938 feet/sec or 640 MPH assuming it was falling nose down. :smile:
For comparison's sake, it if was dropped from 25,000 feet over Mars with its thinner atmosphere, terminal velocity would be 4543 feet/sec or 3100 MPH.
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Broke 300 km/h!
- Thread starter greenberet
- Start date
938 feet/sec or 640 MPH assuming it was falling nose down. :smile:
For comparison's sake, it if was dropped from 25,000 feet over Mars with its thinner atmosphere, terminal velocity would be 4543 feet/sec or 3100 MPH.
I know this is a different subject but I wonder what the top speed of the NSX would be on the Bonneville Salt Flats.
I took my lexus is300 out there last year and did 140mph at 5000+ feet and ambient temp of over 100 degrees at 10am.
I am thinking about taking my NSX out there this year to see what it would do.
189mph, Very Impressive!
I took my lexus is300 out there last year and did 140mph at 5000+ feet and ambient temp of over 100 degrees at 10am.
I am thinking about taking my NSX out there this year to see what it would do.
189mph, Very Impressive!
Who call BS to this only proves to me that they don't know the car they have.. or at least never pushed it anywhere near what it can do.
I posted here a long time ago a video of my cell phone showing my speedo reaching the 300km/h mark... i know my NSX has a difference of 2km/h between speedo and GPS (measured at 290km/h).
i have ended the 5th gear on my NSX (8100 rpm at the tacho) and the speedo was good bit below the 300km/h mark. Based on some calculation, with the tire sizes and gear ratios, i reached a 307km/h maximum for my NSX.
I'll try to host again the little video and will post it here.
Please, i ask that a good ammount of thinking is spent before posting calling others BSers. I think we are all mature and that no one profits anything lying arround.
EDIT: ohh...and my NSX only is lowered 1", has no cats, AIS and a KN filter in stock airbox.... i bought it from germany with 120000kms of Autobahn hi speed use
I posted here a long time ago a video of my cell phone showing my speedo reaching the 300km/h mark... i know my NSX has a difference of 2km/h between speedo and GPS (measured at 290km/h).
i have ended the 5th gear on my NSX (8100 rpm at the tacho) and the speedo was good bit below the 300km/h mark. Based on some calculation, with the tire sizes and gear ratios, i reached a 307km/h maximum for my NSX.
I'll try to host again the little video and will post it here.
Please, i ask that a good ammount of thinking is spent before posting calling others BSers. I think we are all mature and that no one profits anything lying arround.
EDIT: ohh...and my NSX only is lowered 1", has no cats, AIS and a KN filter in stock airbox.... i bought it from germany with 120000kms of Autobahn hi speed use
Are you sure? You are saying it will FALL at almost the speed of sound????
Hugh, I think 640 mph is about the highest velocity an NSX falling nose-down would reach at 25,000 feet. If it were dropped from 25,000 feet, it would take some time to speed up and it would reach its highest velocity at a lower altitude. At that lower altitude, the air would be denser and the terminal velocity would be below 640 mph. But you are in the right ballpark!
davidg, I'm running Falken FK-452 tires and the car felt perfectly stable on the straights except for when I hit the brakes to slow down for a turn. Maybe the aerodynamics changed a little when the nose went down or maybe I just imagined it. Through the turns the car felt completely stable but I wasn't anywhere near the limit of adhesion.
ARFNSXTC, according to this web page, your car should be producing about 19% less horsepower at 5000 feet in 100 degree temperatures than it would in SAE standard conditions. On the other hand, the reduced air density will reduce your wind resistance by the same amount. With the decrease in horsepower your acceleration will be slower but the top speed should not be affected. However, I assume that driving on salt will increase your rolling resistance and therefore decrease your top speed.
