I was wondering what kind of gains would come out of gutting the cat or a straight pipe? would there be any losses?

 

i here that it can lower you low end and give you upper beacause there is no resistance. i did it and there is not really any preformance difference mabye like 3 hp but after you do it you can actually hear the exhaust when you idle.

 

I could tell you but I'm not JPrevost

 

Tas, I did't mean like that.JPrevost has helped me in the past and I appr. any info from any body.

 

There should be no downside doing this to a stock cat. Gains should be noticeable.

 

noticable but slight. blue92 did it to his car, and he was essentially stock with a k&n open el. he said it made a nice difference, mostly exhaust tone, but said it pulled harder all over.

just dont get nailed.

o and btw, jprevost will tell you not to do it because he has some sort of atachment to nature or something and thinks that we should still do what we can to keep our cars breathing clean. at least i think that was him going off on people removing there cats. i dont know. everybody has their own opinions.

 

It makes a HUGE difference if you have a 6000rpm motor with heads/intake/headers/etc but not all that much on a stocker that doesn't rev high AND has low volumetric efficiency, ie doesn't push a lot of air out the exhaust to begin with...

But I'd get rid of the cat, anyway but WOULD NOT gut it. Make a removable "test" pipe like they used to sell in the good-ol days that you can swap into the exhaust in place of the cat. Then, for testing, just put the cat back. Now mind you, I flage the cat and the test-pipe and use stainless bolts to do the attaching so that they come apart REAL easy and all you need to swap is a new cheap flange gasket set of 2, one for each end.

It really does change the exhaust note quite a bit, especially with aftermarket exhausts/mufflers. Just be careful of the smog police!!! Be cool. If you ****-off a cop, he can make you get your exhaust inspected if he's a crank.

 

Thanks guys! I don't have to worry about smog police here in good ole MS.

 

Snuf, just because of that comment I'm going to have to take my car to the track with and without the cat. Gutting the cat will definatly make more noise in the exhaust (duh). Let me just point out something that 80% of the drivers on the road believe: Noice = power.....WRONG! Most of the people reporting that the car ran a LOT stronger with the cat gutted are in that 80%. You will notice a slight difference in the driving of the car but if you have a high flow 3" cat in the first place there should be next to nothing in terms of power gain. After I get my car inspected this month I'm going to slap on Tim's (NJspeeder) setup (straight pipe and Borla adjustable). I'm going to the track either this weekend or next depending on the condition of the car. Right now I'm detailing while I waite for my gears, they're on the way. Then I need to get them installed (2 days down time).
I know this isn't important but today I removed my 3"-2.5" reducer and the car lost some low end noticably but it screams to 6 grand better than before. When I get Tim's setup on my car I hope to have the low end and monster pulling power like the open 3"
This really doesn't mean anything because I still have the cat ( NJ...). I used to be a strong believer in keeping emissions equipment but the more I tune and read the more I hate it. I will stand by my opinion about a daily driver: Keep the Cat! I don't plan on having this car as my daily driver for much longer and I plan on racing. I hate to sound like an ***hole but if you don't have a good platform (strong engine) what is the point of getting every last hp? I think if you race frequently then gut the cat like Tim. It's his daily driver but he also had heads, intake, full exhaust and a racing setup, not your normal daily driver.
I guess what I'm trying to say is hot rod what you have but don't be so crazy that it's a beater making 10 more hp at 4500 than a stock 305 TBI, that's like a riceboy installing a huge muffler on a stock car. Take it or leave it, that's my view on gutting the cat.

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, Jon (350 TBI!)
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