Bruntingthorpe today 156mph

[NSXGOD]

I've had my clock (maybe not that accurate) showing 164mph on a cool night over about a 2.5 mile stretch of road. Thats in bog standard trim, 1992 3.0L manual and with a passenger on board. Might have to pick my time with the new set-up to try again. I'll have to borrow my mate's Tom Tom Sat Nav to try and get a more accurate speed reading. I thought they should be good for 170mph+? Or am I just dreaming?

Lots of nice goodies there. :mrgreen:

the NSX tach reads 1-2% HIGH, I don't know what the speedo error is, but you can figure out what the POTENIAL top speed is by doing the gear ratio X the RPM X the tire diameter etc calculations. (don't forget that the guys running 4.23 or 4.44 or 4.55 will have lower top speeds)

there is a chart on Prime that shows that.

Ways to go faster:
lower the weight
lower the height
remove excess wings and etc
have thinner tires
HAVE LOTS MORE HP :mrgreen:

the chart on prime is located here:

http://www.nsxprime.com/FAQ/Technical/gearratios.htm

[ctrlaltdelboy]

So why did my car only manage 156mph today at VMAX ??

Whatever I did, 156mph every time.

With passenger, without, TCS on/off, wing mirrors folding in/out.

All 7 high speed passes were 156mph, I just ran out of power, I know the weather was not ideal, absolutely sweating with not even a breeze but still.

I think I know what the problem was Simon - the grassy surface was obviously keeping you from getting all your power down effectively - next time try it on the tarmac mate

[jaytip]

Why do i nearly always see the top speed quoted for the 3.0L as 158mph

[AR]

Isn't Senna Driving the NA1 in this video around Susuka at 180 MPH around minute 2.00 ?

http://video.google.co.uk/videoplay?...702526&q=senna

Cheers

AR

[jaytip]

Isn't Senna Driving the NA1 in this video around Susuka at 180 MPH around minute 2.00 ?

http://video.google.co.uk/videoplay?...702526&q=senna

Cheers

AR

It's a JDM car.so it would be KPH not MPH,but i don't think there is a road car in the world which would get up to 180MPH on a circuit anyway.

[modarr]

Damm,Darren.

You should oughta start writing a dang book on the car. You da man wid da big phat NSX brain

I just love the detail, great reading. The NSXGB forums are like University Challenge compared to the Celebrity Love Island level of the other retard forums I'm on.

I feel like writing my kids a quick apology for ruining their future prosperity and getting the car out for a couple of laps of the M25-o-ring just to put this one to bed.

Mo

[ctrlaltdelboy]

thanks Mo - nice to be appreciated

[trackdemon]

ctrlaltdelboy - my retort 'dear boy'

I concede that the 'overall' aerodynamic drag of the NSX may be lower than the Cayman taking into account frontal area - I really ought to have taken this into account! I'd be interested in your data sources though - I couldn't find anything concrete through an admittedly brief google session.

There is no concrete data to prove the NSX power output is anything more than that stated by the manufacturer, so until proved otherwise I'll stay with 286bhp at most.

Weight has little bearing on top speed, a 120bhp/750kg Elise tops around 124mph, and a 113bhp/1125kg MINI Cooper tops around 125mph (source Autocar). Nonetheless, Autocar quote NSX 3.2 @ 1320kg & Cayman S @ 1340kg - insignificant.

There is no supporting evidence which states the Caymans power curve drops off after peak power at 7200rpm; chances are (and this is surely borne out factually by the Caymans S top speed) the power output stays more or less level from then through to cutout.

I do believe the Cayman develops more bhp than an NSX, this conclusion is drawn both from on paper stats (and my interpretation thereof) and actually driving the 2 cars back to back.

So:

1. The Cayman has more power (proven, on paper, factually quoted)
2. Almost exactly the same weight (which has little effect on top speed anyway)
3. Alleged marginally more drag, although sources unquoted

So @ 171mph - speed is higher just as I would expect.

If someone can prove their factory spec NSX is capable of 180mph or more in normal circumstances then I'll happily eat a Honda hat. Otherwise, claims of realistic 175mph+ capability remain poppycock IMHO.

For the purpose of adding balance - people never cease to be impressed my my NSX's acceleration and speed capabilities when they experience it; I am certainly not underestimating NSX performance rather just trying to add a degree of realism to the discussion.

[Minch]

Think you're right Darren.

Just to add to your foot note. I must agree that out of all the high performance cars I've had the pleasure to drive the NSX has got a very good throttle response/acceleration. The only other car which I would say had better response was the Elise, mainly due to the fact that it weighed about the same as an obese ant!

Great car and loving the new mods (which has also improved the throttle response further!!!)

[ctrlaltdelboy]

cool - a proper debate

re the air drag/frontal area - the frontal area of the NSX and all figures for drag and lift are detailed in the Honda spec sheet here (for the early 3.2)

the frontal area of the Cayman is harder to find (as I see you found out!), but some clues can be found here:
http://www.carfolio.com/specificatio.../id/?id=132913
http://www.carfolio.com/specificatio.../id/?id=133903

re the power thing - NSX stated power is 280PS which is equivalent to 276BHP - not sure where you're getting the 286 from.
measured power at the wheels across a variety of different NSXs is viewable on the dyno charts in this document which came out of the NSXPrime Dyno Day in 2002

re cayman power not dropping during the remaining rpm range after peak power is first acheived - I guess some dyno charts would be interesting to look at in answering this one, so I did some searching and on initial research this would appear to be the case:



the above chart shows 269HP at the wheels, compared with the charts from the NSX shoot out showing 252-267HP with non-standard exhausts and 237-267HP with zero or air filter only mods

so as I said before, these 2 cars are definately in the same ball park for power.

re the weight thing, sorry - there are 2 sets of weights bandying around, I quoted the weight from carfolio (above) which is as declared by Porsche under the EC Directive, rather than the DIN weight which they declare as 1350kg (see here) - anyone know what the difference between the 2 different weights is? (or for that matter what consitiutes 'kerb weight' as often used by manufacturers)

1350kg is exactly the same as the original NSX, although the NSX has shed weight since as shown in this diagram:



more detail on NSX weights (in English!) can be viewed here for the early 3.2, here for the facelift 3.2 and here for the NA2 NSX-R


re the speed thing - I consider multiple examples of photograhic evidence, one of which came from a member here (with a gps verified speedometer) who I have known and respected for some years and whose honesty I don't doubt, to be evidence enough.
My belief in the truth of acheivable 187mph is bolstered by my own experience (again gps verified speedo) of 165mph uphill at 7,000 rpm and still pulling strong before losing my bottle.


so if there is no real weight difference (and you claim it is not a factor anyaway) and no real power difference (at least at the higher end of those NSX's tested) and both cars are geared to see speeds higher than the manufacturers' stated maximum, the only differentiating factor between them in attaining a higher speed is the limits imposed by air drag or mechanical gearing.

the Cayman S with standard gears and tyres is geared for 177MPH maximum and fighting a Cx figure of 0.5742 to get there due to it's frontal area of 1.98m2

the 5 & 6 speed NSXs are geared for 183 & 197MPH maximum and have a Cx of 0.5696 & 0.5340 to fight against.

I think the evidence is sufficient to demonstrate that the NSX in all forms should, can and does outdrag the Cayman S.

what is most interesting to me is the difference between all the NSX dyno results with stock or close to stock setups.

this variation could be the very reason why some members have seen 180+ while others no more than 156?

however, all of this is relativlely moot for me, as my gearing will only allow me to get up to 171MPH anyway