[TEST DRyVer]

Ok, so next step is headers. The more I research and learn, the further behind I feel. Any help or experience would be greatly appreciated. I have a 17 ZL1 6mt with an AWE Touring catback exhaust (non resonated), Rotofab intake, and TM ported throttle body (which I just bought from a member here, but have yet to install). I am shopping headers. My car is a daily street build. I might consider pulleys, flex fuel or ported blower next.
CSP 2" headers were first on my list because they seemed to have worked out all the clearance issues, but they do not offer cats. Cats are a must since it's just a street build and do not want to hear my wife complain about gas fumes (as she's done in a few other cars), plus I'm not looking to have straight pipes for excessive sound. So I've narrowed it down to a 1 7/8th's headers with cats. I keep hearing Kooks, but I've had a shop tell me they will not install Kooks high flow headers unless I buy Green Cats. CSP told me they wouldn't even sell me catted Kooks for a ZL1unless I buy Green Cats. The going price is about $2100 just for Kooks headers & Green Cats alone. I would like an alternative that would be effective, yet cost less and allow room (financially) for a catch can and a spark plugs. Please correct me if I'm wrong since I'm more familiar with modding German cars. Are the long tube headers not all fairly similar (as far as brands)? It seems the biggest difference is getting an effective cat that will not fall apart for our boosted cars. In a perfect world, I'd like to find headers with an effective cat, add a catch can and spark plugs for $2k max. Of course my $2k budget does not include install and dyno tune. I found a shop for the install and tune (Cordes Performance Racing in Phoenix). I'm familiar with the brands but not experienced enough with fitment, quality, effectiveness, etc... I just want a quality piece with effective cats for a reasonable price point. Please advise...

[SS 376]

I've not seen Kooks headers with green cats for anything less than $2100. I don't know that I've seen any brand of headers with cats for less than $1700 but don't quote me.

Considering you'll want to tune the car after Cordes installs them (which is more money), I don't see an easy way to do this for less than $2000. Maybe do the pulley or ported blower first and kick the can down the road a bit?

[L78toLT1]

I'm a boosted SS guy running 1 7/8 Kooks with the standard high flow cats. With your mods and a good tune, you couldn't kill the high flow cats if you tried. I've been boosted for around 15k miles, 5k at ~ 6-8 psi/570whp, 10k at ~10-11 psi/750whp. My cats are still like new. I checked them out recently when i dropped the exhaust to do some suspension mods.
From my observations, once you're north of 800whp, any aftermarket cats are on borrowed tine.

[gotswap]

Call CSP and see what options there are. I am sure they have something

[radz28]

What does Cordes say? Unless you push boost past something like about 14-psi or so, it's my understanding you probably won't have much to worry about regarding the cats. It isn't like you couldn't find aftermarket cats to go on an LT set either. I bet Cordes has lots of input and could guide you.

I can tell you, personally, CSP has been great to me. Ted Jannetti has been great, too.

[Flowtie1]

I put ARH on recently with high flow cats and arh long system into factory suitcase. I am extremely happy with the set up. ARH told me 800 hp is the failure time for cats.

[Alain]

No way you'll be able to do all that to your car for less than $2000. Only way you'll come close to achieving that is if you do the installation yourself.

Kooks are an excellent brand, that's why they are so expensive. I'm sure most header fitment issues have been worked out by now for the ZL1 by all the brandfs since it's been out for a long time.

But, I'll share my personal experience, back in 2012 I bought "cheaper headers" because I had the same exact goal you have. Keep the spending as close to $2000 as possible. I ended up having to lightly modify the "cheaper' headers I bought for my 2010 SS to get them to fit.

Sounds like you're not new to modifying cars, never forget you get what you pay for.

[JasonSB]

Get Texas Speed headers and save yourself some money. No need to spend $2k on headers. With the coin you save get a pulley.

I will add that headers are going to make your car very loud.
I ended up adding a couple of resonators inline which made a big difference.

[kropscamaro16]

i have the afe power catted ones on my car fit and finish is super nice and all made in usa


https://afepower.com/afe-power-48-34...-street-series

[DFW_Muscle]

My $0.02:

I think we all wish modding the LT4 was cheaper. Good headers are expensive. I would put KOOKS, ARH, and Stainless Works / CSP in the same bucket as the "best" quality / fit for our cars. KOOKS has the best regarded high flow cat for LSx / LTx boosted cars. There are some budget Camaro6 headers out there, but I would highly recommend you speak with the shop that will be installing them before you buy China headers. You can also buy green cats and add them down the road if you find the catless scent to be too over-powering. IMO, it's not nearly as bad on this direct injected LTx as it is on LSx cars. This could provide the savings you need to get plug wires and a CC.

Lastly, your car will be insanely loud at anything above 30% throttle with headers and AWE touring catback. If you are worried about the wife's reaction to catless scent...jsut wait till she hears the car. Ask me know I know....(I am back to the OEM muffler now).

[20Bluezl1]

So I want through the same exact problem. The shop that is going to do my work suggested kooks system all the way back to my npp. It was $3400 for 1⅞ headers green cats and xpipe not including installation.
Kooks 22602600
Kooks 22605381

I decided to go with ARH #CAV8-16200300LSWC which is there 2" headers high flow cats and long system back to my npp which was $2197 and ARH will weld an extra bung for your wideband if needed.

No way you will do all those mods for $2000 when you need at best $2100 for headers, cats and xpipe not including installation.

[Can'tHave2MuchHP]

If you don't buy green cats, you'll be buying a cat-back sooner than later and who knows, maybe an engine. Supercharged, high HP builds like the LT4 do not play nice with aftermarket cats. GESI cats are the way to go. But they're a very pretty penny, as you've seen. Unfortunately, it's sort of mandatory.

I know there have been a lot of successful builds with regular "high flow" cats but I've seen too many fail personally to trust it on any car that I cared about. Once those cats blow out, you'll have a mess.

Also, ARH and Kooks are the only headers I'd ever put on my cars. Between the two, I'd give ARH the nod as a slight notch above as they use US sourced steel whereas the rumor was Kooks does not and ARH has not had quite as many fitment issues as early Kooks 2" did. Some of this may have changed by now.

JMO.

[20Bluezl1]

Originally Posted by Can'tHave2MuchHP

If you don't buy green cats, you'll be buying a cat-back sooner than later and who knows, maybe an engine. Supercharged, high HP builds like the LT4 do not play nice with aftermarket cats. GESI cats are the way to go. But they're a very pretty penny, as you've seen. Unfortunately, it's sort of mandatory.

I know there have been a lot of successful builds with regular "high flow" cats but I've seen too many fail personally to trust it on any car that I cared about. Once those cats blow out, you'll have a mess.

Also, ARH and Kooks are the only headers I'd ever put on my cars. Between the two, I'd give ARH the nod as a slight notch above as they use US sourced steel whereas the rumor was Kooks does not and ARH has not had quite as many fitment issues as early Kooks 2" did. Some of this may have changed by now.

JMO.

Yes i heard about high flow cats failing but I have read that ARH high flow cats are good for 800ish so I should be good hopefully.

[SJFGTO]

Originally Posted by 20Bluezl1

Yes i heard about high flow cats failing but I have read that ARH high flow cats are good for 800ish so I should be good hopefully.

800ish at the engine or 800ish at the rear wheels? In any event, knowing a part is only “good for” or below a certain number, which is an estimate and not a scientific certainty, is reason #1 why I would spend the money for a green cat or an equivalent GESI cat. FWIW, I’ve seen what happens when a cat fails on a supercharged engine and it was a total loss. Not the place to cut corners IMO.