Advice on High Flow Cats

[Don]

As much as I would like to remove the cats, I have to be capable of passing emissions. Does anyone have any recommendations. The louder the better!

 

[AJT]

Random Techs Metal Substrate cats from Jon at Partsrack!

Sound more like you thought a viper should!

my .02
Andy

 

[ViperJoe]

Really no need for the metal substrates (they're almost twice the price) unless you are going with a power adder.

For tubes and filters, a cat-back and even headers, JonB says RT stainless high-flows will work fine.

 

[ViperRay]

I got the RT stainless high flows from JonB. Great sound (improved further on my Borla Cat-backs). Can't speak to emissions though. You might want to do a search on this as I believe some people have had some problems in that area.

 

[GTS Bruce]

I'd go with the highest flow if I had to go with cats.You never know what mods the Viper monkey on your back might provoke you to do in the future.No sense in having to do it twice. Bruce

 

[Don]

How do the Random Techs compare to the ones Roe Racing sell? Anyone have any experience with these?

 

[sbkim]

Is it possible that high flow cats can go bad after extended usage? ie., inability to flow and or passing emissions? I am thinking about buying a used one but don't want to deal with hassle of "uninstalling" if something is not ok. Any obvious signs that it's bad?

thanks

 

[garolittle]

Random Techs Metal Substrate cats from Jon at Partsrack!

Yes! I agree.

 

[Casey]

Call Sean Roe, he can give you all the details on his 3" cats. I have them on my GTS.

 

[Yves]

Do a search on my name. I posted something in November how I dealt with this issue.
Basically I installed 3 bolt flanges and made an interchangeable system.
I live in Europe now and also have annual inspections. It takes me 1 hour to change the exhaust system and go from drone to whisper.

 

[ViperJoe]

There have been a few posts on the SR high flow oval cats having to be turned just a certain way for the sill covers to go on.

Random Technology is a leader in cat technology.

http://www.randomtechnology.com/

From my observations, most folks here go with RT

Good luck!

 

[RT/ED]

I have the Roe Racing HF round cats and 3" stainless side exhaust. Unbelievable sound improvement, much louder and absolutely no side sill or footwell heat problems. Give Sean a call!

 

[jimandela]

i had the RT substrate cats and they were loud.
they also came with a certificate saying 50 state emisssion legal.
not sure how.. but they say they did....
it seemed like not having cats at all backfires and everything....
sounded just like a racecar.... SWEET!!!!

really p!ssed off the neighbors....

 

[Jerry Scott[CO]]

The stock cats can be easily modified by cutting off the ends of the tapered pipe and opening them to 3 in. diameter, then rewelding to your aftermarket 3 in. pipe. They are a little less noisy than the aftermarket cats and have the internal element designed for the volume of the V10. They are also made of magnetic stainless.

 

[JonB]

Our VIPER SPECIFIC cats are round, for easy fit, stainless bodies, with twin heat shields. 1 faces body. 1 faces sill. 3" in/out, Viper-specific build, not 'universals' with flat sides, oval bodies and 1 heat shield. {intended for a truck) We have 2.5" slip-fit redecers if needed, at cost ($10)

Ceramics flow 439CFM, Honeycomb Metals 528 CFM. 5-year warrantee in writing, and 50-state legal. We have sold HUNDREDS of these, and Doug Levin MOtorsports uses and sears by them, as well as Dan Cragin, CORSA, and many others.

Of all we sold, 2 singles failed emissions in 2-3 years, and were replaced free.
Not as cheap as some, but better than all others. Huge positive referecnce base... Don-t go STINKY-RATTY catless, and risk CE Lites.

THANKS for your inquiry.......

 

[JonB]

Is it possible that high flow cats can go bad after extended usage? ie., inability to flow and or passing emissions? I am thinking about buying a used one but don't want to deal with hassle of "uninstalling" if something is not ok. Any obvious signs that it's bad?

Even if they LOOK GOOD you cannot test the "wash" of metals, including platinum, that coats the substrate. A cat can actually go bad and ruined in 100 miles of rich-running operation if a sticking injector, bad coil, bad wire, bad plug, oil leak, etc etc fouls it and clogs and overheats it. Thats why you should not use SIMS that say "all is OK" when it might not be !!!

There is no way in heck Id consider used cats (without a warranty from someone you trust,) when new ones are under $300 a pair .

 

[dwhitt]

Jon:

What is the flow on the stock Viper cats for a comparison? Are the ceramic high flow cats good enough to handle a mild blower application (e.g. 5 psi of boost - say 530 to 550 hp at wheels)?

 

[garolittle]

Gentlemen. Call Jon B. and order the Random Techs. You will not find a better price or a better vendor. Do not waste your time with flat-sided cats that you have to "tilt" or "slant" just to create a fit. Jon does not sell such products and you should not buy them. You know what they say ...."If it does not fit on a Viper, then Parts Rack does not sell it."

 

[JonB]

Garolittle, many thanks for the kind words.... JonB

To clarify something: The rare but occasional "Rust" rumors concerning Random Tech cats are just WRONG....here's why: All RT cat bodies are stainless, regardless of the ceramic or metal-honeycomb substrate inside.

The metals run so cool, that they need no heat shields.

Stainless is a POOR heat shield. Terrible. Alumanized steel is a great shield.

So, on our Stainless/Ceramic cats we use dual alumanized heat shields, 1 facing the body, and 1 facing the sill. Keeps em COOL! When the sills are off, these heat shields can show some rust, exacerbated by the cat heat behind them, and the water that gets inside washed/rained-on sills. The cats and even the welded-on shields are warranteed for 5 years, and IF they would ever have a problem, RT will replace them. But seeing a 'rusty' RT cat is misleading.
Thanks for reading and sharing

 

[JonB]

Jon: What is the flow on the stock Viper cats for a comparison? Are the ceramic high flow cats good enough to handle a mild blower application (e.g. 5 psi of boost - say 530 to 550 hp at wheels)?

Hi Dave !

Back in Gen 1 we tested a cat in the low 300s.... I recall 330 CFM.

For many years, ONLY the Ceramic was available, and RT handled a lot of blower applications for years. One well known Mustanger told me "I never saw a blower blow out a Random cat" Doug Levin used RT ceramics for many years, until the metals debuted (at PartsRack, Thanks) in mid 2001. We never saw a failure of a blown out RT cat in any DLM car.

Bottom line, Ceramics are a good choice for "Stage One" type boosted cars, even up to 600+HP....

 

[MannyC]

What about S/C'd Gen 2 cars with near 900 RWHP? Any cats that can handle that? I hear they will burn out.

And when they burn out, what happens exactly? Do you just lose some HP or is more drastic than that?