Tubeless tire pressure

Mike V · 06-06-2015, 09:39 PM

I recently changed to tubeless slicks,Hoosier 29 x 9 (bias ply).The car is an automatic weighing 3300 pounds.I am still running 12.75 pounds of air.But after looking at this picture I think I need to raise the pressure.Any suggestions of where the pressure should be?

J.R. Haddad · 06-06-2015, 11:19 PM

What size is the rim? J.R.

Myron Piatek · 06-06-2015, 11:39 PM

I've heard pressures from 14 to 25+ lbs from 9" tire racers. Lot's of variables, but most seem to be in the high teen to low 20 range. I have Hoosier 9"X 30" Lightweight Radial Slicks at 21 lbs on a 10" rim, car weighing 3,540 and footbraking. Wider rims allow more pressure and radials seem to like a little more than bias ply. I fine-tuned it by watching if contact is being made all the way across the tread (may need less if not) or if rubber is being laid over the side (may need more).

Mike V · 06-07-2015, 07:52 PM

They are 15 x 10 rims. The car is working great ,but I'm concerned about how safe it is.Thinking of going up 1/2 to 3/4 of a pound and see what happens.

John Dinkel · 06-07-2015, 07:59 PM

Try 20 PSI. Don't be afraid of more pressure in the radials.

Sean Marconette · 06-07-2015, 08:20 PM

I run 15x10 with 29.5x9 bias ply but a stick car. Never been above 15 lbs unless I want to spin. OP stated bias ply. Try 13 lbs and work up from there.

Sean

NOVALOU · 06-07-2015, 10:50 PM

Quote:

Originally Posted by Mike V

I recently changed to tubeless slicks,Hoosier 29 x 9 (bias ply).The car is an automatic weighing 3300 pounds.I am still running 12.75 pounds of air.But after looking at this picture I think I need to raise the pressure.Any suggestions of where the pressure should be?

What does the car usually 60' like? Definitely more pressure, the tire looks like it's trying to roll over itself.

I would up the pressure a bit, work towards 13-14lbs., and maybe make a shock adjustment if needed also.

I'm no expert though.

Mike V · 06-07-2015, 11:34 PM

Quote:

Originally Posted by NOVALOU

What does the car usually 60' like? Definitely more pressure, the tire looks like it's trying to roll over itself.

I would up the pressure a bit, work towards 13-14lbs., and maybe make a shock adjustment if needed also.

I'm no expert though.

Usually low to mid 1.60's. I will have to up the pressure and mess with the rear shocks.I see a day of testing in my future. Thanks

Kegracing · 06-12-2015, 10:29 PM

Mike,

I run 29.5x9 bias or 28x10 bias on my 67 Firebird when bracket racing. Also run radials at times, but summer heat in TX, I trust the bias more.

I weigh 3350 and 60' 1.48-1.52 depending on track and launch rpm... I normally run about 14 psi in the bias tires. Normally on 10" rim. 20 psi in the radials. Auto with 5200 rpm converter. Footbrake. GM ZZ4 legal crate motor.

Hope this helps. Good luck.

Ken

Stock 412

Dave Muller · 06-12-2015, 10:38 PM

I used to run 14 PSI or less in my 10.5 bias ply slicks. Now I run 20 pounds, I found that the higher I go the more reliably it hooks.

I don't doubt it would be okay with more pressure but it's been so long since they've spun that I stopped experimenting.

06-06-2015, 09:39 PM	#1
Mike V Junior Member Join Date: May 2015 Posts: 8 Likes: 0 Liked 0 Times in 0 Posts	Tubeless tire pressure I recently changed to tubeless slicks,Hoosier 29 x 9 (bias ply).The car is an automatic weighing 3300 pounds.I am still running 12.75 pounds of air.But after looking at this picture I think I need to raise the pressure.Any suggestions of where the pressure should be? Attached Thumbnails

06-06-2015, 11:19 PM	#2
J.R. Haddad Senior Member Join Date: Jun 2012 Posts: 773 Likes: 895 Liked 1,427 Times in 301 Posts	Re: Tubeless tire pressure What size is the rim? J.R.

06-06-2015, 11:39 PM	#3
Myron Piatek VIP Member Join Date: Nov 2001 Location: Florida Posts: 1,542 Likes: 34 Liked 138 Times in 51 Posts	Re: Tubeless tire pressure I've heard pressures from 14 to 25+ lbs from 9" tire racers. Lot's of variables, but most seem to be in the high teen to low 20 range. I have Hoosier 9"X 30" Lightweight Radial Slicks at 21 lbs on a 10" rim, car weighing 3,540 and footbraking. Wider rims allow more pressure and radials seem to like a little more than bias ply. I fine-tuned it by watching if contact is being made all the way across the tread (may need less if not) or if rubber is being laid over the side (may need more). __________________ LOCOMOTION Racing

06-07-2015, 07:52 PM	#4
Mike V Junior Member Join Date: May 2015 Posts: 8 Likes: 0 Liked 0 Times in 0 Posts	Re: Tubeless tire pressure They are 15 x 10 rims. The car is working great ,but I'm concerned about how safe it is.Thinking of going up 1/2 to 3/4 of a pound and see what happens.

06-07-2015, 07:59 PM	#5
John Dinkel Senior Member Join Date: Nov 2005 Location: Pinckney, Michigan Posts: 507 Likes: 394 Liked 261 Times in 68 Posts	Re: Tubeless tire pressure Try 20 PSI. Don't be afraid of more pressure in the radials. __________________ John Dinkel 3295 STK

06-07-2015, 08:20 PM	#6
Sean Marconette Senior Member Join Date: Mar 2006 Posts: 976 Likes: 780 Liked 274 Times in 76 Posts	Re: Tubeless tire pressure I run 15x10 with 29.5x9 bias ply but a stick car. Never been above 15 lbs unless I want to spin. OP stated bias ply. Try 13 lbs and work up from there. Sean __________________ Sean Marconette 84 Mustang 5060 SS/N

06-12-2015, 10:29 PM	#9
Kegracing Member Join Date: Jun 2002 Location: Red Oak, TX Posts: 441 Likes: 0 Liked 0 Times in 0 Posts	Re: Tubeless tire pressure Mike, I run 29.5x9 bias or 28x10 bias on my 67 Firebird when bracket racing. Also run radials at times, but summer heat in TX, I trust the bias more. I weigh 3350 and 60' 1.48-1.52 depending on track and launch rpm... I normally run about 14 psi in the bias tires. Normally on 10" rim. 20 psi in the radials. Auto with 5200 rpm converter. Footbrake. GM ZZ4 legal crate motor. Hope this helps. Good luck. Ken Stock 412

06-12-2015, 10:38 PM	#10
Dave Muller Member Join Date: Apr 2014 Location: Mesa, AZ Posts: 497 Likes: 162 Liked 223 Times in 73 Posts	Re: Tubeless tire pressure I used to run 14 PSI or less in my 10.5 bias ply slicks. Now I run 20 pounds, I found that the higher I go the more reliably it hooks. I don't doubt it would be okay with more pressure but it's been so long since they've spun that I stopped experimenting.