Removal of CATS

[TOPGON]

I understand removing the CATS will reduce the sill heat. I am concerned about exhaust harmonic drone as I have had that problems after modifying other exhaust systems and it was horrible. My only objective is to reduce heat and limit added noise if I get more HP that is of course a good thing. What is my best alternative?

 

[SRTRICKY]

Get some RT Hi-Flow cats! Do a corsa track exhaust and you can touch the side sills no problem even on a hot day!

 

[LW VIPER]

Get some RT Hi-Flow cats! Do a corsa track exhaust and you can touch the side sills no problem even on a hot day!

But what about sound? I did a cat delete in my former 96, and it became much too loud for my taste. I would love to go with hi-flow cats, but I also like the car quiet. Can those two concepts work together, and if so, how?

 

[TOPGON]

LW you nailed it is there such a solution??

 

[SRTRICKY]

If you keep the rpm's low the car is not that loud! Once you get on it thats when it gets really loud! If not do a secondary cat delete and do the Corsa exhaust! The sound doesn't change much with the seconary cat gone.

 

[Sellshomesdrivesviper]

If there is a solution, I'd wanted hear it as well.
The only thing hotter than the side sills/exhaust is my date.

 

[Herc]

Went with the Corsa Track and the RT cats, got rid of the heat prob but too
loud and too much drone. Added CCI 3 disk inserts from Summit Racing, cut
the noise down nicely. Good rumble at idle, fairly quite at cruise with no
drone and loud when you want it to be.

Herc

 

[viperkraz]

Call Velocity Performance at 9723899877. They have done several ex. systems on SRT10s. They can build or order anything you want, plus they are right down the road.

 

[TOPGON]

Will do THX

 

[AllBlack]

Hollow em out... it's what I did and it's a lot cheaper and easier.

 

[Racer Robbie]

what about emmissions, will it pass inspections with the secondary cat hollowed out

 

[SRTRICKY]

I'm pretty sure it will...the secondary cat is a high flow cat anyways! Hollowing it out will not help that much! Theres a chance of it just leading to problems. (Info from Chuck Tator when I was considering this route!)

 

[Skip White]

I just sold a load of scrap cats, to a recycler, and I showed him the Viper sec. cats, and to my surprise, he said they are not really a cat at all. He said the substrate material, was nothing more than a wire grid, and has zero platinum or paladium in them. I was hoping they had regular cat material in them, as catalytic converters are at the world record high. I was paid $60.00 each for the GM style cats, and this is a scrap metal value. I'm sure they will be making a good mark up at that price.

This tells me the so called sec. cat is no more than a back pressure device to help heat up the primary cats. It does act as a silencer I suppose.

No one has really ever explained the sec. cats function, but it by no means has material in it as a primary cat does, so it's not a catalitic converter. Non the less, they appear to be very restrictive. Sure would like to know more about this.

 

[slither]

Yeah the secondaries are only there to help reduce emissions during start-up, once the exhaust system is hot and the primaries become efficient they do nothing more than block the exhaust flow some (and probably muffle the sound a little). No O2 sensors downstream of the secondaries so the cars diagnostics system will never know if they are gone. To me paying for installation of "hi-flow" secondaries is a waste of $$. Gut them if you want or cut them out (although of course I would never recommend or do this - he he he).

 

[Viper X]

Been down this road. Tried almost everything. I too like a relatively quiet car but still want the power. I settled on the full 3-inch B&B system, high flow cats and the B&B step headers. Some people will say it's too quiet at idle or low rpm and it's pretty quiet. At wot throttle, you know there's some serious power under the hood. I like the sound.

Best advice, consider where you want to end up sound wise and power wise. I spent a bunch of money on changes that didn't work out and got to do it over and over again. Tried Corsa tracks, they were great until I added headers, then too loud with a serious drone. Tried cones to quiet them down, no significant change. Tried different mufflers, no change. Put the stock crossover back in, quieter but lost hp.

Try the B&B. I'd be surprised if you don't like it. Ride in few Vipers with various exhausts - this is probably the best way to get what you want. Too loud for some may be just right for others.

 

[slither]

Hey Viper X, good post I hate doing things twice. I've had my "fun" doing all different types of work on my last car, so on this one I want to do the minimum mods to get the maximum HP - and keep it streetworthy. It's fairly easy to get some big HP - keeping it driveable and reliable with a large HP increase is the hard part. The B&B is a really nice system, but big $$ for 30 or 40 HP. I've got a Paxton on my mind, any problems with it so far?

 

[slither]

Oh yeah, TOPGON - use this stuff to remove sill heat:

http://www.thermotec.com/products/full/11031/11031.html

Wrap your stock or aftermarket system with it and you won't have any sill heat problems at all. I put on a Mopar system and wrapped the mufflers and piping with it last weekend, the sill heat is a non-issue with this stuff.