RPM WS6

iTrader: (3)

No LT has a CARB number, so if you face a visual test that is done by the book, you will fail no matter if you add cats or not. Obviously, this is state/test center dependant though, I agree.

Even that quoted source showed a small decrease in power/torque. Cats cost additional money, plus welding fees if you want to add them to an ORY. You are paying extra money for less gains no matter how you slice it.

Again, if you need them for your state inspection then I understand.

For a street car, this would be too loud in most cases. Most people already have some sort of muffler when they add LTs and an ORY, so the muffler is already paid for, adding cats would just be an additional expense with no gains. If you have something that's basically mufflerless (like a Loudmouth, etc.), then cats might be a worthwhile option for volume control if you don't want to change the catback arrangement.

Midnight02

iTrader: (8)

No cats on my car and I love it. I don't have any regrets however it is worth noting that it makes the annual emissions inspection a little dicey. It's always a headache trying to find a station with a blind inspector!

BlackScreaminMachine

iTrader: (17)

I have never said LT's come with CARB #'s and CARB only means something in California. No other state cares if the modification comes with that number. Connecticut has VERY strict emission requirements and we do not even get close to having to showing CARB #'s

What the link showed was how much technology has progressed and no matter how you slice it if it showed no decrease in power it would be not as good as running no cats at all. We are no longer in the 80's and thats the point.

What the OP was striving for was a "Balance" and asking for both sides.

I have run both with equal enjoyment and dealings with Police and Neighbors. In these cases there are Catted Y's that include dual electric cut outs before the CATS and you truely gain a balance. Not to give much credit but PewterScreaminMach ran that and saw decent gains but was able to open it up when needed.

You can approach the subject in many different ways and mod a car infinite amount of combinations but in the end the owner who pays the $$$ will determine what they want.

Black98T/A

iTrader: (5)

Well I just bought the tsp y & just spent $30 to weld the leaks where the clamps weren't working so I really don't want to change that I'd change the catback though..I just hate the way this thing sounds

RPM WS6

iTrader: (3)

That may be true, and I was never debating that. My comments to you began based on the following statement:

My point was that there is a good arguement to be made for NOT getting cats when you install headers, assuming emissions are not an issue for the person in question. Cats are necessary only for emissions purposes, if you have a way around that in your subjective area, then they offer no other exclusive benefit.

I think we can agree on the following (as any reasonable person should be able to):

- Cats do not increase power
- Cats cost more money than an ORY

...so you are spending extra money to gain no additional performace of any kind, and in fact losing a bit of performance (albeit small).

The only advantages I can see to cats are the following:

- Volume reduction (might or might not be an advtanage, depending on opinion)
- Emissions compliance

....as far as the first point, there are other ways to reduce volume/rasp that are cheaper than cats (bullet mufflers are $40 each, if you feel your catback isn't quiet enough). I know there are cheap cats on the market too, but they tend to not last long (especially behind a modified engine). So once again, you are left with the only exclusive benefit of cats being emissions compliance. That is the only factor where cats are exclusively advantageous, and even that factor is lost if you have to pass a strict visual inspection and they are not in the stock location (which they never are with LTs). This may not be a problem in your state, but not everyone lives in CT.

BlackScreaminMachine

iTrader: (17)

The fact is that having the quickest and easiest route to exit the exhaust will be the most optimal for max effort power. I will never disagree with that and having CATS will always to a degree add a restriction.

But in the real world, there is a balance and in the end, when it comes down to a timeslip or a dyno sheet it can be said that "there is still more in it".

I see your point of "Well if its not going to strict emission legal, then might as well go all the way" and to a point I agree but in the end I have seen guys take my set up and on a bolt on/cam only combination not show that much of a difference to make it worth while for the noise/attention. Especially when you get into stainless steel exhaust like a Corsa/Borla or even a LM1.

Will say there are good points both ways but the owner needs to decide if they can deal with the head aches.

I think the OP will have plenty to work with.

sleepy_z

iTrader: (8)

Will there be more or less heat coming out the exhaust if the cats are removed?

BlackScreaminMachine

iTrader: (17)

Willing to wager that it is cooler w/o due to there being no restriction. The point of CATs is to get super heated and burn/scrub off harmful emissions so I see no reason why it would be cooler.