10.9 back to back DR ZR1

[Memphis]

Ranger ran a best on stock tires of 1.90 11.21 130.45 and on drag radials 10.98 (twice back-to-back) 130.97 and 131.87. My 60’ on DRs were modest, 1.76 and 1.78. In light of my guest-driver status, I felt an duty to go particularly easy on the clutch. So I made fast, clean clutch releases, followed by a graduated throttle squeeze. The other two drivers experimented more aggressively with the clutch, with better results. My trap speeds were mostly above 130. That derived from shift-point correctness.

^Bone stock. Below is Ranger's write up


Our Impressions of the ZR1 on the drag strip

A fabulous car, that’s hard to drive well for max acceleration. That’s why the car magazines haven’t shined with it. The torque of the motor is huge, presenting a challenge to avoid excessive wheel-spin. The solution involves heated tires and a progressive throttle-squeeze in first gear. But loss of momentum via bog has disproportionate, adverse impact on the 60’, 330’ and ET. GM set the ZR1 first gear ratio at 2.29 vice the Z06’s 2.66. That difference looms large in making torque at launch somewhat more manageable and allows the ZR1 to reach 67 before the shift. But it penalizes a loss of momentum more in the ZR1 than in the Z06.

The car has a different rpm-making rhythm than the Z06; its rev limiter is at 6600 vice 7120. So a driver transitioning from the Z06 needs to eye the tachometer earlier than the engine-sound indicates. Clipping the limiters extracts an ET penalty. Slamming the limiter drop the car’s nose and kills the ET.

The ZR1 transmission is a pleasure and shifts positively with little fanfare. Perfect. As always, proper hand position is still a must.

The clutch engagement point is in the top-third of travel rather than the middle-third on other Corvettes. That requires getting used to.

On ZO6Jeff’s car we changed the clutch fluid in the reservoir (three swaps) after pass #10 as a prophylactic. It was seriously nasty from infused clutch dust after starting the day perfectly clean. We repeated the three-swaps at pass #20 before mounting the drag radials. Again it had turned very nasty; but three swaps did the trick.

I was very impressed with how stable and planted the car was under max acceleration. If you replay the video of the two 10-second passes, note how straight and true the ZR1 remained with only minimal movement on transitions. It behaved the same way for me on stock tires. I like that. It quickly gave me confidence going down the track.

Finally I was impressed by the robustness of the car under hard running. Nothing broke; nothing felt weak. I had no wheel hop in my 11 passes. The clutches held up. But they do produce smoke through the center tunnel exit when intentionally slipped excessively. But unlike the LS7 clutch, the LS9 dual-disc did not glaze even once. I am happy to see GM has resolved that annoying issue.

Now that I’ve driven both the ZR1 and the Z06 on the same day at the same track, which car is faster? The ZR1 for sure. It feels faster. It is faster. But it’s harder to launch without a loss of momentum. Still, post-launch, the very wide flat power-band of the ZR1 is unforgettable. And of course the exhaust note at full song, sounds like a genuine race-car. Sweet is an understatement. Just re-watch my 10-second-passes in HD widescreen with the volume cranked. That exhaust note is mesmerizing. It's like you are there.

On my DR passes, a slightly more aggressive launch would have put the car into the 10.8s at a 600’ DA. I suspect some owner will get a ZR1 into the 10.60s on DR and the 10.8s on stock tires. racerns came very close to 10s on stock tires and would have been there with better shifts or the same DA we has at the start of the day or in a car not thoroughly heat-soaked from a long drive to MIR and so many passes.

I must note that zosix427 drove seven hours to reach MIR; made 16 passes; and then drove seven hours home to honor business commitments at first-light the next morning. He’s a true car guy and racer who’s already done the driver-mod and wants to improve even further. He set a series of PRs in his ZR1 at MIR and will be knocking on tens in the fall with more seat-time. I forgot to mention to him (but will here) that as I was preparing to do a burnout on a pass in his car, On-Star called with a status report. I showed “mature judgment” in ringing off that call before spinning the rear tires to copious smoke. That was but a small token in return for the opportunity to make three passes in his ZR1.

I extend once again my thanks to ZO6Jeff for the opportunity to join his son racerns in help wring out the ZR1. I know they will continue to drive the car in the full spirit in which GM unleashed it on the Corvette Faithful…often and at various racing venues.

[Magnusen]

hittin' the limiter in 2nd and shifting slow as shit... that car has more in it for sure

[UKunt]

another zr1 with clutch problems?........hmmm thats a few now ive heard of..

[01mmmz28]

WOW.....130+ mph.....wow, def. more in that beast with a better driver and harder launch.

[bmxer99]

Originally Posted by 01mmmz28

WOW.....130+ mph.....wow, def. more in that beast with a better driver and harder launch.

wtf are you talking about a better driver? this driver was the first guy to take a bone stock Z06 into the 10's dude. And took a bone stock 08 Viper on street tires into the 10's as well. Ran a 10.8 I believe.

So as for the driver mod, its there.

and harder launch = wheel hop

[Memphis]

^Different guy with the Viper, thats Jamie Furman. He could've launched harder but it wasn't his car lol

[01mmmz28]

That trap speed suggests that there is A LOT more to be had.

[Magnusen]

He was shifting like a girl... and could have launched it harder imo, knowing that it's not his car explains this.

[01mmmz28]

^ true that.

[bmxer99]

people let me drive their shit but always tell me "you break it you buy it, and if you dont i break your face" so with that said i always tend to drive peoples cars less harder then my own.

[01mmmz28]

^ If you were to give the keys to your Camaro to me and tell me to run it at the track, knowing what it was built for, I'm driving the dog shit out of your car.

[fat_kid]

still such a great car!

[Double]

Originally Posted by 01mmmz28

^ If you were to give the keys to your Camaro to me and tell me to run it at the track, knowing what it was built for, I'm driving the dog shit out of your car.

lol, I'm sure that's true. Therefore I wouldn't hold my breath on an invite.

Funny how we flog our own cars but cringe at someone else trying to get the most out of them. Shouldn't really matter with competent drivers, just goes to show what role emotion plays in our decision making process.

[97talon]

Originally Posted by 01mmmz28

^ If you were to give the keys to your Camaro to me and tell me to run it at the track, knowing what it was built for, I'm driving the dog shit out of your car.

Agreed. If you give someone your car at the track you should expect them to use it like it should be used. On the street just driving around is different. Once you are on the track it should be all go.

Nice ZR1!