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Performance, Brainstorming & Tuning Talk about modifications, or anything else associated with performance enhancements. Have a new idea for performance/reliability? Post it here. No idea is stupid! (please use Detailing and Appearance for cosmetic ideas)

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Old 07-07-2004, 09:21 PM   #1
Sol
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Default To CAT or not to CAT...

that is the question.

The GTP'* debut is immient, and I am doing a lot of research on mods. I have been looking at downpipes.

I really like what R/T offers. They have a 3" DP with high flow CAT that shrinks down to 2.5" so not much torque is lost. Then there is a 3" to 2.5" DP without a CAT. I am having trouble deciding between the two. Michigan does not have inspections, so I do not have to worry about having a CAT or not, but I am wondering which direction I should go.

I am leaning toward the CAT-less DP because it is cheaper, but I'm not sure.


CAT
http://www.pfyc.com/store/merchant.m...ory_Code=GPEXH

No CAT
http://www.pfyc.com/store/merchant.m...ory_Code=GPEXH
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Old 07-07-2004, 09:53 PM   #2
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youll most likely lose alot of torque with no cat. I went with a high flow cat and had very little change in performance but alot in sound. Id go with the cat.
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Old 07-07-2004, 10:37 PM   #3
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Unless you're planning on MAJOR 13-second mods, don't even think about it. Now consider the environmental aspects, and the fact that it'* very difficult to find a shop to do this. If not impossible.

Keep the cat. You'll never know the difference. Hi-flow of any brand.
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Old 07-07-2004, 10:39 PM   #4
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The RT comes with a cat, so I'll be all set. I was leaning toward keeping the cat, but I guess I'll have to fork out the extra bucks.
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Old 07-07-2004, 10:52 PM   #5
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Downpipe and a 3.4 and he will be in the 13'* anyway Get the R/T with cat and be kind to my son'* environment
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Old 07-07-2004, 11:03 PM   #6
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I was thinking the same way not too long ago when I knew TOGs where going on. At first I was leaning towards no cat, try to find a shop local that will do this, I couldn't so, that left me with a hi-flow, got an SLP. So from tog flexpipe is 3in and dosen't reduce till after the cat.

But since it is a GTP don't they bolt up. If your handy the choice is yours.

Oh ya and In IL theres some mult- thousand dollar fine if your caught. Check the law in MI
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Old 07-08-2004, 12:06 AM   #7
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Cat it, your car isn't above the law, or the environment.
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Old 07-08-2004, 02:45 AM   #8
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i vote to keep the cat (think of the children!)
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Old 07-08-2004, 03:25 AM   #9
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Do it...Cat the car!

Everyone else has stated what I believe in firmly, and with a performance exhaust, you will feel the HCF, if yer in the mood to remove things, remove the U-bend
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Old 07-08-2004, 04:53 AM   #10
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Isn't the 3.8 exhaust EXTREMELY raspy without the cat? I believe it'* raspy enough with a new muffler.. lol. I'm not sure if that bothers you enough or not?
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