Advice on Driving on Bias Ply TD Hooisers - Vintage racing
02-19-2012, 07:42 PM
#1
Intermediate
Thread Starter
Advice on Driving on Bias Ply TD Hooisers - Vintage racing
I did a search and could not find any information on this (both on Rennlist and google in general).
I will be racing in my first vintage event in a few weeks at Sebring and will have to drive my 1974 Porsche IROC (Tribute) on TD Hoosiers. I am almost 3 years into this wonderfully addictive sport and have driven extensively (60+ track days) on Hoosier R6's on this car and a similarly set up 1970 911S.
So, my question is -- is there any advice on how to drive Bias Ply tires -- or will I just have to feel it out when I am out on them for the first time?
Sorry if this is a dumb question, but would appreciate any advice that can shorten the learning curve!!!
I will be racing in my first vintage event in a few weeks at Sebring and will have to drive my 1974 Porsche IROC (Tribute) on TD Hoosiers. I am almost 3 years into this wonderfully addictive sport and have driven extensively (60+ track days) on Hoosier R6's on this car and a similarly set up 1970 911S.
So, my question is -- is there any advice on how to drive Bias Ply tires -- or will I just have to feel it out when I am out on them for the first time?
Sorry if this is a dumb question, but would appreciate any advice that can shorten the learning curve!!!
02-19-2012, 08:45 PM
#2
02-19-2012, 08:51 PM
#3
Burning Brakes
02-19-2012, 08:54 PM
#4
Rennlist
Basic Site Sponsor
Basic Site Sponsor
Join Date: Jun 2008
Location: Durham, NC and Virginia International Raceway
Posts: 18,680
Received 2,836 Likes
on
1,670 Posts
Will you be at Sebring March 2-4?
Be glad to give you extensive information on the Vintage TD's on your platform. I also recommend my good friend Jack Lewis in Atlanta and Bob Woodman in South Carolina as sources who are most competitive on these tires on your platform.
Biggest single change you should make BEFORE you get to the track is to stand the tires up as much as possible.
The most successful drivers run no more than 1 degree negative, plus or minus 1/2 degree. You'll run much lower hot pressures than an r-compound radial and initial turn in will take twice as much steering angle to initiate, then after a short delay, the car will appear to "turn by itself" as the slip angle increases with the same throttle input that you're used to.
At that point, you can come off steering angle a bit and balance the car with the throttle.
Initially, it will feel like the car is much looser (more prone to oversteer) than you're used to, but once you get used to it, it's really fun and NOT slow...
Best of luck, Peter
Chief Instructor, SVRA, 1994-present
Lead Coach, Bobby Rahal's Legends of Motorsports, 2010-present
Be glad to give you extensive information on the Vintage TD's on your platform. I also recommend my good friend Jack Lewis in Atlanta and Bob Woodman in South Carolina as sources who are most competitive on these tires on your platform.
Biggest single change you should make BEFORE you get to the track is to stand the tires up as much as possible.
The most successful drivers run no more than 1 degree negative, plus or minus 1/2 degree. You'll run much lower hot pressures than an r-compound radial and initial turn in will take twice as much steering angle to initiate, then after a short delay, the car will appear to "turn by itself" as the slip angle increases with the same throttle input that you're used to.
At that point, you can come off steering angle a bit and balance the car with the throttle.
Initially, it will feel like the car is much looser (more prone to oversteer) than you're used to, but once you get used to it, it's really fun and NOT slow...
Best of luck, Peter
Chief Instructor, SVRA, 1994-present
Lead Coach, Bobby Rahal's Legends of Motorsports, 2010-present
__________________
-Peter Krause
www.peterkrause.net
www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
Specializing in Professional, Private Driver Performance Evaluation and Optimization
Consultation Available Remotely and at VIRginia International Raceway
-Peter Krause
www.peterkrause.net
www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
Specializing in Professional, Private Driver Performance Evaluation and Optimization
Consultation Available Remotely and at VIRginia International Raceway
02-19-2012, 10:28 PM
#5
Burning Brakes
Bias ply race tires are a reward to the juvenile delinquent hidden inside us all.
As Peter mentioned...stand those tires up straight, and watch your pressures. I use TD's or Street TD's (the same tire, actually) on the Red Sled (2700lbs., solid rear axle V8 noisemaker), as they last a few more heat cycles than the Goodyear bias ply. Running a bit less than 1 deg neg. in the front...have a live axle housing in the back that gives me around 1/2 deg. negative. Hot pressures are in the 30-34lb. range, depending on conditions and how often I want to show everyone behind me the numbers on the doors (yeehar).
You can get a bias ply tire incredibly sideways and still in totally in control. Any schmoe can make "hero saves" with them.
As Peter mentioned...stand those tires up straight, and watch your pressures. I use TD's or Street TD's (the same tire, actually) on the Red Sled (2700lbs., solid rear axle V8 noisemaker), as they last a few more heat cycles than the Goodyear bias ply. Running a bit less than 1 deg neg. in the front...have a live axle housing in the back that gives me around 1/2 deg. negative. Hot pressures are in the 30-34lb. range, depending on conditions and how often I want to show everyone behind me the numbers on the doors (yeehar).
You can get a bias ply tire incredibly sideways and still in totally in control. Any schmoe can make "hero saves" with them.
02-19-2012, 10:33 PM
#6
Rennlist
Basic Site Sponsor
Basic Site Sponsor
Join Date: Jun 2008
Location: Durham, NC and Virginia International Raceway
Posts: 18,680
Received 2,836 Likes
on
1,670 Posts
02-19-2012, 11:47 PM
#7
Rennlist Member
There is conflicting advice on camber on a 911.. some people just bolt them on with normal 2-3 degrees and do fine. I lowered my camber once to 1-1.5 and did not like them. Tried them again with lots of camber and they were at least as good. But they wore VERY FUNNY on the outside front - looks like something carved into the tire. Wear is also not good with radial camber settings but I have heard they wear funny on 911s anyway. They brake GREAT and are fun in low speed turns but Lime Rock has three fast corners so not fun for me there.
Trending Topics
02-20-2012, 08:29 AM
#8
Rennlist
Basic Site Sponsor
Basic Site Sponsor
Join Date: Jun 2008
Location: Durham, NC and Virginia International Raceway
Posts: 18,680
Received 2,836 Likes
on
1,670 Posts
When Bob Woodman can take his 3.0 IROC tribute and beat all the Cayman Series cars in an Hour enduro at Hutchinson Island on TD's, that shows me that there's not an insurmountable performance hit.
But as the Professor and Analog Mike point out, it takes a little getting used to.
To the OP, I think we met at the Chin event in Watkins Glen last May. See you at Sebring!
But as the Professor and Analog Mike point out, it takes a little getting used to.
To the OP, I think we met at the Chin event in Watkins Glen last May. See you at Sebring!
02-20-2012, 09:06 AM
#9
Intermediate
Thread Starter
Awesome advice -- thanks so much, this will help me to mentally prepare for them and also tweak my set up. I have heard that they are a blast to drive on and you guys are confirming that! THANKS.
Peter, yes will be at Sebring Mar 1 - 4 and did meet you in Watkins Glen at a Chin event last year, but my yellow car is in 200 pieces right now, so I will be driving a more recently acquired 1974 IROC (tribute).
Look forward to seeing you at Sebring!
Peter, yes will be at Sebring Mar 1 - 4 and did meet you in Watkins Glen at a Chin event last year, but my yellow car is in 200 pieces right now, so I will be driving a more recently acquired 1974 IROC (tribute).
Look forward to seeing you at Sebring!
