Driver training day @ Snett with Malc (Maxx)

[Maxx]

Also interesting on the cornering G info - the Khumos feel to me to be as good as the 888s but from what you were saying I think I'll give Mich pilot Sport Cups a go next (now actually as n/s rear khumo is ready for the bin )

I've done some more analysis of this. I have used 888s myself in my Lotus Elise and they are the tyres that the Mk2 MR2 use. They would be the better comparison as they are close to 1200kgs (with driver), My Lotus was about 940 with driver.

There is a table of analysis below which I think on here you have to click on to view.

http://www.roflsaurus.com/users/Maxx/rolf-888grip.jpg

To explain these are stats from the RT Analysis Software, we are looking at Min and Max lateral G (left/right cornering), we look at 98% max/min to cut out the peaks and the full max/min where you can sometimes get peaks if you hit a curb of something.

I do remember seeing 1.3g on 888s and you can see that Christian gets that as well although you have to take into account spread as the g readings are based on the DL1s mounting and sometimes you cant get it totally flat, especially if it's a temp installation like I had in Christians (and in fact the Elise).

The spread is the difference between max/min, if you divide that by 2 you get the real which is really the amount if lateral g the car was able to pull.

If you look at the table the RED numbers are the ones to look at. As can be seen, for 98% Christians Kumhos are pretty much the same as the 888s but on peaks they are much further behind. Not too surprising as the peaks are probably turn-ins and of course the Lotus is going to be great on turn-in, the MR2 pretty good but the extra weight and front engine layout would restrict this on the GTR32. I also think setup would help a lot here, the car was not very sharp on turn-in, I slacked off 2 clicks of bump at the front to help and thought this was a very slight help but it's more a camber and overall stiffness issue.

I do have data from CSLs on Pilot Sports and GT3 Porsches but all on external HDDs so prob wont get to lookiing at that for sometime but from memory they are better, as a rule of thumbs I 'rate' 888s as 1.3g tyres and Pilots as 1.4g tyres, these are just very general guidelines.

Malc

[Maxx]

Sorry to have made you keep coming with me lol, it's testament to how much I was enjoying myself and how much I was learning!

The follow up mails on set up have also been very useful and also appreciated as of course it's over and above the training day.

Look forward to speaking to you about the datalogging stuff....

No probs with staying in the car all day. I do recommend the driver stops 'thinking/learning' for the last 90mins or so and just drive. This can be with me as 'ballast' but I try not to talk/guide, but def with the race drivers I rec solo so they get a feel for the car without me which in things like Lotus/MR2/MX5 can make quite a bit of difference, not so much with the GTR.

Also, it cements in the drivers mind that it's HIM doing the driving and not just with prompting from me. I do seem to help, even if I don't talk, probably just a confidence thing.

The follow up stuff is pretty much par for the course really, often as much gets done after the day than on it and is one of the differences between driver coaching and instruction.

I was fine about staying in the car and doing a bit of direction/distraction as we lost that sessions video earlier.

Malc

[Maxx]

Just a quick observation re: racing series. I have a few guys racing at Silverstone today, 2 in the Porsche Championship and 2 in the Fiestas. I was watching TSL Live Timing and the Arrowpak series was qualifying. Pole was a 56 sec lap of the National !! which is mental, almost 4 secs quicker than P2. One of my Porsche guys who Qualified in P2 did a 1:06. so thats 10 secs quicker!

It was a Mitsubishi Evo, I did a search and it was running 550bhp 2 years ago so god knows what it's running now. I'm assuming it must be running on Slicks, my Fiestas guys are 1:11s in FP, will probably be 1:10s for Quali.

Malc

[Monster]

I've done some more analysis of this. I have used 888s myself in my Lotus Elise and they are the tyres that the Mk2 MR2 use. They would be the better comparison as they are close to 1200kgs (with driver), My Lotus was about 940 with driver.

There is a table of analysis below which I think on here you have to click on to view.

http://www.roflsaurus.com/users/Maxx/rolf-888grip.jpg

To explain these are stats from the RT Analysis Software, we are looking at Min and Max lateral G (left/right cornering), we look at 98% max/min to cut out the peaks and the full max/min where you can sometimes get peaks if you hit a curb of something.

I do remember seeing 1.3g on 888s and you can see that Christian gets that as well although you have to take into account spread as the g readings are based on the DL1s mounting and sometimes you cant get it totally flat, especially if it's a temp installation like I had in Christians (and in fact the Elise).

The spread is the difference between max/min, if you divide that by 2 you get the real which is really the amount if lateral g the car was able to pull.

If you look at the table the RED numbers are the ones to look at. As can be seen, for 98% Christians Kumhos are pretty much the same as the 888s but on peaks they are much further behind. Not too surprising as the peaks are probably turn-ins and of course the Lotus is going to be great on turn-in, the MR2 pretty good but the extra weight and front engine layout would restrict this on the GTR32. I also think setup would help a lot here, the car was not very sharp on turn-in, I slacked off 2 clicks of bump at the front to help and thought this was a very slight help but it's more a camber and overall stiffness issue.

