New spy footage of 2009 Nissan Skyline GT-R at track

[Phil]

Nope, I know just how inaccurate it can be.

The car club I'm in has users who lent them a Mk1 Golf GTI and Mk4 Golf (can't remember if it was a GTI or R32, think it was an R32) for the 'new vs old' drag races.

In the show the Mk1 wins it (just) but they actually ran the 'race' 3 or 4 times and then showed the only one the Mk1 won after the Mk4 owner bogged down his launch, they simply re-ran the race until they got the result they wanted while still looking convincing.

I would have to view that particular episode again, but without knowing what they had intended to show, I'm not sure you can call it inaccurate or not representative. If anything, such head to head races have to be taken with a grain of salt simply because results can vary depending on the track conditions, driver ability and a bit of luck. Perhaps they found that the Mk4 didn't deserve to win that race simply because it has traction control which the Mk1 wouldn't and wanted to offset that advantage because of it? I'm just not sure if an outsider can effectively judge what happened there, unless they were actual participants of the show. For all there is, the driver in the Mk1 might have done a terrible start which is why they did it a few times?

Anyway, I wasn't directly disagreeing with you - just that I see TopGear in a bit a different light. The inaccuracies you are pointing out are IMO simply opinions expressed in a exagerated style to make the whole thing entertaining. Sure, there are things that are staged - but I think it's quite relevant what is staged and why before blaming the show to be full of inaccuracies.

 

[_xxx_]

Yes they do.
Take the Brabus tuned SL for example.

Bad example, they buy our (AMG) cars and tune them knowingly way out of spec, without any proper (long-run, cold/hot chamber, EM-emissions etc.) testing involved.

The gearbox is already way beyond spec as they use it now (max. is 1000 Nm, with a reserve up to 1200).

But their price covers all the following expenses when they have to swap a motor or a gearbox a few months later

 

[_xxx_]

Nope, I know just how inaccurate it can be.

The car club I'm in has users who lent them a Mk1 Golf GTI and Mk4 Golf (can't remember if it was a GTI or R32, think it was an R32) for the 'new vs old' drag races.

In the show the Mk1 wins it (just) but they actually ran the 'race' 3 or 4 times and then showed the only one the Mk1 won after the Mk4 owner bogged down his launch, they simply re-ran the race until they got the result they wanted while still looking convincing.

The Golf I weighs a few hundred kg less then the Golf 4.

 

[Thorburn]

My mistake, it was a Mk2 GTI.

http://www.youtube.com/watch?v=8XLY9MCXEC4

But as I say the simple fact is they DID simply run the test until it gave the result they wanted.

 

[Thorburn]

The Golf I weighs a few hundred kg less then the Golf 4.

Also has about 40% less BHP.

 

[DJ12]

But from my limited research slightly better power to weight ratio.

 

[Thorburn]

But from my limited research slightly better power to weight ratio.

But with narrower tyres, less torque through the rev range (the Mk4 being used was I believe a 1.8T, not the damp squib 2.0), etc

As I said, the owners were there and the Mk4 was consistantly quicker, yet they used the one run where it didn't win so that when they reached the final race old and new were tied.

 

[_xxx_]

The width of the tyres has nothing to do with friction, just helps the lateral stability. In terms of physics, an idealized tyre will produce the same friction regardless of width, in the real world it might make one or two % difference.

 

[DJ12]

But with narrower tyres, less torque through the rev range (the Mk4 being used was I believe a 1.8T, not the damp squib 2.0), etc

As I said, the owners were there and the Mk4 was consistantly quicker, yet they used the one run where it didn't win so that when they reached the final race old and new were tied.

It is more likely they re-ran the test to get the result they should using the factory specified figures.

The mk5 gti only just beats the mk1/2 to 60 and that is far better car than the mk4.

 

[Phil]

But with narrower tyres, less torque through the rev range (the Mk4 being used was I believe a 1.8T, not the damp squib 2.0), etc

As I said, the owners were there and the Mk4 was consistantly quicker, yet they used the one run where it didn't win so that when they reached the final race old and new were tied.

I'm really not sure what you're getting at - after watching that youtube video, it's not as if it was intended to be anything more than what they're showing: That a Mk1 beat a possibly Mk4 Golf on a drag strip. Anyone that has done dragracers would know that getting a car off the line isn't particularly easy, especially when the newer car has electronics on board to make it easier. Then you'd also have to factor in that the engine wear on the old mk1 - it probably isn't putting out the performance it once was and certainly not as much as the newer Mk4 would be relative to its age.

