Need Advise on Cats

[Aurora40]

My impression is the metal matrix cats flow better than traditional ceramic ones? I'd guess they aren't as efficient though, or manufacturers would be using them instead of ceramic ones.

Mine do not have any heat-shielding. They are slip-fit on the headers and flanged to the exhaust. Marc H. did the work.

I don't know how they fair in VA's emissions test as I have not yet had to go with this configuration. Will you be retaining AIR and EGR?

[Jagdpanzer]

Originally Posted by Aurora40

Will you be retaining AIR and EGR?

The SW headers I have do not have the air tubes installed so I guess I will have to do the same thing most others have done, reduce the weight of the car.

[Hammer]

I think I read about these here before. Anyone tried them?
http://www.performance-curve.com/ind...OD&ProdID=1181

[Nick]

Originally Posted by Hammer

I think I read about these here before. Anyone tried them?
http://www.performance-curve.com/ind...OD&ProdID=1181

Never seen those before, John, but the price is right!

Originally Posted by Hammer

I think I read about these here before. Anyone tried them?
http://www.performance-curve.com/ind...OD&ProdID=1181

I bought a set but have not installed them yet. I'll comment when I get them on, but will won't be this month. I hope it's not get what you pay for, but I'm on a tight budget so oh well.

[Hammer]

Originally Posted by HAWAIIZR1

I bought a set but have not installed them yet. I'll comment when I get them on, but will won't be this month. I hope it's not get what you pay for, but I'm on a tight budget so oh well.

Craig,

I look forward to hearing about these. Great cost savings if they work.

Thanks

[guinnessdood]

Originally Posted by Aurora40

My impression is the metal matrix cats flow better than traditional ceramic ones? I'd guess they aren't as efficient though, or manufacturers would be using them instead of ceramic ones.

Mine do not have any heat-shielding. They are slip-fit on the headers and flanged to the exhaust. Marc H. did the work.

I don't know how they fair in VA's emissions test as I have not yet had to go with this configuration. Will you be retaining AIR and EGR?

I would say the manufacturers use ceramic because they are cheaper...

Here's a word of experience about ceramic substrate cats...I had them in my car...notice the key word...HAD. My PROM (a Z-Industries PROM) was installed at the same time that I installed the headers/cats/Corsa. After about 2 weeks...i was driving the car at lunch time (driving on the base...so no hot rodding) and one of the cats caught on fire. I was able to put the fire out with minimal damage to the car. When we put the car up on the lift and removed the flanges from the headers...we could see that the ceramic substrate had completely melted in both cats and shelled out the cats. The cats were completely destroyed. I sent the PROM to Corey henderson and he analyzed it and said it was no wonder the cats caught fire considering how rich my PROM was allowing my car to run. He recalibrated my PROM with the same settings as Ron Hanselmans (or really close to that)...I replaced the cats with 3" I/O Random Tech metallic substrate cats and have not had a problem since. That was 3 years ago. So...buy metallic substrate cats...AND get a PROM from someone who knows the LT5 intimately.

My cats have custom heat shields and the exhaust installation was done by a true meticulous professional. Very nice work...but he lives here in Utah...

[Hammer]

Uly,

The description on the website is below. Wondering how they might compare with yours. The description says metallic, that why I was inquiring about them.

Thunderbolt cat's are designed to give high performance in limited spaces. This high flow converter features a Metallic brick with 300 holes per square inch. This 100% EPA legal OBDII catalytic converter is designed for engine's up to 5.9L / 6000 lbs. (Not for use in California)

Part # - 415300
Length - 11"
Body - 4" Round
Inlet - 3"
Outlet - 3"
Brick Type - Metallic
Material - 409 Stainless Steel

[Aurora40]

Hey Uly, I'm not sure that's a failing of the cat? The better the cat is, the more heat it will generate. That's what they do, turn excess fuel into heat. I would guess your "tune" was extremely rich, right?

I don't think a metal-based honeycomb matrix would be less likely to melt than a ceramic one, though. And OEM cats are not cheap. If there was something that worked better and allowed new cars to make more power while meeting the strict emissions requirements, you can bet they'd jump on it. On our cars, new car emissions regs are irrelevant. So more power is enough from metallic substrate cats.

RT's website describes metal matrix cats as such:

Random Technololgy also offers metal matrix catalytic converters designed for maximum flow capacity. These high flow converters are designed specifically for use in sanctioned race classes that require the use of catalytic converters.

[guinnessdood]

All I'm saying is that the combination of the ceramic and lousy PROM were not good...I also believe that the metallic cats will "flow" better..based on what RT uses...why would they use metal if ceramic flowed better? They wouldn't. I'm not really too sure why car manufacturers use ceramic or even if they are ALL still using ceramic as their substrate of choice...anyone know if the new ZR1 uses ceramic or metallic substrate cats?

I know there are other cheaper cats that seem to be quite similar to the RTs and I have seen some folks on here say they used them and they worked fine. I would say that they are very similar to the RT cats (the Thunderbolts), but I have no experience with them. I definitely like the price better than the RT cats! I bought mine from Martel Brothers if I recall. What the hell...if you're in need of some cats...for the price I'd try them...if they suck...you're not really out much...and if they work good...WOOHOO!!!