OK guys, what are the scenarios that could play out in this situation.

I'm going to the Texas Mile Land Speed Racing event. One of my front rims has been tampered with, someone added a few ounces of wheel weight to the inside of my front rim while the car was in the shop. It was being worked on by a friend at a local dealership. We did not know about it. I go to the race, bring the car up to speed and go right past the 60-80MPH mark when a steering wheel would normally shake but at that moment 60-80mph goes by in 2 seconds. What would happen at say 160mph+ where the car normally runs? What are the physics involved? Let's say the person who did this is an experienced racer and runs a parts and automotive supply company, is this action criminal? What would you do?

I asked this because I recieved a warning phone call that he had done this to my car by someone who knew about it and realized it could be deadly at those speeds and at first thought it was not a big deal.

Advice please.

 

In this situation, you'd feel the vibration well before high speed and know something was afoot - but still a dirty trick. Probably not a dangerous situation, because the vibration would become untenable before reaching treacherous speeds.

Is it criminal? Ironically, not unless actual damage or harm occurs. Barring that, it is mere misdemeanor vandalism.

BTW: Have you ever had your Crossfire up to 160? How did you do that?

 

i had my old stock srt-6 up to 160 even got it on vid :P .. but i had help was going uphill and hit the limiter right befor the top then right on the downside i slid into 160 but then had to slow down

 

If this happened to me (undoubted truth being known) I would contact his boss and throw his wheels out of ballance. Thats just stupid

 

I ran 163mph at the www.TexasMile.com event in March 2009. To me it's the same as if he tampered with the brake lines in hopes they would burst under pressure. With a wheel out of balance some of you know the wheel will wobble but will level out from the g-force at higher speed until the force comes back around even great at higher speed. So What I'm saying is a 65 you might feel the wobble at 75 it's gone but at 150 it comes back in a massive way.

 

HK, you are right. The problem with what he did is a manifestation of inertia. The eccentric mass compounds as wheel RPM increases. Adding a bit more lateral movement at those rotation speeds could easily add HEAT to the tread. Early failure is a possibility.

Find him.

Bring him to me.

 

I think you should tie some weights on that dumba$$ and see if he can swim.

 

I thought that when you get your wheels balanced, sometimes they have to add a few ounces of weight to balance them anyway? Was he balancing your wheels?

 

Best response of the thread.


My $.02 says that if it is a reputable shop, then you need to escalate it to higher authority (i.e. manager/owner) and see that it is dealt with, if it is not then find another shop.

As for the balancing issue, I would fairly quickly take it to a tire shop you trust and have them re-balance your wheels...all of them.

 

I doubt that it would do anything and youd be lucky to hear the weight hitting anything.

If I was to do it , Id balance the tire well, add lots of weight evenly and then loosen the weights on one side so that the imbalance was sudden and significant.

But if someone were to do this to me no one would know, or what happened to that person - poof

Our weights are usually glued to the wheel and the centrifugal force would tend to hold them on, typically.

SOunds like a prank; and who is stupid enough to do it and then tell another?? Get a better shop if this really occured.

Woody

 

The word "smart" is really anoying to me right now.....

 

FP That smart car looks like a wheel chock for a Hummer

 

HK: If I were you, I'd be madder than a hornets nest right now. And you probably are. The potential of running a deliberately unbalanced wheel at high speeds could be catastrophic. However, just as Dwight said, you'd feel the vibration before it got out of hand and have a chance to back off. But, if you kept on going, the damage could be severe. Even so, it is unlikely that the wheel would come off, but the tire could blow from increased pressure and heat, and you would probably damage the wheel bearings. You would need to drive the car with that vibration going full blast for longer than common sense would allow a person to do so for any chance of major damage, unless your tires were in bad shape to begin with.

When dealing with rotating masses that are out of balance a sort of harmonic motion occurs. This is where the vibration comes from. For anyone that has driven with a wheel out of balance, you probably noticed that the vibration has "sweet" spots and peaks at certain speeds. The rotation of the unbalanced wheel creates an oscillating motion, when that oscillation matches a certain harmonic frequency, the vibration is magnified. As you have also noted, the speeds at which this frequency matches can be multiple - it may occur at 15 mph where you wouldn't notice it, and at 75 mph where you would definitely notice and again at even greater speeds. So if it occurred at 65, it would like occur even worse at 130.

If I were you, I would knock all the weights off all of my wheels and have them rebalanced - at a different shop. I would never go back to the shop that is playing games with you.


FP:
I voted for the Smart.

 

I need to clarify this about the shop.

This was done at a Subaru Shop day. Bring your car in and work along side Subaru techs in an un-official capacity. Since I created the shop day years ago and I'm friends with the GM and service manager, they allow me to bring my other cars in for work, it's a great event. This idiot now runs shop day for our car club (I see this stopping very soon) but he has no affiliation to the dealership in any way. He was just there, he was mad at me for having my SRT6 there when he did not want it there and decided that he would screw with my car.

My point on the vibration at 60-80mph was it would go by so fast I'm not sure if I would have realized the problem in the 1.8-2.2 seconds. Remember, I would have been a full throttle and had the vibration come back up at the higher speeds could it have been deadly?

Is there any difference between this and him shaving/cutting into a break line, both could cause death at this extreme speed had the tire blown and sending me into the soft grass at 130+ mph on three wheels and a rim, the thought is scary. It's an airport runway by the way. If you think so, I think I need to call the DA's office. This was not just a prank but according to the caller, he knew just what he was doing and knew the outcome could have been very bad, but made a choice and did it anyway.

The Marine in me would like to do very bad things to him, the adult in me says, call the Cops and DA's office. I thought about giving him the choice to admit what he did to our group and go away to not be heard from again. He violated the ethics code of car guys everywhere. I would give him 48 hours to come clean or I would make the calls.

 

Of course I will get the tires re-balanced, really....

 

If your "caller" will serve as a witness and serve as a verification of competency for whoever this guy is... I would make it legal, the potential ramifications of this are huge.

In this business world it is called 'opportunity cost' what is gained/loss by one choice is still a very real sentiment even if you realized no gains or losses...

 

HK, I like the later suggestion. Embarrass the heck out of him in front of his peers. Then banish him for life.

 

HK, just to clarify, what he did is not in the same league as cutting someone's brake lines. That would be attempted murder. This is vandalism. Even if you drove the car in Texas Mile with the bad wheel balance, you wouldn't be staying at the "sweet spot" speed for long enough to incur much damage. You be much more likely to incur damage if you stayed at the peak vibration speed for a long distance, say on your way to or from the track.

 

Here's the deal, very simple...it is Criminal Mischief to tamper with someone's car...if you had a witness, he could be arrested for his little trick...let alone fired...and, I would probably jailed myself once I found out...you just don't screw with my car...with that said, you would have some vibration at some speed, not necessarily at 160, but somewhere the wheel wouldn't be tuned right, and would vibrate, but it might iron out after that particular speed...you just don't know...but you do know he vandalized your car...go get him....

 

I would put up signs around his neighborhood saying he's a child molester. He'd spend years trying to convince everyone that it's not true.