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Rockers Arrived!!, Now Best Cat?

Old Dec 22, 2005 | 11:51 PM
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Let'* not turn this in to another no-cat arguement...
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Old Dec 22, 2005 | 11:56 PM
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Originally Posted by razyfoo
Originally Posted by fantastic88
No Cat!
If only a exaust garage would do that. Its illegal here. The only way to do that would be to do it myself. I don't have a welder and am not exaust efficient.
Hollow out your cat. To the inspection places it appears to be there, and usually no one ever actually tests the emissions. The extent in PA is just your gas cap, and a visible cat.
This is very poor advice. Imagine how the recipient of your advice will feel when they get hit with the fine. Some of the quickest cars on this site still run with cats. It'* the legal and responsible thing to do.
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Old Dec 23, 2005 | 12:25 AM
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I found the cats for the 3.8s. Just have to measure the exaust to see if i'm 2.25 or 2.5. I just hope this flows good enough so nothing in the engine gets stressed. One more question. I won't be running a DHP for a while. How do stock PCMs react with rockers?
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Old Dec 23, 2005 | 12:33 AM
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you will not benefit from the higher shift points
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Old Dec 23, 2005 | 12:45 AM
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Originally Posted by Sol
Let'* not turn this in to another no-cat arguement...
x2
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Old Dec 23, 2005 | 12:59 AM
  #16  
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Originally Posted by fantastic88
I found the cats for the 3.8s. Just have to measure the exaust to see if i'm 2.25 or 2.5. I just hope this flows good enough so nothing in the engine gets stressed. One more question. I won't be running a DHP for a while. How do stock PCMs react with rockers?
Stock PCM'* react fine to rockers. You won't get an SES light or anything like that, its nothing to worry about, but when you get a DHP you will see a nice gain.

you will not benefit from the higher shift points
When my dad dynoed his GTP with rockers, the powerband didn't start falling off until ~6200rpms or so. Shifting at 6k instead of the stock 5500 or 5800 rpm shifts (can't remember what they are for his car) will make a big improvement actually. Shifting at 6200 should help a little as well. Any higher than that and it probably doesn't do much. My dad shifted his GTP at 6200 with his rockers and had a 6600rpm limiter and since he set all the stock cam/M90 L67 1/4 mile and dyno records, I'd say it probably worked ok. Although we never turned it that high on the dyno with the rockers, on the street it seemed to pull pretty hard all the way to the 6600rpm limiter with the rockers. Keep in mind however that this was done with 85lb. valvesprings and OR pushrods and should not be attemped with stock springs and/or pushrods.

Shawn
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Old Dec 23, 2005 | 01:18 AM
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The shift points for my car are 5800 1st-2nd and 5400 2nd-3rd. When I do get the DHP i'll have it shift at 6K through all gears. I'd go higher but i'm sticking with the stock springs and pushrods.
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Old Dec 23, 2005 | 01:37 AM
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The 6k shifts should work great and you'll definately see a nice gain as I said before. We have a completely stock valvetrain in the SSEi (besides the rockers) and it shifts at 5950 with no problems at all (even with 160k+ miles on ti) and it pulls hard to the shift too. 6k shift points work very well with rocker'd cars.

Shawn
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