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
  #1  
Old 06-08-2011, 03:54 PM
bman's Avatar
bman bman is offline
Registered Porsche Owner
 
Join Date: Feb 2011
Posts: 146
Downloads: 0
Uploads: 0
Default Re: How To Brake?

Thanks for the feedback! I am with you on long sweepers and threshold braking.

In my experience, T12 at Mid Ohio is indeed tricky if you hold the brake as you approach the apex. As you describe, the track flatens and falls away but has positive camber on the approach. Keeping the front end loaded with the track falling away equals

http://www.youtube.com/watch?v=pLXIyiCfTmo

For me it's best taken with straight line braking, off early, settle, touch of throttle and all is good.

Quote:
Originally Posted by NickW View Post
how large you need the traction circle to be at whichever end you need it at most.
Can you elborate?

I can't imagine the braking in a kart can compare to a GT car at Mid Ohio but what do you do in Keyhole and Carousel?

I find my chassis has the best balance if I apply LIGHT brake at initial turn in and hold the same pressure half way to 2/3 through the corner.....basically braking and turning together but very gently and with steady arc'd steering. The tough part is in not applying too much initial brake and trusting that I can maintain constant pressure and the car will arc smoothly.
Reply With Quote
  #2  
Old 06-08-2011, 05:43 PM
NickW's Avatar
NickW NickW is offline
Registered Porsche Owner
 
Join Date: Apr 2011
Location: Chicago, Orlando, Vail, Hong Kong
Posts: 41
Downloads: 0
Uploads: 0
Garage
Default Re: How To Brake?

Quote:
Originally Posted by bman View Post
Can you elborate?

I can't imagine the braking in a kart can compare to a GT car at Mid Ohio but what do you do in Keyhole and Carousel?

I find my chassis has the best balance if I apply LIGHT brake at initial turn in and hold the same pressure half way to 2/3 through the corner.....basically braking and turning together but very gently and with steady arc'd steering. The tough part is in not applying too much initial brake and trusting that I can maintain constant pressure and the car will arc smoothly.
At the Keyhole we go to threshold brake immediately (braking in a straight line after the chicane), then turn in after braking is complete, apexing twice around the turn, riding the concrete patch for the most traction. Throttle application is immediate because the chassis is settled (unlike a car), increasing the throttle as long as the front end stays planted in the right direction (no lifting). Track out to the runout patch on the left, straightline the track from there to the turn in point at T5 (coming across the track near the emergency lane on the right).

The Carousel at M.O. is tricky because of the big bump in the middle of the apex. That tends to separate ribs if you're not careful. We tend to go through T12 hot, flatfoot on the throttle, then brake in a straight line right before the turn in for T13, double apexing it as opposed to a single apex specifically because of the bump. End result is you lose .1 second on that corner, but you keep your ribs intact, and since T14 comes up quickly, the speed you lose through T13 actually helps give you time to set up for T14.

I should be there in two weeks for the WKA National. I can get some on kart footage and post it if you want.
Reply With Quote
  #3  
Old 06-08-2011, 09:50 PM
csmarx's Avatar
csmarx csmarx is offline
Registered Porsche Owner
 
Join Date: Apr 2011
Location: Santa Barbara, CA
Posts: 29
Downloads: 1
Uploads: 0
Garage
Default Re: How To Brake?

Quote:
Originally Posted by bman View Post
In my experience, T12 at Mid Ohio is indeed tricky if you hold the brake as you approach the apex. As you describe, the track flatens and falls away but has positive camber on the approach. Keeping the front end loaded with the track falling away equals

http://www.youtube.com/watch?v=pLXIyiCfTmo
Wow, what a fun looking track with some challenging turns and lots of elevation change. Too bad it's so far from CA!

IMHO the guy lost it primarily because of the brow he was going with too much steering lock on. To make matters worse he seemed to apply the brakes as well.

I was taught to momentarily straighten the steering when going over brows in a turn. It unloads the tires for a moment until the car settles again on the other side of the brow. It's the short version of making it a double apex.

-Christian
__________________
2004 Porsche 911 GT3 Black, 2010 - Current, Parked at home
1993 Porsche 968 Club Sport M030 White, 2002 - Current, Parked at Nürburg Ring
2003 Porsche 911 GT3 Club Sport Silver, 2003 - 2005, Sold
1998 Ferrari 355 Spyder Red, 2000 - 2004, Sold
Reply With Quote
  #4  
Old 06-09-2011, 08:07 AM
bman's Avatar
bman bman is offline
Registered Porsche Owner
 
Join Date: Feb 2011
Posts: 146
Downloads: 0
Uploads: 0
Default Re: How To Brake?

Quote:
Originally Posted by NickW View Post
the big bump in the middle of the apex. That tends to separate ribs if you're not careful..

I can get some on kart footage and post it if you want.
I know what you mean! It's pretty nasty in a car and can only imagine how rough it must be in a kart.

Yes, please! I'd like to watch.

Quote:
Originally Posted by csmarx View Post
Wow, what a fun looking track with some challenging turns and lots of elevation change.

I was taught to momentarily straighten the steering when going over brows in a turn. It unloads the tires for a moment until the car settles again on the other side of the brow.
It's a blast to drive! I would strongly recommend it for any track junkie. It's also, IMO, a track that will test your braking skills. It requires several techniques; if you want to be quick

Check out the turn before the spin, turn 11. It's exactly the type of turn where you need to open the wheel as you crest a "brow". It's awesome!

I've only been to Mid Ohio twice, most recently last month. It's such a unique and fun track that on my 7 1/2 hour drive home, which is normally a drag, I found myself smiling, seemingly for hours, as I reflected on the weekend. I can't recall ever doing that before
Reply With Quote
  #5  
Old 06-09-2011, 09:22 AM
beez's Avatar
beez beez is offline
Registered Porsche Owner
 
Join Date: May 2011
Location: Las Vegas, NV
Posts: 13
Downloads: 0
Uploads: 0
Default Re: How To Brake?

The Boxster spins because he/she is braking too hard with too much steering input - too much traction on the front, while the rear has hardly any weight on it. Look at the attitude of the car as it begins to enter the corner - it looks to me the driver thought they were carrying too much speed into the corner, and tried to fix the situation with progressive braking - adding more pressure as they continued to turn the wheel - look at how fast the car with the camera in it catches up to the quickly, and progressively slowing Boxster. Unfortunately the back end also gets light because of the slight crest in the middle of the turn - this exacerbates the situation. but the spin actually begins before the elevation change.

IMHO, one needs to use very different braking techniques for each kind of corner... if you're trying to threshold brake at each corner, no matter it's configuration, then you're using your brakes too much, and probably over-slowing the car in many instances.
__________________
brad
24-year PCA member and PCA national DE instructor
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 11:49 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.