Mid-length headers + cat?

[07silvergt]

I've been looking around the Web and it seems that for s197 there are only shorty headers or Full-length headers available. The consensus seems to be that shorties give little to no power upgrade, while Full-length has clearance issues and difficult to run cats. Why does no one make a combo with Mid-length and high flow cats? Would that not make more power than shorties, without the clearance issues of long tubes, while still being emissions-legal?
Also, why doesn't someone make an oval-shaped, flatter collector on long-tubes to improve the clearance issues?

 

[stkjock]

https://www.americanmuscle.com/kooks-header-catted-xpipe-0509manual.html

Kooks are a mid length compared to others

 

[sman247]

I personally went through 2 sets of kooks cats until I decided to go off road setup. I've heard they are prone to failure. Love my off road setup.

 

[07silvergt]

I looked into that just now. Looks like a good product. I like the sound of H-pipes better but it seems to more money for that combo for some reason. In any case, how's the clearance for those that have it? My car is lowered on eibach pro-kit and I already scrape on some things.

 

[RocketcarX]

Our cars don't tend to have ground clearance issues with long tubes, they tuck up into the sub frame nicely. They are def worth the effort to install.

 

[travelers]

My '07 GT had ARH and had no clearance problems.

 

[sman247]

No clearance issues here with kooks. Pypes are made to mimic kooks so I can't imagine they do either. Lowered 1.0" in front 1.5" in back

 

[ghunt81]

I've never heard of clearance issues or difficulty running cats. My JBA's are inside the frame rails and the cats don't hang down any lower than any other part of the exhaust.

The only time my JBA's ever touched the ground was the one time I drove out my street and found out they'd stripped the asphalt off the connecting street...and there was a 2" dropoff at the end of the street Didn't even hurt the headers.

 

[Dino Dino Bambino]

I've been looking around the Web and it seems that for s197 there are only shorty headers or Full-length headers available. The consensus seems to be that shorties give little to no power upgrade, while Full-length has clearance issues and difficult to run cats. Why does no one make a combo with Mid-length and high flow cats? Would that not make more power than shorties, without the clearance issues of long tubes, while still being emissions-legal?
Also, why doesn't someone make an oval-shaped, flatter collector on long-tubes to improve the clearance issues?

AFAIK, none of the full length headers have clearance issues. The main issue with these is that the cats and O2 sensors have to be placed a long way downstream in front of the crossover. As a result, they take longer to warm up (especially on cold winter days) and that can cause cold start driveability issues unless the tune is modified to keep the ECU in open loop for a slightly longer time.
Kooks and their copies (Pypes) are considered as 3/4 length headers, are "tuner friendly", and yield similar power gains as the full length headers.

 

[1950StangJump$]

I've got ceramic coated Kooks long tubes and high flow cats. The PO had them installed by a speed shop, and they sound great.

However, they definitely hang lower than stock. It has only been an issue once, when I dragged the cats over a speedbump when not paying attention. I suspect Kooks has probably updated the design since these were made (2009), but don't know for sure.

 

[07silvergt]

Ok good know. I'm of the mind that when something breaks to replace it with something better. My bank 2 cat is throwing a code for low-efficiency. Not super surprising since I've put 307000 miles on the car and my passenger side cat has a weld seam that is cracked so I'm thinking a set of headers and catted h-pipe could be an upcoming upgrade. Anyone else besides sman247 have issues with kooks cats?

 

[sman247]

I also had the kooks cats way back when so they may be a different design now. I would just get off road now cause it's cheaper and you can always add resonators if you wanna quiet it down

 

[beefcake]

kooks has great clearance, we are running them on our current car, fitment is always spot on

 

[travelers]

kooks has great clearance, we are running them on our current car, fitment is always spot on

Glad to see you guys chime in with some good info. I had the pleasure of chatting with you guys at the NMRA race at the Grove.