Veloce Raptor

All cars should be driven like momentum cars IMO.

ProCoach

Mike, interesting to note that you're better on the brakes than your buddy. Your brake pedal pressure curves are smoother, hence the longitudinal g is better distributed and more consistent.

The reason why he may be unwinding sooner is because he's got it pointed "downstream" sooner.

I'd like to see time slip between the two added.

Hahaha! Yes, I'm SURE Tommy's "Crash or Byrne" pronouncement (indubitably true!) had additional F-word emphasis added!

He is a treasure... A truly no-BS kind of guy.

fleadh

Hah, Thanks! I probably just have a higher survival instinct at this point in my driving career.

I'll take a couple screen shots with the time variance graph included. Overall his lap was about 1.5 sec faster than mine.

-mike

fleadh

Here's it with the time variance graph added. Good example of sacrificing a little on entry to gain more on the exit. But, I wasn't comfortable with that car setup and would have been faster overall with a more balanced setup.



-mike

ProCoach

A LOT of good information there...

Veloce Raptor

+1, for real.

vantage

Great thread. I decided to start at page 1 and am still reading through.

Do you feel that quick steering racks are detrimental to the ability of drivers to drive smoothly? I noticed lately that more and more street cars are coming with quick racks (e.g. 2.2 turns lock to lock) and it's very noticeable when first driving the car and somewhat unnatural in a street car (compared to kart for example). For some cars, aftermarket racks are sold to quicken the ratio and I wonder if this is really something prudent to do. I will say that I was obsessed with reducing weight on my car until my friend drove it and on his 4th lap ever, beat my personal best by 2 seconds at WSIR. That's when I decided to focus on my diving, bought data logging, etc.

Veloce Raptor

IMO a quick rack by itself is good, since it makes it easier to make tight corners with both hands remaining 9-and-3. However, a quick rack on a street car with too much power steering boost--which is the real trend we are seeing--is disconcerting to say the least, and makes the car darty. It is an affectation to fool buyers into thinking the car turnes in really well....sort of like a Sport button that makes the throttle pedal more sensitive & twitchy fools buyers into thinking the car is quicker or has more power.

Good for you realziing that you are the single biggest variable in your car, and focusing on data! It doesn't lie!

teamking

This is a great thread! Thanks for all those who contributed to this resource!

My question: Are there any special rules (or exceptions) to driving a turbo charged car? I've read in this thread and many places about smooth throttle application, not getting on the throttle until you can commit to it, etc. However, I find myself instinctively modulating the throttle in anticipation of the boost very differently than I would be in a a non-turbo charged car. For instance, if in an n/a car, my throttle application would look like 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%; I find that in my 951, I do: 20%, 60%, 90%, 50%, 50%, 60%, 70%, 80%, 90%, 100%. The result is (theoretically) a smooth application of *torque*, since I'm opening the throttle to build boost and then closing it lest it hit too hard.

Is this a good idea? bad idea? Indicative of a need to select a lower gear?

vantage

It's so nice to go into the next HPDE with an actual plan rather than just driving and hoping to improve. Still very much a beginner. Next time out, I want to focusing on improving my entry speed by not over slowing.

I noticed from my data log that the corner speed and lat g graphs are very peaky. I see faster drivers having graphs that are more rounded in shape (i.e. they are carrying more speed and utilize more of the tire's grip for the entirety of the turn). Is this a fair assessment? Below is a graph of my fast laps from the last two outings at Streets of Willow. Improved 1.5 seconds with just very minor improvements to entry speed in a few corners.

Happy to resize pic if it's too large.

Veloce Raptor

Best way to tell if this is helping or hurting is with data. Are your longitudinal G's solid on the accelerating side of the X axis? Does your velocity over distance rise w/o peaks and valleys? If so, it's working. if not, may be best to find a better technique. Work with someone who can really drive, and see how they get the most out of yoru car!

One thing that peaky graphs, especially lat G's show, is turning in too late, with too much steering angle. this usually also comes with peaky long G's, since it necessitates more braking to get the car slowed enough that it can take the high steering angle. Often this is a sign of very lat apexes & squared off corners. Over time, as you get more comfortable with earlier turn ins, with less steering angle, you will see them round out. The real benefit will be MUCH more entry speed, mid corner speed, and exit speed, with MUCH less drama and fighting the car.

teamking

I'm most aware of doing this at the apex of 4 and through 5; and then after 14a into 15.

Here's video (would you prefer to see traces? I don't have throttle position, though):

Veloce Raptor

Traces would be VERY helpful, please!!

teamking

OK...

Fastest lap of the day:


Same lap, Turns 4, 5, and 5a:


Best final sector (from previous lap), Turns 14, 14a, and 15:

Veloce Raptor

So the biggest challenge I see with doing that sort of oscillation on the throttle in those areas is this: the longitudinal G trace shows that the car is exhibiting a corresponding oscillation fore & aft. This means the suspenion is doing relatively small loads & unloads at the front & rear, multiple times in that corner.. The consequence of that is the car might not feel as planted as you would like, and may exhibint more than the usual amount of understeer..and then grip...and then understeer...and then grip...etc..