Dominion Raceway Road Course Fast Laps

[MasterC17]

Last weekend I went out to Dominion Raceway in Woodford, VA, for a track day. It's a really cool course with a Supercharger 10 minutes away and the event was reasonably priced. If you live in the area, I encourage you to visit. The facilities were nice and they also have NEMA 14-50 outlets onsite.

My fast lap was a 1:33.02 - almost broke into the 1:32's. As far as comparable times are concerned, it looks like C7 Z06's run just under 1:30 on R-Compound tires. So, I'm pretty happy being my first time out with only three sessions on a hot day. The car performed great, really the only issue I am running into with the car now is overheating when ambient temps exceed 70f or so. Hopefully @MountainPass will come out with a solution for that soon.

Here's some video from the event!

 

[mattack4000]

I don’t know if it is so much the ambient temp, these cars just overheat if you push it. I did a full session with data overlay, you can clearly see what happened to the battery temp.

uP might have a solution on it soon.

 

[MasterC17]

I don’t know if it is so much the ambient temp, these cars just overheat if you push it. I did a full session with data overlay, you can clearly see what happened to the battery temp.

uP might have a solution on it soon.

I've done a few events at VIR with ambient temps around 50f and I had no overheating issues. The other's I've done (80f-90f) is when I've had problems.

 

[SigNC]

Looks fun, I just never understood why dominion cheaped out so much on the road course and didnt' make the run offs safe. It completely eliminated it ever being a motorcycle course and it's scary how close those barriers are in a car.

 

[mattack4000]

I've done a few events at VIR with ambient temps around 50f and I had no overheating issues. The other's I've done (80f-90f) is when I've had problems.

Maybe I am being California here. 50F is not normal, 80-90F seems like the typical track weather. I did an event back to back weekend, one at 95 the other at 75, both overheated around the same time. Heck, the 75 I heat up even quicker.

 

[MasterC17]

Looks fun, I just never understood why dominion cheaped out so much on the road course and didnt' make the run offs safe. It completely eliminated it ever being a motorcycle course and it's scary how close those barriers are in a car.

They definitely seem worse in the video than they do in real life. Then again, I'm not looking at the walls haha!

Maybe I am being California here. 50F is not normal, 80-90F seems like the typical track weather. I did an event back to back weekend, one at 95 the other at 75, both overheated around the same time. Heck, the 75 I heat up even quicker.

Our track season typically spends time in the 75-90 range, but a few events a year are in the 50's or 60's which is nice.

 

[Mash]

I have a theory that regen braking overheats everything and without it issue would be gone.

Also, I'm thinking whether removing whole frunk should help radiators to release hot air faster.

 

[MasterC17]

I have a theory that regen braking overheats everything and without it issue would be gone.

Also, I'm thinking whether removing whole frunk should help radiators to release hot air faster.

Someone recently tried running with no regen and said it made no difference. Not sure how scientific it was.

 

[mattack4000]

I think next time I go to Laguna, I will try a lap without regen just to see how it works. I do recall when my car had no regen after the ABS went out, the pedal was super long and hard to apply.

Speaking of brakes, I do remember something interesting. I had some issue last track day and I was driving slower than normal. I was using the brakes maybe a tenth more per corner more than usual to compensate. With such a small adjustment, the car was beeping at me much earlier about the brakes overheating. I pretty much drove the same except I held the brakes a split sec longer. It's amazing how sensitive the car is.

 

[MasterC17]

I think next time I go to Laguna, I will try a lap without regen just to see how it works. I do recall when my car had no regen after the ABS went out, the pedal was super long and hard to apply.

Speaking of brakes, I do remember something interesting. I had some issue last track day and I was driving slower than normal. I was using the brakes maybe a tenth more per corner more than usual to compensate. With such a small adjustment, the car was beeping at me much earlier about the brakes overheating. I pretty much drove the same except I held the brakes a split sec longer. It's amazing how sensitive the car is.

The method in which the brakes are applied has a lot to do with how hot they get (and how quickly they get hot). I'm sure there's a good resource if you search google, but usually when you think you are being more gentle on the brakes you are actually putting more heat into them not less. The quicker you can get the braking done the better.

 

[Mash]

The method in which the brakes are applied has a lot to do with how hot they get (and how quickly they get hot). I'm sure there's a good resource if you search google, but usually when you think you are being more gentle on the brakes you are actually putting more heat into them not less. The quicker you can get the braking done the better.

Rotors lose heat faster when they hotter and speed is higher. They lose it through air convection, radiation and heat that goes to calipers, wheel hubs, rims and brake fluid. Rotors gain heat from kinetic energy difference minus what was dissipated through tires, air drag and bearings.

