Comparison 1: Same driver, different cars/setups
How significant can 0.4" tire diameter change be? My 225/255 setup vs Jason's 245/275+springs:

You can see that despite less grip in the corner, the gearing is significantly better with higher top speed on the straight despite starting out slower from the corner.

However 245/275s + springs do have their advantages in cornering grip, and they were consistantly faster over the course of an entire lap. Here carrying 4-5mph of more speed through the fast sweeper section:


Comparison 2: Same car
What about shift points? Shifting to second in T1 definately overslows the car and makes it hard to carry speed into T2 since you hit the rev limiter before you turn in for T2:


However, carrying 3rd is not always the best (despite what Jason says! ). In T3, it definitely pays to downshift to 2nd:


It always pays to have data. Of course there are other things too but we can't give away everything.

 

Nice! I would love to get one one those units.

You aren't planning to park your car unlocked outside anytime soon?

Thanks for the info on Gingerman, I am sure I will be running there a few times next year.

 

Jeremy, could you clarify what you're comparing? Different drivers in different cars? Different drivers, same car? Something else?

I think what we need to see is same driver, same car, but different tires, correct?

 

The first 2 graphs about the tire size/spring effect are the same driver but different cars with 2 different setups: T2 legal tire size with dampers only vs bigger tires + heavy springs

The last 2 graphs regarding gearing are from the same car with the same tire on all of the runs.

edit: added a header in the first post for clarity

 

The last graph just looks like a line difference to me more than gaining time by better acceleration out of the corner. Jeremy, you're turning in earlier which is apparently the faster line.

Are the ripples in the lat G trace oversteer?

 

I'll look back at the data some more to see if I can tell anything about the line but some of the difference is steering input timing is due to the responsiveness (i.e. delayed steering input) of the big springs & 245 fr tires.

 

Cool logging thingie. 1:34.5 in a T2 S2k that's pretty quick! Nice driving!

 

Ah no. That would be the springs & wide tire setup, currently not T2 legal.

1:36.2 was the T2 setup on old Victoracers.