Type S Track Day - Speed Governor
- Thread starter W_Orlando
- Start date
At a reported top speed of 191 mph, I doubt there is a governor on the car. More likely the car is limited based upon power and aerodynamics. That is a lot of air to push out of the way. Most of the magazines report top speed as stated by Honda. There are few tracks around that will allow enough time on a straight/oval to hit that speed. In my opinion.
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I will confirm the top speed is not restricted
Thanks. I think I may have run into a speed limiter that goes along with the warning light I got 'Tires underinflated for high-speed driving". That warning light came on and my pressures were 34-35-35-35 (I think) which is OK for daily driving. For high-speed driving you need to up the cold pressures, which I didn't do. The car flat-lined almost exactly at that number in the door sill. It's just some guessing from my perspective. I didn't notice the warning light until cooling down on the track.
I believe it was SOS’s Chris Wilson who first mentioned that the NSX tires must be force balanced, otherwise if the car senses vibration coming from the wheels that the full power of the engine/electric motors is restricted. All the NSX techs force balance the NSX wheels. If you are not familiar with that process imagine a traditional tire balance machine. As the tire spins there is a small wheel that is pushed against the spinning tread. The force is sufficient to actually deflect the tire. I guess it duplicates super high speed where the tire deforms as it meets the surface of the road. I watched them balance my tires a couple of years ago.
Having said the above, I don’t recall a message about under inflation occurring.
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I've got the 'Tires underinflated for high-speed driving' once - at 280 km/h on the Autobahn while travelling to the Honda shop in Leipzig to get annual service and replace my worn SportContact6 with new SportContact7.
I don't think I noticed any enforced speed restriction, but I more or less immediately slowed down to around 250 km/h to avoid any tire explosion.
As a side note my wife wants me to keep it below 250 km/h so I seldom go faster.
(The NSX is rock steady at 250 km/h, but starts to get slightly excited at 260-270 km/h. Probably because I don't have the rear spoiler that was designed for high speed stability.)
The manual says that normal driving requires the OEM Tires to be at 32 psi cold. For sustained driving over 167 mph the tires should be at 38 psi cold. So if you were showing 34 to 35 was that cold pressure or was it the pressure showing when you got your warning? If the tires were hot at 35 psi then cold would be somewhere around 31. I would be surprised if you got up beyond 145 mph, and if so probably for a short time frame?
By the way here is the write up by SOS on Road Force Balancing: New Tires & Power Loss? Insist on Road Force Balancing for your Second Gen NSX / ScienceofSpeed
By the way here is the write up by SOS on Road Force Balancing: New Tires & Power Loss? Insist on Road Force Balancing for your Second Gen NSX / ScienceofSpeed
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Quote of the day. I'm sure she's thrilled you stop at 250 km/h. Ha:redface:
drmanny, I did not read the high-speed warning about boosting the cold pressures ahead of time. So, I'm pretty sure my cold temps were around 31 or 32. Which then got me to my driving temp of 34-35-35-35. When I saw the warning, it looked like it was identifying the left front which was the "34" tire (I could be wrong about the position of the light, it could have been for any one of the four, but it lit-up near the left front). I scrubbed the tires a little more and the warning light went away, and they all finally read 35 psi. So, the next lap I tried the top speed run again and it really seemed like it had plenty more legs until it hit the 172MPH mark and flat-lined. Granted, it was a short run, and I may have run out of track and slowed before all the data sunk into my brain. It was just my perception at the time. I'm not trying to be an absolutist.
Anyway, if cold pressures for high-speed runs are at 38, hots would be say 44psi, I was nowhere near that. It was fun. Next track day I'll definitely adjust the pressures.
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