Poor-sha

I put together a video tonight going through the data from the Summit Point session with the ZR1 and the Z06. Hopefully that will help folks understand the differences in lap times better.

Kappa

Great post.

Leadfoot01

keagan

Where else you gonna get this type of data? Great post Poor-Sha

Monkey D. Luffy

Thanks Poor-Sha, Great Video !

Newton06

Sean, do you actually work? LOL

How do you find the time to do all of this cool stuff?

Thanks - very informative!

Palantirion

Thanks for this great analysis!

What you experienced reminds me of similar "issues" I had with lap time after putting an ESS supercharger kit on my Z4 M Coupe. (This was after a few years running NA with extensive suspension, brake, wheel/tire mods.) More straightline speed made over-braking more likely, which would sometimes compromise a corner (entry, fluidity, etc.). Which lead to less overall benefit from the extra power since it is only used on a small fraction of the track compared to the slightly better pre-blower lateral grip which was used extensively throughout a lap. Regarding redline: sometimes the additional power would cause issues running to redline shortly before a brake point. But I also learned that the extra torque with the supercharger meant I could short shift and still pull harder than when the car was NA. At Cal Speedway I tested this coming out of the infield back onto the Nascar banking and if I kept near the the top of 3rd prior to track-out or short shifted to 4th and pulled from about 1000rpm lower I would still reach 120mph at the start/finish line. Even though it felt slower.

traind

Thanks for the effort to make and share that video. You are really good at explaining telemetry! I am sure it will enlighten anyone who takes the time to watch it. And of course your driving is impressive too.

Is all the telemetry driven from the built in pdr or do you use a second program?

Poor-sha

Thanks! All the telemetry is in the PDR file that comes out of the car. I use the Cosworth Pi Toolbox software to display and analyze it. They just released v9.1 and that was used in this video.

buddylight

The ZR1 is a beast.

OnPoint

This thread should be a sticky.

And as such could be a great place for any additional A/B data Sean wants to share.

Newton06

Looking forward to the VIR Full post mortem!

I was hoping to attend, but was late to register. I reached-out to their CI, Mike Newlander & they have a surplus of instructors.

Unless he contacts me tomorrow, I will sit this event out.

Was hoping to meet you & see this beast in action firsthand.

I think your data analysis is spot on. Last weekend I was working on getting on the throttle earlier & harder, especially out of T17 (Hogpen). When I did it right, I picked up >5MPH by the T1 #6 brake marker. My speed at the apex and track-out however was slightly slower than when I entered T1 at a lower speed. I guess I've got to work on recalibrating my braking. When I looked at the telemetry, I was surprised to find that my lap times were generally lower when my TV was higher on the straights.

BrunoTheMellow

From what I can tell, under your hands so far, the zr1 is providing no more lateral grip than the z06 on the same tires at that track. So the downforce seems the same, just less drag on the straights.

Telepierre

Just finished watching F1 in France. Since I am not a tracker, I was reminded this is a game played at hundredths and thousandths of seconds (milli-fractions of seconds)...

Within this context I wonder whether you feel the weight difference (subjectively or objectively on time) between the Z06 and ZR1?
I listened to Tadge/Corvette recommending the 1ZR package for hard core tracking..do you think it would make a big difference to you?

Thanks much for data to chew on!

Poor-sha

I tried to explain this in the video but it sounds like I didn't do a very good job. Short of some very large skidpad this is kind of hard to test, at least for me. I did show where in high speed corners I often saw an extra 0.1G peak which is significant. However, it's really tough to do this empirically when you are talking about high speed corners that don't really have any runoff other than gravel pits. It takes time to work up to entering those corners with more speed.

Palantirion

-No, the downforce is certainly NOT the same. The ZR1 weighs more. If it's lateral Gs are the same as a modded Z06 on the same tires then it can only be due to the ZR1 having more downforce.

That being said, Poorsha still has a lot to learn about pushing the ZR1 and he is going about learning the performance envelope the right way. I look forward to having the same challenge...

BrunoTheMellow

Not a modded Z06. All it had was a DSC controller which doesn't quite help with max Gs, it helps a lot with transitions. The zr1 also only weighs some 50 lbs more. Hardly noticeable.

Palantirion

- 50lbs is noticeable to physics if not to a given driver.

Pizz

Great comparison Poor-sha. Can you comment on the effects of air temps for both runs? Looking at the trees in the background, it looks like the Z06 was run on a spring day (cooler?) and the ZR1 was on a warmer day. Just looking for your insight on this relative to HP and tire performance.

Poor-sha

ZR1 was run in mid-March with an ambient of 61F, the ZR1 was run in June with an ambient of 80. I expect this had some effect on the power but honestly power wasn't the issue as much as driver and corner speed.