“The Skidpad”
Davis K. Powers
Test Report
July 30th, 2005


My cornering capabilities were put to the test on a hot July day at a private testing facility in West Virginia. The results on the skidpad were exciting and rewarding as I realized I had met and exceeded 1.0 lateral G’s. What a ride!

Often a car’s quickness is described in terms of horsepower, torque, 0-60mph, and quarter-mile times. But, when it comes to how well a car can “hold the road”, the skidpad is where the truth is revealed. After fine tuning my driving and making a few minor adjustments to air pressures, I was able to make a best G-Force rating of 1.0738.

I’ve always known my Subaru WRX STi was a good handling car, but with the HKS Hipermax RS coilovers and R-compound tires, I never imagined that my cornering G-forces results would surpass high-end Ferraris and Porsches. With a few more tweaks to my car and driving, I’m confident 1.1+G’s is attainable.
The lessons I learned on the skidpad were immeasurable. I’m eager to apply these techniques on the AutoX and road courses ASAP.
Details of my car, and other articles can be found on my main page: www.skuttlemotorsports.com

Here are the direct links to the videos of the skidpad event:
(right click save as..)

Skidpad high resolution video 21MB (http://www.skuttlemotorsports.com/videos/skidpad/skidpadhires.wmv)

Skidpad low resolution 5.0MB (http://www.skuttlemotorsports.com/videos/skidpad/skidpadlowres.wmv)

Skidpad Slalom Combo 13.3MB (http://www.skuttlemotorsports.com/videos/skidpad/davisskidpadcombo.wmv)

Skidpad Fun Run 7.5MB (http://www.skuttlemotorsports.com/videos/skidpad/davisfunrun.wmv)


http://www.skuttlemotorsports.com/photos/skidpad/Skidpadftpg.jpg

Very cool, I'd love to run my car and see what it's capable. I swear sometimes it's going to fling me out the window.

How was this measured? Please don't say you used a G-tech :lol:

-Tom

And please don't say that "best" means peak. You have to maintain it all the way around, not just for one quick tug of the wheel at a single point around the pad.

Not to continue the hazing, but methinks a high-end Ferrari could probably do better if it were on R-Compounds ;)

Rubbing on the fenders is bad. Raise the ride height, get stiffer springs, flare your fenders, or run narrower tires.

This testing facility has a dedicated skidpad where accurate times are measured. Some very interesting race cars have tested here and have gone on to road courses with great success.

My time around the course was 9.25 seconds on a 75ft. radius skipad. (see vids) (so it is not a TUG at the wheel)
If I were to improve some on my smoothness and some more tweaks to my suspension, I would get and maybe exceed -1.1 g's.

http://www.skuttlemotorsports.com/photos/skidpad/skidpadsm.jpg



any questions, please post!

Not to continue the hazing, but methinks a high-end Ferrari could probably do better if it were on R-Compounds ;)
True, the comparison I made earlier delt with stock cars vs. my modded car.

Matter of fact, a stock Ferrari 360 actually doesn't do that well on the skidpad. "Plows alot" was a quote I heard from a member who has 1000+ hrs on that skidpad yet will decimate nearly anything on a road course.

Rubbing on the fenders is bad. Raise the ride height, get stiffer springs, flare your fenders, or run narrower tires.

Yep, working on it. Funny I didn't really hear it rubbing but the video sure proves otherwise.

I saw you r # in my phone last Wednesday. We were closed. I clal you back and left a message too.


Myles

True, the comparison I made earlier delt with stock cars vs. my modded car.

Matter of fact, a stock Ferrari 360 actually doesn't do that well on the skidpad. "Plows alot" was a quote I heard from a member who has 1000+ hrs on that skidpad yet will decimate nearly anything on a road course.

I could care less about Ferraris, but was this on R compound tires?

I could care less about Ferraris, but was this on R compound tires?
Yes, Hoosier Cup tires 245/45/17

http://www.skuttlemotorsports.com/photos/skidpad/skidpadsm.jpg

any questions, please post!

I wonder how many cars have gone off into those trees. :eek:



And where in WV is this facility?

-Matt

I wonder how many cars have gone off into those trees. :eek:



And where in WV is this facility?

-Matt

No cars that I've heard of have been badly damaged there. Believe or not, I felt that the run-off was fine. Remember I was maxing out only around 35mph....no serious speed there.
It was a private event with legal contracts to sign. Sorry but I cannot give details on the location of that testing facility.

Any thoughts on how a "stickier" auto-x R-compound would do compared to the Hoosier Cup tires, which are geared more towards road racing?

What about differences between clockwise and counter-clockwise?

Nice grip. What other mods? Alignment? Did you get on track later that day? How did the car feel?

As I am sure your aware, the skid pad is not where you want to be fine tuning the car (unless you race on a circle ;) ). I have always used it as a "Since I was last on the track I did XYZ to the car, lets see how the car reacts at the limit / on throttle / on lift. " I rarely change alot after leaving the skid pad. Most changes have come after a session or two to feel out how the car is turning-in, tracking out, or how the tires are wearing / heating up.

Its my understanding that most street cars are going to turn faster laps at a less than optimal skid pad setup.

In any event, 1.07 is a lot of grip in a subie. :banana:

Any thoughts on how a "stickier" auto-x R-compound would do compared to the Hoosier Cup tires, which are geared more towards road racing?

What about differences between clockwise and counter-clockwise?

I'm sure the Hoosier AutoX tires (A05's) would be better as they heat up quick and provide serious stick. My Cup tires, like you said, are really for the open course and mine were really used, and were runied after that day. (but very worth it!)

My quicker laps were going in counter-clockwise. Part of that is becuase you can line up easier with the edge of the skidpad and the other part is jsut that my clockwise driving needed some bettter tuning. (ie, be smoother)

Nice grip. What other mods? Alignment? Did you get on track later that day? How did the car feel?

As I am sure your aware, the skid pad is not where you want to be fine tuning the car (unless you race on a circle ;) ). I have always used it as a "Since I was last on the track I did XYZ to the car, lets see how the car reacts at the limit / on throttle / on lift. " I rarely change alot after leaving the skid pad. Most changes have come after a session or two to feel out how the car is turning-in, tracking out, or how the tires are wearing / heating up.

Its my understanding that most street cars are going to turn faster laps at a less than optimal skid pad setup.

In any event, 1.07 is a lot of grip in a subie. :banana:

The mods I have on my car is the HKS Hipermax RS coilovers, and Hoosier tires. Whiteline swaybars are coming in this week and should help some on the rubbing issues (see video). I'm hopeing less body roll will solve the small rubbings I was getting.

Alignment is -3.0 front and -1.5 rear. toe has not been meassured on my race setup, just street.

I did not really get "on the track" that day after the skidpad testing. Probably next time. My tires were hashed, heheh

Car felt great that day and was pleased with the results. I could've spent 2-4 hrs. just messing with settings and putting down some faster times but that was not in the schedule. Tire pressure adjustments were my main changes that day.
Next time I'll have adjustable sway bars (another thing that will keep me busy tuning) better tires and some previous skidpad experience.

Modding the car is fun, but I've forgot how crazy you can get on tuning, testing, tuning, testing, tuning, testing etc....

Thanks :cool:

I saw you r # in my phone last Wednesday. We were closed. I clal you back and left a message too.


Myles

hi Myles, thanks for the call back. AOK.
I didn't returen cause my question about spacers was answered.