Radial tire chatter
 

I put a set of MT Street Radials on my truck and have developed tire shake on the launch in warm weather. I have increased the 60 ft times and made better reaction times but when the track warms up I get severe tire shake. I started at 15 lbs, reduced it ti 14 1/2 lbs and got my best 60 ft and best et ever. That was @ Super Chevy @ Fontana and the air was great. The next weekend it got hotter than hell, 99-100 degs air and I started to get tire shake as soon as I let off the brake. I footbrake a 4000 lb P.U. that runs 10:70-10:80 on pump gas. I do like the tires but we are approaching summer and I'm going to break something with the tire shake. What am I doing wrong?

Re: Radial tire chatter
 

Floyd, The owner of the dealership I work at has a low 11 sec.Pro Street AMX . ...During the hot weather months we have to switch to bias plys to avoid spinning or shaking. ........The McCreary DOT bias ply tires we run are almost as fast as the drag radials, about .05 slower, but we can hook every time.....Tom

Re: Radial tire chatter
 

We run ours as low as 13# in the summer on our Mustang.. they still spin alittle but dont shake.

Re: Radial tire chatter
 

Radials don't like low air pressure. try 20 lbs and if your 60' doesn't change go up.

Re: Radial tire chatter
 

I was trying different pressures but we got into eliminations and I need the points. I had another thought. I might have my shocks set too soft.

Re: Radial tire chatter
 

what size rim?, what size tire? stick or auto? i may be able to help.
dj raiser
SS/GTAA

Re: Radial tire chatter
 

Most of the time I see cars with tire chatter with radials, it's due to either too low of air pressure, or the shocks out back are set too soft.

My car likes the back end very stiff, both rebound and compression.

Re: Radial tire chatter
 

Don, The rims are 10" wide, the tires are 325X60R15 MT. It's a turbo 400.
I'd appreciate the help.

Re: Radial tire chatter
 

Todd, the backend is already stiff with 250 lb springs but I do have the shocks set soft. Like I said, I started at 15lbs, dropped to 14 1/2 in the cool weather and was doing great. 1:452, 1:453, 1:452 60 fts. 2 weeks later it got hot and first I lowered the pressure to 14 then I raised it to 16. The last pass I eased it out trying to win the race and broke out by .005 so I didn't really get to try the highr pressure.
Thanks for the response.

Re: Radial tire chatter
 

That's the same size tire I run. I've run the BFG's, M/T's, now the Hoosiers. All have worked with 18 psi cold, as high as 19.5 psi hot. Typical usable range for me is 16 to 18 psi. I can't remember ever going to 15 psi.

I run 120 #/in rate coil springs out back (stock type coils) and double adjustable shocks. You need the firmness to come from the shock valving (control), not so much the springs themselves.

My car has 60's a best of 1.289 footbraking, mid 9 second naturally aspirated 454 bbc, th400, 6000 flash 8" converter, th400, 4.33 gear.

Hot & greasy tracks are a big challenge for the radial tires. For this reason, I now have a second set of rims with a pair of 10.5 x 28 Hoosier stiff sidewall slicks for when conditions are at their worst.

hth
Todd

Re: Radial tire chatter
 

Todd,
My truck is a '68 GMC shortbed 1/2 ton that weighs 4000 lbs. It has a pump gas 540, turbo 400, ford 9", ladder bars , alston shocks in the rear, Q1's in the front.. It runs high 10's but I'd like to get it down to DGas times. In perfect weather it has gone 10:70 with the radials. I'm going to miss the Heritage race this weekend cause I didn't have any time to service it or change tires. But, in 2 weeks we have another Heritage race in Vegas and I just have to figure out if I need to change tires or suspension setup.
By the way, those are impressive times from your ride.

Re: Radial tire chatter
 

you have a section width of 13.1, on a 10 inch rim. i would start at 18 psi, and go up not down in tire pressure. best of luck.
dj raiser

Re: Radial tire chatter
 

Floyd,

Do you run inner tubes? I have a 3000 lbs 64 Nova in Super Street, Leaf springs and slapper bars. I was having problems with the same thing and a good friend of mine with a 71 El Camino told me to put tubes in. He had the same problem and after over $4000.00 in changes he put the tubes in and problem solved.
I run a Hoosier 28x10.5wx15 with inner tubes and no problem.... Except i lost a axle this weekend!!!!
I run 13 pounds of air in the rear. car hooks great

Hope this might help

Re: Radial tire chatter
 

Lee, no, I don't run tubes. I've always run MT's tubeless and never had a problem. I have softer springs coming and I'm going to up the air pressure for the coming Heritage Race in Vegas. If I can get another set of wheels before before the first of May I will take the bias tires also just in case. I'm also going to crank up the shocks.
Floyd
By the way, thanks DJ, I'm going to try the 18 lbs.

Re: Radial tire chatter
 

i have at stk elim car and want to put radials on it,30 x 9 x15 who has the best hoosier,goodyear are my two choices.i will be running crate motor in ihra.

Re: Radial tire chatter
 

I see Hoosiers on most.