Anyone with dual cats?
Thread Starter
Race Director
Joined: Mar 2001
Posts: 11,601
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From: San Francisco CA
St. Jude Donor '07
Anyone with dual cats?
I'm looking for advice from anyone with dual cats with dual exhaust. I know they're not street legal, but I still want to be as environmentally friendly as possible. The thing is, I don't know what kind of cats I need, or how far away from the engine they need to be without frying. Any ideas?
Drifting
Joined: Jun 2000
Posts: 1,752
Likes: 1
Re: Anyone with dual cats? (Buffalo Dude)
Contact Steve (forum member 'Pacin Calilfornia') he's got em and by the sounds of it, he's damned pleased with them. You can just get the free flow cats from Summit and have someone weld them in near the stock location. I thought about doing it myself (and still lmay one day).
-terry
-terry
Race Director
Joined: Jan 2000
Posts: 12,399
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From: San Jose CA
Re: Anyone with dual cats? (Buffalo Dude)
I have dual cats and am running them parallel to the stock location.
My emissions test was great. ;)
All 0's, except HCs which were 3 ppm @ idle and 7ppm @ 2250 rpm. I'm running rich, so this was to be expected.
I don't think they're that much quieter than Terry's 77 with dual 2.5" and no cats. His is a little growlier thanks to heads and cam, of course.
-Steve
My emissions test was great. ;)
All 0's, except HCs which were 3 ppm @ idle and 7ppm @ 2250 rpm. I'm running rich, so this was to be expected.
I don't think they're that much quieter than Terry's 77 with dual 2.5" and no cats. His is a little growlier thanks to heads and cam, of course.
-Steve
Burning Brakes
Joined: Sep 2002
Posts: 1,179
Likes: 3
From: SF East Bay CA
Re: Anyone with dual cats? (Buffalo Dude)
I am running them (in CA) and they are in the stock location. Originally ran the pipes back through the crossmember, but then modified for the 700r4. Kept the cats in same place. No problem... also Flowmaster 40's You won't have any smog **** problems either. (I am in Bay Area)
Thread Starter
Race Director
Joined: Mar 2001
Posts: 11,601
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From: San Francisco CA
St. Jude Donor '07
Re: Anyone with dual cats? (timbo79)
Thanks a whole lot everyone! This is to be my summer project, along with learning how to weld and teaching myself guitar :eek: Hopefully I'll be able to weld the cats in myself.
And so it begins, I have officially entered no-fun mode: finals week after next :eek: :cuss
And so it begins, I have officially entered no-fun mode: finals week after next :eek: :cuss
Burning Brakes
Joined: Jun 2002
Posts: 792
Likes: 2
From: Norcross GA
Re: Anyone with dual cats? (Buffalo Dude)
I've got them with Flowmaster Delta 50's. http://home.attbi.com/~jchadwick/exhaust.htm
Instructor
Joined: Jul 2002
Posts: 105
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From: spring hill fl
Re: Anyone with dual cats? (Buffalo Dude)
i've got true duals with two cats welded in place. mufflers two, =monza type=.thats it. the sound is good the emissions are passing in fl when we had them. :smash:
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Race Director
Joined: Apr 1999
Posts: 11,520
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From: CORVETTE 77 385 C.I. TEXAS
Re: Anyone with dual cats? (Buffalo Dude)
Just a general rule- Put as far back as possible yet still work- basically as the CA. guys are doing.
No cats.
[Modified by Ganey, 9:42 AM 5/10/2003]
No cats.
[Modified by Ganey, 9:42 AM 5/10/2003]
Racer
Joined: Oct 2002
Posts: 328
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From: Marlborough MA
Re: Anyone with dual cats? (Ganey)
Just a general rule- Put as far back as possible yet still work- basically as the CA. guys are doing.
Why move them farther from the engine? I've read moving them closer to the engine gave the car companies cleaner emissions. They reach operating temp faster (or something like that)
Race Director
Joined: Apr 1999
Posts: 11,520
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From: CORVETTE 77 385 C.I. TEXAS
Re: Anyone with dual cats? (75 BBC Stingray)
That's from a performance perspective as the futher back the less the effective restrictions. However if they are moved too far back they may not get hot enough to lit off.
Another thing is what stds. before 80 !!! :eek:
See http://www.epa.gov/otaq/12-miles.htm
"HC standard is delayed until 1980 and the CO standard until 1981. The NOx standard is delayed until 1981 and is relaxed to 1 gram per mile. " :eek:
Note that CA has it's own stds.
It might be possible to mount behind crossmember w/ Xover before them.
PS Don't bet I could not get them hot enough. :cool:
Another thing is what stds. before 80 !!! :eek:
See http://www.epa.gov/otaq/12-miles.htm
"HC standard is delayed until 1980 and the CO standard until 1981. The NOx standard is delayed until 1981 and is relaxed to 1 gram per mile. " :eek:
Note that CA has it's own stds.
It might be possible to mount behind crossmember w/ Xover before them.
PS Don't bet I could not get them hot enough. :cool:
Thread Starter
Race Director
Joined: Mar 2001
Posts: 11,601
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From: San Francisco CA
St. Jude Donor '07
Re: Anyone with dual cats? (biltogo)
Don't C4's have one cat? Why not use one of those? You get the emissions and crossover in one unit.
