HPDE experiments, results and observations

[Bartledoo]

I watched your LRP slide. You should practice not completely lifting when you get some oversteer. It will really help your confidence and you can maintain most of your speed, and sometimes more depending on the corner. The car is very easy to manage in oversteer, and it will actually help you learn to throttle steer with confidence.

Another thing is the steering wheel shuffling you used to correct the slide. You almost never need to move your hands to countersteer this car with its quick rack. The added benefit of not moving your hands is better control and faster correction. The max correction would likely have been less without shuffling because of this.

For example look how much steering angle I have here without moving either hand.

btw this was a huge waste of slick tires lol

[rhyary]

Originally Posted by Bartledoo

You should practice not completely lifting when you get some oversteer.

Another thing is the steering wheel shuffling you used to correct the slide.

I agree. I need more practice.

My right hands gets jammed against my wheel, I am not sure what to do about it.

[Bartledoo]

Originally Posted by rhyary

I agree. I need more practice.

My right hands gets jammed against my wheel, I am not sure what to do about it.

I'm guessing you mean your hand hits your leg? Possibly raise the wheel a bit, if so.

[rhyary]

Originally Posted by Bartledoo

I'm guessing you mean your hand hits your leg? Possibly raise the wheel a bit, if so.

I might be sitting too close to the wheel.
I was taught to put my hand on the wheel so my wrist rest on top of the wheel. But that perhaps too close?

I will have to figure out the issue

[Kelse92]

Originally Posted by rhyary

I might be sitting too close to the wheel.
I was taught to put my hand on the wheel so my wrist rest on top of the wheel. But that perhaps too close?

I will have to figure out the issue

That’s the correct seating position, but agree, may need to adjust the wheel up a bit

[rhyary]

Originally Posted by Kelse92

That's the correct seating position, but agree, may need to adjust the wheel up a bit

Thanks.
I will take a picture how I feel my hand get jammed, perhaps it will be obvious what I am doing wrong

[dparm]

I learned a nearly identical seating position at Bondurant as well.

[Bartledoo]

Originally Posted by dparm

I learned a nearly identical seating position at Bondurant as well.

The funny part is the mirror adjustment. It is a huge pet peeve of mine that nobody sets their mirrors like this! It just isn't logical to set side mirrors to see the side of the car, causing huge blind spots. Yet people still try to argue against it...

[rhyary]

There is a lot to the science of tires and at times it is showing up as non obvious at all. For example, an RE050A 265/35/19 has more rubber on the road than 285/30/19. I suspect the 285 will be better in the rain.

RE-050A
265/35/19 265 - (6+9+10+9) = 231mm
285/30/19 285 - (2+17+16+15+8) =227mm

[//steve\\]

Originally Posted by rhyary

There is a lot to the science of tires and at times it is showing up as non obvious at all. For example, an RE050A 265/35/19 has more rubber on the road than 285/30/19. I suspect the 285 will be better in the rain.

RE-050A
265/35/19 265 - (6+9+10+9) = 231mm
285/30/19 285 - (2+17+16+15+8) =227mm

What are the numbers in parentheses? I've been looking at this post for a few minutes and just can't figure it out.

[Bartledoo]

Originally Posted by //steve\\

What are the numbers in parentheses? I've been looking at this post for a few minutes and just can't figure it out.

He's measuring the width of the circumferential grooves.

[rhyary]

I just did personal best on street tire at NYST today. 1:36.92.

video and status later

[dparm]

Where did you pick up the time?

[rhyary]

Originally Posted by dparm

Where did you pick up the time?

With the PS91 285/30 (1:37.33) I was faster turn 3 - 8

With RE050A 285/30 I was faster turn 1 and 2 and from turn 8-18

With the RE050A I did today 1:37.25, 1:37.01, in addition to 1:36.92

Theoretical lap of four sessions was 1:35.05

[rhyary]

Stats
Date: Sep 22 2020
Organization: Private Day
Track: New York Safety Track (NYST)
Weather: Dry

Track Time: 4 x 20min, 3 x 30


Tires Front: RE050A 2018
285/30/19 day 1

Tires Rear: Proxes RR
295/30/19 day 2

Time: 1:36.92
PB on max performance tires

Comments:
This video has few 1:37 laps.
Also, you can see the record holder Corvette passes me on the second lap and the speed difference.
.
Video
.

[dparm]

Jeez, what was with the Mustang not giving you a point-by for a whole effing lap?

[rhyary]

Originally Posted by dparm

Jeez, what was with the Mustang not giving you a point-by for a whole effing lap?

It was friendly. I know the guy.
I was giving him tips on certain corners and was following him to watch. We were 6 guys in the advanced group and I could have either push to pass him, or just slow down.

[dparm]

Ah cool, makes sense. I noticed you both take different lines from each other, and the Corvette's is different still.

How are you liking the RR? Will you just run that all around? Do you find that having a stickier tire out back is inducing some understeer up front?

[rhyary]

Originally Posted by dparm

Ah cool, makes sense. I noticed you both take different lines from each other, and the Corvette's is different still.

How are you liking the RR? Will you just run that all around? Do you find that having a stickier tire out back is inducing some understeer up front?

The 295/30/19 RR are the best for me.
I could not find anything better.

The front my only choice in RR is 235/35/19.
this is a very fast front. but at -3.5 I consumed the inside in one day.

So If I want to run the RR 235, I will have to bring the camber to -2.5. This would be a problem for 265, 275 and 285 fronts.

[rhyary]

Choices and Compromise

So the front -3.5 camber showed to be a winner on very fast laps. The outside wheel shows more or less even temp across the width

But...
The inside wheel gets overly hot on the inside, there is at least 30deg difference between the inside and the outside.

So I want to bring the camber back to -3.0, alas I am not sure I can clear the fender with 285. So as a compromise ACM is going to bring it back to -3.25 for the Sep 30th trackday. will monitor clearance and temp.

The rears are not getting temps to the outside. We will bring it back from -2.2 to -2.0 and monitor.

This is not ideal but looking for a compromise that I can live with. I am also optimizing it for Max Perf tires and the 285/30/19 in particular.

I may need to be more vigilant about switching tires left to right mid days, rather doing a whole day on one side.

[dparm]

Okay, so you're seeing some temperature variations, but is this leading to accelerated wear? I don't think you're ever going to see perfectly consistent temps.

[Bartledoo]

Your temps and wear, particularly inside on the front inside tire, may be from excessive understeer. I get the same thing on the inside rear from excessive oversteer.