2010 SS L99 Headers Help

[steveo9043]

only issue i had with the axle back is that you have to measure and cut the stock exhaust and if you cut too far the tips will be too far in or if you don't cut far enough you might have clearance issues.

I have the Mach XL catback and I couldn't be happier.

[GoldBowtie]

Originally Posted by steveo9043

only issue i had with the axle back is that you have to measure and cut the stock exhaust and if you cut too far the tips will be too far in or if you don't cut far enough you might have clearance issues.

I have the Mach XL catback and I couldn't be happier.

Steve
Thanks for the info. After looking at the site, I may try contacting (calling) their guy, Steve (coincidence?) for more on catback vs. axleback for my case.
Thanks again

[davidmk001]

Originally Posted by GoldBowtie

What is the detail on SOLO "axleback" with J-pipes. When I checked their site, all I could find is "cat-back" systems.
I have an tuned L99 with Kooks headers/Hi-Flows and no center resonator (x-pipe, instead) and would consider switching from SLP cat-back to Solo --- but I only want to change from the axle back. Any advice is appreciated.

Honestly I love their system with the j-pipes technology. Virtually 0 drone! I was amazed when I first had it put on. Also I noticed it took some miles to have it 'break-in' I guess you can say. That's when its true sound potential was unlocked.

For all its worth to you, I am very happy and would do this setup again if I had another shot at it.

*** sorry, I should also add that since you have the L99, you're really going to hear the AFM kick in and it does make it sound, well, annoying! Look into the RANGE AFM Disable device. Well WORTH the money.

[davidmk001]

Originally Posted by RJT-SS

You are correct on the smell going without cats.

You won't go wrong with Stainless Works. SW, ARH, and Kooks are pretty much the top-shelf standard (there are others....not trying to ignite that debate). They are also made in the U.S.A. (there are others as well), if that is important to you. Their fittment is great and weld quality top-notch.

If looks and quicker heat dissipation is important to you, consider getting them coated.

You do not need another set of header gaskets or bolts. The OEM ones are perfectly fine.

Do NOT use thread locker on the header bolts. Use anti-seize if anything.

Based on your mods, you do not need the low temp T-stat either.

After your header install, I seriously recommend getting a tune. It really wakes up the L99.

Your axle back will cancel the drone. If you detect any after the header install, adjust the J-pipes.

Good luck!

Okay. I am really excited now! lol

BTW, how much power gain did you get with your headers + tune ? What can I expect ? I know the LS3's are apparently picking up more than the L99's ... Not too sure what type of gain I can expect or consider to be a 'good gain' on the auto

[RJT-SS]

I have not dynoed my car. I am not that into numbers as many are. I prefer the "butt dyno".....and it is noticeable. You can find endless numbers by checking out the L99 dyno sticky at the top of this forum. I think headers and a tune translate to 25-35 RWHP as a conservative/reasonable average but every car is a little different. LS3's have more RWHP "out the box" and do not benefit as much as the L99's due to the AFM and auto tranny loss.

BTW, you might want to consider getting a ported throttle body as well. It does not translate into much (if any) RWHP but it noticeably improves throttle response. Another one of those "butt dyno" gains.