I run a 28x10.5 M/T PBR tire on my S-10 pickup. The truck is as good as anything on the racetrack if the track temp is below 110-115 degrees. If the racetrack gets hot/greasy in the heat of the day, I might as well just load up and go home. I currently have stock leaf springs with homemade Caltracs, Viking double adjustable shocks on all 4 corners, and plenty (5"+) of front end travel. I've managed to help the situation with tightening the compression way up in the rear, running the extension full loose on the rear and dropping the leave RPM way down, but it's still slipping the tires in the heat. Am I just stuck until I put better leaf springs under the rear of the truck, or do I have options to minimize/eliminate 60' problems in the heat? The truck runs 6.90s-7.0s and I run 16-17psi in the PBR tire.
Radials typically don't like hot track conditions, you get up over 130 degrees and it's pretty tough to get them to work.
I put 29.5x10.5 PBR's on my car last year, I have coilovers and dbl adj Afco's. I had similar results at tracks. I fixed the problem last week when I went back to bias slicks. The radials were a little quicker and faster and when they worked they were good. The slightest tire spin and you were toast.
I run 31.5x13 PBR's...40 passes so far and all on tracks with 120-140* track temps...no problems at all...I run 17 lbs. in them...
I run 29.5/10.5 PBRs, no problem with track temps in the Deep South.
19 psi, very short burnout- roll thru water, hit line lock, stomp it, release line lock as soon as it shifts, power out 7-8 feet, lift and hit N right before tires chirp.
Playing with shock adjustments really helped mine.
Shorten your burnout up.. Those tires need to just be cleaned off when the track temps are that high. As soon as you see smoke, STOP
Mickey Thompson Tires
330-928-9092 X 3142
i do the same with my pbr on my s10 17 psi and shorter burnout when hot - we ran all summer 105 t0 108 air temp - no spin
2012 West Coast Pro Gas E/Gas Champion
over 140 passes on 29.9 X10.5 PBR's lots of ups and downs. heavy door car 3150lbs used to be a 10.3 car now 10.5 car to make the radial work. Seems like wheel speed at launch is crucial, tough thing is cutting a light adjusting the rpm to control spin. I'm still tryin to figure it out after 3 yrs
Why run radials if your bracket racing and having problems? I used to run them and they were exactly as you describe... Great on cool tracks then in the heat it would soon out of nowhere. Went to bias tires and car is less than .003.. Most times dead on.
Another option which I also use to tame wheel stands is the grid. Pull timing for 2 seconds and ramp it back in.
Either are good. Both are the best. Who cares how fast your going.. It's bracket racing. .1 sec to kill some starting line power won't hurt a thing.
Configuration: 3350#, 555 C.I.,
60 - 1.24
1/8 - 5.69@ 123MPH
1/4 - 9.03& 152MPH
3700#+210lb driver, FULL interior, through mufflers, 10.5 tire.
60'-1.333 (IN 4000ft DA! Joisy Math excluded; 1.25sec using JOISY MATH.)
1/4 - 9.60@144MPH
Add about 75 lbs in the rear of the bed will probably make a huge difference.
Agree with others on the short burnout. I'm running the Hoosier radials and any burnout at all is almost too long. As soon as the tires break loose I let off the line lock and then put it in high gear. Feather it out past the "marbles". I keep doing shorter burnout and haven't yet found the limit.
I haven't used a line lock for a burnout in about 20 years. Been running 9" radial slicks since 1995. Mostly Hoosier with a few sets of Goodyear mixed in.
I laugh all the time when my kid does the wimpiest burnouts I've ever seen and dead hooks every pass in any weather. It's amazing how far tire technology has come lol
This our 4-5 year history with running small tire radials. Most of the runs over the years on Hoosiers & recently a 100 runs on the M/T PBR. My home track is Las Vegas, NV. & the majority of our races are mid day. With air temps well over 100 degrees with the sun beating down, I don't bother with taking track temps. Both tires work great & never had hook issues in the heat. That's using a short burnout.
The issue I have is when the track is cooler with no sun. I've had wheel spin with the Hoosiers 3 times & 1 time with the PBRs over the 4-5 years. All caused by me not doing a more aggressive burnout for the cooler conditions.
No reason for me to go back to a bias ply slick. The sidewall life, consistency & more runs per tire; are the seller for me!
Pump Gas 434
4.10 Rear Gears
Car Detuned for high 9s/low10s @ 133-34 mph
With radials, the hotter the track, the shorter the burnout. Even in cold temps my burnout will be 5 seconds or less.
Changing from bias to radials isn’t a simple bolt on swap. Shock settings are different as is the instant center of you want to optimize for the tire. Radials need to be hit hard to stick the tire. Looser rear rebound and stiffer compression. Rear should separate at a controlled rate.
Also, with th launch retard. Don’t take timing out on the brake. I hit the tire with full power then drop the timing out at .2 from the brake release, then ramp back in. I never ramp in any longer than the 60’. Any longer will just slow the car. With the radial, if you can make it past 10’ your good to go for the rest of the run unless your a power adder deal brining in power further down track.
I’ve run radials for over 20 years now. I run an index class where 75% of the cars run a 10.5 x 33 bias slick compared to my 10.5 x 30 radial tire. We don’t get radial prep so I had to learn how to get down a marginal/hot/bald spot track. I wind up going on bracket days to test since the track only preps in the morning and doesn’t do much more other than a little gold dust and bug sprayer spritz touch up to bald spots. Setting my car up to carry a small wheelie has helped me get down a poor track surface when others can’t.
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