I do have data from CSLs on Pilot Sports and GT3 Porsches but all on external HDDs so prob wont get to lookiing at that for sometime but from memory they are better, as a rule of thumbs I 'rate' 888s as 1.3g tyres and Pilots as 1.4g tyres, these are just very general guidelines.

Malc

Again, very interesting reading. I'm not surprised that the peaks are lower if they include things such as turn-in, unless it's a fully stiff slick shod car then it's unlikely a heavy front engined car like a gtr will have anything like the turn in of an Elise or Mr2 isn't it?

It would be very interesting to compare tables like of that my car on 888s v V700s. The Khumo's are hard compound wheras the 888s of course aren't - which I why I tried them. I would think that over a number of laps you would see potentially higher G's produced by the 888s due to compound fall away quite quickly as they couldn't deal with the heat, thats certainly my experience of driving them (falling off, not the higher g's) but again, the data is great to prove you wrong - or indeed right.

Still, if I try some MPSCs next and have some logging data I can compare to the khumos.

[Monster]

Just a quick observation re: racing series. I have a few guys racing at Silverstone today, 2 in the Porsche Championship and 2 in the Fiestas. I was watching TSL Live Timing and the Arrowpak series was qualifying. Pole was a 56 sec lap of the National !! which is mental, almost 4 secs quicker than P2. One of my Porsche guys who Qualified in P2 did a 1:06. so thats 10 secs quicker!

It was a Mitsubishi Evo, I did a search and it was running 550bhp 2 years ago so god knows what it's running now. I'm assuming it must be running on Slicks, my Fiestas guys are 1:11s in FP, will probably be 1:10s for Quali.

Malc

Arrowpak is a great series and yes they do run slicks, it's open as to which ones from memory. The regs are very open so you can get highly modified cars - like that EVO, and ex BTCC cars running, along with Cupra's and Clios. It makes it interesting as they are all better in different areas. My pal Steve ran his 800 odd bhp supra in it season before last and really enjoyed it.

Sounds like that EVO is pretty sorted though

[Maxx]

Again, very interesting reading. I'm not surprised that the peaks are lower if they include things such as turn-in, unless it's a fully stiff slick shod car then it's unlikely a heavy front engined car like a gtr will have anything like the turn in of an Elise or Mr2 isn't it?

It would be very interesting to compare tables like of that my car on 888s v V700s. The Khumo's are hard compound wheras the 888s of course aren't - which I why I tried them. I would think that over a number of laps you would see potentially higher G's produced by the 888s due to compound fall away quite quickly as they couldn't deal with the heat, thats certainly my experience of driving them (falling off, not the higher g's) but again, the data is great to prove you wrong - or indeed right.

Still, if I try some MPSCs next and have some logging data I can compare to the khumos.

The peaks are transitions and yes, i'd expect a Lotus to get slightly higher than an MR2 and an MR2 to be slightly higher than a car of the GTRs layout and weight but not by as much as you see. In fact the MR2 pulls slightly more (real peak) than the Lotus. I can't remember but suspect the MR2 would be on very good tyres in terms of condition and I know the Lotus was on pretty poor ones. It was all the data I had to hand at the time.

Also it was from Donington, the peaks could be OHP where you get a significant compression, although you get a similar compression at Bombhole.

I also remembered today that the Boxster guys I work with run 888s and they are 1325kgs min weight so i'm sure I'll have data for ~1425kgs. Mid-Engines though and they run pretty low so still not an ideal comparison, the CSL data I have would be nearest, will try and take a look next week, am away at the moment.

I think your view is also pretty accurate in that the 888, in ideal conditions and within it's optimum heat range might be a bit grippier but they do go off earlier, esp on a heavier car, not a huge issue with the Lotus but the MR2 suffer tyre dropoff on a warm day about 10-12 mins into a session/race.

Malc

[Monster]

Yeah CSL is probably the best comparison you would have. Against the Mr2 tho the gtr is heavier again and with so much more power to put down and then stop then it must be much harder on it's tyres. Even v a csl I would think?

Look forward to trying the MPSCs

[Maxx]

Yeah CSL is probably the best comparison you would have. Against the Mr2 tho the gtr is heavier again and with so much more power to put down and then stop then it must be much harder on it's tyres. Even v a csl I would think?

Look forward to trying the MPSCs

Christian,

Yes, I couldn't see a set of 888s lasting much past lunch on the day we did, if that ;-)

Weight is not such a huge issue in terms of cornering g as, even though you have more weight to shift, you have more weight over the tyre to give you more grip.

Malc

[Maxx]

I took a look at my uploaded videos to see if I had any footage from an MR2 at Snett, to give you some idea, I wanted to show how flat they corner.

The only one I had in an MR2 was one of my Driver Coaches Diaries ... I wont say any more but it is quite entertaining and shows that 'thing' that you were a bit worried about, right at the start LOL

http://www.youtube.com/watch?v=AHy4jqTbZck

I do have this external footage from Mallory which shows them cornering very flat at the Hairpin (prob need to wind on a min or two)

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

Malc

[Monster]

Agreed, it's killed the Khumo's too though, although the clock says we did 260Kms on track!

Yeah understood, my comment was in regards to how long they would actually produce the Gs, i/e not long before my car makes them go off because of the weight/power