NSX v C6

[Edgemts]

Toyo RA-1
I don't know the steady state cornering - there was no skidpad to do that type of test.
It would be fun to see, though, because it could be even higher than 1.33

I only did a few laps with the device in my car, so there wasn't a bunch of data to look at. Also, since I was trying to not fly off the track and hit something, I was below my max grip level (I am a fairly conservative driver).

On a skid pad, I could accelerate until it spun out, so I'm sure I could go higher...I just don't know how much higher.

Most likely it would be the opposite of what your thinking,
a skid pad is flat, steady state cornering, almost all mechanical grip as speed is kept relatively slow,
Race tracks have many banked or on-camber turns increasing g- force as per your gauge as well as elevation changes that will load and unload the suspension creating more traction at times.
Not that your not doing good at 1.33 but I believe the Noble is on street tires on a skid when it got 1.19, give it track tires and a race track and a G-tech or similar you would probably see 1.75+

I did .828 on a wet skid with PS2's and .998 on a dry pad again on ps2's.
I had major understeer problems at the time and I feel I am probably in the 1.08- 1.1 range now.
I have had over 1.5 on a g-tech at the track on Ps2's.

 

[NobleForums]

"Actually, it's 2337 curb weight, sans aircon.

If you're willing to drive about an hour north, I'll give you a ride."

Sure, & you can drive my 94 if your interested.

You got a PM.

I've been giving rides left and right since I got the car.

 

[LS1NSX]

The latest model tested there was the NSX-R, not the stock model (latest was in '97). Times were posted multiple times here.

For the sake of an arguement was it faster than 7:42.9?

Just checked the internet and it turns out that the NSX-R ran a 7:56........ in my book that makes it seem as if the Z06 handles better and has the power to use the track.

As for the craftsmenship..... I like something I can beat on and not have it break, there are sacrifices for performance. Besides hardcore GM fans don't care about how the inside of their car looks as much as how it runs.

 

[NSX-Racer]

Race tracks have many banked or on-camber turns increasing g- force as per your gauge as well as elevation changes that will load and unload the suspension creating more traction at times.

I'm pretty sure you won't measure more lateral g in a banked curve than in a non banked. The g forces are just transformed into vertical g which means you can have zero lateral g in a high banked curve but high vertical g. The differences we have between the R&T measures on skidpads and measures of german mag "sport auto" on racetracks (usualy much higher g) are the result of the different surfaces I guess. Speed won't play any big role with street cars as these have usualy no downforce that would increase lateral g at higher speeds (e.g. the stock NSX has a small amount of upforce).

The added (virtual) weight in a banked curve loads the suspension and presses the tires more to the ground but it adds also weight to the whole car which may compensate the better grip. I didn't see any evidence in former track tests that added weight increases corner speeds.

The corner where sport auto used to measure lateral g is on Hockenheim short track, is not banked, has no elevation changes but still shows significant more lateral g forces than the U.S. skidpad tests with the same car (I hope it's also the same tires).

 

[Gansan]

I'm pretty sure you won't measure more lateral g in a banked curve than in a non banked. The g forces are just transformed into vertical g which means you can have zero lateral g in a high banked curve but high vertical g. The differences we have between the R&T measures on skidpads and measures of german mag "sport auto" on racetracks (usualy much higher g) are the result of the different surfaces I guess. Speed won't play any big role with street cars as these have usualy no downforce that would increase lateral g at higher speeds (e.g. the stock NSX has a small amount of upforce).

The added (virtual) weight in a banked curve loads the suspension and presses the tires more to the ground but it adds also weight to the whole car which may compensate the better grip. I didn't see any evidence in former track tests that added weight increases corner speeds.

The corner where sport auto used to measure lateral g is on Hockenheim short track, is not banked, has no elevation changes but still shows significant more lateral g forces than the U.S. skidpad tests with the same car (I hope it's also the same tires).

No, you will measure a LOT more lateral acceleration when you have a banked curve. The "virtual weight" you speak of acts exactly like aerodynamic downforce without adding mass to the car, adding to the cornering capabilities. In fact, any upward curving surface to the turn applies temporary downforce, improving cornering force (if you look at a banked turn from the viewpoint of the car, you will see it curves upward away from you). You can see this in places such as the Eau Rouge at Spa, where touring cars must run six degrees of camber on their tires to take the tremendous cornering force.

