top speed

[greenberet]

Wow, fantastic figures.
I would very much like to know more about your homemade front undercover.
What did you make it from.
Also, do you have some more information about your engine output. I read that you had the camshafts done.
If possible, post some pictures.

I'll get my NSX somewhere that can lift it high enough that I can take some decent pictures. On my jack stands at home, I'd be so close that I could only get you some macro pictures. :smile:

Regarding the horsepower, attached is a dyno graph that was made in 1997. As you can see, the power at the rear wheels (Prad) was measured as 195.5 kilowatts, which is about 265 horsepower. According to the old FAQ section of NSX Prime, 3.0 NSX engines with the full Comptech naturally aspirated modifications usually put out 265-270 rwhp, so mine falls right in there.

The dynomometer that measured the horsepower was used for vehicle certification tests by the government, so it should be relatively accurate, but who knows. In any case, I'd imagine that my car now probably has a few less horsepower because it's a decade older.

 

[goldNSX]

In any case, I'd imagine that my car now probably has a few less horsepower because it's a decade older.

NSX engine normally gets better the longer they have been driven (hard). :wink: It's said that after 100k km it frees some horses (mine has just a little bit more than that and the power increase at exactly 100.001k km was phenomenal and unbelievable! :tongue: J/K)

Interesting: What did you do exactly to your engine? Any measures of torque?

 

[greenberet]

I didn't get a torque graph from Bosch, but I think you can calculate the torque based on the hp and engine speed. Or in this case, calculate the rpm from the km/h, and then the torque from the rpm and kW. Hmmm, not something that sounds very attractive right now.

Regarding what I did to my engine: Comptech air box and foam air filter, extrudehoned intake manifold, Comptech ported and polished cylinder heads, milled for increased compression ratio (~10.6:1), Comptech modified VTEC lobes on the camshafts, Cantrell ceramic coated headers, HKS muffler, Autothority custom programmed engine management chip, Comptech high flow oil pump

 

[areout]

In southern Germany this morning, I managed to get my NSX up to 299.3 km/h (186.0 mph).

After rounding a bend on the Autobahn, I saw a long straight in front of me so I floored it. In the middle of the straight I caught up with another car and slowed a little while overtaking. Once safely past, I floored it again and kept it floored until I needed to brake for another bend. By the end of the straight, I had gotten up to 299 km/h. The car was barely accelerating anymore, but if the straight would have been longer, if I hadn't slowed while overtaking that car, if it would have been cooler out (OK, enough excuses), the GPS would probably have shown just a bit over 300 km/h. Maybe another day.

I was in fifth gear and at that speed, the tachometer was pretty much at 8000 rpm, similar to where it was when this picture was taken. There was no whistling from the windows, there were no vibrations, and the car felt very stable (the absense of wind doubtlessly helped here).

My car has a complete front undertray, which is the same size as that on a 2002 NSX-R, don't have a vented hood, and the coolant temperature gauge never budged from its usual position just below the halfway mark. Driving through city traffic on a hot day, the coolant temperature never changes, either. Maybe you would need a vented hood if the engine is running at full load a lot but you're not going fast enough to get decent airflow. Maybe this could happen on tight tracks. However, in city driving and on the Autobahn, you don't seem to need a vented hood even if you have a full front undertray.

For the record, I timed my car using my Palm Pilot, a bluetooth GPS receiver, and Cetus GPS software.

What mods and how much HP?!

 

[goldNSX]

What mods and how much HP?!

are stated in #203

 

[MvM]

I didn't get a torque graph from Bosch, but I think you can calculate the torque based on the hp and engine speed. Or in this case, calculate the rpm from the km/h, and then the torque from the rpm and kW. Hmmm, not something that sounds very attractive right now.

