Cats
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,163
Likes: 5
From: Houston
Cats
I'm interested in perspective from those with personal experience rather than theory.
With and without cats, what have you seen? What about offroad pipes vs punched out cats? Power differences, problems, etc.
I have been running kooks high flow cats for over 2 years now, and I suspect they are causing a bit of a lean condition now since nothing else on the car has been touched, and it needs more fuel. I'm debating just punching them out, re-tuning and moving on. Can anyone name any cons here other than maybe the smell?
With and without cats, what have you seen? What about offroad pipes vs punched out cats? Power differences, problems, etc.
I have been running kooks high flow cats for over 2 years now, and I suspect they are causing a bit of a lean condition now since nothing else on the car has been touched, and it needs more fuel. I'm debating just punching them out, re-tuning and moving on. Can anyone name any cons here other than maybe the smell?
Tech Contributor
Joined: Apr 2007
Posts: 10,924
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From: Forney Texas
I've seen many clog up and cause huge power losses. When I built GolfinZ's motor, I was tuning it and it made 570RWHP, nosing over hard up top. I swapped it with my offroad midpipe and it made 8xxRWHP.
Melting Slicks
Joined: Nov 2008
Posts: 2,008
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From: NOLA
^^
Wow
I don't have any real experience but I have been running high flow cats that came with my ARH without a problem . A friend of mine had his clog I decided to have mine taken out and do a retune in the near future.
Wow
I don't have any real experience but I have been running high flow cats that came with my ARH without a problem . A friend of mine had his clog I decided to have mine taken out and do a retune in the near future.
Original Founding Member!
Joined: Jul 1999
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From: Granby, MA
Cruise-In 1, 3, 9. 10 & 11 Veteran
HP gains seem to be here/there...some swear by running no cats is the only way to go for max flow and HP...others run high flow cats and crank out just as much HP so I guess you decide what is best for you.
Last edited by XtremeVette; Oct 27, 2011 at 01:32 PM.
Original Founding Member!
Joined: Jul 1999
Posts: 9,037
Likes: 88
From: Granby, MA
Cruise-In 1, 3, 9. 10 & 11 Veteran
Hey Bret...first off your build is looking awesome!!!...
800-570rhwp = 230rwhp difference...hmmm wow...damnnnnnn???? can ya get into that a little more...did you take the belt off the blower or prevent half of the cylinders from firing? lol...j/k. The exhaust/cat would of had to have been plugged up better then 75% to cause something like that man? Correct?
Last edited by XtremeVette; Oct 27, 2011 at 01:47 PM.
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Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
Hey Bret...first off your build is looking awesome!!!...
800-570rhwp = 230rwhp difference...hmmm wow...damnnnnnn???? can ya get into that a little more...did you take the belt off the blower or prevent half of the cylinders from firing? lol...j/k. The exhaust/cat would of had to have been plugged up better then 75% to cause something like that man? Correct?
800-570rhwp = 230rwhp difference...hmmm wow...damnnnnnn???? can ya get into that a little more...did you take the belt off the blower or prevent half of the cylinders from firing? lol...j/k. The exhaust/cat would of had to have been plugged up better then 75% to cause something like that man? Correct?
You would be amazed at how little blockage it takes to kill power. The cats looked better than User_name's and it hurt the power that badly.
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
I'm not going to assume that when you get this mess cleaned up that your car will run better than it ever has. And just in time for a possible fun event
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,163
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From: Houston
You are making me wonder now. I'm going to dyno it. I'm not going top push this stock shortblock past 720rwhp or so though.
Tech Contributor
Joined: Apr 2007
Posts: 10,924
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From: Forney Texas
If your factory 02 voltages were bouncing around at WOT, you're most likely dealing with misfires or detonation from the back pressure and each can/will cause a lean reading on the wideband.
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,163
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From: Houston
I'm adding the second meth nozzle tomorrow anyway. I can definitely run more than the 12* timing I had at peak tq then, but I will see what the dyno looks like.
Le Mans Master
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From: Houston TX
St. Jude Donor '11
Melting Slicks
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From: NOLA
Burning Brakes
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From: Camarillo/Oxnard CA
Burning Brakes
Joined: Oct 2005
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From: Kauhava, Finland
Is it because engine builders tend to go with rather high compression which indirectly means quite small ignition advance at WOT?
It can't be just because of F/I, since LS9 can live with boost, as well as so many other engines with turbos.