I had m/t et streets on my car with no issues size 26x11.50x16 . I put on a new pair of 255x60x15 m/t drag radials and now get very bad wheel hop . Their are no changes made to the chassis between changing the tires . I have spohn lca w/rod ends ,lca brakets ,trq arm w/rod ends , sub frames 6point cage ,3 way adj rear shocks , air bag in pass rear . Anybody have this problem . checked u joints ,rod ends , pinion angle all are fine

 

if you are getting more grip, then it makes sense that you are getting wheel hop.
try lower control arm relocation brackets and move them down a notch at a time.
you could also get stiffer rear springs
another option would be slightly stiffer compression damping on your rear shocks.



oops, you already have LCARBS... then either move them down or try the spring thing


what kind of times are you running?

 

What is the air pressure that you are running At the track! Might just have to play with that a little! If you have any other questions feel free to ask and I will be glad to help!
Thanks
Brad

 

i'd run those radials at 18-20 lbs. that's where they work the best for me, wheel hop is the enemy!

 

as other have noted:

- play with the air pressure; start around 15psi, move in 1psi increment till you get close, then move in 1/2 psi increments; try more and less and see how the car responds
- shocks/springs; wheel hop is the shocks inability to control the movement of the rear end. It can be caused by improper geometry or to soft of springs, but the botom line is it's the shocks duty to control the dampening and it's not doing so at your current settings
- control arm angle; the lower the mount hieght is at the rear, the more initial "hit" the suspension will have, but the stiffer the springs/shocks need to be to keep it from re-bounding and unloading


I would bet the radials have more initial bite and are causing the suspension to unload after they initially bite. Slicks have a significantly higher slip rate than radials. If the geometry was right before, then it is now just figuring out the tire pressure vs the shock dampening.

 

I will try some more tomarrow if able 70% chance of rain . My lca's are set to the lowest setting on the lca brackets , the tire pressures I have tried are 16 - 17.5 . I will try more pressure . The springs in the car are replacement napa IROC springs . My shocks are set at 50/50 firm I will put them on 40/60extra firm . Their is no air in the pass side air bag seemed to help . I like the tires so far minnus wheel hop but that is a chassis issue . I ran my new best to date on the second run of this year with a not so good 60' compaired to the e/t streets . The new is 1.67 -60', 11.54@117(only change was tires and 1* timming advance) compaired to old e/t street 1.61 -60' , 11.62@116 . Hopefully when I get the wheel hop dialed in I can better my time a hair . Thanks again !

 

go full tight on the rear shock
DB

 

I will give that a try to when I had the db air up tried 15 - 25 psi the car whould pull very hard to the left , when hitting full throtle. I have'nt been able to drive the car due to the weather .

 

could be the posi dying on you. sending more power to one side than the other

 

I hope not I had that happen with the nine bolt . I now have a nine inch with a detroit locker in it . It seems to be working properly the car is up on jack stands know and have been going over everything on the car the past couple of days . I wonder if going to a taller tire is messing up my pinion angle . 245/50/16 to 255/60/15 granted it is only going to be a 1/2" differance , I doubt it whould.

 

Changing tire size will not change the pinion angle.

Unlike a posi, a locker either works or it dosen't.

The increased mph would lead me to believe your car likes the decrease in tire growth on the big end, as compared to the radials.

Depending on your ride height, the bottom hole of the lca brackets may be too low, thus causing more initial hit than needed and causing the tires to rebound/unload, a situation that would be multiplied by having the shocks loose. The et streets, being considerably softer, would have less tendency to rebound than the radials. - With new stock type springs I would consider this a decent possibility.



Try stiffening the shocks first, if this helps, try moving the lca up a hole so that you don't have to have the shocks overly tight. Running them too stiff makes it hard to maintain traction on the big end. Besides that, the lower the rear mount of the control arm, the more it is trying to lift/transfer weight instead of going forward.

 

That is alot of info thanks , the ride height is stock . I will tighten up the shocks first try that, then move the lca's up one hole , tire pressure . It looks like the weather is going to be nice the hole weekend so I can finally drive the car to get this problem dialed in . Again thanks for everybodys input .

 

I worked on the car today finally got some nice weather. I set the rear shocks to extra firm 40/60 , air pressure in the tires 20 psi , and set the pinion angle to -3* just to try . Also took all of the air out of the pass side air bag . Took the car for a rip and guess what . NO WHEEL HOP!!!!! Thanks again for everyone's help with this . Now I can't wait to get back to the track to see how the car runs . Hopefully a little better without having to worry about leaving a axle or driveshaft behind .

 

cool!
well i was about to suggest that your lcarbs were too agressive.
what happens if you have more anti squat than you need is the car actually raises up with torque on the driveshaft.
and like shagwell said, when you hit the gas, the tires jam into the ground with as much force as they can, the car lifts up, the tires break traction, the suspension unloads and the wheels are stuck spinning in the air for a split second.

try playing with it some.
adjust your lcas, play with the shocks and air pressure.
you are probably overcompensating with one of the variables to cover the other ones.
i believe that you want the least ammount of damping you can get away with on a drag car.
try bringing your lcas up a hole, decrease the shock stiffness, ect.
you may find that your 60' times will go down.

 

I 'll try that today(never satisfiedalways think can do better) raising the lca's up one that easy to do . then take it for a rip . With the shocks on the firm setting the car rides like a lumber wagon , but thats ok . Does anyone think I should but any air in the pass side air bag or is that overkill the rear of the car seems very stiff now . i know baby steps,

 

only change one thing at a time.

 

I will, did'nt get to work on it yesterday . Today I can , but you know what they say . Easy to say hard to do .

 

Leave the air-bag fown unless you have body roll issues or issue with a right pull during launch.

I'd definitely try raising the lca's a hole and loosening the shocks back up some. - Like I said, you want to transfer as much energy as possible into moving the car forward, not up. As Red Dragon noted, being softer(but not too soft) is nice on the big end to help keep it planted.

 

If I move my lca's up one hole will that mess up my pinion angle ,and than to reset it . I can check it pu a pain in the a$$ have to put the car on jack stands .

 

Lca's should not alter the pinion angle. They play no part in controlling the rear-end angle.

 

Cool !