phantasms

Gentleman,

This Friday I'm taking my 30k mile M7 Z07 to Cecil County for some drag racing fun. This is traditionally a very fast track with very good prep. I'm going with a group of Buick guys for a track rental and this will be my sixth time going to this event although first with the C7Z.

I know this has been discussed but the information was spotty at best. I had asked similar questions last year when the car first came out but back then no one really knew the answers. I hope some people here have mastered this thing so I can get some better answers this time around.

FWIW mods are, PSS tires, lowered on stock bolts, X-pipe, Halltech CAI, ported TB. I also have the DashDisplayController for monitoring numbers I pretend to understand and a VBOX Sport.

I ran very strong times in my C5Z and C6Z at this track...which sadly got me thrown out due to lack of roll-bar before the stock rule came about. My best at the track was 11.2 in my essentially stock C6Z so I can row them alright.

1. Mode? What mode is the best mode? Some say tour to soften the launch, others say track is a must. If track, then what setting in track? Traction control off I presume. Back in the day people thought you needed "track" to get the "full power" out of the car. I think we can all agree at this point that that was a misunderstanding. The tour to soften the launch makes sense however I'd be a bit concerned about the slower throttle. So those of you who have knocked off sick 60 foot times in this car, what do you say? Is Sport the happy medium?

2. Tire Pressure? Do I take a few pounds out or will that hurt more than help considering it's a run-flat tire with a stiffer sidewall?

3. Launch RPM? This of course depends on the prep, temp, ect....but what are people finding is the best way to go? When I had my other Z06's I lived on Long Island and there were traffic lights everywhere. I could practice launching the car all day long. Where I live now there's almost no traffic lights and I almost only come across them in Manhattan. Needless to say Manhattan isn't the best place for test launching your 700hp car.

4. Shifting/NLS In the past I got ok launches but I was a very fast shifter. Usually I'd do a half power-shift 1-2 and full power-shift the rest. From what I've read with the M7 it seems some people say the best way is to not power shift it and not to speed shift it as the computer cuts power. I've heard just a normal quickish shift is the way to go. What's the deal? I'd like to do No Lift Shift but I'm not that familiar with how that system is programmed in the Z. Again, I'm a very fast shifter. I preload the stick and stab clutch blah blah blah. But if I'm doing NLS what is the best RPM to stab the clutch at so I don't bang the redline? What is the computer programmed to do with NLS? Maybe understanding how it's programmed will help me do it best.

5. RaceGas. What's the deal with that? I always run 93 and intend to run on 93. However if I get desperate or whatever maybe I'll throw something else in there. The track has all kinds of fuels. What's ok to run the car on? Any percent mixture I should be looking for?

6. Cooling Anyone have suggestions on cooling this thing down between runs? When I used to go I'd literally go like 10 times back to back. My friends joked that I was running a NASCAR track. I don't see this going that way sadly. Other than having the hood up while waiting for my turn is there anything else I can do? Does it makes sense to easily drive up and down the empty parking lot to get air in there or does simply turning the car off cool it down quicker? Throw ice on top of the supercharger? The science guy in me says that I'd just end up with a bag of water after one run. Also, what AIT, AIT2, Coolant temps, other temps should I be looking for to be good to go for a run? Basically what's the temp cutoff between losing power and good power...and temperature of what?

7. Burnout I know this is pretty standard but just want to get people's opinions on best methods. The PSS tires have plenty of tread on them. I'm not afraid of burnouts as I'll be throwing on my winters in a few weeks anyway.

Again the car is a Z07 with the stage 3 winglets in front and the clear wicker from the rear removed. I know getting rid of the winglets would help but it's a pain in the a$s and I want to run it just like I use it on a daily basis.

Any other suggestions? Anything I need to know? Unfortunately this rental is earlier in the season than I would have liked. My goal is to get a very solid time on that fast list that reflects the added power of the Halltech CAI because I'm not buying the fact that the Halltech cars aren't faster than the stock cars on the fast list because they can't get traction.

Love,
Gene

juanvaldez

Don't know about the rest but the Z06 (and other C7 M7s) is designed for no lift shift. Keep your foot on the floor.

phantasms

That I know...just looking for much more detail on the process.

Thanks!

Dfwz06

+1. I'd like to know too. My c6z was crazy fast but it was a completely different car. I saw a video where Formato seemed to launch at like 5k with drag radials. Is this normal? If not in track mode, can you still get to the sub-modes for traction?

davepl

https://www.google.com/search?q=site...hrome&ie=UTF-8

testpros

Great questions. Would also love to hear responses.

