High flow cats on stock car?

[mralbuquerque]

How much hp is there to be had by installing high flow cats on a stock vehicle? Does anyone have any sound clips of just this mod?

 

[RCC]

I can't answer the sound question but I have a set on new in the box random technology cats and a corsa cat back that I bought for my Gen 4 (I believe Gen 3 and 4 are the same) and decided to go another route. PM me if interested.

A few pictures-

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[Canyon707]

I found it ran better with the stock cats and corsa. The noise was was also way to loud with the high flow cats. The power ban seem very flat. I removed them and went back to stock. thats just what I did

 

[mralbuquerque]

Thanks Canyon707, how much louder was your vehicle with the Corsa cat back? I want to gain some power but I don't like my vehicles loouudd.

 

[Hamrhead]

Thanks Canyon707, how much louder was your vehicle with the Corsa cat back? I want to gain some power but I don't like my vehicles loouudd.

You may want to go another route if you don't like 'loud'.

I did Roe H/F Cats and Corsa on my '08 and it definitely is louder and throatier. Screams at WOT!

I did the Corsa on my '06(w/ Stock cats) and it had a nice sound - not loud at all during cruise, but opened up a little at WOT.

Can't help you with power gains - never been to a dyno. Though many have posted that installing just a Corsa really does nothing for power.

 

[slysnake]

I would guess high flow cats would be smellier too, yes?

 

[jknappster]

PM sent......

 

[Canyon707]

Thanks Canyon707, how much louder was your vehicle with the Corsa cat back? I want to gain some power but I don't like my vehicles loouudd.

it's a much improved sound. power wise not sure since i never checked it. It does sound nice. the high flow cats were to much for me sounded like a boat. The Corsa installation is also pretty straight forward. Removal of the cross over exhaust is not that hard either.

 

[VIPER GTSR 91]

How much hp is there to be had by installing high flow cats on a stock vehicle? Does anyone have any sound clips of just this mod?

Very little hp gains but the advantage especially on the Viper is a lot cooler on the side sills, sounds better, and a weight reduction which is always good. You take the chance though of some CEL issues though. Some owners get them and some dont.

 

[bushido]

Very little hp gains but the advantage especially on the Viper is a lot cooler on the side sills, sounds better, and a weight reduction which is always good. You take the chance though of some CEL issues though. Some owners get them and some dont.

What do the stock cats weigh? Thanks.

 

[viperbilliam]

The HF cats will add drone.

 

[purplesnake]

I would guess high flow cats would be smellier too, yes?

After so much consultation with JonB that I thought I would drive him nuts, I went with R/T Metal high flow cats and Corsa catback on my 08, and stayed 2.5 inches to help with drone and maintain low end torque. No smell, screams at WOT. I acatually wish it was a little louder and I am 49! JonB is a good one to talk through the ramifications of all the possible combinations. Good luck.

 

[neo_rambo]

The HF cats will add drone.

I did the Custom high flow cats removed my second cat after o2 **** installed Cobra pack 28" Chambered exhaust mufflers packed and It's loud but not annoying and there is NO drone. Depends on the mufflers that you get I felt a huge difference in power on my 06 plus I don't smell the gas smell I used to with Stock Exhaust. I will capture some video and send you a link.

 

[JonB]

There are TWO substrate options, and 2 bore-options for cats. Cats dont create drone.....the V10 engine does. More FLOW increases the decibels...of the good and the bad sounds. Only CORSA is design-engineered to cancel out the drone coming from the V10. Those who prefer a deeper note, and civilised decibels can choose the bolt-in ceramic substrate at oe size; Those who dont mind more decibels can choose the SHF Metal Honeycomb....and bump to 3" metals if you want LOUDer....Intuitively, you know that less restriction will probably yeild a few HP. But + / - of 1.5% dyno accuracy = about 8hp on Gen 3...and the cats alone claim to make about 10HP. SOunds like it, but hard to prove. Do it for COOLING; Do it for TONE; Do it becasue catless STINKS. JonB ~~~~:

 

[05Commemorative]

Agree with Jon. I have done this on my 05. Only mod was the cats. It sounds better, little deaper tone and slight rumble. 8-10hp is probably right, but hard to tell. Biggest reason to do is cooler (much cooler) inside and lighter. (guess is 10-15lbs lighter on each side.

btw, I did not want loud, so this was the route I was very happy with. Buddy has corsa with same hi-flo cats and way way too loud for my liking.