When you look at VW's own numbers and test reviews, a Mk1 is quicker off the line than a mk4 1.8t. Considering these numbers, it probably did deserv to win and if the results showed otherwise, it wasn't a very accurate "test" to begin with.

And last but not least, how serious can you take such a test when Clarkson doesn't even go into specifics on which cars and models he's testing? This "test" was nothing more to show that older cars were better before cars started to get heavier etc. That was the point and the one that was exagerated to make a point. That it happened to be an Mk1 that 'beat' the Mk4 isn't really the relevant bit.

It's not as if one is to call TopGear inaccurate simply because they showed Clarkson come back to the camp with a cow on his car which surely wouldn't be possible in the first place if it hadn't been staged. That's what they do. Make a point and exagerate it to make it entertaining.

 

[Thorburn]

It is more likely they re-ran the test to get the result they should using the factory specified figures.

The mk5 gti only just beats the mk1/2 to 60 and that is far better car than the mk4.

How many cars that age really produce there factory stats though?

This is like hitting your head against a brick wall, what more do you want me to say? The Mk4 was consistantly faster, if you are worried about pure honest facts then thats what you'd show and in the context of the piece on the show it was certainly relevant.
It is simply sensationalist results for the sake of entertainment.

Don't get me wrong I love the show but they twist the facts to suit there angle. Plain and simple.

 

[Phil]

... but they weren't trying to show that a 25 year old car with x engine wear is faster than a newer car with y engine wear - it was to show that the car of the same model was quicker in its day than the newer one is. And the point wasn't really one to take serious to beginn with! It was just one of the exagerated points of the show to illustrate what many enthusiasts are thinking today: That newer cars are always getting heavier, more sophisticated, complicated, more side tracked etc.

Again, the example you're are arguing wasn't a serious test to beginn with and was never intended to be one. If you think so, perhaps the show really isn't for you.

 

[DJ12]

That is what I said in a previous post.

A brand new Golf mk1 was quicker to 60 than a brand new mk4. The point they were showing was that newer doesn't mean quicker, so wear and tear shouldn't be a factor in it.

I fully agree that a mk1 unless has been loving cared for all it's life is likely to be slower than a newer car, but I don't believe that is what they were trying to get across.

They could've easily used the figures to prove the point and no one would've have been able to argue, but it's a TV show and visual representations are preferable.

I wouldn't be surprised if they actually told the guy in the mk4 to let the mk1 win to be honest with you.

 

[tongue_of_colicab]

Nope, the Evo's are VERY expensive cars to run, I'd suggest its in the same ball park as a 911 Turbo to service, perhaps even more when you consider the frequency esp. with the FQ400.

What I heard of it 911 are very reliable cars so that would mean maintanance wouldnt be so expensive. This one guy a m5boards racked up 120.000 on his modded GT2 with only the normal service intervals.

Than again, what is expensive? fith gear had a show with some stats on maintanance on a Enzo and a Mclaren F1. The enzo costs a couple of thousend every 6months (if nothing expensive breaks) and the F1 could cost up to 30.000 every 6 months (or 6miles I believe).

Lambo's might be considered exotic, but I wouldn't call them very quick around a track.

New lambo took the 6th place on the topgear track waaay above the EVO. If 6th place along with the Enzo, Zonda, Koeningssegg, Carrera GT, Mclaren SLR isnt very quick around a track than actually what is?

The fact is most people buy sports cars because they are fast, not because of the way they look or the materials they are made from.

Looks are definitly one of the reasons why people by exotic supercars. Maybe even more than speed because 99% of supercar owners just leave the thing in the garage or drive it to a restaurant in the weekends but never use it for what its built.

 

[MPI]

The width of the tyres has nothing to do with friction, just helps the lateral stability.

No way. Contact patch area has a lot to do with friction. In fact, the friction force is pretty much linear with the contact area, that is, the actual area of the interacting surfaces, on a microscopic level.

In terms of physics, an idealized tyre will produce the same friction regardless of width, in the real world it might make one or two % difference.

Not 'idealized', but 'simplified'. It's a _lot_ more complicated than that.

The constant friction coefficient for materials is high school level physics, when you get beyond that it gets a lot stickier, if you pardon the pun.

It just so happens that for most materials the lateral force tends to be roughly linear with the normal force ...for a while. When you apply a wider range of normal force the contact patch gets saturated, i.e. law of diminishing returns kicks in, and it gets well off linear. In a still pretty simple friction model this is modelled by a factor called 'load sensitivity', which acts by lowering the coefficient slightly according to how much normal force is applied.

The reason wider tyres give better traction is b/c they have more contact patch area -> less pressure per square centimeter -> less saturation -> higher friction "coefficient".

