Top speed. What does it take....

[UnhuZ]

Dave,

when i mention "heat soak" i'm thinking about something like this:

SC NSX and a NA NSX go for a long drive, then after 30m of high speed,
always above 150mph, the NA NSX will reach higher top speed than the
SC one....

The outside temperature will only make the heat soak happen sooner or
later.

If you do a beat and run, then i think you never suffer of "heat soak",
even in july... it's a run.... 10m tops... the heat will have limited effect
on performance...

Nuno

- - - Updated - - -

.... and so you understand better what i'm saying:

Before i had the NSX, i had an ITR powered civic and i did tests with
friends with ITRs and Subarus....

These tests consisted on multiple 1st gear pulls to top speed.... along
20kms of highway (speeds of 155+mph).

Results:

- On cold nights, the subarus would go ahead and ITRs could
only go along "pulled" by their vacuum
- On warm summer nights, the subarus couldn't even keep up with the
ITRs to catch their vacuum (don't know what is the english term).

The cars were the same with the same mods....it all depended on the
outside temperature.

Nuno

 

[greenberet]

Guys FYI.... I ran my CTSC car last night to about 158-160 and at that point it was pulling HARD, and can tell you for sure I could have broken that by at least 30 MPH. A friend with a CTSC also contacted me and said he has been close to 180 before deciding to slow down and the car had more. I can tell you at least in both our cases, there seems to be no "160 limit due to heat soak" thing happening. I was accelerating at a very hard rate at that speed.

If your and your friend’s CTSC’d NSXs maintain full horsepower during extended full throttle, maximum rpm driving – fantastic. Then European owners should try to figure out what in their setups is preventing them from unlocking their CTSC’s full potential.

In any case, if your engine management system doesn’t pull ignition timing, you should be able to go really fast. If a stock 2002+ NA2 can go 175 mph with about 250 rwhp at 6900 rpm, 350 rwhp at 7700 rpm should allow it to go about 196 mph. And to go 203 mph, 390 rwhp (450 crank hp) at 8000 rpm should do the trick.

 

[nsxtasy]

When my avatar picture was taken, the car got up to an indicated 8000 rpm in one direction on the Autobahn and 8050 in the other with 245/40 17 rear tires.

Those rear tires won't affect the speed significantly. If your car is a '91-93, the 245/40-17 size is only 0.6 percent smaller than the stock 225/50-16 - a difference of about 1 mph in a top speed run, and less than the variation between new tires and worn tires.

 

[sca037]

"to catch their vacuum" (don't know what is the english term)

We would call that drafting.

Brian

 

[UnhuZ]

^ drafting!!! thanks.... now you said it, i recall it from watching
motorsport races on TV

 

[SFNSXguy]

I doubt that any NSX can hit 200mph -- even with FI -- without MAJOR aero work. 180 is leagues away from 200. That last 5-10mph is a killer.

 

[Blacknot]

Guys FYI.... I ran my CTSC car last night to about 158-160 and at that point it was pulling HARD, and can tell you for sure I could have broken that by at least 30 MPH. A friend with a CTSC also contacted me and said he has been close to 180 before deciding to slow down and the car had more. I can tell you at least in both our cases, there seems to be no "160 limit due to heat soak" thing happening. I was accelerating at a very hard rate at that speed.

I agree with you. At the top of 5th im at 155mph and the car still has plenty left to go. After 160 or so I let off. Guess im not as nuts as I used to be

 

[NetViper]

I agree with you. At the top of 5th im at 155mph and the car still has plenty left to go. After 160 or so I let off. Guess im not as nuts as I used to be

We need to rent out the landing strip at NASA for our next nsx Florida meet and find out how fast we can go.

 

[TURBO2GO]

I doubt that any NSX can hit 200mph -- even with FI -- without MAJOR aero work. 180 is leagues away from 200. That last 5-10mph is a killer.

I bet any turbo NSX, any of the cars with 500+ whp can hit 200 if they have the gears and not some giant wing or weird aero.

 

[docjohn]

Alex F has done some standing mile comps,If he can give us his data and how much more his car had left if say the distance was 3 miles....well then we will have more fun stuff to banter about.

