Go Back   PCA GT2, GT3 and Cup Car SIG Forums > GT2/GT3/Cup Car Register Discussions > AutoX, DE and Racing Discussions
Register Forums FAQs Search

AutoX, DE and Racing Discussions All discussions related autoxing, DE, amateur and professional racing activities

Reply
 
Thread Tools Search this Thread Display Modes
  #106  
Old 05-18-2011, 09:17 AM
Dell's Avatar
Dell Dell is offline
Registered Porsche Owner
 
Join Date: Apr 2011
Posts: 79
Downloads: 0
Uploads: 0
Default Re: Close Call at South Bend

Looking forward to it as well! And thank you for taking the constructive tips. I am always hesitant to offer advice. I still have PTSD from all the smackdowns you see on Rennlist when advice is offered up.

I wouldn't necessarily say that you are turning in too late but that would definitely contribute to increased steering angle. I would have to see the steering angle input. It's great that you have video as we can always use that to verify. The places we will really check for steering angle input is T4 (Left Hook), T11a (Oak Tree), and T14a (Roller Coaster).
Reply With Quote
  #107  
Old 05-18-2011, 09:49 AM
bman's Avatar
bman bman is offline
Registered Porsche Owner
 
Join Date: Feb 2011
Posts: 146
Downloads: 0
Uploads: 0
Default Re: Close Call at South Bend

Quote:
Originally Posted by Dell View Post
And thank you for taking the constructive tips.

The places we will really check for steering angle input is T4 (Left Hook), T11a (Oak Tree), and T14a (Roller Coaster).
How can anyone not appreciate it when someone takes the time to watch and comment? I've been know to buy a few drinks in appreciation

That's where I watched yours and it looks like you're crossed over, just slightly and very briefly, in those corners. I need to watch footage of when I was not releasing the wheel......I think I was crossing over more than you, probably because I was turning in later and adding more steering. I've changed my line since then, so I'll work on holding my hands this weekend and see how it feels/works.

I really don't understand "determining slip angle and slip angle correction". I understand the meaning and concept but don't know how reconginize, apply or correct it effectively. Should make for good apres' track discussion.
Reply With Quote
  #108  
Old 05-18-2011, 10:03 AM
Dell's Avatar
Dell Dell is offline
Registered Porsche Owner
 
Join Date: Apr 2011
Posts: 79
Downloads: 0
Uploads: 0
Default Re: Close Call at South Bend

Slip angle is probably easier to explain over a beer

However, the quick explanation is that when you deform the contact patch the tire (lateral load) will travel in a direction not the same as the direction of travel of wheel input. As counter-intuitive as it seems, you actually WANT to deform the contact patch. Grip will INCREASE as you deviate from a delta of 0 degrees. However, there is a limit for each tire. Could be as little as a couple degrees up to as much as 6, 7, or more depending on the type of tire (i.e., slick vs. DOT-R vs. street). Your goal is to take that slip angle to the limit and NOT cross over. This premise is the very reason why weight transfer is the enemy. The more weight transfer, the more lateral load you generate and thus quickly exceed the slip angle. Once you get a good feel for what the slip angle is for your specific car and setup you can take the car right up to it and then modulate throttle, brake, steering angle, to dance on that line.

**rest of reply edited for discussion over beer **

Last edited by Dell; 05-18-2011 at 08:54 PM.
Reply With Quote
  #109  
Old 05-18-2011, 10:43 AM
bman's Avatar
bman bman is offline
Registered Porsche Owner
 
Join Date: Feb 2011
Posts: 146
Downloads: 0
Uploads: 0
Default Re: Close Call at South Bend

Quote:
Originally Posted by Dell View Post
Slip angle is probably easier to explain over a beer
I hope so....

Thanks! I am with you.

I have been working a lot on feeling the chassis. Trying to be more aware of weight transfer and balance while braking, coming off brake and applying throttle. But everything with me is feel.....
Reply With Quote
  #110  
Old 05-18-2011, 08:36 PM
FTS's Avatar
FTS FTS is offline
SIG Advocate
 
Join Date: Feb 2011
Location: Germantown, MD
Posts: 967
Downloads: 12
Uploads: 7
Garage
Default Re: Close Call at South Bend

Ummm, sorry, but... how is VIR T1 a decreasing radius, I always thought it is increasing radius actually
__________________
Fatih Selekler
997.2 GT3
Reply With Quote
  #111  
Old 05-18-2011, 08:53 PM
Dell's Avatar
Dell Dell is offline
Registered Porsche Owner
 
Join Date: Apr 2011
Posts: 79
Downloads: 0
Uploads: 0
Default Re: Close Call at South Bend

Good catch. I was typing and thinking just the opposite in my explanation. T1 is actually increasing radius. Bonus points for Fatih! Another reason it is better explained over a beer

What I tried to say and what I typed are two different things. Post edited and tabled for discussion over beer
Reply With Quote
  #112  
Old 05-18-2011, 09:17 PM
FTS's Avatar
FTS FTS is offline
SIG Advocate
 
Join Date: Feb 2011
Location: Germantown, MD
Posts: 967
Downloads: 12
Uploads: 7
Garage
Default Re: Close Call at South Bend

Quote:
Originally Posted by Dell View Post
Bonus points for Fatih! Another reason it is better explained over a beer
Love the idea, but over beer that critical turn might actually become a straight
__________________
Fatih Selekler
997.2 GT3
Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -5. The time now is 06:08 PM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Garage vBulletin Plugins by Drive Thru Online, Inc.
©2010-2018, Porsche Club of America. This site is owned & operated by the Porsche Club of America, and is not affiliated in any way with Porsche AG or Porsche Cars North America.