Launching
 

Whats is the safest rpm i can launch my stock c6 z06 on drag radials ?

Heading to the track with DR's for the first time and i really dont want to break anything but i want better than a 1.85/60' that i did on street tires last saturday .

I launch around 4000rpm. I would say there is no set answer. Depends on how hard the track hooks, and how much you slip the clutch. I have about 20 passes this year with no clutch issues at all on drag radials and stock clutch.

You're going to get a bunch of people saying, "0 rpm"...I'm calling it now...

However, if you do a quick slip from a moderate rpm (under 5k for sure) your chances are better, but nothing is guaranteed when you add sticky tires into the mix. Do not deadhook the car or wheelhop it and you should be ok. But think, the lower the 60ft, the more it stresses the drivetrain, there is no magic 'under 4,000 rpm and you're safe' solution.

Stock clutch? You should be able to get into the 1.7xs easy without straining anything too much.

Your question is very subjective because there is no "safe" RPM limit that will keep you from doing any damage and provide consistant times for everyone. There are too many contributing factors like track prep, driving style and and other things. I can safely launch my car at 4,500 with the right slip and cut consistant 1.5x short times, but there are a ton of people that can't do the same. I see people spinning wildly with a 3k launch and others that will bog or break stuff at the same RPM.

I would say that with not much slip, you are somewhat "safe" around 3k.

This track has "so-so" track prep and its hardly ever sticky unless theres an event going on .

These tires are also 1" shorter , 25 inches instead of 26"

Whats that going to do for my mph ?

With the 26" street tires im crossing the line in 3rd and hitting the rev limiter at the exact same time .

With a 25" tire , im going to have to shift to 4th right or is it the other way around ? ?

With 25 " tires, you're definetly going into 4th gear around the 1000-1100 ft mark.

I 'll also give you my .02 worth.......
If you are on a stock clutch, with a perfect "Ranger" launch you're looking at a launch rpm no higher than 3500 RPM with a little slip of the clutch for the first 10' or so. With the stock clutch, don't expect sub-1.70 60'...even with drag radials, if you wish to limit the shock and possible damage to the axles, or want the clutch to last any appreciable time. The C6 Z06 clutch is notoriously finicky and doesn't/won't take the high rpm dumps the C5 Z06 clutch's took.
Me personally, I try to run as much sidewall tired drag radial I can fit under the rear quarters, again, to soften the shock to the rear end. Anything over 28" is going to kill your rear axle ratio (3.42) and over power the clutch if you hook hard....stay at or under 27" for a stock car.
On 295/45/17 MT (27" tall) I was able to cut a 1.70 60' with a STOCK clutch and rear axle. I think Ranger's best 60' is also a 1.70 on a stock car, and he own's the title of fastest stocker on this forum. :cheers:

Ive been doing the Ranger thing and its been working good .

I will try a smidgen of slip at 3500 :)

Thankz

:thumbs: You are wise to listen and learn from what Ranger has done.
315/35/17 or 315/30/18's are going to give you plenty of traction and keep you under 27" tall, so you won't kill your rear gearing.
25" tires are going to give you a higher numerical rear gear (around 3.55) so if you can manage to get the neccassary traction your car is going to accelerate faster :thumbs:

You want enough sidewall on your dr to absorb the inital shock of launch, wide enough to give you some traction without a dead hook, and short enough as to not kill your rear gearing. Mix that in with the lightest tire/wheel combo you can fit on the back (17" wheel minimum to fit over the calipers on a Z06) and you've got a winning combo :cheers:

It was not a z06 but a car and driver road test TV program stated they launched the 2009 zr1 at just above an idle and rolled into the gas and they were getting 11.2's at 130 mph.

LS9 clutch there....whole different monster with greater clamping force and not as succeptable to glazing when slipped.

I was thinking on the road test C&D they just flat out dumped the clutch at 1100-1200 rpm no slipping--- than rolled into the throttle.

When i had my c4 zr1, that was the launch technique i used and that was good for a 12.7 on that car. Have not taken the c6 z06 to the track yet. The ls7
z06 is a flat out torque monster compared to the Lt5 and the c6z is at least 400 to 500 lbs lighter than the c4 zr1. I would think this would work good with the
z06 and and would not be terribly abusive to the car or clutch.

I have read allot of different guys post talking about launch rpm....it seems as the consenses is around 3500 rpm. But as others have stated, there are allot variables. I know GM set up launch control algor at around 3500-3700 rpm. Have not yet used launch control but my owners manual states so.

:iagree:

Tonight the track was prepped pretty good in the beginning of the night but just like always , the track goes away after the 2nd run through .

Its pretty sad that i didnt get to run better than an 11.8 all night because by the time i kinda sorta figured out how to launch on the DR's , the track went away :/

The 11.8 was boggin off the line and scratching 3rd slightly ,, haha

It should have been an 11.5 second night if not better .

There was a VY GS out there tonight with an 19" rim and the new Nitto dr's and was spinning like a mad man . No side wall to speak of .

Im going to widen my c5 z06 wheels to 11"s and get the 315/35/17's :)

Any of those magazine guys cannot launch any Vette as well as a well seasoned person who drag races these cars.

what size wheel and tire are you currently using ?

That is not typical from what I have seen on those tires. I consistantly cut 1.5x short times in our car on those tires. I think the driver just needs a little more practice. I also am impressed with how well they wear. We have 45 passes on them and still not to the wear bars yet.

Here is a video of one of my passes on the Nitto NT05R 345/30/19. It is hard to see the times because the camers is focusing on the car, but the 60' was a 1.58 and the ET was a 10.59 @ 134.7 MPH



Here is another run prior to that day. It was the very first time out on the NT05R's. I had a couple 1.58-1.61's that day, but this one was a 1.63 short time.

My friend ran the NT05R in 19" and was bogging launching at 3500-3600. He went from 16psi to 22psi and spun. Maybe the GS didn't play with tire pressure or do a decent burnout.

If I launch below 3700 or so on the MTs I bog.

OP's stock clutch won't tolerate launches with high rpm.
On a stocker, the trick is to not put too much tire on the car and the clutch release for the first 10' or so. A very fine balancing act for sure.

I'm on a stock clutch and so is my friend. We haven't had any clutch issues so far.