Tire Testing - Strange, but interesting results...

[Troux]

Tires in this game are really botched. As has been mentioned before, hard-soft don't seem to wear out any quicker than one another. Here's another big mistake: Try running the X1 on Racing Soft tires, then pit and switch to Comfort Hard, and see if you can tell a difference. I can't. I haven't tried this on other cars, but it simply shouldn't be.

 

[VBR]

Something occurs to me.

If PD didn't model the different widths of tyres for say, a Mini and a Corvette, what's to say they modelled the different widths of tyres on the front and rear of a Yellowbird? Or any other car with tyres of different widths front and rear? This would presumably affect quite a lot of MR and RR cars who tend to have this setup, as well as a lot of muscle cars. And the JGTC Silvia, which has wider tyres on the FRONT (go figure).

I'd love to be able to test this theory, but I'm struggling to think of a way to test the front and rear tyres of a car separately.

Until someone can figure out a way to test it, the assumption is probably that they haven't bothered to model it. Any method of modelling a staggered setup that would show results, would automatically show results between the Mini and Corvette as well.

I smell something fishy here. If this is as I suspect it means that the behaviour of some cars is fundamentally flawed.

Exellent point imari, maybe some cars should have a softer compound on the rear to compensate for the inaccuracy, for example: Sports Hard front & Sports Medium rear.


👍


PS: Regarding the YellowBird, your discovery might explain why it's so easy to drift this car in GT5 whereas IRL it's extremely hard. If they haven't modeled the extra wide rear tyres it would make the back more slippy than the front & affect the cars handling. I think we should defo go for split tyre choices (SH/SM) on some cars Calan, time to update the Google Doc maybe!

 

[OTB]

Thank you Calan,
For the theory. Like you say its not an exact theroy, but its the best method i've heard of or read concerning tyre choice on GT5. Anything to get away from the false feel of RS, Which imo is masking the true physics of the car. Many of us realised there was something a miss quite quickly, but struggled to understand how to choose the correct tyres. i applaued you for your brilliant idea.
I read earlier that different magazines & sites are giving slightly different ratings for lateral G. IMO this would be because of the differing surfaces that they where tested on. ie, concrete, ashphalt. and the composition of the ashphalt. Not neccesary to figure into your theory i know, due to you choosing the average rating you find. What i would like to put to you is the differing levels of grip that each track has on GT5, Does the TGTT offer a average grip level compared to the rest of the tracks in your opion. Or is the grip level the track offers to small to make a difference on your findings,,,

Thanks Again, for doing PD's job

 

[calan_svc]

Something occurs to me.

If PD didn't model the different widths of tyres for say, a Mini and a Corvette, what's to say they modelled the different widths of tyres on the front and rear of a Yellowbird? Or any other car with tyres of different widths front and rear? This would presumably affect quite a lot of MR and RR cars who tend to have this setup, as well as a lot of muscle cars. And the JGTC Silvia, which has wider tyres on the FRONT (go figure).

I'd love to be able to test this theory, but I'm struggling to think of a way to test the front and rear tyres of a car separately.

Until someone can figure out a way to test it, the assumption is probably that they haven't bothered to model it. Any method of modelling a staggered setup that would show results, would automatically show results between the Mini and Corvette as well.

I smell something fishy here. If this is as I suspect it means that the behaviour of some cars is fundamentally flawed.

Exellent point imari, maybe some cars should have a softer compound on the rear to compensate for the inaccuracy, for example: Sports Hard front & Sports Medium rear....

I think we should defo go for split tyre choices (SH/SM) on some cars Calan, time to update the Google Doc maybe!

While I appreciate the thought and agree with you, I don't really see a good way to test or implement it.

For one thing, GT5's FFB is so flawed (at least on the G25) that it's almost impossible to tell which end of the car is loosing traction sometimes. And of course there is no temperature data for the tires either. Even if you could verify this effect consistently, I don't know how you would measure the grip imbalance from front to rear.

Second... On a skidpad, almost all cars IRL would start to lose grip at one end or the other first due to it's natural understeer or oversteer, so I don't know how you could contribute that to inaccurate grip at one end, rather than the car's inherent balance.

My goal was to get overall grip levels closer to IRL; I think when you start mixing tire types you'll just end up making the car "better", but not necessarily more accurate.

Very interesting point though, and I'm open to any suggestions on how we could pursue this idea. Maybe we could change front or rear tires by one rating on cars with a known amount of contact patch difference. But how do we define what that difference is and how it effects the tire choice in GT5?

 

[Imari]

My goal was to get overall grip levels closer to IRL; I think when you start mixing tire types you'll just end up making the car "better", but not necessarily more accurate.