I have experienced this personally when driving the road course + oval at California Speedway. It is a very weird feeling, as you turn the wheel harder and harder, and the slip angle of the tires is dramatically less than what they should be as the cornering force goes much higher than you ever encounter on normal turns.

 

[NSX-Racer]

Mmh - thanks for the explanation but I still don't get the whole point. So there's a difference between weight and mass for a car in a corner? And aerodynamic downforce acts the same as a positive banking?

Speaking of Eau Rouge: I drove this corner many dozen times and what I mainly feel is that I'm pressed into my seat. This means in my understanding: My weight increases (if I had 200 pounds at 1 g vertical I have 400 at 2 g, right?). Therefor I assume that the weight of the car also increases at the bottom of eau rouge which is also a bit banked.

At this special point I may achieve more corner speed than usual (if I would be brave enough) but would a lateral g meter really show more? Or would it somehow be compensated by the vertical g (I learned something about resulting forces long time ago but I may also be way off)?

 

[NSX-Racer]

For the sake of an arguement was it faster than 7:42.9?

Did I miss the post where this time was mentioned or the magazine where it was published? Which car, which tires, tested when and by whom on the Nordschleife?

 

[Gansan]

Mmh - thanks for the explanation but I still don't get the whole point. So there's a difference between weight and mass for a car in a corner? And aerodynamic downforce acts the same as a positive banking?

Speaking of Eau Rouge: I drove this corner many dozen times and what I mainly feel is that I'm pressed into my seat. This means in my understanding: My weight increases (if I had 200 pounds at 1 g vertical I have 400 at 2 g, right?). Therefor I assume that the weight of the car also increases at the bottom of eau rouge which is also a bit banked.

At this special point I may achieve more corner speed than usual (if I would be brave enough) but would a lateral g meter really show more? Or would it somehow be compensated by the vertical g (I learned something about resulting forces long time ago but I may also be way off)?

Yes, there is a difference between the weight of a car seen by the tires and the mass of the car. For example, aero forces will increase the "weight" of the car on the tires, but not the mass. When a car with downforce is in a corner, the tires will have more friction with the road. Something similar happens with banking.

Friction force = Coefficient of friction * Normal force

The Normal force is the perpendicular force pressing the tires down against the ground. Aero forces do this, and a banked turn will do this. So it's clear that as you increase the Normal force, you are increasing the friction the tires can generate.

Now if we consider that the friction force generated by the tires is trying to accelerate the car toward the inside of the turn, you end up with the lateral acceleration figure. We're back to F=ma, and the mass 'm' of the car is not increased by anything we have seen thus far. So if you increase 'F', 'a' must also increase.

One other point is this, which is what you may be thinking of: The banking allows the car to navigate the turn with only part of the acceleration as pure lateral acceleration. If you imagine a 90 degree banking, you can actually corner with infinite speed with zero lateral acceleration (and the vertical forces will be infinite as well). As the banking flattens, more and more of the cornering is dependent on lateral acceleration from your car, and so the total corner speed is a combination of what component is vertical to your car and what component is lateral.

This is a really simplified explanation, and it needs force diagrams to be more clear, but the main points are these:

1. Banking does not increase the mass of the car.
2. The banking increases the force on the tires, which increases their ability to generate friction forces.
3. The increased forces generated by the tires can now provide better lateral acceleration.
4. Banking will cause part of the cornering to be handled by the vertical component of force on your car, reducing dependence on lateral acceleration to make the turn.

 

[NobleForums]

Did I miss the post where this time was mentioned or the magazine where it was published? Which car, which tires, tested when and by whom on the Nordschleife?

Scanned from a recent issue of "Bilmagasinet" - danish car mag.
Interview with Jan Magnussen about (among other things) his record lap at NBR.
Here´s a translation:

[Top pic, Magnussen and Vette:]
Thursday morning, Southern Germany. General Motors have discreetly rented the legendary german Nürburgring track for an hour between 7 and 8 in the morning.
The temperature is more comfortable than at Le Mans, and the track is empty apart from a couple of early rising spy photographers.
It takes more than a blue Vette to exite them - they recognize it, it´s the Z06 version, the brutal Vette with 500 BHP. What they do not know, is that it´s Jan Magnussen behind the wheel.
The objective is to beat Walther Rörhl´s laptime in a Porsce GT3 RS - it´s 7:43,0 min for the 20,8 km heavily varied track with 73 corners.
The record was set in 2004 in a standard version of the Porsche.

