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Tracking the NSX in 95+ degree temperatures

Joined
3 January 2003
Messages
588
Location
Newport Beach, CA USA
Summer is here and I'm having trouble waiting until the temps cool down to take my car to the track. Is it bad to track the car when the air temps are over 90 degrees? Even though I track my car, I still like to baby it as much as I can.

I always religiously look at my water temps each lap, but I'm concerned if it's tough on the motor and drivetrain. Also, how tough is the heat on R compound tires? I hear that at 95 degrees air temp, the track can get to over 140 degrees!

Any thoughts?
Ryan Rush
 
Don't worry, you will suffer more than the car (if you put off the A/C to maintain the nominal engine power). If all mechanical and electrical systems are okay, your coolant system is well bleeded and so on your engine will most likely not overheat (I had a lot of overheating issues due to some failures but that did occur also at way lower temps).

But if your engine really would get too hot you will get a warning: Maximum rpms are reduced in this case to about 7000 or below (been there, done that, no damage to the engine).

Regarding the tires: Sport and race tires work best in a temperature window of appr. 176 - 195 degr. F. Tarmac temperatures of 140 deg. are not the main issue there but your driving style - of course when you overstress the tires you will encounter the point where driving gets squirmy earlier than in colder conditions. So drive smooth and watch the recommended hot pressure (depending on the tire brand and type you may need more or less pressure to prevent overheating) after some laps. (Yes, usualy you need to reduce pressure but there are also tires like the Yoko A 005 slicks that react vice versa and need more pressure).
 
As I found recently at the track:

- look and smell for leaks after every session. I run without my engine cover so I could see steam on the back glass and noticed my engine temp starting to rise. We found one of the hose clamps was loose on a small fitting above the engine.

- remove any "radiator shields"

- remove your front license plate (especially if you have the low mount one like I do)

I hadn't had any problem until a recent track day that wasn't very hot - but the sessions were 30+ minutes (vs the 20 or so minutes you normally get). The problems I had didn't appear until end of the 30 minute periods. The coolent leak didn't even show up under a pressure test at the track. The track brings out things that you sometimes have trouble testing for. FYI
 
Search on topics of overheating on track,the cali crew has some guys who would have increased temp on hot days,some had dali radiator shields while others felt they might be following behind cars too closely,I have'nt had problems during 20-30 min sessions in hot weather.
 
Overheating is also a function of the track. At Big Willow, a large section of the track is under full throttle, such as front straight (between turn 9 and 1), between turn 2 and 3, and between turn 6, 7 and 8. The engine is under more stress than at Street of Willow. I had one overheating incidence at Big Willow with an ambient temp of 110 deg F. It was an extremely hot day and the track temp was in the mid 140s in the early afternoon. My car was overheated after two hot laps in the afternoon session. I terminated the session early and cooled down my car. Pay attention to the coolant temperature and the tire pressure. The most important item to prevent overheating is you. Drink a lot of fluid and have some sugar.
 
ryneen said:
Summer is here and I'm having trouble waiting until the temps cool down to take my car to the track. Is it bad to track the car when the air temps are over 90 degrees? Even though I track my car, I still like to baby it as much as I can.

I always religiously look at my water temps each lap, but I'm concerned if it's tough on the motor and drivetrain. Also, how tough is the heat on R compound tires? I hear that at 95 degrees air temp, the track can get to over 140 degrees!

Any thoughts?
Ryan Rush

Hey Ryan,

With really hot track temps, you will notice that even the R-compounds can start to become slippery after a 20-25 minute session.

You can partially get around that by monitoring your tire pressures and starting with tire pressures that are about 2psi less than what you are used to running hot and work from there.

As far as overheating, you will definetely experience it if you are pushing your engine hard, one way to temporarily get around the problem is by installing a vented hood, another way would be by installing a radiator with more cooling capacity. I'm sure that the folks at AutoWave can hook you up with a good setup :D

Keep an eye on your brakes as well, high track temps can lead to problems with braking as well.

One other thing to keep in mind is that because of the tempartures the engine will be down on power and your tires will lack grip as well, so your laptimes might suffer about a 1 to 2 second differential depending on the track, so don't be too surprised if your laptimes are higher.

Ken
 
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