So if incoming energy per stop is the same (same in&out temps) there is a balance of not letting rotors become too hot and also letting them become hot faster at higher speed so that they remove heat with air more effectively rather than with soaking it into brake fluid. But too jerky brake application unsettling a car and that ends up with less grip and so you have to brake more now...

Unfortunately, without instrumental tests it would take way too long to find that balance and it will be shifting with air temperature and humidity. I'm considering to put whole set of rotor, caliper and tire temp sensors. You can have fun without it, but I'm a geek.

 

[FlyNavy01]

The ambient temps do make a large difference, I had very little overheating problems in the 60-70 winters here in FL, but overheat after 2 laps with the humidity and heat index 100-110 in the summers. I'm waiting for temps to cool back down before I track again.

The Unplugged Pikes Peak car has aftermarket radiator(s) that peaked my interest. It also appears they're using a CO2 system for extra battery cooling that I'd be curious to learn more about.

 

[MasterC17]

The ambient temps do make a large difference, I had very little overheating problems in the 60-70 winters here in FL, but overheat after 2 laps with the humidity and heat index 100-110 in the summers. I'm waiting for temps to cool back down before I track again.

The Unplugged Pikes Peak car has aftermarket radiator(s) that peaked my interest. It also appears they're using a CO2 system for extra battery cooling that I'd be curious to learn more about.

It looked like from what I could see in the videos/pics that they replaced the stock radiator (there's only one) with a bigger Setrab looking unit including new lines. They also cut those holes in the front bumper cover to feed more air and replaced the stock louvres/ducting with a big aluminum shroud (to give a path for the new air). Do you have more info on the CO2 system?

The stock radiator is tiny, so I think that is the most obvious thing to replace.

 

[FlyNavy01]

It looked like from what I could see in the videos/pics that they replaced the stock radiator (there's only one) with a bigger Setrab looking unit including new lines. They also cut those holes in the front bumper cover to feed more air and replaced the stock louvres/ducting with a big aluminum shroud (to give a path for the new air). Do you have more info on the CO2 system?

The stock radiator is tiny, so I think that is the most obvious thing to replace.

This photo and short clip from twitter shows two small black heat exchangers that they have beneath each headlight. Looks similar in size/shape/location to oil coolers in a traditional ICE car. Not sure what they're being used for, maybe just supplemental to the main radiator?

https://twitter.com/Sofiaan/status/1299436682098352129?s=20

You can see in the in-car videos, there's a "CO2 ON" light placed right in front of the driver, and someone commented they were using it
for battery cooling. I've been trying to find more info on it.

 

[MasterC17]

This photo and short clip from twitter shows two small black heat exchangers that they have beneath each headlight. Looks similar in size/shape/location to oil coolers in a traditional ICE car. Not sure what they're being used for, maybe just supplemental to the main radiator?

https://twitter.com/Sofiaan/status/1299436682098352129?s=20

You can see in the in-car videos, there's a "CO2 ON" light placed right in front of the driver, and someone commented they were using it
for battery cooling. I've been trying to find more info on it.

Interesting, it looks like they removed the stock radiator but retained the stock A/C condenser. Then put an aftermarket radiator on top of the stock louvre/shroud in the center of the car. But to your point they also added two coolers behind the fog light inlets. I wonder if those are going to the drive units? The drive units are primarily cooled by oil, but the stock setup has no oil cooler(s). Increasing capacity and adding cooling would definitely help temps. That being said, those hoses LOOK like they have coolant, given the size and clamps.

 

[mcbarnet007]

Awesome driving, very consistent. You really are putting those RS-4 to work. I love the balance of your car, do you mind sharing your alignment and sway bar setting?

 

[Zcd1]

...The Unplugged Pikes Peak car...peaked my interest...

I see what you did there....very clever... ;-)

 

[MasterC17]

Awesome driving, very consistent. You really are putting those RS-4 to work. I love the balance of your car, do you mind sharing your alignment and sway bar setting?

Thanks! The RS-4's are holding up great

UP Sways with the front set to the softest setting and the rear to the medium setting. -2.5 degrees of Camber all around, 0 toe in the front and .25 degrees of toe in the rear.

 

[Dolemite]

Dammit I thought overheating was a Model S thing.

 

[TwoK4drSi]

This photo and short clip from twitter shows two small black heat exchangers that they have beneath each headlight. Looks similar in size/shape/location to oil coolers in a traditional ICE car. Not sure what they're being used for, maybe just supplemental to the main radiator?

View attachment 582355

https://twitter.com/Sofiaan/status/1299436682098352129?s=20

You can see in the in-car videos, there's a "CO2 ON" light placed right in front of the driver, and someone commented they were using it
for battery cooling. I've been trying to find more info on it.

It looks like veterans are now drinking the ev juice. Skip to 6:05.....dry ice for cooling the car. EV car racing is gonna be the newest thing.