[Splash in middle]
Jan made 7:42,9 thereby beating the Porsche GT3 RS by 0,1 sec.


[Two lower photos]
"The photo is taken at Flugplatz. I´m going 240-250 km/h at full throttle in 4th gear and the car is actually jumping twice: After the first jump it lands so hard that it takes off again, as you can see in the second picture. As it lands the second time I have to take a sharp right immediately after.
The car is a standard car with street setup - had it been my racer it would hardly have left the tarmac. At NBR the street car reaches 295 km/h on the long straight in 5th gear (6th gear is an overgear for saving gasoline). At NBR there are no run-off areas like other tracks,. You simply have to stay on the track. When you are halfway around the 20 km, you think it´s a good thing there are only half as many places left you risk running off the track" Jan says.

[About the track and the car]
"The stree Corbette has virtually no grip compared to my race car which has a large rear spoiler. But it does have almost as many BHPs as my Le Mans racer and is almost as fast. The rev limiter sets in at 7000 rpms, and it does have more than 500 BHPs.
It´s fast.At the record attempt I drove 2 x 2 laps with a cooldown lap in between for both mine and the car´s sake.
I couldn´t have driven one single lap more. I wouldn´t have liked to drive a single meter (3 feet) more with myself at the wheel at that speed", Jan finishes.

That's actually very very impressive on the Corvette's lower performance tires. The GT3RS uses Pirelli P-Zero Corsa System (Asimmetrico + Direzionale) DOT-R tires.

 

[NSX-Racer]

Thanks Gansan, so I was not that way off with my previous sentence that you could drive a high banked curve with nearly no lateral g.

Thanks also to NobleForums. This must have been an awesome driving by Jan which explains a lot of this laptime. But only 14 or 22 seconds difference (depending on which driver you count) for the NSX-R doesn't sound that bad if you see the 200 PS difference.

BTW: The new record for street legal cars is now unbelievable 7.15,63, driven by race driver Patrick Simon on a Edo competition Porsche GT 2 (of course no stock car) with 542 PS.

 

[heySkippy]

1. Banking does not increase the mass of the car.

True, but keep in mind that mass does increase as you approach the speed of light so the faster you go, the more mass your car has.

 

[NetViper]

True, but keep in mind that mass does increase as you approach the speed of light so the faster you go, the more mass your car has.

I guess I should disable the Hyperdrive I installed on my NSX for track days. :biggrin:

 

[BioBanker]

Dave - your car is the correct color for something approaching very quickly! I say dont disengage the hyperdrive!

 

[NobleForums]

Thanks also to NobleForums. This must have been an awesome driving by Jan which explains a lot of this laptime. But only 14 or 22 seconds difference (depending on which driver you count) for the NSX-R doesn't sound that bad if you see the 200 PS difference.

I'd love to see what that Z06 will do on good DOT-R tires like the Advan A048R, Pilot Sport Cup, or Pirelli Corsa instead of those heavy, hard run-flats. I'd bet they'd pick up at least 5 seconds or so, dropping the time surprisingly close to the Carrera GT.

 

[LS1NSX]

Gotta love GM perfomance.

 

[Edgemts]

Thanks Gansan, so I was not that way off with my previous sentence that you could drive a high banked curve with nearly no lateral g.

Slight correction, a 90deg bank would give you 0 lateral g once on it, but it better be a pretty tight bank to keep enough force to keep you on it.
Even at Daytona or at the Nurburing(spelling way off) Karussell with 30deg plus of banking you will have greater lateral g's than on a flat corner of equal radius, due to the forces as decribed in a previous post.
Biggest difference when you talk of Mass and weight/downforce included, is that the force of the mass is making the vehicle move to the outside of the turn, any additonal weight over and above the mass as created by downforce or other factors will add weight pushing down on the tires but not out towards the outside of the turn therefor increasing friction without increasing mass.
This is an overly simplistic explanation. There are many other factors with accelerating the mass, changing directions, application of forces etc etc.

 

[Edgemts]

By the way since I have gotten completely off topic
NSX VS C6
The C6 is a good car, and the ZO6 will be very fast and be fast around the race track, but its comunication with the driver SUCHS.
I have driven a lot of cars at the track, from 360's to old 911's and have not found anything that I like as much as the NSX.

