mark kibort

much of the time, the slicks will be faster, but the suspension might act like it is too soft and follow characteristics of a "too soft " suspension. In the reverse, the slick set up might be too stiff and you could end up with a bad push, for example, by just bolting on a set of DOTs on a Slick chassis set up.

The NSX for example, was running pretty fast, as fast as most anything that we ever see at the track, and running with slicks and DOTs on near the same set up. they might be softening shock settings between run groups , but the same geometry and spring settings.

As far as the "Kiwi" comment to the V8 supercar series cars, The Kiwi's have a car in it, but I shouldnt have called the car, a "Kiwi car".
http://www.teamkiwiracing.co.nz/

mk

Larry Herman

Hey, at least you're separated by water. Here they come pouring over the border!

333pg333

They dug a tunnel years ago. Comes straight into Bondi Beach.

mark kibort

I did have a chance to use toyos and Hoosiers on the same weekend of racing and raced with the hoosiers in both races. Although the car was more firmly planted and some oversteer was corrected, the times were only about .25 seconds faster than my previous times out at laguna. My times at laguna with the new engine dropped by 1 to 1.5 seconds with 50 more hp as of last seasons end of 1:37.8 at laguna. Iwas able to eek out a 1:39.7 in april and with the Hoosiers was able to run a more consistant and generally slightly faster, 1:39.5. (1:39.8 in race two of the weekend) . In prior races, I wasnt able to run faster than a 1:38.3 in the race, but qualified at 1:37.7-8 in prior race weekends. One thing for sure, they do have more grip, just at laguna I wasnt able to turn it much into a 1 second difference as I had hoped and was trying to do. the gains in the turns and under braking, just didnt buy me that much time.

Here are the videos of the toyos and the Hoosiers weekends. (april on my normal Toyo, almost new from WCGT, this last june race on Hoosiers)

Hoosiers - race 2 last laguna: (1:37.8) start video at 4.05

http://www.youtube.com/watch?v=xYbFe...e=channel_page

Toyos -race at the prior April Laguna '09 (1:38.3) start video at 2:06

http://www.youtube.com/watch?v=x-FzG...eature=channel

2BWise

Did you make any changes? Or did you just switch one for the other? You're not going to see any significant improvements unless you optimize the car for the tires you're running. Tire pressures and temps will be much different and without tuning the alignment settings and general setup how can expect to ever see a difference in lap times.

Veloce Raptor

+1. Details like this are often lost on him, however....





Professional Racing and Driving Coach

Larry Herman

Looked to me like you were driving much more aggressively on the Toyos, and you were still 1/2 a second slower. Maybe you should try driving the Hoosiers harder and you would find that full second, but what do I know.

dmwhite

you say that you used both tires (toyos and hoosiers) in the same weekend but then you compare your hoosier times to lap times times at "previous times out at laguna" - comparing lap times from one day to the next can give you poor results...comparing lap times from one weekend to the next is pretty much useless

if you ran both tires at the same event, what lap times did you get from each tire at that event? (not comparing to a different weekend/event)

are these comparisons/lap times from the same day or at least the same event? if not, it's a pretty pointless comparison...

mark kibort

As you know, I have a lot of races at laguna. I felt like I was pushing them hard, as several turns would show the limits as the rear stepped out under earlier power applied on exits and during threashold braking areas. BUT, I see what you are seeing. There is a chance there is a little more in some cornering areas that I wasnt taking advantage of. However, as I mentioned, the last time there, times were 1:37.7 qual and 1:38.3 race, while this time 1:37.7 and 1:37.5 race, making me think that the tires were about .5 seconds faster. I totally understand there are a ton of variables. But, as I was saying, my tests (for me) are pretty valid, as the car didnt change and we have a ton of race laps there with a narrow range of times.

Ill see if I can kick up the aggression factor next weekend at Thunderhill. Ill also be doing more of a back to back test wih the toyos.

mk

mark kibort

I dont think the comparisons are pointless, knowing laguna and my marks on a given lap as I do. BUT, you are right, there is certainly things that change from day to day. I really cant compare the practice session of a 1:39, because on the only hot lap I had, I got stuck behind a couple of cars on one of the most critical turns. Having knowledge of what that kind of slow down costs in time, I would judge that the car was on pace for my usual times of sub 1:38, no problem) With the new hoosiers, there just was a lot more basic grip, although it did require a slightly different style of driving.

Again, I will be doing a more apples to apples comparison with my relatively new toyos and the 1 race weekend old hoosiers this next race. a clean lap is pretty important to judge and compare the times

Thanks,

mk

mark kibort

What type of changes would you look at. the car was more neutral, the push was reduced to almost none, and the tire wear was very even, along with tire temps being near identical across the tire, 10 degrees apart, (inside hot, middle and outside section)

So, what types of things do Hoosiers require? you cant give a camber or pressure recomendation, due to all cars being different in geometry and weight. But what kind of things do you look for?

generally, Ive heard if you are getting good luck with a setup, it should work for slightly varied tire grip.

Pressure was changed to a radically different value based on a similar weighted car and top times.

thanks,

MK

Larry Herman

My experience with the R6s is that they are very sensitive to pressure changes, especially with heavier cars, and that a lb or so can make a big difference. With my RSA I found them to be about 1/2 to 3/4 of a second faster at 37/38 lbs hot than at 35/36 lbs at Watkins Glen. You could only tell by times and pressures because they felt pretty good at 35/36.

mark kibort

That is interesting, as the Griggs folks are racing a pretty heavy car and running the fastest times of anyone, playing with the higher pressures and then ending up at 30psi hot. (1 second slower at the 35psi range, as well as greasy and wear issues)

Its such a black art. Ill try some higher pressures and see what I see. what would be the clues to too low of pressure? Generally, when i get too high, the entire is not being used, and the centers are slightly hotter.

I forgot to mention, these are A series not R.

Thanks,

mk

Larry Herman

I have found that once you get with-in 3~4 psi of the best pressure for Hoosiers, they feel pretty good. It's just that as you get closer to the optimum, they keep getting faster and faster (read more grip with less drag) until you go over, and they get greasy pretty quickly. If your optimum is 37/38 it is much easier to feel when they get to 39/40 (and they go off) then if they only get to 35/36 and still feel "good". It requires testing to know where the best pressure is, and then good record-keeping to know what pressure to start at depending on the weather/track temp etc.

I can't advise you on the A6s except to say that they are a different compound and that can make all the difference in the world. It is logical to assume that they being a softer compound would work at a lower pressure, as it is with race tires.

Veloce Raptor

I have found the same behavior with the Hankook Z214's.





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