A related subject is why wider tracked cars corners faster given the same tyres and same weight...

 

[Skrying]

I was always of thought that surface area is nearly independent of friction. The benefit of tires being that of rolling friction.

I always hated physics.

 

[tongue_of_colicab]

Well I dont know anything about physics but dont you use very thing tires, like cyclists have because they have very low drag but can only get low power because they are so thin (not a problem since a human is on the bike) but for cars you need big wide tyres because you need to get all the power to the ground and have alot of grip in corners. So you have alot of drag compared to the thin tyres but you are able to get more power and grip to the ground.

 

[_xxx_]

Not 'idealized', but 'simplified'. It's a _lot_ more complicated than that.

Idealized = contact area is just a "perfectly" thin line and there are no deformations.

Also, wider tires will reduce the stress per unit area of each tire - that's why you can corner easier with wider tyres when driving high-speed, less because of higher friction. Narrower tyres would be too stressed and blow.

the amount of frictional force is proportional to the surface area of contact, but it is also proportional to the pressure with which the two surfaces are "pressed" together.

If you increase the surface area however, you will by definition decrease the pressure since pressure is "weight divided by surface area." So a change in surface area will cause two counterbalancing effects that leave, as you said, only the weight of the object to be considered.

Back to the real world: as you said, larger tires are used in order that softer material can be utilized. The greatest force required from the tires occurs during cornering. If a certain force were required to make a turn at high speeds with thin tires, the material itself could fail (similar to the fact that a rubber band will snap). You can see that this happens in racing when you get a close look at the old tires at they are replaced: small chunks are often ripped out.

 

[Phil]

What I heard of it 911 are very reliable cars so that would mean maintanance wouldnt be so expensive. This one guy a m5boards racked up 120.000 on his modded GT2 with only the normal service intervals.

Than again, what is expensive? fith gear had a show with some stats on maintanance on a Enzo and a Mclaren F1. The enzo costs a couple of thousend every 6months (if nothing expensive breaks) and the F1 could cost up to 30.000 every 6 months (or 6miles I believe).

Obviously, it's not that expensive as a F1 or Enzo is in a leaque of its own, but an EVO holds up quite well for being simply a sporty saloon. Servicing is more expensive than you'd get in a track-focused Lotus and comes quite close to other more expensive cars such as Porsche's etc. Turbo revision intervals if I stand corrected are around 6000 miles mark.

New lambo took the 6th place on the topgear track waaay above the EVO. If 6th place along with the Enzo, Zonda, Koeningssegg, Carrera GT, Mclaren SLR isnt very quick around a track than actually what is?

The TopGear track is hardly any reference and there's still a large number of dedicated track cars that haven't been tested yet that would absolutely kill any Lamborghini. I.e. Caterham's, Radical, Ultimas etc. Besides, the one that got 6th place is the special version LP640 anyway - the others (and the one that was mentioned above that was used in a direct comparison with the EVO FQ400 was the standard Murcielago) which are a far cry from the time the new one just achieved. Besides, all TopGear times should be taken with a grain of salt since each track and surface conditions change by the day. It's a good performance indication for that specific track - nothing more, nothing less.

Besides, I do agree that a Lamborghini is quicker around the topgear track than an Evo. I already said so further up - I still stand by my point though that a Lamborgini isn't exactly a definite benchmark for around a track. Now if they ever make a Lamborghini with stripped out interiour, no carpets, hifi and fancy electronic equipment and manage to bring out a car that's closer to the tonne than double, I might change my mind. As it stands, Ferrari's, as much as I dislike them, are a lot more driving machines and track focused than any Lamborghini.

Looks are definitly one of the reasons why people by exotic supercars. Maybe even more than speed because 99% of supercar owners just leave the thing in the garage or drive it to a restaurant in the weekends but never use it for what its built.

For what are "supercars" built though. When I look at a Lamborghini, I hardly see something that's ment to go quick around a track. It's nothing but a fast car with stunning looks and costs a lot of money. Now look at a stripped out GT3 RS or a 360 CS that lacks just about everything that's not needed to drive (sans hifi) and you have something that's a lot more dedicated to its purpose than any Lamborghini. It's like the Veyron - a stunning achievement that lets you do 400+ km/h without any large excitement - yet around a track, it'd be absolutely awful as it weighs nearly 2 tonnes and probably doesn't give much feedback with all the electronics it packs.

 

[tongue_of_colicab]

Yeah I agree with you on the Veyron. Thats probably the reason why Bugatti doesnt let TG put it around their track.