BJ67

Heat soak a issue, keep it as close as you can to 190 water temp between runs. Drop rear tire pressure to 25 psi before your burnout.
Back into water, pull out of water, stationary burn out till see smoke (aim 1 mirror down to rear tire). Before burnout, track mode or whatever mode helps with weight transfer, traction control off. I would also unbolt and remove the front swaybar and links. Pump front tires up to 45-50 psi. Do not use launch control. Definitely no lift shift as close to 6500 rpm as possible, maybe making the shift at 6300 so you don't hit the 6600 fuel shut off (reaction time to make shift) if you react at 6300 you could actually be at 6500 by the time you initiate the shift. The NLS will hold whatever RPM you finally initiate the shift at.
I would hold RPM at about 2500 for launch, slip clutch a little and roll it to the floor. No popping clutch and no wacking gas to the floor. Its been said high octane fuel will lessen possibilities of KR. These cars are sensitive to water temp, IAT's , spark knock, all of which cut down timing at the slightest hint.

Have no advise on anything else.

firstgear

With drag radials the first two times I left at 3000 rpm and the car bogged but the third time I left at 4000 rpm and hooked really great. Next time out I will try launch control.....

BJ67

Launch control has its merits, but to get your best 60ft time and ultimately best ET, learn to launch without it.

BJ67

BTW phantasms, no lift shift technology was designed for the supercharged CTS-V Caddy, the ZL1 Camaro and the ZR1 . The technology maintains boost while upshifting with your foot to the floor, in a naturally aspirated car, intake volumn is maintained.

phantasms

I was lucky enough to practice with Ranger at Cecil Country Dragway nearly a decade ago. Unfortunately the C6Z and C7Z is apples and oranges and our drag strip superhero is nowhere to be found.


Best,
Gene

tail_lights

I don't recommend this. IIRC A good friend of mine that raced one of the first C7Zs (who has tons of experience shifting manual Corvettes) said that the car "laid over" bad when he tried to do this. Again this was one of the first ones made, maybe the programming is different on the ones now.

Edit- Reading the rest of the posts, is this something you have to turn on? If not it definitely wasn't working right on his when he ran it. ??Maybe he ran it too close to the fuel shutoff??? I just read his texts again and those were his exact words 'laid over' and that he ran faster not doing it.

Ehhhhh... Just trying to help..... But what do I know, I have an automatic

Gene, good luck!

phantasms

Haha thanks Lights. Yeah there's so much conflicting info with this car it's rediculous. Every time I've tried a NLS which has been testing at lower RPMs on the highway it definitely does not hold the RPM. I figured maybe it must be done near redline to function. When I test it's usually a 3-4 at 80mph or so and a very very fast shift. RPMs fly up and it gets pissed. My car was also an early build...27th off the line.

Anyone else? Friday is getting here real quick!

Best,
Gene

tail_lights

Paging VinnieA or Anti_Venom

Dfwz06

I thought you had to be within 500 of redline, for it to work?

BJ67

Here it is right from the corvette engineer himself (if I can post it correctly.

https://www.corvetteforum.com/forums...hift-work.html

phantasms

Thank you!

Funny enough I found your info far better than Tadge's. After reading this I once again am planning on using the feature.

I'll post it here for the benefit of the thread and future readers.

"when you initiate a no lift shift , foot on the floor and keep it there, do your shift as close to 6500 as you can with out hitting the rev limiter first. If for instance you initiated your 1-2 shift at 6400 rpm, the NLS feature keeps the rpm at 6400 during that split second foot to the floor blip the clutch and shift all at the same time technique. The feature holds the rpm you initiate the shift for a very short time. If you are slow doing the power shift or screw up, the system just lets the engine hit the rev limiter which is 6600 rpm if you are slow to lift of the throttle."

Best,
Gene

BJ67

Gene, the best safest way to practice power shifts, is when the engine /trans is warm from a drive and parked with engine off. Go thru all the motions of real power shifts repeatedly.. 1-2, 2-3, 3-4 over and over again with appropriate time in between as if the engine was winding out to the correct RPM in your head. Keep the foot to the floor, blip clutch, push or pull your upshift , all at the exact same time.

phantasms

Bump!

Tomorrow's the day. Input!!! Need more input!!!

This will keep it towards the top....

tail_lights

Wish you'd got more info, but looking forward to your results!