Z/28 at Thunderhill 5-Mile - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

brt3 · 09-30-2014, 12:22 AM

Spent a great weekend at Thunderhill -- and this time the highs were in the 70s and 80s, instead of 105 degrees like last time. I am still learning the track, but got my time down to 3:40. My camera kept freezing, so the second and third laps in the video are 3:44 and 3:48. Had a blast; this car is MEGA. It continues to attract a huge amount of attention; people really seem to love this car...

Video is here: CLICK HERE TO WATCH IT NOW

brt3 · 09-30-2014, 12:23 AM

One thing I've realized with this car is that it's all too easy to switch off the brain and go into Hooligan Mode. The car has such high limits and is such a blast, but over-driving the car is slower and -- more importantly -- hard on the tires. Which means $$$$ instead of $$...

The crux of this is the weight of the car. Even with those massive contact patches, the brakes are so brutally strong that you can overpower the tires. The final turn on the new (west) circuit has a short straight where you pop over a crest, go downhill, and have to brake hard to make a 90-degree right onto the old (east) circuit.

I was playing with a GT3 and was amazed by how I could really close on him in this area. I was braking later and later, and shortening the braking window by really slamming on the brakes. I got to the point where the tires started slipping and chattering, and at that point I went back to really paying attention to transitions in order to be smoother.

I find heavy cars are a little more like dancing. You really need to think ahead and set the rhythm for the car to follow. Simple actions -- like easing off the throttle to give the fronts a little more bite on fast sweepers -- really seem to make a difference. Slow in, fast out is how I prefer to drive the Z/28.

Guy Gamba of OnEdge Performance is always on hand, with a full crew, at most Hooked On Driving events. I think Guy has forgotten more about tires than most of us ever knew. He uses Pirelli Trofeo Rs on his daily-driver BMW, and he really knows the ins and outs of this tire.

One of the services Guy provides is a full check after a session, with pyrometers and tire gauges. I've included the two checklists I received on Sunday. You can tell that it got cooler as the day went on; we even had a smattering of rain.

Guy was hugely complimentary about the car and could tell, from the temps and pressures, that I was driving the car smoothly. I won't say well as I'm still learning the car and building my confidence in its limits, but it felt great to me. He also said that the tire chart was exceptional for the Thunderhill 5-mile track. You can see, from the videos, that there are some extreme loads going on, and not many places where the car gets a rest during a lap.

Look at these numbers. All about the tires? No way. This really shows how Team Z/28 designed the car to function as the sum of its parts. From the photos above you can see how well-controlled the MultiMatic shocks and suspension are. On my car each corner has 6+ less pounds to cope with, because of my custom wheels. When driven just under or at the limit without aggressive control inputs, the tire temps are remarkably even.

After playing with the tire pressures, I can attest that 32 psi seems to be the magic number (at the tracks and conditions I've driven) for the Z/28–Trofeo/R combo. IMHO, of course...

brt3 · 09-30-2014, 12:24 AM

One more thing...

As I'm reaching the limits of the car, I'm realizing that a harness is mandatory for track usage. Under maximum braking there is simply no way to avoid bracing yourself with your legs, feet, arms and hands. I have no doubt, after this weekend, that this compromises control. I realize there are mixed feelings about this, but I think I'll be placing an order with Brey-Krause this week. This seems to be one of the best engineered harness bars on the market, and it's also said to work for tall people...

Mikamaro · 09-30-2014, 11:15 AM

Nice report! thank you.
Any chance to get to see the video on youtube?

brt3 · 09-30-2014, 12:16 PM

Quote:

Originally Posted by Mikamaro

Nice report! thank you.
Any chance to get to see the video on youtube?

Does the Vimeo link at the top not work for you, or are you just suggesting it would be better to post this on YouTube?

Nor Cal ZL1 · 09-30-2014, 10:31 PM

Hi R,

Those tire temp spreads look pretty good. Were these after a hot lap and measured as soon as you exited?

brt3 · 09-30-2014, 10:35 PM

Quote:

Originally Posted by Nor Cal ZL1

Hi R,

Those tire temp spreads look pretty good. Were these after a hot lap and measured as soon as you exited?