 

[poplifedc]

This is my first post so I had to chime in. As an owner of the C4 and C5 Vettes, the interior of the C6 is the best to date. You can see and feel where Chevy put most of the development money. However, the style leaves something to be desired.

When I had my C4 (which I think is the best looking modern Corvette) the C5 came out and I didn't like them at all. I still don't. The back is just too big. However, one drive and I was hooked. Sure the interior looked and felt like it came from a Cavalier, but the thing was light years ahead of the C4 as far as performance. Then you'd see them as much as BMW's, Porsche's and Accords. Also the 6speed was a killer in heavy traffic. So after about 2 years I sold it and got into motorcycles. Now that that C6 is out, the interior is the best. But the style has gotten worse. Perhaps it would grow on me.

But now, I'm looking for something sexy and exotic like the NSX. Even after driving the Vettes, the best all around car I've owned was the '89 CRX Si. It fit like a glove and drove like a race car. At the time my friend had an '86 Firebird with some modes. We'd take it to the highway and he'd always get the jump on me...until a curve came up, then I'd pass him. Great fun that car.

 

[CerberusM5]

The C6 is a good car, and the ZO6 will be very fast and be fast around the race track, but its comunication with the driver SUCHS.

This is absolutely the weakest link in C5 and C6 Corvettes. The cars have always lacked precision and feel in the handling department. I had a couple of C5 Z06's that cornered quite well, but always felt a little disconnected, like I was wearing a pair of thick gloves. However, the C6 Z06 will be a very impressive performer on the street and track.

 

[liftshard]

Thanks Gansan, so I was not that way off with my previous sentence that you could drive a high banked curve with nearly no lateral g.

Slight correction, a 90deg bank would give you 0 lateral g once on it, but it better be a pretty tight bank to keep enough force to keep you on it.
Even at Daytona or at the Nurburing(spelling way off) Karussell with 30deg plus of banking you will have greater lateral g's than on a flat corner of equal radius, due to the forces as decribed in a previous post.
Biggest difference when you talk of Mass and weight/downforce included, is that the force of the mass is making the vehicle move to the outside of the turn, any additonal weight over and above the mass as created by downforce or other factors will add weight pushing down on the tires but not out towards the outside of the turn therefor increasing friction without increasing mass.
This is an overly simplistic explanation. There are many other factors with accelerating the mass, changing directions, application of forces etc etc.

No, this stuff just isn't correct.

Banking uses the weight of the car to balance the centripetal acceleration due to the car's attempt to go around a corner. With zero banking, the tires and friction accomodate this centripetal load. Banking permits you to have reduced lateral acceleration on the tires, enabling higher cornering speeds.

Banking will also produce downforce, but this is NOT, repeat NOT, why banking is used to increase cornering speeds. A 90 degree banking would not produce 0 lateral acceleration. You would have -1G pulling you towards the ground. You would have to rely upon downforce-induced traction to overcome this. There would be no upward acceleration. Without sufficient traction, your car would slide off the banking and fall on its side.

In the best-case scenario, the banking exactly balances the cornering load and you have NO lateral acceleration whatsoever. Gravity tends to pull you down and the corner tends to pull you up and these offset one another perfectly. How steep a banking you'd need would depend upon the radius of the curve and the speed you were driving.

Downforce increases the maximum cornering load your tires can sustain. Banking DECREASES your cornering load by offsetting it against gravity.

 

[Gansan]

No, this stuff just isn't correct.

Banking uses the weight of the car to balance the centripetal acceleration due to the car's attempt to go around a corner. With zero banking, the tires and friction accomodate this centripetal load. Banking permits you to have reduced lateral acceleration on the tires, enabling higher cornering speeds.

Banking will also produce downforce, but this is NOT, repeat NOT, why banking is used to increase cornering speeds. A 90 degree banking would not produce 0 lateral acceleration. You would have -1G pulling you towards the ground. You would have to rely upon downforce-induced traction to overcome this. There would be no upward acceleration. Without sufficient traction, your car would slide off the banking and fall on its side.

In the best-case scenario, the banking exactly balances the cornering load and you have NO lateral acceleration whatsoever. Gravity tends to pull you down and the corner tends to pull you up and these offset one another perfectly. How steep a banking you'd need would depend upon the radius of the curve and the speed you were driving.