Very interesting point though, and I'm open to any suggestions on how we could pursue this idea. Maybe we could change front or rear tires by one rating on cars with a known amount of contact patch difference. But how do we define what that difference is and how it effects the tire choice in GT5?

We do have a very limited amount of temperature data, in that you can see which tyres are going up in smoke.

I tried a simple test, running a car in the tightest circle I could at 40kmph and measuring the G. If you put too much steering lock on you start burning out the front tyres, even in a rear wheel drive car. The assumption then is that this test is STRONGLY dependent on the front tyres of the car.

I tested this on a '97 MR2 and the '06 F430. I tested them with Comfort Softs on both ends, and again with Comfort Softs on the front and Sports Softs on the rear. I did a similar thing to you with a scale taped to the screen, and within the margin of error I had I got the same results for both tests. That suggests to me that by using that test it would be possible to (mostly) isolate the front tyres.

I couldn't find a way to isolate the rear tyres though. I was hoping that running through high speed banked corners a la Daytona/Indy/HSR might do it, as you often find the rear washing out in such corners. Unfortunately, even though the rears often tended to lose grip before the fronts in that situation, the difficulty in driving a car with low grip tyres on the rear around a high speed banked corner made it impossible to get any sort of consistent measurement.

The thought was that if I could isolate front and rear in this fashion I could compare between cars. The MR2 and the F430 are fundamentally fairly similar in drivetrain and layout. The MR2 has 195/55 R15s front and rear, but the F430 has 225/35 ZR19s on the front, and 285/35 ZR19s on the rear. If the ratio between the front and rear tyres for both cars was similar, I would have taken that as strong circumstantial evidence that the tyre width is not modelled for cars such as the F430.

 

[calan_svc]

...What i would like to put to you is the differing levels of grip that each track has on GT5, Does the TGTT offer a average grip level compared to the rest of the tracks in your opion. Or is the grip level the track offers to small to make a difference on your findings...

I really couldn't tell you to be honest. To me, the game doesn't have enough resolution to be able to tell a difference from one track to another. The FFB is nothing but a centering spring on my G25, and with no temperature indicators for the tires it's really tough to tell for sure.

I really don't think it matters much anyway in the grand scheme of things.

 

[VBR]

Got 2 new numbers for the Mini Cooper S:


Mini Cooper S 2007: "Lateral acceleration - 0.86 g (avg)"

http://www.motortrend.com/roadtests/oneyear/112_0711_2007_mini_cooper_s/index.html (chart at bottom of page).


Mini Cooper S 2003:

"On the skidpad, the Cooper S was able to achieve 0.84 g of lateral acceleration."

Source: http://www.ehow.com/list_7403921_03-mini-cooper-specs.html (look under performance at the bottom).



Maybe we should split the difference & say Comfort Mediums instead & put older Minis on Comfort Hards for the time being?



👍



PS: The 0.78g number was for a 2006 Mini Cooper S, so isn't applicable anyway imo: http://www.insideline.com/mazda/mazdaspeed-mazda3/2007/2006-sport-compact-comparison-test.html

 

[calan_svc]

Thanks for the data!

Since the Mini changed platforms in 2007 (MK II), that would most likely explain the improved performance for that year. The Cooper S '05 should be about the same as the '03.

The .79g number is from the standard '02 Cooper, not the "S" model; although they should be similar. (I just marked the wrong one initially).

I've updated the Google doc for the Mini's, and added recommendations for many more cars as well.

 

[VBR]

If I find anymore numbers I'll post them here in this thread.

👍

I tried the Camero SS 2010 again last night with Comfort Softs & have to say that they felt more appropriate for the car, tried Sports Hard aswell & they felt dull with too much grip. Comfort Mediums, as you sugested in the op, were a lot of fun to race on cos they were a challenge, maybe that'd be what it's like to drive it on a really cold day, hehe!

 

[Vince_Fiero]

interesting read

 

[VBR]

Regarding the Zonda R:

"...Pagani’s claim of 2.0g of lateral acceleration..."

Source: http://www.autocar.co.uk/CarReviews/FirstDrives/Pagani-Zonda-6.0-V12-R/252416/

Controversial considering this: https://www.gtplanet.net/forum/showthread.php?t=180406

I know this thread is about stock cars but, Clarkson said the Zonda R has loads of grip & was easy to drive, yet in GT5 this isn't the case even on Racing Softs. If it did have tyres on that pulled 2.0g in GT5 (combined with aero), it would also produce much faster laptimes on The Ring & Top Gear Test Track, what's wrong with this picture?

 

[pay2021]

I didnt try it but its posible to make the tests with wet tires in any dry surface??