Yes. I was also staying close to the limit until the pit exit, and got to the tire station as quickly as possible.

owhite3003 · 11-01-2014, 04:12 PM

Very nice!!

FKNGRSY · 11-01-2014, 05:40 PM

Uggh. These Z28's are just fantastic. Looks like alot of fun, Noticed you have the "wickerbill" add on for the wing. Did you notice much difference with that on? Curious how much added downforce it offers. Thanks!

UF4LIFE102SS · 11-01-2014, 05:52 PM

Loved it (video) nobody wants to see the Z/28 on dat azz!!!!!!!!!!!!!!!!!!

cornerspeed92 · 11-01-2014, 07:16 PM

BruHop · 11-01-2014, 07:54 PM

That car is fast! I also noticed you weren't pointing anyone by. Must have an empty rear view mirror.

What a great track.

brt3 · 11-02-2014, 06:03 PM

Quote:

Originally Posted by FKNGRSY

Uggh. These Z28's are just fantastic. Looks like alot of fun, Noticed you have the "wickerbill" add on for the wing. Did you notice much difference with that on? Curious how much added downforce it offers. Thanks!

It's very hard to say how much difference the wickerbill makes -- as far as what you actually feel. I wish I'd done a before and after at a track I know well, like Laguna Seca. The first time I ran Thunderhill's 5-mile circuit was without the wickerbill. However, this was the very first time I'd driven the track, and I was learning it and not really pushing. Furthermore, they had to switch us around from the full circuit to the old circuit, a couple of times. The pavement started lifting on the new circuit, as the temps were over 104 degrees. This made it really hard to learn the track and be consistent.

The second time I drove the Thunderhill 5-mile is what I posted here. I was starting the get the hang of the circuit and getting a better feel for the limits of my car. I can't wait to get back on that track and see just how far and how fast I can pedal the Z/28...

09-30-2014, 12:22 AM	#1
brt3 Runs with scissors... Drives: '14 Z/28s SIM/SW Join Date: Jan 2013 Location: Austin, TX Posts: 1,439	Z/28 at Thunderhill 5-Mile Spent a great weekend at Thunderhill -- and this time the highs were in the 70s and 80s, instead of 105 degrees like last time. I am still learning the track, but got my time down to 3:40. My camera kept freezing, so the second and third laps in the video are 3:44 and 3:48. Had a blast; this car is MEGA. It continues to attract a huge amount of attention; people really seem to love this car... Video is here: *CLICK HERE TO WATCH IT NOW* __________________ Last edited by brt3; 09-30-2014 at 12:17 PM.

09-30-2014, 12:23 AM	#2
brt3 Runs with scissors... Drives: '14 Z/28s SIM/SW Join Date: Jan 2013 Location: Austin, TX Posts: 1,439	One thing I've realized with this car is that it's all too easy to switch off the brain and go into Hooligan Mode. The car has such high limits and is such a blast, but over-driving the car is slower and -- more importantly -- hard on the tires. Which means $$$$ instead of $$... The crux of this is the weight of the car. Even with those massive contact patches, the brakes are so brutally strong that you can overpower the tires. The final turn on the new (west) circuit has a short straight where you pop over a crest, go downhill, and have to brake hard to make a 90-degree right onto the old (east) circuit. I was playing with a GT3 and was amazed by how I could really close on him in this area. I was braking later and later, and shortening the braking window by really slamming on the brakes. I got to the point where the tires started slipping and chattering, and at that point I went back to really paying attention to transitions in order to be smoother. I find heavy cars are a little more like dancing. You really need to think ahead and set the rhythm for the car to follow. Simple actions -- like easing off the throttle to give the fronts a little more bite on fast sweepers -- really seem to make a difference. Slow in, fast out is how I prefer to drive the Z/28. Guy Gamba of OnEdge Performance is always on hand, with a full crew, at most Hooked On Driving events. I think Guy has forgotten more about tires than most of us ever knew. He uses Pirelli Trofeo Rs on his daily-driver BMW, and he really knows the ins and outs of this tire. One of the services Guy provides is a full check after a session, with pyrometers and tire gauges. I've included the two checklists I received on Sunday. You can tell that it got cooler as the day went on; we even had a smattering of rain. Guy was hugely complimentary about the car and could tell, from the temps and pressures, that I was driving the car smoothly. I won't say well as I'm still learning the car and building my confidence in its limits, but it felt great to me. He also said that the tire chart was exceptional for the Thunderhill 5-mile track. You can see, from the videos, that there are some extreme loads going on, and not many places where the car gets a rest during a lap. Look at these numbers. All about the tires? No way. This really shows how Team Z/28 designed the car to function as the sum of its parts. From the photos above you can see how well-controlled the MultiMatic shocks and suspension are. On my car each corner has 6+ less pounds to cope with, because of my custom wheels. When driven just under or at the limit without aggressive control inputs, the tire temps are remarkably even. After playing with the tire pressures, I can attest that 32 psi seems to be the magic number (at the tracks and conditions I've driven) for the Z/28–Trofeo/R combo. IMHO, of course... __________________

