Reaction time difference, bias ply vs. radial slick

Tim Ellis · 12-21-2014, 11:54 PM

Anyone tested reaction times on their car bias ply slicks versus radials? Naturally one would assume the radials would be quicker because of more air pressure and a stiffer sidewall,no wrinkle, but how much??? Remember I'm talking R.T not E.T. thanks

Joe DeMarzo · 12-22-2014, 10:43 AM

Tim, I saw nothing you could measure in RT, I guess it depends on how much air pressure you run in the bias tires. The travel distance to hit the tree is minimum so it can't be that much if you are consistent in your launch. The 60 ft's are about .03 to .04 slower depending on the time of year. Hope it helps.

Ed Wright · 12-22-2014, 10:56 AM

With my car, I gave up using biased tires to help slow it down. I'm not good enough to adjust my driving for the change.

A lot of added weight effects mine too. Took 200 lbs out for first round of class at Indy, went red. Put it back in for eliminations. Thought it was a fluke, until I duplicated it later testing. Guess I need to buy a Just in Time button. Don't have any spacers to pull off my Biondo button.

Pvt Parts · 12-22-2014, 01:37 PM

Quote:

Originally Posted by Ed Wright

With my car, I gave up using biased tires to help slow it down. I'm not good enough to adjust my driving for the change.

A lot of added weight effects mine too. Took 200 lbs out for first round of class at Indy, went red. Put it back in for eliminations. Thought it was a fluke, until I duplicated it later testing. Guess I need to buy a Just in Time button. Don't have any spacers to pull off my Biondo button.

Easy to do with a third pedal Ed.

Ed Wright · 12-22-2014, 02:16 PM

Quote:

Originally Posted by Pvt Parts

Easy to do with a third pedal Ed.

Sure be a lot more fun. I'm not up to the extra work.

Dwight Southerland · 12-22-2014, 06:14 PM

Keeps your joints limber.

Tom keedle · 12-22-2014, 08:30 PM

Quote:

Originally Posted by Dwight Southerland

Keeps your joints limber.

http://classracer.com/classforum/ima...ons/icon14.gif

Tim Ellis · 12-22-2014, 09:29 PM

Thanks Joe and Ed. Anyone else ?

7423 · 12-22-2014, 11:55 PM

Zero RT difference between bias @15 psi and my radials @ 24psi. Radials are .10-.15 faster ET in my 12 second car. Your mileage may vary. .

Ed Wright · 12-23-2014, 09:09 AM

Mine would not come close to hooking with 15 in the bias tires. 9 or 10 for mine.

12-21-2014, 11:54 PM	#1
Tim Ellis Member Join Date: Dec 2004 Location: Beavercreek Or. Posts: 264 Likes: 22 Liked 6 Times in 5 Posts	Reaction time difference, bias ply vs. radial slick Anyone tested reaction times on their car bias ply slicks versus radials? Naturally one would assume the radials would be quicker because of more air pressure and a stiffer sidewall,no wrinkle, but how much??? Remember I'm talking R.T not E.T. thanks Last edited by Tim Ellis; 12-21-2014 at 11:59 PM.

12-22-2014, 10:43 AM	#2
Joe DeMarzo Senior Member Join Date: Oct 2002 Location: Mahopac, NY Posts: 666 Likes: 48 Liked 114 Times in 9 Posts	Re: Reaction time difference, bias ply vs. radial slick Tim, I saw nothing you could measure in RT, I guess it depends on how much air pressure you run in the bias tires. The travel distance to hit the tree is minimum so it can't be that much if you are consistent in your launch. The 60 ft's are about .03 to .04 slower depending on the time of year. Hope it helps. __________________ Joe DeMarzo 1317 STK

12-22-2014, 10:56 AM	#3
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 389 Times in 168 Posts	Re: Reaction time difference, bias ply vs. radial slick With my car, I gave up using biased tires to help slow it down. I'm not good enough to adjust my driving for the change. A lot of added weight effects mine too. Took 200 lbs out for first round of class at Indy, went red. Put it back in for eliminations. Thought it was a fluke, until I duplicated it later testing. Guess I need to buy a Just in Time button. Don't have any spacers to pull off my Biondo button. __________________ Ed Wright 4156 SS/JA

12-22-2014, 06:14 PM	#6
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 1,980 Likes: 52 Liked 724 Times in 177 Posts	Re: Reaction time difference, bias ply vs. radial slick Keeps your joints limber.

12-22-2014, 09:29 PM	#8
Tim Ellis Member Join Date: Dec 2004 Location: Beavercreek Or. Posts: 264 Likes: 22 Liked 6 Times in 5 Posts	Re: Reaction time difference, bias ply vs. radial slick Thanks Joe and Ed. Anyone else ?

12-22-2014, 11:55 PM	#9
7423 Senior Member Join Date: Dec 2006 Posts: 640 Likes: 0 Liked 1 Time in 1 Post	Re: Reaction time difference, bias ply vs. radial slick Zero RT difference between bias @15 psi and my radials @ 24psi. Radials are .10-.15 faster ET in my 12 second car. Your mileage may vary. . Last edited by 7423; 12-22-2014 at 11:57 PM.

12-23-2014, 09:09 AM	#10
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 389 Times in 168 Posts	Re: Reaction time difference, bias ply vs. radial slick Mine would not come close to hooking with 15 in the bias tires. 9 or 10 for mine. __________________ Ed Wright 4156 SS/JA