Downforce increases the maximum cornering load your tires can sustain. Banking DECREASES your cornering load by offsetting it against gravity.

That's a good point about using gravity to counteract the centripital force, liftshard, but while you are agreeing that the downforce it produces increases the cornering capacity of the tires, you are then discounting their newfound capacity to increase cornering speed. Basically, your analysis is holding the speed of the car constant while varying the amount of banking, while what I was thinking of was always cornering at the maximum speed possible with the available traction, and then seeing how that changes with varying banking.

As a driver, when you are driving through a banked turn, you are always trying to go through turn as fast as possible, and you will increase your speed until you make up for the reduction in cornering force that the banking will provide you.

 

[Bryan]

Downforce increases the maximum cornering load your tires can sustain. Banking DECREASES your cornering load by offsetting it against gravity.

My turn to play at physics The above is only true if you maintain the same speed before and after. There are two reasons you can go faster on banked corners.

Banking lets you go faster for a given cornering load because of the gravity offset against the cornering load. On a 45 degree bank you can go roughly 1.4 times faster with the same lateral Gs (in the plane of the pavement) due to this effect.

You can go even faster because extra downward force on the tires means you can increase the cornering load. For a given angle of banking you might be able to pull 1.2G (in the plane of the pavement) instead of 1.0G just due to the increased downward force on the tires. (This is very similar to the increase you get from aerodynamic downforce.) This effect is rather non-linear and highly dependent on your tires and suspension.

All of the above assumes you are not horsepower limited. You won't go any faster if you don't have enough motor.

 

[Edgemts]

No, this stuff just isn't correct.

Banking uses the weight of the car to balance the centripetal acceleration due to the car's attempt to go around a corner. With zero banking, the tires and friction accomodate this centripetal load. Banking permits you to have reduced lateral acceleration on the tires, enabling higher cornering speeds.

Banking will also produce downforce, but this is NOT, repeat NOT, why banking is used to increase cornering speeds. A 90 degree banking would not produce 0 lateral acceleration. You would have -1G pulling you towards the ground. You would have to rely upon downforce-induced traction to overcome this. There would be no upward acceleration. Without sufficient traction, your car would slide off the banking and fall on its side.

In the best-case scenario, the banking exactly balances the cornering load and you have NO lateral acceleration whatsoever. Gravity tends to pull you down and the corner tends to pull you up and these offset one another perfectly. How steep a banking you'd need would depend upon the radius of the curve and the speed you were driving.

Downforce increases the maximum cornering load your tires can sustain. Banking DECREASES your cornering load by offsetting it against gravity.

As I stated I was trying to explain a few things in a very basic way. Yes there are many other factors.
Your using the word downforce where we are using mass, the term downforce is typically used in terms of aerodynamics, once you turn the car sideways at 100mph that force is now horizotal also countering or helping counter the gravitational forces pulling it towards the earths center. Yes at 90 deg you would actually have in essence neg lateral accerleration due to the gravity pulling it down, thus as I stated it would take extreme speed etc. to increase the forces/ traction etc that would be needed to counter gravity, while you will always have neg lat accel #s they would infinetely decrease as speeds increased and or the radius is shortened.
By the way the bankin getc is the constant, yes max corner speeds are increased due to banking which was the point to start with.
Anyways this is way off topic.
:smile:

 

[whiteNSXs]

As I stated I was trying to explain a few things in a very basic way. Yes there are many other factors.
Your using the word downforce where we are using mass, the term downforce is typically used in terms of aerodynamics, once you turn the car sideways at 100mph that force is now horizotal also countering or helping counter the gravitational forces pulling it towards the earths center. Yes at 90 deg you would actually have in essence neg lateral accerleration due to the gravity pulling it down, thus as I stated it would take extreme speed etc. to increase the forces/ traction etc that would be needed to counter gravity, while you will always have neg lat accel #s they would infinetely decrease as speeds increased and or the radius is shortened.
By the way the bankin getc is the constant, yes max corner speeds are increased due to banking which was the point to start with.
Anyways this is way off topic.
:smile:

I think you need to get the facts right. What you stated so far on this subject is not making any sense at all. What is your understanding on "lateral acceleration" in a "simplistic" way?
Steve

 

[khappucino]

perhaps someone should bust out the force diagrams with normal forces and stuff..... *cough* NOT!.... :biggrin: