Comparing car lap times: Equal tires?

[midenginebias]

great tires will inflate results on both great and shitty chassis. if it does the same things to both ends of the spectrum, how is that hiding anything?

So would you rather have the chassis with weaker tires that puts great numbers?

Or perceived "worse" chassis with great tires that puts out equally great numbers?

[Kunzite]

@WolfpackS2k:
For no other reason, other than being able to compare with ones posted by DarkSunrise:
http://www.ft86club.com/forums/showp...postcount=1311

@fatoni, and who do you want to turbocharge the car? Car magazines? On cars borrowed by the manufacturers? You forgot to be reasonable in your demands.
But of course, turbocharging an engine is the same as changing some tires for you...

How on Earth did you get that "different skidpads"? It's the exact opposite of what I'm asking for: same testing conditions (surface, radius), same tires - so we'll test the car itself, not the tires, not the skidpad.
And you get upset when I'm saying sometimes you don't make any sense.

[DarkSunrise]

Originally Posted by Kunzite

@WolfpackS2k:
For no other reason, other than being able to compare with ones posted by DarkSunrise:
http://www.ft86club.com/forums/showp...postcount=1311

At risk of getting tangled up in this inane debate, these are Edmunds' numbers for the ZR1 and Elise:

1.06 g / 74.7 mph / 96 ft -- Corvette ZR1 (Michelin PS2)
1.03 g / 71.6 mph / 109 ft -- Elise (Yoko A048 LTS)

Originally Posted by fatoni

skidpad tests are not only next to worthless as far as handling goes but they should only be compared on the same surface with the same radius. close to the elise skidpad numbers? was that the .95g or the 1.03g. the zr1 posts higher numbers than the elise ever did. is the corvette a better handling car than the elise?

Depends what your definition of handling is. Objectively, the ZR1 generates more lateral grip and shorter braking distances than the Elise. In other words, it'll carry higher speeds through corners than the Elise and can delay braking until a later point in the brake zone. So from a performance perspective, the answer is clearly yes.

Subjectively, the ZR1 is known to be a handful when pushed to the limit. It's also apparently not the most rewarding car to drive, an area where the Elise might shine.

[fatoni]

Originally Posted by midenginebias

So would you rather have the chassis with weaker tires that puts great numbers?

Or perceived "worse" chassis with great tires that puts out equally great numbers?

i guess it depends on the cars were talking about. im obviously on this forum. i still dont think the tires hide things. good tires work on both good and bad cars.

Originally Posted by Kunzite

@WolfpackS2k:
For no other reason, other than being able to compare with ones posted by DarkSunrise:
http://www.ft86club.com/forums/showp...postcount=1311

@fatoni, and who do you want to turbocharge the car? Car magazines? On cars borrowed by the manufacturers? You forgot to be reasonable in your demands.
But of course, turbocharging an engine is the same as changing some tires for you...

How on Earth did you get that "different skidpads"? It's the exact opposite of what I'm asking for: same testing conditions (surface, radius), same tires - so we'll test the car itself, not the tires, not the skidpad.
And you get upset when I'm saying sometimes you don't make any sense.

i dont care who does all that jazz to the car. im just saying is that anybody can pick a conclusion and find evidence to support it. i got "different skidpads" from the fact that you are using data to support your claims that was collected on..."different skidpads"

sorry if i sound mad. im not mad, this is the internet

Originally Posted by DarkSunrise

At risk of getting tangled up in this inane debate, these are Edmunds' numbers for the ZR1 and Elise:

1.06 g / 74.7 mph / 96 ft -- Corvette ZR1 (Michelin PS2)
1.03 g / 71.6 mph / 109 ft -- Elise (Yoko A048 LTS)



Depends what your definition of handling is. Objectively, the ZR1 generates more lateral grip and shorter braking distances than the Elise. In other words, it'll carry higher speeds through corners than the Elise and can delay braking until a later point in the brake zone. So from a performance perspective, the answer is clearly yes.

Subjectively, the ZR1 is known to be a handful when pushed to the limit. It's also apparently not the most rewarding car to drive, an area where the Elise might shine.

i know we can analyze the term handling but i think objectively it might still be up for debate as to which is the best handling car. obviously the vette puts up tons of grip. its obviously the better high speed handler (thats what it was designed to do) but i wouldnt be surprised if figure 8s and slalom tests show the elise performs better in the low speed and transient handling areas

[Captain Insano]

I personally prefer when a comparison is done that it be done on the most even playing field as possible. If I am wondering about car handling performance, yes most definitely I would prefer the cars being compared be on the same tire. That helps make things an even test - obvioiusly a car with all season tires versus a car with high performance summer tires, there is a clear advantage if a test is being conducted between those two cars...

That being said, a test is a test is a test. There is no perfect test. But using the same tires so things are "more level", there is a bit better comparison to me.

Example of no perfect test... Say you have two car models. You put them on the same tire. They are driven by the same driver. On the same day. On exactly the same track. But... What if the cars compared have AWD in one and RWD in another. And the driver has grown accustomed to AWD cars more so than RWD cars. And so the AWD is the "clear winner" in the contest because it gets a better time in the track runs... What if you take another driver and this driver is more accustomed to RWD cars and the RWD gets best times on this test run?? Which car is better.

There is no perfect test and we can argue all day long about how tires make it better or tires are irrelevant because there are too many other variables. In my humble opinion, using the same tire does even the playing field a bit, but there are enough other factors in a car comparison test that sometimes you can get misleading results.

The only real test you should care about at the end of the day... Is if you are the driver and you are conducting these tests because you are going to be buying one of the cars in the test. That is the best test and the only test that really matters.

[rice_classic]

Originally Posted by Captain Insano

I personally prefer when a comparison is done that it be done on the most even playing field as possible. If I am wondering about car handling performance, yes most definitely I would prefer the cars being compared be on the same tire. That helps make things an even test - obvioiusly a car with all season tires versus a car with high performance summer tires, there is a clear advantage if a test is being conducted between those two cars...

That being said, a test is a test is a test. There is no perfect test. But using the same tires so things are "more level", there is a bit better comparison to me.

Example of no perfect test... Say you have two car models. You put them on the same tire. They are driven by the same driver. On the same day. On exactly the same track. But... What if the cars compared have AWD in one and RWD in another. And the driver has grown accustomed to AWD cars more so than RWD cars. And so the AWD is the "clear winner" in the contest because it gets a better time in the track runs... What if you take another driver and this driver is more accustomed to RWD cars and the RWD gets best times on this test run?? Which car is better.

There is no perfect test and we can argue all day long about how tires make it better or tires are irrelevant because there are too many other variables. In my humble opinion, using the same tire does even the playing field a bit, but there are enough other factors in a car comparison test that sometimes you can get misleading results.

:happy0180:

I just wanted to address a couple items that stood out and they are not attacks just counter-argument or perspective.

The bolded parts:

1: "no perfect test". I think that's obvious with just about any test.. we're not operating in a vacuum so the point is increasing the internal validity of the test and also what's being tested. We want to remove the most significant variable between to the two cars, the "low hanging fruit" if you will. You named a few: same track, same day, same driver... that's easy. As for AWD and RWD, it doesn't matter which one "wins" because it's not a competition... it's a test. It seems like we're making things up for the sake of over complicating things.... Think "Ceteris Paribus"... All things being equal. "Test cars with equivalent tires.. Ceteris Paribus."

2: A bit? you and I have a difference of opinion of the term "a bit". I think a difference of 2 seconds per lap on the same car is significant and the single most cost effective way to reduce lap times is tires. If you think about it.. Ceteris Paribus, what would it cost you to find another 2 seconds adding HP alone? 1k?, 2k? maybe even 3k? I think you'd have to add another 40hp+ to see another 2 seconds without changing tires. I have not proof of this but it is something I'd like to test.

It's kind of like the Power vs Weight analogy: "Power makes you faster down the straights, being lighter makes you faster everywhere." Tires apply to the same principle. On a track a stickier tire puts into the corner later, through corner and corner exit faster.

Ugh.. i need to get back to the racetrack.

[Captain Insano]

No worries man. Remember I said I prefer same tires as it will definitely yield a "better" test... :-)

I was just pointing out you can do all the things people are talking about to get "a good test" and there are still so many things that can skew results whether intended or unintended. The "best" test is you driving both cars and making up your own mind.

[carbonBLUE]

Originally Posted by SubieNate

I think it's common knowledge that some manufacturers put really really sticky summer tires on their cars stock so that in magazine reviews they will come out with better numbers even though the suspension design may not be as good as some of the competitors.

Knowing that, I think comparing the grip level the tires provide when looking at lap times is important. I think it's telling that the twins on stock tires are pulling skid pad times and lap times that are comparable to some other performance cars on much stickier tires.

Nathan

yeah our cars did very well in 30+ reviews 28+ reviews giving our car the hands down winner. I personally cant wait till i put more grip on the car aka a tire swap, im pretty sure coil overs AND tires can net a 1.08g+ on the skid pad under the right conditions, ive pulled over over .98g's in a corner on the stock tires, so i dont doubt its out of the questions

[fatoni]

Originally Posted by carbonBLUE

yeah our cars did very well in 30+ reviews 28+ reviews giving our car the hands down winner. I personally cant wait till i put more grip on the car aka a tire swap, im pretty sure coil overs AND tires can net a 1.08g+ on the skid pad under the right conditions, ive pulled over over .98g's in a corner on the stock tires, so i dont doubt its out of the questions

a peak of .98g doesnt count for much. those kind of singular instances are not really related to static sustainable lateral grip. that being said, you could probably set your sights a little higher than that. an na miata with decent coilovers and 225 rs3s will do 1.25-1.33g on the skidpad.

[midenginebias]

Originally Posted by fatoni

a peak of .98g doesnt count for much. those kind of singular instances are not really related to static sustainable lateral grip. that being said, you could probably set your sights a little higher than that. an na miata with decent coilovers and 225 rs3s will do 1.25-1.33g on the skidpad.

.98g counts for much for the given stock tires.

That's what I mean. You talk about a Miata with coilovers and 225 RS3s, ... so how will the FR-S/BRZ do?

Great tires work for all cars. Yes. But if a chassis puts up great numbers as opposed to a "lesser chassis" with great tires putting up equal numbers, then the great chassis just has more potential; e.g. Miata and FR-S as opposed to Mustang GT.

[fatoni]

Originally Posted by midenginebias

.98g counts for much for the given stock tires.

That's what I mean. You talk about a Miata with coilovers and 225 RS3s, ... so how will the FR-S/BRZ do?

Great tires work for all cars. Yes. But if a chassis puts up great numbers as opposed to a "lesser chassis" with great tires putting up equal numbers, then the great chassis just has more potential; e.g. Miata and FR-S as opposed to Mustang GT.

you are taking that entire post i made out of context just so you know.

[Kunzite]

Originally Posted by DarkSunrise

At risk of getting tangled up in this inane debate, these are Edmunds' numbers for the ZR1 and Elise:

1.06 g / 74.7 mph / 96 ft -- Corvette ZR1 (Michelin PS2)
1.03 g / 71.6 mph / 109 ft -- Elise (Yoko A048 LTS)

Thank you. Impressive, indeed.

Originally Posted by fatoni

i guess it depends on the cars were talking about. im obviously on this forum. i still dont think the tires hide things. good tires work on both good and bad cars.

i dont care who does all that jazz to the car. im just saying is that anybody can pick a conclusion and find evidence to support it. i got "different skidpads" from the fact that you are using data to support your claims that was collected on..."different skidpads"

sorry if i sound mad. im not mad, this is the internet

Agree with "good tires work on both good and bad cars" and again, this is an argument for using equal tires.
But if a "bad car" must use high grip tires (and rock hard suspensions) to meet its performance targets, which are easily achievable by a "good car"...

It's the thing about "potential" midenginebias is talking about: given equal performance, I would get the "better car" because I can easily change the tires, and get even better performance.
And FYI, changing tires it's something that can be done in half an hour by pretty much anyone, and will not void the warranty. That's to avoid comparisons with turbocharging an engine

Where did I used data collected on "different skidpads"? I was using DarkSunrise's data, and afaik he only posted Edmunds results, specifically to allow direct comparisons.

"sorry if i sound mad. im not mad, this is the internet" - same here (plus the language barrier)

[fatoni]

Originally Posted by Kunzite

Thank you. Impressive, indeed.


Agree with "good tires work on both good and bad cars" and again, this is an argument for using equal tires.
But if a "bad car" must use high grip tires (and rock hard suspensions) to meet its performance targets, which are easily achievable by a "good car"...

It's the thing about "potential" midenginebias is talking about: given equal performance, I would get the "better car" because I can easily change the tires, and get even better performance.
And FYI, changing tires it's something that can be done in half an hour by pretty much anyone, and will not void the warranty. That's to avoid comparisons with turbocharging an engine

Where did I used data collected on "different skidpads"? I was using DarkSunrise's data, and afaik he only posted Edmunds results, specifically to allow direct comparisons.

"sorry if i sound mad. im not mad, this is the internet" - same here (plus the language barrier)

i still dont know what you think makes a chassis good or bad in an objective manner so i wont touch the whole first part of your post.

going to a track can void a warranty so why are we even doing track tests if that the criteria you have established?

it doesnt mean that all the data was measured by the same people, in the same conditions, at the same track, with the same radius just because the data was compiled by a single organization. just look a couple posts back. road & track tested the zr1 twice and got two different numbers
potential doesnt stop at the tires.

[Kunzite]

In other words, arguments that doesn't support your point of view are irrelevant and should be ignored. Excuses, red herrings, strawmen would help you do that.
But don't insult my intelligence, by being too obvious. "The criteria I have established"? When and where? I only remember mentioning it as a difference between just changing some tires and extensive car modification; because you don't seem willing of distinguishing those two.

How many tracks does Edmunds have/use? How much does the radius differs in their tests? Just curious.

And again, you're not making sense. If there are variables which makes the result inconsistent, then those variables must be identified and eliminated. Ignoring one such variable (tires) is not such a smart idea.