UnhuZ, so your car is a stock 1997 3.2 except for the air intake scoop, the K&N air filter, no cats, and being lowered 1"? Wow. With a 5th gear ratio of .914 and a final drive ratio of 4.062, 8100 rpm should get you 258 km/h if the tires have zero wear. If you got to 307 km/h (7560 rpm in sixth gear with new tires) on a flat road without wind, your engine must be a real cherry. I'd love to see the video and a GPS measurement!
davidg, I'm running Falken FK-452 tires and the car felt perfectly stable on the straights except for when I hit the brakes to slow down for a turn. Maybe the aerodynamics changed a little when the nose went down or maybe I just imagined it. Through the turns the car felt completely stable but I wasn't anywhere near the limit of adhesion.
ARFNSXTC, according to this web page, your car should be producing about 19% less horsepower at 5000 feet in 100 degree temperatures than it would in SAE standard conditions. On the other hand, the reduced air density will reduce your wind resistance by the same amount. With the decrease in horsepower your acceleration will be slower but the top speed should not be affected. However, I assume that driving on salt will increase your rolling resistance and therefore decrease your top speed.
UnhuZ, so your car is a stock 1997 3.2 except for the air intake scoop, the K&N air filter, no cats, and being lowered 1"? Wow. With a 5th gear ratio of .914 and a final drive ratio of 4.062, 8100 rpm should get you 258 km/h if the tires have zero wear. If you got to 307 km/h (7560 rpm in sixth gear with new tires) on a flat road without wind, your engine must be a real cherry. I'd love to see the video and a GPS measurement!
eaeaheah... my car is a 97 one...but it is NA1, as it says my signature :wink:
so...no 6th gear... no 3.2 engine ... only 5 speeds and 3.0 engine :wink:
in fact, my car was assembled somewhere during 95. It was sold new in Germany, March 97, to a gentlemen that become a friend after i bought the car.. i bought one (the oldest) of his 3 NSX's... he say that his 04 one will be mine ... hope so ...:biggrin: :biggrin:
i've had the opportunity to be in several NSX at top speed... this one is the strongest i've been on. it's amazing the speed he can reach with virtually no mods...
the 307km/h weren't on a flat road...was in a desert highway we have here, at about 2am... i was cruising at about 260/270 and i saw ahead a slight downhill...so i floored it to see what the NSX was capable of...it was a straight descent of about 4km...at the middle of it, my 5th gear ended at 8100 rpm (read at the tacho).
in a flat road, the maximum speed i could do was 300km/h at the speedo...297km/h at gps...and the NSX seems to not be able to go further no matter how much kms i would force him....
I suppose that with a exhaust+headers system and with a front to back flat bottom (with extractor at the tail) i would be able to cut the 5th gear on a flat road :wink:
congratulations on your german autobahn activities eaheahhaehe
all the best,
Nuno
EDIT - i'll try to find that old 300km/h video (it was on a flat road).
You are running the same tires as I am. What sizes are you using?
A bit off topic here but are you also coming to the Ring when the UK guys are there also?
I'm running stock 2002+ sizes, so 215/40 17 in the front and 255/40 17 in the rear. And unfortunately no, I wasn't planning to be at the Ring when the UK guys are going.
just want to chime in on this debate of bs or not, the 2004 Acura TL can reach 160, but is limited to 160. that is with 220 WHP and around 190 WTQ, it is a heavier car with more air resistance. I am sure that the NSX could reach 190, even with a 5 speed and 3litre motor, but it would take some time.
I’m starting to think that rpm are not a very accurate way of measuring top speed and that you really need to do a two-way run to determine the car’s “real” top speed.
Top speed cannot be accurately calculated from rpm
When my GPS showed that I was going 304.1 km/h, the needle of the tachometer was covering the lowest of the three horizontal portions of the 8. Looking closely, that’s 8140 rpm. With a 0.771 gear ratio, a 4.062 final drive ratio, and 255/40 17 rear tires, that should have equaled 311.5 km/h. Somewhere, I was losing 7.4 km/h and was traveling 2.38% slower than the rpm indicated.
