augydog

My car:

'04 Z06
Miles=7500 (Dynajet dyno corrected 364.4 rwhp 358.2 torque, bone stock).

Ordered the Kooks 1 3/4 LT headers with the hi-flow cats and X-pipe. (Received them Feb 22)
Shipping took 3 days UPS, when the headers arrived I noticed the header airtube sticking out of one of the boxes. Good ole UPS Fortunately nothing was damaged.

The headers are really nice. Finish and workmanship 1st class. Even has a welded on plate with the Kooks name on it.

Had a friend that works at a local Chevy dealer do the install in his spare time.
He said it was a PITA. These were the newer revised Kooks, I was told these were easier to install?

Brief background of my likes:
I love the way the Z06 sounds with the Ti's and H-pipe, a nice gurgle and rumble. Actually I was totally satisfied with the sound, just wanted more sotp feel, thats why I went with the Kooks, high-flow cats and X-pipe.

My friend finished the install this afternoon. I started it, no codes, no ticking, no leaks. Everything was great.

Impressions while still fresh on my mind:

First thing I noticed, it was not as loud as my stock system.
Most of the gurgle and rumble were gone. (still using my Ti's)
Drove about 3 blocks and got on the interstate, and put the pedal to the metal. Definitely has more power, sounds different, more like a nascar than a muscle car when you get on it.

You can tell the engine is not working as hard to develop the power..

Drove it about 60 miles, to let it go through the relearn cycle. 5th gear feels almost as strong as 4th used to before the headers.

All in all I am pleased with the new exhaust, don't know if I'll get a tune, or just leave it. I'm satisfied with the power gains at this point. I probably will punch some holes in my stock air box.

augydog

Cobra4B

Sweet.... w/ Kooks w/ cats mines most definately louder and it pops and crackles just as much. I definatley agree w/ the distinct Kooks sound. It's beacuse of the equal length primarys.

RPO_Z06

I have the same headers on mine and love em..

SoulDad570

Conventional wisdom is a tune is required after adding headers, etc.

I am eventually going to add headers, but am concerned about the downsides. My experience with headers on previous cars show the following downsides:

1) HEAT! under-hood temps rise a bunch. Can fix this with header tape or ceramic headers. Also, headers convey more heat into the Z06 passenger compartment. This can be fixed with foil insulation on the tunnel plate.

2) Longevity. Headers are made of thin sheet metal, not thick cast iron. Over time, the extremes of heat cycles causes headers to crack. Header tape aggravates the problem.

3) Leaks. I recall great frustration keeping the dang headers from leaking at the flange. Numerous times I would hear the dreaded "tick tick tick" and have to torque down the header bolts.

Am I off-base on these concerns?

Ciao,

Rick

augydog

Your concerns are worth noting, but IMHO I think the upside out weighs the downside.

augydog

Mopar Jimmy

Just had my KOOKS installed with the high flow cats and x-pipe on my 02 Z and i am making 383rwhp and 370rwtq with Vararam and B&B BUllests. Car pulls stronger now and has a more deeper fuller sound and at idle it is actually a bit quieter vs. stock manifolds and H-pipe! Overall, i am very pleased so far after putting only 100 miles on the car since the KOOKs and i am quite pleased wit everthing!!! I was hoping for 390+rwhp but realize most guys making this on bolt on Zs are running catless,etc.!!!

AFVETTE

That's about what I experienced when I installed FLP LT headers, high flow cats and their x-pipe on my 99 coupe a few years ago. What's funny even though I had the Corsa Indy's at idle buddies cars with just a cat-back like Borla Stinger's, B&B ext sounded more aggressive (at idle and part throttle) but when I would go WOT they marveled have wicked my car sounded vs their cat-back only sound.

I like the fact that at idle and around town cruising the car was as tame as stock, but go WOT and it was unreal.

I also gained 25 RWHP (w/o tuning I might add) just from the header package alone. The Corsa's netted me 8.

That's why I keep telling folks to keep their Ti's and spend their mod $$$ on LT headers.

Tom

Millenium Z06

I guess this anwsers the debate of which is better LG or Kooks, I dyno'd today 382 rwhp and 363 tq. Seems pretty close. Did you have it tuned; mines not and I have a Blackwing.

As for the reasons not to go whit headers, my underhood temps seem the same if no lower, no caotings, no wraps. The headers are fairly thick and the only place that I can see them cracking is at weld seems and I havent heard of many who have had that happen; for what its worth, cast iron manifolds can/do crack just as often as headers. No leaks either, and no ticks.