Martin S.

"Fast through a corner -- 1960s technology still shines." It's Jack that is shinning. Drive a 1:27 at Willow Springs on Nittos...the driver is shinning. Also consider that Jack could perhaps take off an additional 2 seconds with a fresh set of Hoosier R6 tires, maybe even more with a set of slicks. And let's not forget, Jack's car is street drivable too.

For those that look down at Willow Springs as a non-Technical track...try putting your foot to the floor at the exit of Turn 5 all the way through Turn 8, and then tell me that keeping the car on the track, in a position for a 100 mph exit out of Turn 1 is not technical? Please....that's plenty technical.

Also consider when entering Turn 9, it is a decreasing radius Turn...you can't see the exit until you have reached the point of no return...now that's technical and it takes a set of huge brass ones to do it right.

Try approaching turn 1 at 135+ mph and making the left turn with just a down shift and a light breaking, now that is technical, a set of brass ones helps here too.

Watch Jack's Willow Springs instructional video ou You Tube. I always watch it at least 10X before I go to Willow....going there 12/6 and 12/7 with the Porsche Owners Club.

JackOlsen

Thanks, Martin.

But I want 1.05 seconds more there.

And since this thread became about something else, I've started a new one here.

78SC

Maybe the corner speeds are partially explained by the splitter and 70 inch wing? It would be interesting to see how much downforce the cup makes vs Jack's car.

Martin S.

We also need to consider the aero....it is a blessing and a curse. Yes there is down force...and then there is drag.

I'd like to see how fast Jack would be with an IROC tail and a matching front splitter? Now add in a set of slicks....

I believe Jack's car has close ratio gears as well, that really helps getting the power down early compared to stock gears.

The fastest part of Willow Springs is found from Turn 5 through Turn 8, mostly a sweeper. Those monster tires Jack uses are a help there coupled with the aero.

Jack gets more out of a street legal car than most...I am sure the wing, the splitter and the skirts are off for the street.

turbochad

One other way to explain the similarity in mid corner speed is to consider how the tire's mechanical grip is being used differently in the two different cars, high HP vs low HP. The tires have a fixed amount of mechanical grip available for the combination of both lateral and longitudinal acceleration. The cup car has better braking and longitudinal acceleration and must trade off these forces for lateral acceleration more quickly than the lower powered car to be quick. Consequently, a cup car driver might sacrifice mid corner speed to apply more acceleration sooner. It is for this reason that higher powered cars carry a much different line in and out of most corners. Low HP cars slow down less, carry a rounder line, and accelerate less out of a turn, though mid turn speed may be quite good. More important than mid corner speed in this case is the average speed in the corner from turn in to turn exit.

All things being equal, the cup car would generate significantly more lateral g's on a skidpad than your car and will have higher average corner speeds.

Still, old cars, properly set up and using modern technology tires, spring rates, wings etc. can be quite quick in the right hands. Nice work Jack. Now if you had some seat time in a 997 cup I'm pretty sure you would see the vast difference in speed that lies between the two cars.

quickxotica

Nicely said. Thanks.

JackOlsen

Just to be clear again. My car is not faster than a Cup Car. I haven't been able to find any WSIR laps by a Cup Car that are slower than me -- or even only a full second faster than me.

But here's a non-Cup-Car video that I posted this in my follow-up thread. Of course, it's no surprise that James Sofronas is 8 full seconds faster than me in his GMG Racing World Challenge Spec V10 Audi R8. But it's interesting to look at just the segment of the track where he doesn't completely destroy me -- in this tiny piece, he's only about .04 seconds faster than me. But the more interesting part might be the grabs of individual pieces (and speeds) in the corners.

Here's the clip:

KaiB

Well said Chad, thanks.

ProCoach

Good explanation. The area in bold is why VR, JvO, myself and others have job security, helping "fill in the blanks" and co-develop a strategy with drivers to do just that. It also shows WHY so many cars of that ilk are underutilized. Because those transitions are HARD to do, fast... And without error.

I do disagree that the line changes required are "much" different and I do disagree that, especially without aero, low speed concerning grip is too far ahead on the modern cars, so the skid pad example would not show the potential difference.

While we are comparing data points, the whole exercise is dynamic, not static!

Still, an interesting tidbit and a data-driven comparison...

Veloce Raptor

^^^ +1 ^^^

Augustomf

You are the biggest proof of my argument against paying a fortune for a X51 package to add 30-40hp on a 991.
Much better to spend the money on acquiring more driving skills. You drive better then the GT3 Cup driver, and his extra 120hp made little difference.

ProCoach

And his extra tire/geometry/ratios/aero... The list goes on and on...

"The Driver is the Greatest Variable in the Performance Driving Equation."

JackOlsen

Well, I'm also the guy who spent 13 years working with the same (basic) car on (mostly) the same track. I'm closing in on having shaved 30 seconds off of my initial 1:56 lap time at Willow. With 20/20 hindsight, I could have saved a lot of time and money by working with someone like Veloce Raptor or Peter early in the game.

But we live and learn.

And for the record, I'm not a better driver than Brent Holden or James Sofronas. I have no idea where the 997 Cup was in its development when those laps were driven. Through this thread, I've connected with the previous owner of the car, and a lot of work has been done to change the thing -- which probably explains why the 1:25 isn't a 1:23.

RickBetterley

Wisdom for the ages.
But you've had more fun than most in those many years.

Veloce Raptor

Very kind of you to say that, Jack. But as Rick says, you have had more fun experimenting than most!