 

[calan_svc]

I know this thread is about stock cars but, Clarkson said the Zonda R has loads of grip & was easy to drive, yet in GT5 this isn't the case even on Racing Softs. If it did have tyres on that pulled 2.0g in GT5 (combined with aero), it would also produce much faster laptimes on The Ring & Top Gear Test Track, what's wrong with this picture?

The claim of 2.0g on a standard skidpad test seems highly unlikely, considering that even F1 cars pull something like 1.4g tops. Given that the early C12 pulled .93g and was then later improved to .98g, something around a 1.2g max would be more likely. Given that, SS (or perhaps RH) tires would probably make the most sense.

IMO, the Zonda feels comparable to other cars in its class. On my new matchmaker app it scores an ABH rating of 8.97 compared to a 9.19 of the McLaren F1 GTR Race Car (which has a slightly lower P/W ratio...but then again it is a GTR race car). . If the Zonda R isn't handling like it should around a particular track on SS or RH tires, it's probably a suspension setup issue or a driver mod is needed.

I didnt try it but its posible to make the tests with wet tires in any dry surface??

All bets are off when it comes to wet grip levels. I've seen enough weirdness in GT5 under wet conditions that I'm not even going to attempt to go there.

 

[VBR]

The claim of 2.0g on a standard skidpad test seems highly unlikely, considering that even F1 cars pull something like 1.4g tops.

I've seen F1 cars on TV pull up to 4 to 5 G's on certain corners from the telemetry that's displayed on screen! Am I missing something here?

This car's registering about 3.6g through some corners.

http://www.youtube.com/watch?v=jWsYffV0sLw

 

[mu22stang]

Downforce is not significantly in play for a standard skidpad test, so even an F1 car will have relatively low lateral G figures.

 

[VBR]

Downforce is not significantly in play for a standard skidpad test, so even an F1 car will have relatively low lateral G figures.

I see, of course, DOH!

 

[VBR]

Some people are saying that the physics have been tweaked in the 1.06 update, just wondered if you've re-tested the tyres for a known car again to see if the grip levels have changed?

 

[SLAPHAPPYFRANKY]

Nice to see, Ive wondered what the tires are for the cars.

 

[calan_svc]

Some people are saying that the physics have been tweaked in the 1.06 update, just wondered if you've re-tested the tyres for a known car again to see if the grip levels have changed?

I haven't even tried the new patch yet. I'm hoping to play around with it a little this weekend and see if anything has changed in relation to tire grip.

 

[CoolColJ]

Don't know if the physics are different, but it sure feels different with a pad, much easier to drift now, car slides around a lot more, your less likely to oscillate

 

[PAPPACLART]

I have not read through the whol thread so not sure if somebody has mentioned it? Is it not true that many car magazines or even suppliers of cars will often fit more sporty tyres to give the said car a better showing on track or in skid pad tests. Certainly in the motorcycle world, during bike group test, many of the motorcycles being test would often have sticky rubber put on. If a bunch of sports cars are being tested on track, dragstrip and skidpan, i w ould imagine this would be the same. due to this possibility it may be the cae that many cars tested on skidpans perform better as they are often not on stock rubber?

 

[calan_svc]

I have not read through the whol thread so not sure if somebody has mentioned it? Is it not true that many car magazines or even suppliers of cars will often fit more sporty tyres to give the said car a better showing on track or in skid pad tests. Certainly in the motorcycle world, during bike group test, many of the motorcycles being test would often have sticky rubber put on. If a bunch of sports cars are being tested on track, dragstrip and skidpan, i w ould imagine this would be the same. due to this possibility it may be the cae that many cars tested on skidpans perform better as they are often not on stock rubber?

It's always a possibility, but for the most part Road & Track and other reputable magazines have always been pretty neutral on their tests. If anything, they tend to be on the conservative side and seem to go out of their way to prove the factory advertised numbers wrong.

In any case, I try to verify test results through more than one source...and surprisingly they usually always end up being very close; at least within a few tenths. As an example, I've seen slightly different numbers for the 2010 Camaro from various reputable sources, and they range from .87 to .91...so I would consider a value of .89 or so to be a reasonable number for that car.

A bit of common sense and knowing the history of auto technology helps narrow it down was well. For example, if someone claims anything higher than mid to high 80's for a road car built before 1985 or so, you have to look at that with a bit of skepticism unless there are multiple sources.

 

[PAPPACLART]

I can see that you have a put allot of time into this, and by the way great job. Personally I always had suspisions as I always fealt that some cars had more or less grip than they should, and through your work have proven this.

