Balance drag slicks ?

[fastfredracing]

I've always balanced them. This guy , said either way , he does not care, he has several sets, some are balanced, some are not . Said he never noticed a difference either way . This is a sub 11 second car.
I am going to balance them anyhow, but wondering if it makes any difference, these tires are constantly changing size and shape going down the track , and losing lots of rubber at every launch .
Pics for attention .

[masraum]

Interesting. I have no experience with drag slicks.

My first thought was "at the speeds that they could hit, better to be balanced."

But, they hit those speeds for only a few seconds, and as you said, the tires see so many changes over those few seconds, I'm not sure how much it would help.

Still, if it was me, I would probably want to ensure they are not way out of balance.

[Nickshu]

Does it take special equipment to balance those?

[masraum]

Are they drag radials or wrinkle-wall slicks? That would probably make a big difference.

[pete3799]

I would think that tire distortion under acceleration would negate any balancing but i'm not a drag racer and i didn't sleep at a Holiday Inn either.

[john70t]

It's not the acceleration phase, it's the final 200mph vibration.

You installed the tires. CYA and document.

[masraum]

Originally Posted by john70t

It's not the acceleration phase, it's the final 200mph vibration.

You installed the tires. CYA and document.

well, 11 second car is what, 130-140mph trap speed?

I think to see 200mph trap speeds, it'd have to be a 7 second car.

[john70t]

(I dont know the specs but hey you know what I mean)

[sc_rufctr]

How much does it cost in time and money to balance them?
- Not much is my guess so considering what one run costs you why wouldn't you balance them?

This may sound strange but I build bicycle wheels as a side gig and I wouldn't feel right selling an unbalanced wheel.
(after the tires are fitted) But there are lots of wheel builders I know who don't balance their wheels.

[fastfredracing]

My thoughts as well. His comment to me was " you don't have to balance them if you don't want to "
I see no real downside to balancing , other than an ounce or two

[sc_rufctr]

Would a big drag slick fit on a balancing machine?

[Jeff Higgins]

I ran a few big block MOPAR "B" bodied cars in the late '70's through late '80's, with the fastest one breaking into the high 9's at about 130 or so. Had to give it up as marriage, kids, and career intervened. So, when presented with the opportunity, I eagerly volunteered to help crew an NHRA AA/FC class car - yes, a full up, blown nitro Funny Car. This was in the mid '90's. It was running low five second passes in the 280-290 mph range. Even held the mph record at Denver's Mile High Raceway for a couple of years. As an interesting aside, we ran the Donovan 417 motor, an aluminum version of the old 392 Hemi. One of the team owners was a machinist in the tool fab shop at work, that's how we hooked up. He wound up on the cover of National Dragster, holding a cylinder head he had whittled out of a block of 6061-T6. It was a three valve head, with two exhausts. They were on the car when it set the record. He was hoping for fame and fortune through selling sets of them, but it just never worked out.

Anyway, NONE of those tires on any of those cars were ever balanced. I'm not even sure if it would have even been legal. No sure-fired way to ensure they stay on the way that Funny Car shook everything.

[cockerpunk]

dunno about drag racing, but i balance my road racing tires, and i mount them dry too. if you mount them with lube they will rotate on the wheel in the first braking zone, and oh man, you will feel that out of balance vibration next time you hit 4th. id assume youd want to do the same with drag tires.

[Scott Douglas]

I would think weights flying off at speed would be more of a concern than if the tires were actually balanced.

[fastfredracing]

I would use stick on weights, lots of centrifugal forces holding those weights on , they ain't going anywhere. I use them on road race tires also .

[javadog]

Yes, you balance them, most people use a bubble balancer. I would put a steel tape on them and check their circumferences too. Obviously, you want those to match.

[john70t]

Originally Posted by cockerpunk

dunno about drag racing, but i balance my road racing tires, and i mount them dry too. if you mount them with lube they will rotate on the wheel in the first braking zone, and oh man, you will feel that out of balance vibration next time you hit 4th. id assume youd want to do the same with drag tires.

Good point. My understanding is to rotate the tire until the least natural OOB is found first. Then weights.

There might be special weights needed, or national/local drag car org standards.

[A930Rocket]

Originally Posted by fastfredracing

I would use stick on weights, lots of centrifugal forces holding those weights on , they ain't going anywhere. I use them on road race tires also .

We always used a layer of HVAC tape to make sure the stick on weights stayed on.

[Jeff Higgins]

It appears there is a lot of conflicting advice in today's drag racing world. Back when I was doing it, nobody did it. Just wasn't worth it. The first burnout negated all of that anyway. Maybe that was kind of an extension of what we answered with when road and oval racers asked us how we broke in our motors - "on the first burnout".

Summit Racing, who I respect a great deal, now recommends that racers static balance their slicks. Knock me over with a feather... I would take that as the definitive word today, though.

[Brando]

Out of curiosity, what speed would you balance the wheels at? If the car is hitting over 150mph, can your machine balance that?