ACR E Watkins Glen weekend impressions info

[ek1]

Just came back from a wonderful weekend at Watkins Glen with Hooked On Driving.

As some of you may recall, I managed to destroy a pair of front tires at Lime Rock a while ago. After that I got scared and bought a set of front wheels with Hoosier R7s, so that I can drive the entire weekend and not worry about tire wear. Unfortunately, being a forgetful idiot that I am, I manage to leave the spanner wrench at home, so I found myself shitting bricks in the paddock at 7PM on Friday, thinking that my weekend would be ruined. Reality, however, was different.

My car setup:

Lime Rock:

Front -2.6 camber 0 toe, rear -1.5 camber .22 total toe in
Height: 4.5" Front, 5.75" Rear.
Shocks: Front: Compression: 1, Rebound: 1, Rear: Compression: 1, Rebound: 1 (Factory default)
Wing: Position #2 (Factory default)

Watkins Glen:

Front -2.6 camber 0 toe, rear -1.5 camber .22 total toe in
Height: 4.5" Front, 5.75" Rear.
Shocks: Front: Compression: 7, Rebound: 5, Rear: Compression: 5, Rebound: 3
Wing: Position #1 (Less rear downforce)

At Lime Rock I started out with 32 PSI cold all around, which was a mistake because by the end of the 2nd session my fronts were in the 39-40 PSI range. So for the Glen I decided to go much lower and started out with 28 PSI all around. Keep in mind that ambient temperature on Saturday morning was 38 F (yes, 38 F) and the track was super cold. After the second session on Saturday I noticed that front temps are creeping up, so I proactively bled all four tires to 32 PSI hot. On Sunday afternoon the ambient temperature climbed into 70's and I noticed my front left was going higher than I would have liked, so I bled it down from 34.8 PSI hot to 33.8 PSI hot.

Here are my tire pressures throughout the day on Saturday:

20546

And on Sunday:

20551

Here are my tire temps after the last session on Saturday:

20548

And after last session on Sunday:

20549

NOTE: Pyrometer readings are read from the "top view" of the car, meaning three numbers in the upper left represent the front left tire and three numbers on the bottom right represent the rear right tire. Readings are from outside in, so within a cluster of 3 numbers the first one is outside, 2nd one is middle and 3rd is inside. For example, on the Saturday reading screen, front left tire outside temp was at 133 F, front left tire middle temp was 142 F and front left tire inside temp was 152 F, and so on.

I will post pictures of actual tires in the next post.

I also wanted to say that Hooked on Driving is the best HPDE organization out there. I have been attending their events for the past 3 years and they treat customers like family. Everyone is friendly, instructors are professional and safety is the #1 priority at all times. If anyone is considering learning how to drive on a racetrack, you can't go wrong with H.O.D.

[ek1]

Pictures of front tires:

Front Left:

20552

Front Right:

20553

[ek1]

Pictures of rear tires:

Rear Left:

20554

Rear Right:

20555

[ek1]

Few more various pieces of info:

The track was super cold on Saturday morning, but warmed up significantly later and grip was great.

Check out the video of the fastest lap: https://youtu.be/8kDEn6PBFPU

I am not a very experienced driver and I still dont know how to heel and toe, so for now I always drive in 4th gear. I wasn't really pushing the car yet (still learning it's limits). I figure I can shave off at least 2-3 seconds by downshifting in a few places and upshifting in a couple more.

In the mean time, I think this info proves that with careful tire management, the front Kumhos CAN survive a 2-day weekend at a track like Watkins Glen and STILL be good for at least another track day.

By the way, I am still on my original rear tires and they are doing great!

[Dfunk]

Nice write up. The tire wear looks nice and even. I too have noticed tire pressure playing a big roll in keeping the Kuhmos alive.

[MK2_Viper]

Thank you for all the info

[Darth Viper]

I was at Watkins Glen, my first time with my ACR.
Been to the track several times before.
I was just lucky to have ek1 there.
Our cars were side by side, and ek1 gave my the best advice, which he describes here, and allowed me
to maintain my tyres in good shape.
I started slow, particularly Saturday, first session, track cold, but after several session I started to feel better
the car, gained more confidence, and I really think that this car is something.
Agree on the comment about Hooked on Driving. By the way they had Ross Bentley giving classes to the drivers,
and he is really good.
All in all a fantastic weekend

[Bill Pemberton]

Sounds like a great weekend as there were some acquaintances in the same class who have Mustangs and they were raving about Ross Bentley also. Sounds like a class many will want to take as his book , " Speed Secrets," is sort of the bible for many of us that track our cars.

[SlateEd]

Awesome writeup EK!

only other thing it looks like you changed was suspension settings... do you have thoughts on how that impacted handling, tire wear, both?

[quickster2]

Ross Bentley's book Ultimate Speed Secrets is a must read for all that want to drive the Viper on or off of the street as it was meant to be driven. An 'easy' read as well quite engaging.

Nice video what mount were you using for the windshield? Thx

[Eugene Lee]

great information

[ek1]

Sounds like a great weekend as there were some acquaintances in the same class who have Mustangs and they were raving about Ross Bentley also. Sounds like a class many will want to take as his book , " Speed Secrets," is sort of the bible for many of us that track our cars.

Ross Bentley is the man. Hooked On Driving has a relationship with him (to my knowledge, no other HPDE organization does) and he will be coaching / lecturing drivers at more H.O.D. events all over the country. I have (and read) all of his books. The stuff he writes really works. Anyone trying to become a better driver should read those books.

[ek1]

Awesome writeup EK!

only other thing it looks like you changed was suspension settings... do you have thoughts on how that impacted handling, tire wear, both?

I changed:

1. Compression / rebound shock settings
2. Wing attack angle
3. Tire pressures

I am not experienced enough to be able to tell which adjustment played a biggest role and I did not have enough time to try one adjustment at a time. Instead, I gathered all the info that all the other track drivers posted on this forum and applied it, hoping for the best.

I know for a fact that I left much less understeer in fast corners and that was probably due to the wing adjustment. Anyone who tracks their ACR-E should probably move it to position 1. On the other hand, I completely understand why Dodge ships the car with the wing in pos. 2. All modern cars are set up to understeer for safety reasons (i.e. to minimize the number or morons crashing their cars due to oversteer)..

I am going to try Hoosiers if I manage to attend another track event this year because the car still understeers more than I like and bigger tires should help.

Forgot to mention one thing: traction control was fully off both at Lime Rock and Watkins Glen.

[38D]

Any videos of your laps?

[ek1]

Any videos of your laps?

Yes, scroll up to post #4

[ek1]

Nice video what mount were you using for the windshield? Thx

I am using a GoPro suction cup mount with a Garmin Virb Ultra 30 camera. I hate both. The Garmin camera picture quality is sort of crappy (as you can see in the video), the claimed video stabilization does not work for shit (I did not notice it working) and the GoPro mount still shakes. I got the Garmin cam because it has built-in telemetry features and it can connect to a variety of sensors, such as OBD II dongles, heart rate sensors, and other stuff. I was going to go for an AIM Pro system, but was quoted around $2.5K for it, so I decided to try a $399 Garmin.


My buddy uses an iphone 6 with a very rigid mount and it works great (but no telemetry and then you have to dick around with Track Addict to add all of that stuff.

[ek1]

Some pics:

Sunset at the paddock:
20591
20592

Front straight:
20593

Dynamic duo:
20594