Some of that is surely due to tire wear, a slightly inaccurate tachometer, maybe the tires didn't have exactly the circumference you'd expect straight from the factory, etc. When my GPS showed that I was going 147.6 km/h, the tachometer showed 3900 rpm. That should have been 149.2 km/h, so all of those factors were causing the car to travel 1.07% slower than the rpm indicated.
At top speed, that gap had increased from 1.07% to 2.38%. Either the clutch was slipping or the tires were slipping by an increasing percentage. Since I have an uprated Comptech clutch, I put it down to the tires. How much the tires slip is affected by amount of torque they are transmitting, the road's coefficient of friction, the amount of weight pushing the tires onto the road, etc. Due to all of these variables, you cannot calculate the actual top speed based on the indicated rpm very accurately. To measure the top speed accurately, you need either a GPS device or a stopwatch.
You need to do a two-way run to determine the car’s “real” top speed
304.1 km/h was the top speed I reached in January according to GPS. I can’t say that’s the “real” top speed of the car, though. Driving on the A92 along the Isar river by Dingolfing and dropping 14 cm per kilometer, the slope should have added 0.09 km/h to my top speed. However, if the drop was actually 1.7 meters per kilometer that would have added 1 km/h to the top speed and such a slight drop would be hard to see with the naked eye. A tailwind of 1 km/h would also have added about 1 km/h to the top speed. The wind socks weren’t showing any wind, but maybe there was a tailwind in one of the many places where there was no wind sock. In any case, without doing a two-way run, I cannot be sure that there were neither slope nor wind adding to my car’s top speed.
The last time I did a two-way run is when the picture in my avatar was taken. Back then, the car had the same engine and aerodynamic modifications it has now except it didn’t yet have the front undertray and the front blinker covers. Without the undertray and blinker covers but with two people on board, it pulled to an indicated 8050 rpm in one direction (avatar picture) and to an indicated 8000 rpm in the other direction. With 245/40 17 rear tires, that calculates out to 304.2 km/h and 302.3 km/h. Without having a GPS on board, I can’t say how fast it really was, though. If I knew the two actual speeds, then the average of the two would be the car’s “real” top speed before it had the undertray and blinker covers. To prove to third parties that I had actually turned the car around and ran both directions, I would have probably needed a video camera.
Whatever
The undertray and blinker covers should make it a bit more aerodynamic now. Maybe the engine is making a few more horsepower due to looser bearing clearances and carbon deposits on the pistons, increasing the compression ratio and meaning that the 100 RON octane fuel I fill it up with isn't wasted (the engine computer was programmed for 98 RON). Or not. In any case, whether my car's "real" top speed is a bit over or a bit under 300 km/h, it broke 300 on that run, making me happy camper!
Top speed cannot be accurately calculated from rpm
When my GPS showed that I was going 304.1 km/h, the needle of the tachometer was covering the lowest of the three horizontal portions of the 8. Looking closely, that’s 8140 rpm. With a 0.771 gear ratio, a 4.062 final drive ratio, and 255/40 17 rear tires, that should have equaled 311.5 km/h. Somewhere, I was losing 7.4 km/h and was traveling 2.38% slower than the rpm indicated.
Some of that is surely due to tire wear, a slightly inaccurate tachometer, maybe the tires didn't have exactly the circumference you'd expect straight from the factory, etc. When my GPS showed that I was going 147.6 km/h, the tachometer showed 3900 rpm. That should have been 149.2 km/h, so all of those factors were causing the car to travel 1.07% slower than the rpm indicated.
At top speed, that gap had increased from 1.07% to 2.38%. Either the clutch was slipping or the tires were slipping by an increasing percentage. Since I have an uprated Comptech clutch, I put it down to the tires. How much the tires slip is affected by amount of torque they are transmitting, the road's coefficient of friction, the amount of weight pushing the tires onto the road, etc. Due to all of these variables, you cannot calculate the actual top speed based on the indicated rpm very accurately. To measure the top speed accurately, you need either a GPS device or a stopwatch.