Regarding what I did to my engine: Comptech air box and foam air filter, extrudehoned intake manifold, Comptech ported and polished cylinder heads, milled for increased compression ratio (~10.6:1), Comptech modified VTEC lobes on the camshafts, Cantrell ceramic coated headers, HKS muffler, Autothority custom programmed engine management chip, Comptech high flow oil pump

I am wondering about the type of Dyna your car was dynoed on.
My car has the same kind of output as yours (about 269 RWHP) but has had a lot less work, I only have Taitec headers and exhaust, SOS BBTB, Cantrell air intake, Unifilter and Dali Chip.
I would have expected that your car with aftermarket cams, changed cylinder heads etc. would have had more power.
However, my car was dynoed on a Dynojet and not all dynoes are the same.

Apart from that, achieving 299 km/hour (186 mph) is a great achievement. It's nice to know the NSX is able to do that if given some room to stretch its legs :smile: :smile: What was your tachometer indicating ??

 

[RON98]

165.

ran out of road and courage, accelerating very very very slowly.

 

[areout]

Whoa thats really nice cant think of some other (production) car able to hit real 300 kmh with 270 RWHP

 

[satx]

Whoa thats really nice cant think of some other (production) car able to hit real 300 kmh with 270 RWHP

an FD RX7 has similiar frontal area and drag (although you'd probably need a new engine afterward any top speed runs:biggrin: ).


BTW, my own calculation is that an otherwise stock NSX would need ~305 rwhp to achieve 186MPH.

 

[greenberet]

I am wondering about the type of Dyna your car was dynoed on.

What was your tachometer indicating ??

I checked with the company that dyno'd the car and the dynamometer was a Bosch FLA 203. Bosch claims it's accurate, but I'm sure everyone claims that of their dyno's.

When I was trying to max the car out, the speedometer indicated over 180 mph but I think it was still within the range where there are little dashes. The tachometer was around 8000 rpm. I wasn't keeping that close an eye on them because I figured the GPS would keep track of the maximum speed attained - and because I wanted to keep my eyes on the road!

 

[gdae]

Top Speed?
In the 1991 NSX: 110
1993 Civic Hatch: 115
I intend to change these results soon. I haven't had the NSX that long.

 

[Ron A]

130mph for 2 seconds.

I cruised 130 mph for few minutes in my '95 Infiniti G20 5spd. You are slow. Chicken......

 

[Synthesis]

407kph in a bugatti veyron....

<object width="425" height="350"><param name="movie" value="http://www.youtube.com/v/0OvFq0GZil4"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/0OvFq0GZil4" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"></embed></object>

the turbo'd hayabusa is still more impressive..... ~240mph on a public road oh, and it's a BIKE

 

[Synthesis]

can't remember if i posted it before.... but i'm referring to this....
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[amgnsx]

has anyone seen this?

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[goldNSX]

Yes, he shifts a little bit early from 4th to 5th but it must be like a barrier above 240 km/h.

 

[nsxtcy85]

I hit a new top speed in the nsx about a week ago. 165mph

 

[SENNAF1]

135 the wife was screaming louder than the car.The guy that was by me a r32 vw blew his motor.Thats when I backed out.Not because he blew his motor my wife started smacking me.

 

[TOOLTIME]

my top speed 88mph.:biggrin:

 

[mcano]

Does anyone know what the top speed is for an automatic NSX 91-94 and 95-2005? My owner's manual says that the car shifts from 3rd to 4th gear at 117 mph, but does not list a top speed.

How fast have you driven your auto? Fastest for me in my 95 auto is 120 mph, before I ran out of straight road.

 

[greenberet]

A few weeks ago I managed to get in another run on the Autobahn but the top speed was measured as being the exact same as it was this summer: 299.3 km/h, or 186.0 mph (post #198 above).

This time I didn’t have to slow down for traffic, it was cooler, and as before, there was no wind. Either that’s just my NSX’s top speed or my GPS software is having difficulties measuring higher speeds.

I read somewhere (in the car magazine Evo, I think) that some automotive GPS devices can’t measure speeds above a certain point but that Garmin devices seem to work well even at really high speeds. The easiest way to test whether my Cetus GPS software running on a Palm TX and getting fed with data from a Navilock GPS receiver can measure speeds above 186.0 mph is to take it on an airplane, I guess.

