Can anyone suggest quality cats that aren’t going to drastically impede performance? Do they even exist? Do “high flow” cats truly help and do they actually work?
Thanks.
This is a good question. To better help you here I have to ask when you say help what help do you want from the cats. What do you want them to do. like do you want them to help quiet the car. Do you have a strong smell on warm up that you want the cats to help with or is there other goals
Remember by there nature cats will be somewhat restrictive as the entire point of the cat is to slow down exhaust gasses to the point where they collect and heat up drasticlly.
Cats what is that ;D Ain’t nobody got time for that!
Yes HFC work. Assuming you do not mind noise I like well flaking exhaust without outs before the HFC, that way you can run without on the track and with on the street. If you do not care no cats is deal that way the tune can be optimized if you want cats then tune for it appropriately. When I had by Subaru u think I went from 3-4 cats down to one HFC, could have gone completely catless but i was ok wth leaving 5-8hp on the table and a well tuned car is fairly well with emissions except on startup and cold if you took out the rest of the emissions equipment like the SAI etc.
This is from Subaru land I assume it’s similar work audis but not sure?
Can’t remember if you have the V1 headers or not, but if you do, you’re welcome to try out my high flow cats since I no longer need them being back in Chicago. If you like them you I’ll sell them to you cheap.
I am pretty sure that Axel has high flow downpipes.
As per my sig, I’m currently catless and the smell is starting to get to me. MDUBZ, I’ll pm you tomorrow. Thanks.
Oh damn, my bad. I’m always on Tapatalk so I don’t see signatures unless I go to the user profile.
Axel if you dont get the cats from mdubz keep in mind that the warmer summer months are almost here. Generally the smell on warm up is just that the car giving itself a little more fuel to run rich to warm up the car faster. That isnt needed as much in the summer. Not saying that will fix the rest of the year just thought it was worth mentioning.
It’s not on start-up that it’s getting annoying. It’s in city traffic. The constant stop and go means that all the exhaust fumes come travelling to the front of the car and with my windows down most of the time (because nice weather), it stinks up the car. I actually can’t smell anything when the car is idling or on the freeway. Just when I stop at a stop sign or a red light with the windows down (which is all the time when living in a big city).
Get one HFC. I still had a faint smell with that but it was much better after going 3-4 to 1
What do you mean “get one”? Wouldn’t that screw up the flow if there’s only one mounted on one side instead of two (one per side)?
hands down…the fastest
?
What’s the “fastest”?
I’m so confused by these cryptic posts lol.
Sure one or two however it makes sense to flow back evenly
He was joking because your title is which cats are best. Since cheetahs are the fastest cats, he says they’re the best.
Last year I added a pair of 100cell catalytic converters to a JHM v1 header setup that previously was non-cat. I really don’t notice any smell except for maybe cold start-ups. I haven’t performed any before and after tests, but I cannot tell a performance difference.
You’ll certainly want at least 1 per down pipe, so 2 total. Anything that’s 200cell or less you probably won’t notice much if any performance difference. I’m certainly no expert though.
These is the specific ones I used: http://mandrelbendingsolutions.com/mbs-4-100cell-cpsi-high-flow-converter/
jambalaya
Doh! I had forgotten that I named the thread as such. Thanks 
Cool, good to know. Thanks for chiming in.