You need to do a two-way run to determine the car’s “real” top speed
304.1 km/h was the top speed I reached in January according to GPS. I can’t say that’s the “real” top speed of the car, though. Driving on the A92 along the Isar river by Dingolfing and dropping 14 cm per kilometer, the slope should have added 0.09 km/h to my top speed. However, if the drop was actually 1.7 meters per kilometer that would have added 1 km/h to the top speed and such a slight drop would be hard to see with the naked eye. A tailwind of 1 km/h would also have added about 1 km/h to the top speed. The wind socks weren’t showing any wind, but maybe there was a tailwind in one of the many places where there was no wind sock. In any case, without doing a two-way run, I cannot be sure that there were neither slope nor wind adding to my car’s top speed.
The last time I did a two-way run is when the picture in my avatar was taken. Back then, the car had the same engine and aerodynamic modifications it has now except it didn’t yet have the front undertray and the front blinker covers. Without the undertray and blinker covers but with two people on board, it pulled to an indicated 8050 rpm in one direction (avatar picture) and to an indicated 8000 rpm in the other direction. With 245/40 17 rear tires, that calculates out to 304.2 km/h and 302.3 km/h. Without having a GPS on board, I can’t say how fast it really was, though. If I knew the two actual speeds, then the average of the two would be the car’s “real” top speed before it had the undertray and blinker covers. To prove to third parties that I had actually turned the car around and ran both directions, I would have probably needed a video camera.
Whatever
The undertray and blinker covers should make it a bit more aerodynamic now. Maybe the engine is making a few more horsepower due to looser bearing clearances and carbon deposits on the pistons, increasing the compression ratio and meaning that the 100 RON octane fuel I fill it up with isn't wasted (the engine computer was programmed for 98 RON). Or not. In any case, whether my car's "real" top speed is a bit over or a bit under 300 km/h, it broke 300 on that run, making me happy camper!
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Sunday morning I wanted to shoot a video to post on NSX Prime. No music, no voice-over, just the sights and sounds you get driving an NSX flat-out on an almost deserted Autobahn with a GPS device showing the speed. Unfortunately, fortune did not favor me.
I got up at 3:30 am so that I could make it to Germany at first light. I lashed my tripod to the glove compartment with a belt, mounted my little digital picture camera on top, and stuck my Garmin to the windshield in front of the camera.
By 5:30 am I reached a straight, flat section of the A92 heading west towards Munich. There was enough light that I no longer needed my headlights and there was almost no traffic. I hit record on the camera and opened the throttle all the way. At the end of a long straight, the Garmin showed I had just gotten up to 301 km/h. Last time I did a top speed run, I only measured in one direction so this time, I wanted to do a two way run. I slowed down to 100 km/h so that the car could cool down, took the next exit, and turned around. At the end of that straight going the other direction, the GPS showed 298 km/h. Not satisfied, I turned around, went back, and then repeated the run eastwards again. This time, I accelerated through the turn before the straight at full throttle as well and at the end, the GPS showed that I had gotten up to 299 km/h, giving me a two-way, GPS-measured, video-documented top speed of 300 km/h.
Shifting my attention to the camera, I saw that the message “card full” was showing. Did the camera record getting up to 299 km/h on that last run? I pulled off the Autobahn and put the card into my notebook’s card reader. Instead of showing the files on the card, the computer said the card was not formatted and asked whether I wanted to format it. No! I put the card back into the camera and now the camera displayed “card error”. Despite profuse cursing, cleaning the contacts repeatedly, and trying both devices back and forth, I could not see the contents of the card on either the camera or my laptop.
Since the videos seemed to be gone anyhow, I let my laptop reformat the card so that I could record some new runs. After reformatting, my camera still said “card error” and further attempts didn’t help. I couldn’t record any new videos. Pissed off and disappointed, I tossed the memory card into the coin tray, mounted the Garmin in the middle of the windshield so that I could see it better, and headed back home.