Unfortunately, I have a feeling the problem isn’t with my measuring equipment. But it is quite a coincidence that the top speed is the exact same down to a tenth of a mile per hour. Maybe that’s where the rev limiter kicks in when the tires are worn down a bit. It would have been nice to have seen a top speed of 300 km/h. Oh well. With winter here, there aren’t going to be any more top speed runs this year.

It would be really interesting to see what an NSX could do with a 6th gear in the transmission and a 3.8 liter engine!

 

[goldNSX]

I'm still impressed by the good numbers you've reached. I didn't think of the cylinder headtuning contributing that much.

I don't think the 3.8 l can withstand autobahn speeds in the long run.

As you've mentioned after the winter the testing starts again, for me too.

 

[RON98]

165mph (provided the odometer is accurate. they are not usually calibrated for that kind of speed so im sure there are fudge factors in that )

91 5 speed.

ran out of road, ran out of steam. :smile:

closed course obiviously :biggrin:

im sure you can go faster.. but at 165... the car was accelerating but really really reallly really slowly. probably like 5-7 seconds for an extra mph.....

​

you need a serious streach of road/race track.

its scarry... i kept getting mental pictures of me losing control and getting wrapped around something soild.

only when we get closer to death do we feel alive.

wow great pictures btw,

this has all the nessary information to send law inforcement to you house including gps location and your max speed. :biggrin: :biggrin: :biggrin:

avg speed of 67 mph :tongue: OVER the speed limit. :smile:

j/k. great numbers.

 

[Synthesis]

A few weeks ago I managed to get in another run on the Autobahn but the top speed was measured as being the exact same as it was this summer: 299.3 km/h, or 186.0 mph (post #198 above).

This time I didn’t have to slow down for traffic, it was cooler, and as before, there was no wind. Either that’s just my NSX’s top speed or my GPS software is having difficulties measuring higher speeds.

I read somewhere (in the car magazine Evo, I think) that some automotive GPS devices can’t measure speeds above a certain point but that Garmin devices seem to work well even at really high speeds. The easiest way to test whether my Cetus GPS software running on a Palm TX and getting fed with data from a Navilock GPS receiver can measure speeds above 186.0 mph is to take it on an airplane, I guess.

Unfortunately, I have a feeling the problem isn’t with my measuring equipment. But it is quite a coincidence that the top speed is the exact same down to a tenth of a mile per hour. Maybe that’s where the rev limiter kicks in when the tires are worn down a bit. It would have been nice to have seen a top speed of 300 km/h. Oh well. With winter here, there aren’t going to be any more top speed runs this year.

It would be really interesting to see what an NSX could do with a 6th gear in the transmission and a 3.8 liter engine!

unless you have a lot of mods done to the car, the car wasn't actually moving that fast. in stock form, the car can't break 167, due to wind resistance. top of the trans is 186.

even in the newer ones, with the better aero and some extra power, the max speed is 175, with top of 6th ending at 186 (same as the 5 speed)

either way, i'm not doubting you were going fast

my max in the nsx is 150. but i did take my buddy's STi to 155.

 

[greenberet]

unless you have a lot of mods done to the car, the car wasn't actually moving that fast.

In 1995, I bought and installed all the horsepower-related modifications in Comptech's NSX catalog except for the polished intake manifold and the engine management chip. Comptech said extrude honing the intake manifold might yield even better results, so that's what I went with. In addition, to make sure the engine management chip was getting as many horsepower as possible out of my specific engine, I had it custom programmed by Autothority with the car on a dyno and high octane fuel in the tank. I've listed all the modifications to my car in my "Public Profile".

According to my GPS setup, the speed limiter in my BMW kicks in at exactly 155.0 mph (249.4 km/h). It's supposed to kick in at 250 km/h but since my tires are going to need replacing soon, the decreased circumference and slightly lower speed seem to make sense.

In my NSX, the current speed in the GPS display smoothly increases to 186 mph without any wild jumps. I think it's accurate.