 

[TURBO2GO]

I think if I ever go OJ I can seriously get away from the cops.... I think I could... LOL

Think how awesome that would be. You all would see me on the news with the TV anchor saying "the guy is getting away in a silver Ferrari"... And then heat soak would come in at the worst time...

 

[docjohn]

I think if I ever go OJ I can seriously get away from the cops.... I think I could... LOL

please don't stab Aubrie.....

 

[TURBO2GO]

please don't stab aubrie.....

lol...

 

[IndependentLemming]

I'm at 386 at the wheels, CTSC, milled throttle body, K&N cold air intake, up grade exhaust. Radar indicated 181 (thank you Tennessee State Trooper). I dont have the suction I need right now to hold the car down to go much faster but i think a drop of about an inch in front will get me another 10 mph. BTW I did not have traction control off. I dont know if adding the management system bypasses the wall of 168 that others have hit with the TCS on or not.
p.s. No ticket, he has a Vette and I have ran into him out and about a few times, I can't get him to go above 170, he gets nervous.

 

[jond]

I'm at 386 at the wheels, CTSC, milled throttle body, K&N cold air intake, up grade exhaust. Radar indicated 181

Was that all the car had, or is that when you decided to let off?

 

[IndependentLemming]

Was that all the car had, or is that when you decided to let off?

Still more but you can feel the front lift as a said just not enough suction in my current set up.

 

[TURBO2GO]

I bought a Passport 9500ci to install...guess I better get around to doing it.

Yeah and also get around to editing this detailed post...

 

[crazyukrainian]

Since I changed the aerodynamics of my car, it should require less horsepower than stock to reach a given speed.

what aero changes did you make? are the effects of any of them noticeable at highway speeds? (meaning 60-80 as opposed to 186 :smile

 

[IndependentLemming]

Yeah and also get around to editing this detailed post...

Happy?

 

[TURBO2GO]

Happy?

LOL... Just looking out for you man, doesn't affect me. I like your prime name lol

 

[greenberet]

what aero changes did you make? are the effects of any of them noticeable at highway speeds? (meaning 60-80 as opposed to 186 :smile

When my avatar picture was taken, the car was lowered with Eibach springs and the a/c openings in the nose of the car were blocked off with pieces of Styrofoam. That’s it and the car felt completely stable like that. My colleague who took the picture got the car up to an indicated 8000 rpm in fifth and said he was amazed how glued to the road the car felt.

When the video was shot and the car probably went a few km/h faster, it also had a 2002+ trunk lid spoiler (under the rear wing) and homemade front and rear undertrays. I was surprised how little impact the undertrays seem to have made. I got up to a GPS measured 299 km/h in one direction and 301 in the other without the rear undertray and with it – the exact same. Theoretically the undertrays have to help but practically, I haven’t noticed it. The car is completely stable with them and it’s completely stable without them, at 80 mph and at 180 mph.

If the alignment is correct, that is. If the alignment is a bit off, the car can squirrelly at really high speeds.

 

[TURBO2GO]

So do you change alignment settings?

 

[greenberet]

I don’t use the stock alignment settings. My NSX was my daily driver and only car for about a decade. In the rain I didn’t like now nervous the car felt when the tires on one side were on wet road markings and the tires on the other side weren’t (like when changing lanes). So I had the toe set to 0 all around. For the track, I’m sure that would be awful but for everyday driving in rain and snow, I find it makes the car much more pleasant.

The car was squirrelly at high speeds after my shop removed and reinstalled the right hand driveshaft but didn't align the suspension afterwards. It turns out they should have checked to make sure the alignment was still even left and right.

 

[NoelWatson]

The NSX speedometer is generally pretty darn accurate, even at high speeds, unlike most cars. But there are always variables. Just to cite one variable, the difference in outer diameter between a tire that is brand new and one that is worn down to the treadwear indicator bars is around 2 percent. That won't affect the speedometer reading at any given RPM, but it will affect your actual speed (and therefore the speedometer accuracy).

The NSX 02+ cars' speedos are miles out at higher speeds - indicated 177 is more likwe 164.

 

[nsxtasy]

The NSX 02+ cars' speedos are miles out at higher speeds - indicated 177 is more likwe 164.

I've never heard that stated before, never seen it reflected in any of the magazine tests. Do you have a published reference for that?