as much as i dont want to CATS THREAD!

[Crazy Blu]

ok i like in the DFW texas area and cops in my town for sure are cutting down on cats big time... I have longtubes and ORY and i really really dont wanna put cats back on but dodging emission check points just to get on the HIGHWAY sucks big time... so today i went and gotta qoute on two high flow cats and im just going to have my y pipe split so i can put to of them then my exhaust... i just want some opinions i know NO CATS is better obviously but its getting ridiculous around here...

i have also thought of going back to shorties and some bad^ss highflow cats just to be safe... thanks for your time guys!

see you are SAR in FEB

[CHEVROLADE]

shouldnt be too bad since there high flow cats....

[lechez71]

or just get the dummy cats. there hollow inside.

[decibles]

actually factory ls truck cats will flow everybit as much as aftermarket high flow cats. The one thing you need to remember about a cat is that if the pipe isn't straight leading into and away from it even the best cat is restrictive. I would take factory cats and if the you are running larger diameter exaust just cut the cat where it bells out at the same diameter as your pipes. believe me I have seen them on a flow bench produce higher rates than any aftermarket high flow I have tested.
Just remember the most important factor is to locate them as far from any bends as possible a minimum of ten inches of straight is recommended

[Frenchy]

Here we have to do emissions checks tailpipe, obd2 and visual. So the best we can find that still works as a cat without being a total restriction is the Magnaflow 50000 series.

[decibles]

I have installed magnaflow cats and I am curious how you are able to maintain obdII emision compliance, if as you are saying it is being checked magnaflow will not pass the OBDII required twc tests which happen every run cycle which the engine reaches 165 degrees. I suspect either they are only looking for dtc's and you have a tune that has eliminated many obdII tests or that they only want to see the components and verify it isn't producing high hydrocarbons and co's since the magnaflow cat doesn't eliminate enough nox to be meeting standards.

Can anyone provide info to show the restriction of the factory cats, compared to high flow cats? I know we took a set of 02 denali cats cut the flanges off and welded them to 3 1/2 pipes and the pressure drop across the cat throughout the entire rpm range at full load was under a half inch of water column which would be less restrictive than a single 90 degree mandrell bend in the same pipe.

This is probably useless information to everyone I just figured it might help if everyone is aware that the the factory ls truck cats can produce much higher flows with a few mods and you still maintain 100 percent functionality. However if they are not in good working order any cat will become a huge restriction.

[Crazy Blu]

thanks thought long and hard and just think im stickin with no cats... unless of course i find a deal on my gears and posi... then maybe ill go ahead and get those cats...