Are high flow cats really pointless?
 

I got my solo high flows installed today with my borla atak (LOVE the sound) but the guy who installed it was telling me that most people dont run cats and they I "wouldent pick up any power gains" with the solo high flows. Is this true? Is there any power difference or gains by adding the high flows or would I get more HP if I deleted the cats? I just want them so I can pass emissions and so the car doesn't smell like rotten eggs lol. Any info would be appreciated!

Why would it smell like rotten eggs?

You'll gain a Lil bit, Lt's are the way to go I your looking for powa!

Definitely more gain from a delete but cats are the most restrictive part of your exhaust so any gain in flow through them will gain you more power.

Stop taking advice from that guy. He is pretty much completely wrong on all counts. With modern high flow cats there is essentially no performance advantage to a cat delete. They flow 99.9% as well as straight pipe. On a dyno you might see 1-3 rwhp in the mid RPM range. Going with a cat delete does cost less but the biggest draw back for street driven cars in my opinion is the smell of running without cats. Others are the potential legal issues and the inability to pass emissions testing and inspections. For track cars none of these are a concern so save the money and apply it elsewhere but if your car is used primarily on the street high flow cats are probably your best bet.

Cats filter out all the unburnt fuel oils/nasty smells I thought

Yeah I figured that lol. Thanks man. I think he was just trying to talk up his header/tune/full exhaust system. I didnt buy the cats from him

Some say they smell the unspent fuel others say that their eyes start crying but I think their cars are tuned kinda rich. I've gotten rid of my cats all the time and never experienced this. On my 4th gen I have lots of over lap but my kids n wife love it anyways. Why? Because RACECAR lol.

i wouldnt call it rotten egg smell id call it more of a fuel smell....but it does bother some people. I get it until my cats are warmed up.

I have cats on mine. I mean, if they flow just as good, why not have a cleaner exhaust so you're not killing the guy behind you and drawing a lot of negative attention. I'm no Al Gore nutswinger, believe me. But I just figure why not make good power and run clean too? I feel better about having the cats.

In my experience Apex Chase is right high flow cats and cat delete is not really work the hassle or power. They have come so far in technology that unless you cant afford the extra cost at the moment get the high-flows for the street. Another thing to note I have heard (never tested) some people running high-flows that have been gutted tend to hurt performance as they cause and slow down in velocity and tend to act like a restriction.

Now I do seem to find the smell without cats is more of a fuel smell (think about the smell at the drag-strip), and the smell with cats is more of the rotten egg smell but thats mainly running richer A/F.

You will pick minimal hp gains by deleting cats. No rotten egg smell, but a heavy fuel smell until she warms up, after that no smell. I got rid of my cats due to boost. Cats and boost no bueno. Think I've heard that somewhere around here before. Lol
Cat delete is free where a high flow cat can be expensive, I do not support paying for high flow cats

yeah the smell of no cats is a nuisance, one of the reason i'm actually looking to buy some 200-cell high flow cats from MBS and have them welded in, lol... my g/f says the car gives her a headache at red lights, and it is a strong smell, even I have to agree

I agree, my car without cats doesn't smell like rotten eggs, it smells like high octane Bad@ssness emitted through a natural speaker producing "Muscle Car Music" :headbang:

Also, when sitting at red lights I dont smell the exhaust at all. Not until I get behind my car, then I smell a faint scent of Burnt gas is all

Damn straight!!!