ervtx

Roger, Roger. What's our vector, Victor?

And I thought 7 years was too short. I guess one man's investment is another man's consumable.

MJHanna

Do you mean the Kumho Ecsta V710's? It's the tire of chose in CVAR as we are not allowed to run R6.

stuttgart46

They don't run a dry sump in Koni Challenge cars? Are they allowed?

JW in Texas

Mark,
Yeah, that's them. I picked up a used set from Carl A. on the cheap to beat on & they were decent tires.

mglobe

My guess is that the moment of inertia would not matter, just the lateral g-force.

How many heat cycles are the Kumho's good for?

MJHanna

They wear out before they heat cycle out, they don't last long.

JW in Texas

I don't know about that. I would think the further from the center of the car the sump is, the more slosh you are going to get.

mglobe

In the case of oversteer that you catch and correct, I agree, the affect would be higher in the rear engine car. If we're just talking about pulling high g's as you go around a corner, I would think it would be the same.

Of course if you're talking about HP vs torque while running a plane on a conveyor belt...

jakermc

Can anyone add some data to this discussion? In terms of 'high g's', what are we really talking about? Has anyone looked at their data logger to know what they are pulling?

I'm curious to see the g-load you 996 guys are pulling with the R6 relative to our Spec Boxster with the Toyos. I'll pull my TraqMate data this weekend and see what I was doing in the Club Race. Jay - have you looked at your data yet?

himself

I pulled some data a while back for max LatGs (only) and saw 1.1+, with a max of almost 1.3 at MSR (around 1.27 actually). I seem to recall ECR was about the same. As for LongGs, I also see around 1.1G.

I'll dig up some extreme data points tonight, as I seem to recall hitting 1.5+ in some corners with sticker tires, but I can't remember exactly where/when.

-td

TR6

Actually, 8-9-10 is very light on braking for me at ECR. I hardly touch the brakes there. Just a quick dab before 9 and barely breathe on the brakes before 10. I brake much harder elsewhere at ECR. And in terms of lateral G's, I don't think 9 is any worse than 3 or 6.

jakermc

Looking at a 2:04.9 lap in the SPBOX on Toyos I saw max lat g of 1.71 in turn 9. Turns 3 and 6 were less, at 1.44 and 1.45. Besides a slower speed in these turns, I take more of a diamond approach than most and don't make long sweeping turns here. Especially in 6, where I displace the apex and don't track out, being more concerned about cutting the distance and just getting out of the corner.

I got these readings looking at the Max Rt Load and Max Lt Load columns in the segment analysis. Strangely I don't see readings as high in the Lateral G graphs. Not sure why?

Max braking was 1.15g.

himself

I went back to my March data, and picked run times around 2:05 to closely track your 2:05. [996 C2, PSS9, R6]
Max LatG overall was 1.651 coming out of turn 2.
Turn 3: 1.387
Turn 6: 1.476
Turn 9: 1.616
Max LongG overall was 1.379 going into turn 3.

JohnG drove my car (2:04.7) and his data showed:
Max LatG: 1.690 (turn 5)
Turn 3: 1.265
Turn 6: 1.471
Turn 9: 1.461
Max LongG: 1.481

Based on just our data points, it looks like a 996 on R6s pulls similar Gs to a Barbie on Toyos.

-td

jakermc

Interesting. Not sure how the rear engine versus mid-engine plays out with regards to these effects on the long term health, but looks like a good opportunity for an Accusump group buy!

mglobe

On a 2:05 lap running R888's on my 996, my max load is 1.56 in T9.