ashmostro

fleming23

Consistently reliable - you are talking about a modded car vs a stock/warrantied car? If that is the case, Z06 all day, regardless of professional installation. I don't think a supercharged GS for track use would be the route most would take though.

ashmostro

Dcasole

Looks like you own the GS , I would put the supercharger on it and call it a day . There will be no worries about overheating like on the ZO6
Just my two cents .... are you looking at a Centri or a PD blower
Dave

c5racr1

ashmostro

I should have added in regards to the Z06, only considering 2017+'s with 7MT which I'm told eliminates concern for significant limp mode in all but the wiliest of conditions.

ashmostro

Good question, not decided yet. Not looking for max power. Am looking for reliability, linearity, not taxing the stock fuel system beyond capacity, known trustworthy warranty, etc.
​​​​​​
Been looking at a lot of the brands yall have recommended here but I can tell it's two-party environment.

Edelbrock, Magnusson, etc.

Thanks!

BrunoTheMellow

I have a manual procharged 2015 z51 making 570 rwhp and none of the later added cooling. I track extensively. It overheats in 90+ degrees in about 10 minutes if I'm going 100%, one 7/10s lap and it's back to 230ish. I have wrapped my pipes by the transmission and that got rid of overheating trans which was the first to go before. Now trans is not a problem. Just watch coolant #s. 25k miles so far, some 20 track days. And I also abuse it heavily on the street. only problems I had was 2 burned burned plug wires. Put sleeves on them and no problems since. I've replaced my plugs since also just as preventative maintenance.

I may do the external oil cooler from LG before the next track season. That likely will get rid of my issues in anything but 100+ weather.

PD blowers will naturally run hotter due to being on top of the engine and the heat exchanger setup. Procharger, ECS, A&A all have intercooler that don't block the radiator however you need to figure out how to make the aux radiator work if you got one. I think ECS has a relocation kit for that. I don't have that radiator so my intercooler goes there.

ashmostro

X25

It is often very hard to match the reliability of an OEM setup with aftermarket. After all, manufacturers are spending their years on testing and R&D for a reason. If you need FI, and have the means, I'd definitely recommend Z06 over a supercharged GS. LT4 comes with forged internals, upgraded fuel pump, etc., and is designed to take a good amount of abuse at these power levels. LT1 simply isn't. Finally, if you'd like to go with a bigger blower, you can always change the blower on the LT4, leave pretty much everything else since it's already setup for supercharger, and achieve the same results with a forged bottom end.

davepl

Factory Supercharger > Aftermarket for design, engineering, testing, driveability, reliability, etc...
Aftermarket > Factory for power and selection

ashmostro

This is pretty convincing logic... Thanks!

0HorsePowerAddicts

For the road coarse I would either get a Z06 or do a Heads/Cam setup on your Grand sport. Although the only way i see you keeping any kind of warranty is getting the Z06 and leaving stock.

BrunoTheMellow

It depends how much you want to spend in the end. My setup has been bulletproof at 570 wheel. So stock Z06 power.

I've also been debating quitting mods on my 2015 z51 and spending 25-30k to trade up to a z06. But it would have to a 2LZ, with PDR, torch red, 2017+, so not the easiest to find.

I'd get 35k on mine + 1000 for DSC sport, maybe 500 on track wheels and tires, and maybe 3000 on Procharger kit.

Finish paying off 1000 a month in 1.5 years or drop payment to 500 a month for the next 5 years?

Im thinking mod mine a little more to keep me happy and go c8z when it comes out. Smart mods. LG sway bars, track wheels. Things I can get good return on.

Bill Dearborn

I have a 15 Z06 M7 with the GMPP Secondary Radiator installed (stock on 2017+ M7s) and have driven in mid 90 degree temps without coming close to over heating. Highest coolant temps I have seen are mid 220s and highest oil temps have been mid 270s.

The only issue I ran into was an intermittent high rpm misfire (5200 rpm) on cylinder # 8 under wide open throttle conditions in 3rd and 4th gear. This was resolved by making sure almost all of the air was removed from the intercooler circuit. As delivered from the factory the intercooler has too much air for sustained high rpm operation so has to be vacuum bled until reservoir shows air bubbles no larger than a quarter. This is based on recommendations made by Corvette Engineering. Too much air lets the rear two cylinders charge air intake temperature get too high as the rear cylinders have higher combustion temperatures than the other 6.

The car runs hard and turns excellent lap times and does this without issue time after time. Once you go aftermarket if you run into a problem you more than likely will not be able to get it resolved as easily as I did the intercooler fill issue. That only took about 18 months.

From what I have seen most aftermarket modifications are designed around short bursts of power not extended wide open or near wide open throttle operation that lasts 20 to 40 minutes at a time. Professional installation means finding somebody who understands the different operating scenario and knows how to address it. Just because somebody is a top installer of equipment for drag racers doesn't mean they will provide the best solution for a road course engine. A road course engine will see more wide open throttle operation in one day than a lot of drag engines will see over a period of a few years.

Bill

c0ntract_thrilla

It really depends on what kind of tracking you are doing drag, auto x, time attack/lapping.

For me it comes down to a few key factors; the type of racing you prefer, your skill sets as a driver and your comfort level. I have seat time in both a Z06 with z07 package and I own a 17' GS. When I went out to purchase my new track car I was originally going to get the z06/z07 but I decided against it after driving one for a few reasons. First I mostly do lapping days and I prefer a manual transmission, secondly was the cost difference and finally it was how damn good the GS is.