Along the way, the Autobahn headed through a hilly area. On a downhill stretch, the car easily got past 300 km/h and at 305 km/h it abruptly ran into the rev limiter. The engine stuttered just as it does if you run into the rev limiter in one of the lower gears and with the stuttering, the speed on the GPS display dropped to 303 km/h. I remembered that my camera has enough internal memory to take a few pictures if there’s no memory card installed so I shot a picture after slowing down a bit.
I now know that my NSX has a real top speed of 300 km/h and if the conditions are favorable (downhill or with a tailwind), it can run into the rev limiter at 305 km/h. It was interesting to see first hand how much the top speed is affected by the conditions and when I got up to 304.1 km/h in January (first post of this thread), I must have had a tailwind.
PS: The Bosch Aerotwin windshield wipers you can see in the pictures below don’t wipe very well on the driver’s side at higher speeds on the downward stroke, at least not in the 600mm and 530mm lengths. I have yet to try 500mm on the driver's side. However, they do reduce wind noise.
I got up at 3:30 am so that I could make it to Germany at first light. I lashed my tripod to the glove compartment with a belt, mounted my little digital picture camera on top, and stuck my Garmin to the windshield in front of the camera.
By 5:30 am I reached a straight, flat section of the A92 heading west towards Munich. There was enough light that I no longer needed my headlights and there was almost no traffic. I hit record on the camera and opened the throttle all the way. At the end of a long straight, the Garmin showed I had just gotten up to 301 km/h. Last time I did a top speed run, I only measured in one direction so this time, I wanted to do a two way run. I slowed down to 100 km/h so that the car could cool down, took the next exit, and turned around. At the end of that straight going the other direction, the GPS showed 298 km/h. Not satisfied, I turned around, went back, and then repeated the run eastwards again. This time, I accelerated through the turn before the straight at full throttle as well and at the end, the GPS showed that I had gotten up to 299 km/h, giving me a two-way, GPS-measured, video-documented top speed of 300 km/h.
Shifting my attention to the camera, I saw that the message “card full” was showing. Did the camera record getting up to 299 km/h on that last run? I pulled off the Autobahn and put the card into my notebook’s card reader. Instead of showing the files on the card, the computer said the card was not formatted and asked whether I wanted to format it. No! I put the card back into the camera and now the camera displayed “card error”. Despite profuse cursing, cleaning the contacts repeatedly, and trying both devices back and forth, I could not see the contents of the card on either the camera or my laptop.
Since the videos seemed to be gone anyhow, I let my laptop reformat the card so that I could record some new runs. After reformatting, my camera still said “card error” and further attempts didn’t help. I couldn’t record any new videos. Pissed off and disappointed, I tossed the memory card into the coin tray, mounted the Garmin in the middle of the windshield so that I could see it better, and headed back home.
Along the way, the Autobahn headed through a hilly area. On a downhill stretch, the car easily got past 300 km/h and at 305 km/h it abruptly ran into the rev limiter. The engine stuttered just as it does if you run into the rev limiter in one of the lower gears and with the stuttering, the speed on the GPS display dropped to 303 km/h. I remembered that my camera has enough internal memory to take a few pictures if there’s no memory card installed so I shot a picture after slowing down a bit.
I now know that my NSX has a real top speed of 300 km/h and if the conditions are favorable (downhill or with a tailwind), it can run into the rev limiter at 305 km/h. It was interesting to see first hand how much the top speed is affected by the conditions and when I got up to 304.1 km/h in January (first post of this thread), I must have had a tailwind.
PS: The Bosch Aerotwin windshield wipers you can see in the pictures below don’t wipe very well on the driver’s side at higher speeds on the downward stroke, at least not in the 600mm and 530mm lengths. I have yet to try 500mm on the driver's side. However, they do reduce wind noise.
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I am sorry about this. If you need so, I can send you some formatted memory cards so I can see video.
I am pulling for you. Good luck and be safe out there!
I am pulling for you. Good luck and be safe out there!
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