 

[SilveRT8]

Here is the sound of my 08 when the only mods were Mopar PCM and Roe HF cats with stock mufflers.
It's defenitly louder than stock, no drone and to me it sounds similar to adding a catback to a stock car.

http://s91.photobucket.com/albums/k306/SilveRT8/?action=view&current=HFCats.mp4

Also a pic of the Roe HF Cats vs the stock ones.
I now have Belanger headers with HF cats but still with the stock mufflers wich sounds a bit deeper than HF Cats only, still no drone.

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[purplesnake]

Jon B spelled out the options, but nobody ever talks about what they did specifically: ceramic or metal on the cats; 2.5 or 3.0 on the Corsa, and how it turned out, or why they made the choice they did.

There are TWO substrate options, and 2 bore-options for cats. Cats dont create drone.....the V10 engine does. More FLOW increases the decibels...of the good and the bad sounds. Only CORSA is design-engineered to cancel out the drone coming from the V10. Those who prefer a deeper note, and civilised decibels can choose the bolt-in ceramic substrate at oe size; Those who dont mind more decibels can choose the SHF Metal Honeycomb....and bump to 3" metals if you want LOUDer....Intuitively, you know that less restriction will probably yeild a few HP. But + / - of 1.5% dyno accuracy = about 8hp on Gen 3...and the cats alone claim to make about 10HP. SOunds like it, but hard to prove. Do it for COOLING; Do it for TONE; Do it becasue catless STINKS. JonB ~~~~:

 

[PirateViper]

I got 09 exhaust and Random Tech combo through Jon B on my 06 vert and it sounds great and is so much cooler.When I start it in the garage with the top down while the door is rising it sounds like its gonna detonate......awesome!!!!!!!!!!!!!!!

 

[scottcot]

Random Tech metal on my 04 in 2009. Cabin temp is way down, and I definitely like the sound over the stock. It's louder and angrier.

 

[viperbilliam]

Hmmm.......Purplesnake, you're right I needed to provide more details: At the time, I had the Kooks headers with the metal 3 in cats. No drone when the stock w/crossovers mufflers were in place but the cooling I was looking for wasn't reduced enough. I removed the crossovers utilizing the 08 muffler/tips and the additional power and cooling was significant but the drone was pretty bad. One could say the headers were the cause due to large bore and collector design over the stock. I thought going from the 4 cats to two would be the contributor. Or perhaps it was the combination. SilveRT8, your Viper sounds pretty quiet - sounds good but not loud which is good in my mind. The SRT engineers said the 08+ intake design through the cams have a lot to do with the quieter sound as opposed to the Gen III V10s. My 05 entire exhaust system is identical to the 08+ system but is still louder than the stock 08+.

 

[purplesnake]

Hmmm.......Purplesnake, you're right I needed to provide more details: At the time, I had the Kooks headers with the metal 3 in cats. No drone when the stock w/crossovers mufflers were in place but the cooling I was looking for wasn't reduced enough. I removed the crossovers utilizing the 08 muffler/tips and the additional power and cooling was significant but the drone was pretty bad. One could say the headers were the cause due to large bore and collector design over the stock. I thought going from the 4 cats to two would be the contributor. Or perhaps it was the combination. SilveRT8, your Viper sounds pretty quiet - sounds good but not loud which is good in my mind. The SRT engineers said the 08+ intake design through the cams have a lot to do with the quieter sound as opposed to the Gen III V10s. My 05 entire exhaust system is identical to the 08+ system but is still louder than the stock 08+.

Thanks for sharing. My 05 had chrome tips and had a great sound and I just assumed it had corsa or borla cat backs. When I got the 08, I knew I wanted exhaust and so decided to do H/F cats too, but which way to go? metal n 2.5, metal n 3.0, ceramic n 2.5, or ceramic n 3.0. Kinda wish I had done 3.0. Anyway at the same time, with what I had read about gen 4s throwing codes with upgraded exhaust, I did the Mopar PCM. The car runs great and screams at WOT, but is quieter than the 05, the rest of the time, with whatever it had, and, I lost my decel burble, which I miss.

 

[SilveRT8]

Yes HF cats only on my 08 was probably halfway between stock and the full Belanger set-up, with NO drone.
Nice for a civilised Viper but still screams at WOT
I now have headers with stock mufflers and prefer this slightly louder set-up