IMHO The GS is perfect for auto X, time attack and lapping. I know the 200 extra HP in the Z06 looks appealing but in my experience it is a challenge to maximize your times because you have to be careful not to overwork the car managing that extra power. When I say over work, I don't mean over heat, I mean you are constantly correcting and trying to be effective with throttle management, this makes it harder to be able to maintain consistent racing lines to run consistent times. The Z06 is a bit of bull on the track, I find the power is not useful %90 of the time as your either relying on it to make up the lost time on the straights that you wouldn't have been worried about if it was not fighting you through every turn. Now I know a lot of Z06 owners are going to chime in and say they can handle the power and that you get used to it... but myself and others who have driven it hard find the car unbalanced on road courses. Even C/D and R/T had similar experiences where the GS was faster than the z06 at multiple tracks despite the massive power gap. The z06 has so much power you are constantly trying to fight the car, where as the GS might be a bit under powered comparatively but it is much easier to drive and it is very well balanced. The GS benefits by having all the best parts of the Z06 and while I do think it is a bit under powered, you can make it a near perfect lapping car with some bolt ons and a tune.

At my track I am constantly lapping with Lambos, ferraris, vipers and other vettes (Zr1 and Z06's) I can hang with all of them despite having a notable power gap. The biggest strengths of the GS is the balance, the grip, the breaks and the neutral feeling of the car. The GS gives you a lot of confidence where I find that lacks in the z06 because you are fighting the car so much.

If your focus is drag racing I would %100 take the z06 but in automatic. I would invest in some good drag radials, find the best tire pressures to run and go have fun. I know that many like the M7, but I am one of the few who think the M7 is better in the stingray and the GS, but sucks in the z06. I find the cars power is hard to modulate due to the power when you are pushing the car hard. Plus the auto is so good, it makes it very easy to run good times right from the factory. When it comes to drag racing it is hard to beat the new breed of automatics.

Anyway this is all just my opinion. I don't know how good of a driver you are, how much racing you do, where you race or how competitive you are with it. While I do think the GS is a fantastic car and might be a little underpowered for lapping, I don't think it is 200 hp under powered. I think the GS is perfect around 550 BHP NA.

Cheers

BradT

If it is settled that you are going to have a supercharged C7 to take the track, then I would go with the Z06. I track my grand sport and don't think I would be too much faster around a track with a Z06. I enjoy track driving but I am not interested in being the fastest one on the track. Most Z06's only get away from me on the straights and at those high speeds with stock safety equipment the risk of getting seriously hurt goes way up.

I would take the warranty and dependability of a stock Z06 over the potential of getting a bad tune and having issues with a highly modded GS. Track days are expensive and having a car that has issues on track days just doesn't appeal to me at all.

ashmostro

Very much appreciate the last three replies in particular - thanks fellas.

I should provide more context:

• Use case: 75% street (weekend/fun days/road trips) and 25% track (HPDEs @ Summit Point, VIR, Dominion... hope to get to The Glenn and NJMP one of these days)
• Driver: I am an intermediate/advanced (think 3rd run group out of 4 at tracks I know well, and 2nd at new tracks until I get comfortable with the line). ~35 track days under my belt across four platforms, all RWD and ranging from 330 to 500 HP.
• Vehicle mods: Essex/AP BBK front and rear with DS1.11 pads; 18" track wheels with NT01's for rubber; no engine mods; DSC recommended alignment; will be adding 4/6 point harnesses this spring.
• Why I'm considering more power: Main interest is that I am so in love with this platform, I feel that upgrading to 600+ HP will check every single box for me from a sheer joy perspective. The perfect platform. As you'll also see below, I'm wondering if my driving style wants more torque down low.
• Concerns: I agree, I don't want to end up killing all the balance of the car and stop having fun on the track. That said, the strengths and development opportunities I have as a driver may not be adversely affected by the extra power and potential for lost balance:
• What I'm working on as a driver: braking deeper and trail braking more, partially to rotate the car more with means other than the steering. I tend to put too much heat into the tires by excess input on the front end (I also need to steer with the throttle more on exit as well, which I did a lot more on my more torquey F80 M3 that was modded). The lack of torque or "speed in the pedal" on this platform results in me applying steering with the throttle way past the prime opportunity in the turn. I can probably recalibrate myself to this, but I've also wondered if my driving style wants more sensitivity and torque off-throttle.
• What I do well as a driver (per instructors): smooth steering; good and consistent line; patient; not easily affected by bad driving in front of me; smooth on brakes and throttle, well-paced and smooth shifting.

To be clear, I'm not decided on this path forward. That's why I'm asking the question - I respect the opinions here and they help me think through things. I have also considered the option of sticking with NA and just having a plan to go with cam/header/intake/tune to urge another 80+ HP out of the LT1, perhaps with a Katech kit. But my understanding is this is a much more costly ($ per HP) path than FI. BUT, if the end result is something that is a lot more fun than a Z06, I'll definitely consider it.

Hope this additional information helps. Thanks again everyone.
-Ash

samwint77

I'd just go with the z if you have the means.

jcp911s

As a PCA National certified instructor and racer for over 20 years, I recommend keeping your GS totally stock, putting on a set of Hoosier track tires. I Track a dead-stock Z51 and can tell you that more HP is not what you need. Half the time, I can't get the existing power to the wheels, and the TC is on. What you need is not a supercharger. You need more traction and more track time.

Also, have you installed safety equipment? Rollcage, full containment race seats, nets, a HANS device?