Cats or not?
Thread Starter
Instructor
Joined: Sep 2004
Posts: 240
Likes: 0
From: Shawnee Oklahoma
Cats or not?
I've just purchased a set of FLP longtubes, the X pipe, high flow cats and a Borla stinger system. I'm having them installed the 21st. The performance shop is recommending that I leave the cats out. He said it'll be a little louder but will give at least 10 Hp more. With LT headers, X pipe, and new Stingers I'm already thinking it's going to be loud. Should I have the cats put in or leave them out? It's all going on a 99 vette. What you think?
Le Mans Master
Joined: Aug 2000
Posts: 8,762
Likes: 2
From: Murphy TX
W/O cats will be pretty loud...and you may notice and increase in gas smell.
Also, I'm not familiar with OK, do they do a sniff test when you get it inspected? I'd be a bit concerned about passing emissions here in TX w/o anything.
I've heard of folks having an intermediat pipe put in so they can actualy bolt cats in and out to get around this. Either way it isn't exactly legal.
If it were me, and I've considered LTs, I'd probably leave the 10hp on the table and put cats in. I want power but at the same time they are there for a reason.
Also, I'm not familiar with OK, do they do a sniff test when you get it inspected? I'd be a bit concerned about passing emissions here in TX w/o anything.
I've heard of folks having an intermediat pipe put in so they can actualy bolt cats in and out to get around this. Either way it isn't exactly legal.
If it were me, and I've considered LTs, I'd probably leave the 10hp on the table and put cats in. I want power but at the same time they are there for a reason.
Team Owner
Joined: Jul 2004
Posts: 124,349
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From: .... NJ
Cruise-In VII Veteran
St. Jude Donor '05 thru '19
What does the law say in your state? I think it may be illegal no matter where you live. Anyway I thought the newer cats of today did not restrict HP that much? That is unless you want to make major HP.
Race Director
Joined: Oct 2002
Posts: 16,477
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From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
It takes less than a half-hour to undo the 4 clamps and switch between the cats and straight pipes with the FLP system. I recommend you try it both ways and stick with what you prefer.
I run mine without the cats most of the time. It's definitely louder, and I like it that way.
As for power...around town, with the cats it seems to have a bit more low end tq. It feels snappier and a little more responsive off the line, but that punch seems to die off when really getting on it.
Without the cats, it pulls noticibly harder in the upper rpms. Definitely the way to go for more power.
I run mine without the cats most of the time. It's definitely louder, and I like it that way.
As for power...around town, with the cats it seems to have a bit more low end tq. It feels snappier and a little more responsive off the line, but that punch seems to die off when really getting on it.
Without the cats, it pulls noticibly harder in the upper rpms. Definitely the way to go for more power.
Thread Starter
Instructor
Joined: Sep 2004
Posts: 240
Likes: 0
From: Shawnee Oklahoma
Thst's why I love this forum! No substitute for experience. There are no longer inspections in Oklahoma. It sounds like it's not going to be that hard to change back so I might go ahead and have the cats put in, especialy at first. It'll already be a big change with the headers and stingers I'm sure.
Race Director
Joined: Jan 2003
Posts: 14,285
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From: Houston, Tx Got traction?
CI 5-6-7-8-9-10 Veteran
St. Jude Donor '07-'08
I'm not running any cats, and i love it. My car is quite loud especially with the LT's, X-pipe, B&B PRT's and the Camshaft. If you're paying to have the car tuned, pick which way you will be driving the car the most, before wasting your money on a dyno tune.
Chris
Chris
Drifting
Joined: Apr 2003
Posts: 1,833
Likes: 68
From: Bowling Green KY
Originally Posted by Barnett
I've just purchased a set of FLP longtubes, the X pipe, high flow cats and a Borla stinger system. I'm having them installed the 21st. The performance shop is recommending that I leave the cats out. He said it'll be a little louder but will give at least 10 Hp more. With LT headers, X pipe, and new Stingers I'm already thinking it's going to be loud. Should I have the cats put in or leave them out? It's all going on a 99 vette. What you think?
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Burning Brakes
Joined: Dec 2004
Posts: 905
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From: Rhode Island
Originally Posted by tblair7500
If your car is a DD, I would leave in the cats. But if it is just a pleasure car, lows miles per year (like mine), leave the cats out.
Last edited by 400hp; Mar 6, 2005 at 05:34 AM.