 Hoosier R7 Air Pressures, Autocross and road course |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
  |
| dan10101 |
 Oct 2 2019, 08:47 PM
Post
#1
|
|
TORQUE-o-holic  Group: Members Posts: 1,140 Joined: 29-April 03 From: Eagle Point, Or Member No.: 626 Region Association: Pacific Northwest  |
I know these aren't the ideal tire for the purpose, but I just want to get the tire pressures as good as they can be.
295x30x18 and 245x35x18 2500# Yes it's my V8 car. The current situation at hand is our Enduro autocross. It's about a 4+ minute run of 5 laps. (unless you're Britain Smith, then it's closer to 3:30...) I would also like to know how this changes with a normal Autocross of about 1 minute and then again how it changes with a 20 minute road course. Thanks Dan Attached thumbnail(s) 
|
   |
 
|
| GregAmy |
Oct 3 2019, 08:08 AM
Post
#2
|
|
Advanced Member Group: Members Posts: 2,264 Joined: 22-February 13 From: Middletown CT Member No.: 15,565 Region Association: North East States 
|
I presume you mean 295/30-R18 and 245/35-R18?
Radial DOT R7s you're probably looking for around 36-38 hot. For autocross you should probably be running A7s. I run A7s on my 2600# road race car in cool weather, and shoot for 38 hot with either tire. https://www.hoosiertire.com/images/content/...es/TCTR7_A7.pdf |
|
|
|
| jmz |
Oct 3 2019, 01:50 PM
Post
#3
|
|
Member Group: Members Posts: 165 Joined: 11-April 16 From: Lone Star State Member No.: 19,886 Region Association: None |
I run A7s on my 914/6 GT as a road race tire. Since the car is so much lighter than the big american iron they a/x compound seems to work well as a road race tire for these cars. I start very low at about 17-18lbs cold and shoot for 24-25 hot. I would think for a/x the R7 wouldn't even get warm...
QUOTE(GregAmy @ Oct 3 2019, 09:08 AM)  I presume you mean 295/30-R18 and 245/35-R18? Radial DOT R7s you're probably looking for around 36-38 hot. For autocross you should probably be running A7s. I run A7s on my 2600# road race car in cool weather, and shoot for 38 hot with either tire. https://www.hoosiertire.com/images/content/...es/TCTR7_A7.pdf |
|
|
|
| dan10101 |
Oct 4 2019, 09:46 AM
Post
#4
|
|
TORQUE-o-holic Group: Members Posts: 1,140 Joined: 29-April 03 From: Eagle Point, Or Member No.: 626 Region Association: Pacific Northwest |
QUOTE(jmz @ Oct 3 2019, 12:50 PM) I run A7s on my 914/6 GT as a road race tire. Since the car is so much lighter than the big american iron they a/x compound seems to work well as a road race tire for these cars. I start very low at about 17-18lbs cold and shoot for 24-25 hot. I would think for a/x the R7 wouldn't even get warm... QUOTE(GregAmy @ Oct 3 2019, 09:08 AM) I presume you mean 295/30-R18 and 245/35-R18? Radial DOT R7s you're probably looking for around 36-38 hot. For autocross you should probably be running A7s. I run A7s on my 2600# road race car in cool weather, and shoot for 38 hot with either tire. https://www.hoosiertire.com/images/content/...es/TCTR7_A7.pdf Thanks for the response guys. I know I should be running A7s but these came along, so I'm trying to make them work. I have a practice day tomorrow, so I'll play with pressures and temps and see how it goes. Heating up the rear tires shouldn't be the problem. |
|
|
|
| andys |
Nov 22 2019, 10:15 AM
Post
#5
|
|
Advanced Member Group: Members Posts: 2,165 Joined: 21-May 03 From: Valencia, CA Member No.: 721 Region Association: None
|
Some years back, I had a conversation with one of the engineers at Hoosier regarding a tire pressure starting point for non DOT race tires. He advised to run pressures at 1% of the vehicle weight. From there, adjust the pressures to attain best temp profiles when combined with the proper suspension adjustments.
Andys |
|
|
|
|
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 20th April 2024 - 01:29 AM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.