Post up some videos once you have them installed. I am thinking about the same setup on my C7 Z51 but going with the CORSA Xpipe instead.

 

All of the major companies are good, ARH, Kooks, LG, Borla, BB. I will be following you and adding headers in the future. But if you really want to wake up your cars performance, supercharge it!!

 

Oddly enough, I just got a GoPro for Christmas. I'll do before and after videos and post them up.

 

I wish I could throw on a supercharger. If it wasn't my DD and had warranty extended, I would more than likely do it. I would love to have an A&A unit on it with a little meth.

 

Nice I love my GoPro look forward to the videos.

 

I installed the Kooks 1 7/8" Long tubes + Kooks green cats and can attest that they have not thrown a CEL on my 2015 Z51. I have not tuned the car and ran them for over a month before putting it in hibernation and no CEL surfaced. The new exhaust note is an amazing improvement over stock, but I don't notice an increase in performance. Perhaps if I had dyno'd it before and after the install, the increase would be measurable, but from the butt dyno, I'm not feeling it. With that said, I did not install them for the performance. I solely wanted the improved sound without having to tune out a CEL and this setup has accomplished that and then some. I also fully understood the need to tune it to achieve maximum HP gain from the headers. Once she falls out of warranty, I will tune it.

For my case, the green cats performed as they have been hyped up to. YMMV...

 

Couple of ??'s
How long did you have to wait for the headers, from Maryland Speed
??
And no seat of the pants improvement, seriously, that's disappointing to hear
Ever thought about doing the Diablo Sport tune so that you could return it to stock for any warranty work ??
Thanks
NSF

 

1) The Maryland Speed wait was excessive. I was initially told 2 or 3 weeks before delivery. Ended up being about 8 or 9 weeks. They did give a good discount so you'd have to weigh the cost benefit vs wait time to determine if it's worth the savings. I understand that if you pay closer to their web prices, you'll get them sooner, but that's a whole other thread...
2) I honestly don't feel the increase. Had I been drag racing the car, I'm sure that I would see a small increase in performance. I suspect that part of the reason I'm not feeling it is likely due to the car being so damn fast to begin with. Several years back, I installed Kooks 1 7/8" LTs + their high flow cats/midpipe on my 2009 Pontiac G8 GT and tuned it and I could actually feel the increase with it, but it's L76 was originally rated at 361 HP from the factory so a 30 or so HP gain on it was a larger percentage over stock compared to a 15-20 HP gain on 460 HP engine. With that said, the stock 460 HP is fine for my needs. This car can get me into trouble real quick on the local streets/highways with the way it performs. For reference, my G8 ran a quarter mile best of 12.26 and my stock C7 feels considerably faster than my G8, which I'm good with.
3) I own HPTuners so I could tune it and put it back to stock if I wanted, but it's my understanding that the dealers are able to determine if the ECM has been flashed outside of a dealership performing the flash, so I'm hesitant to tweak it. Does the Diablo Sport mask the flash in some way?

 

Honestly I don't know about that. Maybe someone more familiar with Diablo Sport can answer for you.
From talking with members that have installed headers they say you definitely feel seat of the pants improvement, definitely!! This is on LS3 motors thou if that makes a difference.
I find it hard to believe Maryland Speed has this rep as I never heard of it till now, and in a couple of threads to boot.
Not looking forward to a disappointing time period on delivery, damnit! I purposely did not get any coatings which I understand delay delivery.
NSF

 

For the 10 to 20 HP increase with the headers, you're probably looking at a 0.1 to 0.2 second quarter mile improvement, which for me is difficult to feel on a car that already runs high 11s/low 12s in the quarter mile. I will say that if you factor in the louder exhaust note, it certainly gives an experience that it is faster, but I'm not sure that I actually feel a huge increase, because it already sits me back in the seat pretty hard when I'm into the throttle. Also, just because I don't notice doesn't mean that you won't. So don't get too bummed out based on my feedback.

I didn't get any coatings either. Hopefully, your wait time won't be as extreme as mine. When I ordered my G8 headers back in 2010 from Maryland Speed, I got them within 2 weeks and I ordered them in December, so perhaps it's hit or miss on the timing or tied to when you order them in the year. I'm sure that spring and summer are busier times than winter so that might be in your favor. I'm keeping fingers crossed for you!!!

 

With headers and a tune I was able to get .2 quicker 0-60 and 429.5 on the Dyno

 

Thats because the power is in the tune. Thats why I bypassed the headers and went straight to a super charger for massive gains in power.

 

^^ I didn't install them for the power. I did it solely for the sound. If I was after power, I would have added cold air intake and cam along with the headers or went straight for the a super charger. As I have stated in another similar thread, 460 HP is plenty of power to get me into trouble on the local streets and highways.