I was thinking that the reason we may not have TT leaderboards is that we will eventually get a physics update. And the more we pick the game apart from a physics perspective the more likely we will get an update. We have clearly been given an unfinished game, that as we play is slowly being finished.

Keep it it up.

 

[charliec]

Regarding the Zonda R:

"...Pagani’s claim of 2.0g of lateral acceleration..."

Source: http://www.autocar.co.uk/CarReviews/FirstDrives/Pagani-Zonda-6.0-V12-R/252416/

Controversial considering this: https://www.gtplanet.net/forum/showthread.php?t=180406

I know this thread is about stock cars but, Clarkson said the Zonda R has loads of grip & was easy to drive, yet in GT5 this isn't the case even on Racing Softs. If it did have tyres on that pulled 2.0g in GT5 (combined with aero), it would also produce much faster laptimes on The Ring & Top Gear Test Track, what's wrong with this picture?

Lateral acceleration doesn't have to mean lateral acceleration on a 200' or 300' skidpad. This can just be maximum lateral forces observed during cornering, which allows aerodynamics to come into play during high speed cornering. To be fair, the Autocar article never specifies that figure was pulled on a skidpad.

 

[VBR]

I haven't even tried the new patch yet. I'm hoping to play around with it a little this weekend and see if anything has changed in relation to tire grip.

Cool, I think it's just racing tyres that've changed according to what I've heard, I hardly ever use them so don't know for sure & I doubt it will affect road & sport tyres anyway.

Lateral acceleration doesn't have to mean lateral acceleration on a 200' or 300' skidpad. This can just be maximum lateral forces observed during cornering, which allows aerodynamics to come into play during high speed cornering. To be fair, the Autocar article never specifies that figure was pulled on a skidpad.

Good point, thanks.


👍

 

[Griffith500]

Cool, I think it's just racing tyres that've changed according to what I've heard, I hardly ever use them so don't know for sure & I doubt it will affect road & sport tyres anyway.

...

The absolute grip levels don't seem to have changed much on the other tyres, but something seems to have changed in the overall model of these other tyres, so that they feel quite different.

I also think something has changed with the default track conditions, affecting handling perhaps by way of temperatures. I had a race on Eiger online and it was like driving on ice with Sports Hard and Sports Medium tyres. Similarly, the Elise 111R feels more squirrelly on SHs now at Suzuka and Autumn Ring.

 

[VBR]

...the Elise 111R feels more squirrelly on SHs now at Suzuka and Autumn Ring.

I'll have to try this at Suzuka again as the 111R is my fav car, I'll be on SM as these have similar grip as the car IRL according to calan_svc's method for testing in this thread.

I've got a 2nd PS3 (old 40 gb fatty) which has the 1.05 update on it, I might turn both on & do some direct comparisons just out of interest, if & when I can be bothered.

 

[RWB1213]

How much longer last the soft tyres compared to the hard?

It seems that the wear rates (within catagories comport/sport/race) track similarly provided the car setup is solid and tires aren't breaking loose under braking or acceleration. You'll notice under lockup or wheelspin, your tire temp indicators will flash to RED, meaning overheated. It is under these conditions that tires go away quickest (by a very large margin) in my experience. I notice heavy tire wear in B-Spec more than A-spec, as my bob's aren't as capable of avoiding lockup/wheelspin.

I can't really say how accurate this model is, as the only real vehicle I have piloted with racing slicks is a Go-Kart. Based on what I have seen IRL motorsports, wear rates in GT5 seem to be too similar- however the counterpoint is how well some F1 drivers managed option tires this season. Who's to say?

 

[Griffith500]

I'll have to try this at Suzuka again as the 111R is my fav car, I'll be on SM as these have similar grip as the car IRL according to calan_svc's method for testing in this thread.

I've got a 2nd PS3 (old 40 gb fatty) which has the 1.05 update on it, I might turn both on & do some direct comparisons just out of interest, if & when I can be bothered.

That would probably be invaluable. 👍

 

[VBR]

I just thought, seeing as replays of 1.05 still work this means that the grip levels couldn't have changed. If the grip levels had changed in the update, the replays wouldn't work as the recorded telemetry would be driving cars with more/less grip resulting in chaos. Just like replays recorded in GT5P Spec 2 wouldn't play in Spec 3 after that physics update. I think the engine noise has changed & maybe the FFB too giving the impression of a physics update, but haven't got round to checking it out yet. I wonder if replays of cars on Racing tyres still work, as that's what most people say has changed?

By the way, we raced the Maserati Gran Turismo S '08 on the recommended Sports Hard tyres last night at my Saturday Stock Car Series event & it was great, had lots of fun & two particularly epic races. I'll try & get round to uploading some video to You Tube soon when I can be bothered.