09-30-2014, 12:24 AM	#3
brt3 Runs with scissors... Drives: '14 Z/28s SIM/SW Join Date: Jan 2013 Location: Austin, TX Posts: 1,439	One more thing... As I'm reaching the limits of the car, I'm realizing that a harness is mandatory for track usage. Under maximum braking there is simply no way to avoid bracing yourself with your legs, feet, arms and hands. I have no doubt, after this weekend, that this compromises control. I realize there are mixed feelings about this, but I think I'll be placing an order with Brey-Krause this week. This seems to be one of the best engineered harness bars on the market, and it's also said to work for tall people... __________________

09-30-2014, 11:15 AM	#4
Mikamaro MikeNoMaro Drives: A 2016 Challenger R/T M6 STP Join Date: Sep 2009 Location: America Posts: 2,375 View My Garage	Nice report! thank you. Any chance to get to see the video on youtube? __________________ Track Day Videos: http://www.youtube.com/user/mrgoodman2000/videos Built #83817, Born January 18th, Christened June 11th 2010, Stolen October 3rd 2016.

11-01-2014, 05:52 PM	#10
UF4LIFE102SS Treasure Coast Camaro 5 Drives: 2010 2 SS Join Date: Nov 2010 Location: Vero Beach, FL. Posts: 4,239 View My Garage	Loved it (video) nobody wants to see the Z/28 on dat azz!!!!!!!!!!!!!!!!!! __________________

09-30-2014, 10:31 PM	#6
Nor Cal ZL1 Drives: 2013 ZL1 M6 Join Date: Oct 2013 Location: Nor Cal Posts: 1,825	Hi R, Those tire temp spreads look pretty good. Were these after a hot lap and measured as soon as you exited?

11-01-2014, 04:12 PM	#8
owhite3003 Z-BEAST Drives: 2013 JDP ZL-850 Track Spec ZL1, Join Date: Mar 2013 Location: Oregon City, OR Posts: 1,470	Very nice!!

11-01-2014, 05:40 PM	#9
FKNGRSY Drives: 2014 1SS Join Date: May 2014 Location: Canada Posts: 158	Uggh. These Z28's are just fantastic. Looks like alot of fun, Noticed you have the "wickerbill" add on for the wing. Did you notice much difference with that on? Curious how much added downforce it offers. Thanks!

11-01-2014, 07:16 PM	#11
cornerspeed92 Drives: 2013 1SS 1LE Join Date: Jul 2012 Location: Colorado Posts: 4,188 View My Garage	__________________

11-01-2014, 07:54 PM	#12
BruHop Drives: 2014 2SS 1LE,RS,NPP,Recaros in SW Join Date: Apr 2012 Location: Sacramento Posts: 401	That car is fast! I also noticed you weren't pointing anyone by. Must have an empty rear view mirror. What a great track.