Nick

[Freshmeat]

I've read that those sidepipes are horrible for backpressure... but it'll run fine. I'm only running two cats on true dual exhaust. Then, again, we don't do the exhaust probe down here. If they probe your exhaust, I don't know what you'll need.

[Archangel]

Freshmeat, what do you mean by "horrible on backpressure" - create too much of it, or almost completely elliminte it?

[boXman]

All my boxes have/had 2 cats....I dunno how some of you ended up with 4 lol.

[Grand Marquis GT]

All my boxes have/had 2 cats....I dunno how some of you ended up with 4 lol.

Some had 4!

My 89 did...

[Freshmeat]

I don't know how many were on the wagon... before I even looked, I had ripped off half the exhaust when I caught the edge of the pavement leaving a friend's house. Her dad probably still has it in his pile of junk...

I mean the sidepipes eliminate backpressure, from what I've read. As heavy as our cars are, we need to be cautious to retain a legitimate amount, for torque purposes.

[Nick52284]

hmm..... i guess my best bet would be to just run regular duals then? what about stock dual exhaust systems if i changed out the mufflers? theres a guy on ebay selling stock dual exhaust systems for 8X mercury grand marquis..... what kind of sound would i get if i threw 2 flowmaster 40 series or equivelant on there?

Nick

[Grand Marquis GT]

A custom setup would be a good idea...

I got a custom setup, and haven't looked back since

[Paul_]

It would still be a fairly quiet system. The Flowmasters would definitely be louder than the stocker mufflers, but to really bring out the noise, you need to gut your cats. :devil2:

[Grand Marquis GT]

Just cut em off! :hacksaw:

[Paul_]

Depending on where he is in PA, he might not be able to.

[Grand Marquis GT]

I forgot that it isn't the same PA I grew up in :nonono:

[Nick52284]

hmm, i guess i could just go with straight pipes from the headers to a muffler and then the over the axle pipe on each side?? yea we still have emissions....... fuckin bastards. i thought there was a law that if a car is a certain age its emissions exempt???? can anyone verify this??

Nick

[Paul_]

I wouldn't do straight pipes. You'll lose some of the low end torque these cars need to get rolling.

[Nick52284]

dammit, lol what would you guys suggest that i do? i might be able to remove the cats and just throw some on for inspection when the time comes, but i'm not sure, other than the cat issue what do you guys run for good backpressure and performance when it comes to exhaust on these cars?

Nick