I give up... A few simple questions for High Flow Cat Owners

[Ron]

I've tried every idea I could think up to lower side sill temps, such as improved insulation, enhanced airflow, etc. All improved the situation but nothing really helped the dreaded "shut down" heat rise.

While I'm sure the really high tech insulation would work, I can't swing a $4k solution. Bottom line, while I fought it all the way, I now think High Flow Cats are probably the most economical heat solution. I'm currently stock and looking for 2.5" cats but it would be nice to get 3" with reducers for later upgrading. Do not want significantly increased decibel level and heat reduction is the primary reason for upgrading rather than increased flow. Cat removal is not an option as I do want to be able to pass emissions testing and the sound level would be unbearable.

There seem to be 5 Viper Cat options out there, 4 round and one oval, with prices of 239, 269, 289, 325 and 529. While I've done the searches, my selection process would be greatly helped if some current Hi Flo owners could comment on the few questions below:

<ul type="square"> Which ones did you buy?

Did your cat selection really lower sill temps in all driving modes including post shutdown? (any post install sill temp readings?)

Assuming you did no other exhaust work during cat install, how much louder did the High Flows make your exhaust?

How "exact replacement" were they, i.e. cut the old off and weld the new in, or was there a bunch of fabrication required?

Any downside and would you do it again?
[/list]

Thanks for your comments...

 

[BADVENOM]

I went with borla cat back rear exhaust with high flow cats all from sean roe. Installation did not require welding. Sound was much louder although I like the sound. At least my viper sounds like one and not like a UPS truck.LOL

Adam

 

[Snake Bitten]

So said Ron

Cat removal is not an option as I do want to be able to pass emissions testing and the sound level would be unbearable.

Thanks for your comments...

Uhm...I think you'd be totally surprised...especially at the sound level...One of our guys recently removed the cats, from a totally stock 2001 ACR...just the cats...Sound level was only barely increased, and the 2001 ACR picked up 16 rwhp...Get a muffler shop to "flange" them so you can put them back whenever you want to pass an emmission test...

 

[Will]

I went with 3" Random Tech high flow cats (purchased from Jon B. and installed by Apex Motorsports). I purchased them in conjunction with a CORSA exhaust. Side sills are MUCH cooler and the sound is great!

 

[KenH]

I also went with the Random Tech cats from PartsRack. I already had the Corsa 3" catback and when I added the 3" HF ceramic cats, the sound level went up significantly and had a raspier quality to it. They do seem to lower the side sill temps some, though mine generally never really got all that hot to begin with.

--- Ken

 

[jimandela]

Ron,
I went the expensive way the Random tech substrate $500 cats and i love them!
the sidesills only get lukewarm NOT hot!!!
but with my 3 inch B&amp;B catback the car is louder, going back to stock exhaust will make the car louder
I would guess...

The Randomtechs did come with reducers so you can have 3 inch cats that you can grow into.

For lower sill temps I see no better, cheaper solution.
good luck
Jim

 

[Jim Wilson]

Ron,
I put RT high flow cats on after installing a Corsa Cat-back, and the addition of the cats made a significant increase in sound (I have a sound level meter and can give you decible readings if you like). At first I thought it was a bit loud, but I really like now. As far as heat reduction goes, I'm not sure how much cooler the side sills are but I think that it did help decrease the heat a bit. Installation is a breeze, just cut off the old and weld on the new. I have not ran it through emmissions yet so I don't know how well/if they pass.

btw, how is that Nusbaum lift working out for you? I think I might buy one.

Jim

 

[Ron]

Thanks all for the input. Sound like heat is subjective and so far there seems to be a bit of a mixed message. Regardless, thank you and please keep the comments coming.

Jim,

The Nusbaum is working out great. The best garage item I've bought beyond the Viper itself. I have a pdf of the owners and installation manual if you'd like a copy plus remember I have a VCA discounted price that I can share.

Send me an e-mail if you want more.

 

[AJT]

Ron, I have 3" Corsa cat back &amp; Random Tech ceramic substrate cats from Jon @ Parts rack. They reduced the heat a lot on my RT. They used to be scorching hot after a afternoon ride, now you can lay your hand on them after a trip around hot Houston. The sound got louder (popping) on decelaration, &amp; a little louder on hard acceleration. If your not getting on it, they are not much louder.

Best addition I made to my car. Now my wife does not burn her leg getting out.

Andy

 

[Docta Vipa]

I also installed the ceramic Random Tech high-flow cats, and the Corsa exhaust, about six weeks ago. I was really surprised at just how loud the exhaust is now. I must had the door open the first time I started up the car, because I really jumped when I first heard the sound. I don't mind the sound personally, but I am concerned as to what the neighbors think (a little concerned) and I got busted at Laguna Seca even after letting up significantly on the throttle going past the sound check booth (a 90 db day). Letting off almost 100% succesfully kept me below 90 but the line of cars behind me every time I went past the booth got pretty old kind of quickly.
Personally, I like the sound, especially at the track. I even like the increased popping when I back off the throttle.
Any ideas on how I can quiet it a bit??

 

[NCVCA]

I just installed metallic Random Tech cats (the expensive ones) and immediately went to the track.

Floorboard which was previously very hot was cool. They definately cured my heat issue not only at the sills, but in the floorboard as well.

 

[ViperJoe]

Adam, your setup required NO welding of the cats??

ANYONE with hi-flows and STOCK exhaust??


Thanks