Topic: Torque wheel lug nuts each stop?
Do team check lug nut torque on each stop? Each day?
What is the best practice?
Has anyone had a wheel fall off in the race due to loose lug nuts?
The 24 Hours of Lemons Forums → Lemons Newcomers → Torque wheel lug nuts each stop?
Do team check lug nut torque on each stop? Each day?
What is the best practice?
Has anyone had a wheel fall off in the race due to loose lug nuts?
Fyi.
You cannot touch the tires in the hot pits.
You can only
1. Switch driver
2. Add ice to the cool suit cooler
3. Ad gas after the driver has exited and before the next one enters
It's good practice to check the lug nut torque each time you pit. It can be done while the driver gets out of the car and before fueling begins or afterwards as the driver gets back into the car and belts up.
I just worked at a local car club endure race (10 hours). I observed pits stops for any safety violations and made sure they observed the 5 minute minimum pit stop time if they fueled the car. It was no problem for even one crew member to do this task as I described above in the time needed for the driver to exit and/or enter the car.
Under our rules we even allowed work on the car such as this to be done as long as it was on the opposite side of the car from where fueling was being done. Not Lemons legal.
We torque them down before the car goes out on the track day 1 and then again on day 2. In the northeast, we use the hot pits so you can't do it unless you pull the car in.
We don't re torque at each stop. Read somewhere that when heated, the studs lengthen, and by torquing when hot you in effect over tighten the studs causing them to stretch and break prematurely.
We don't re torque at each stop. Read somewhere that when heated, the studs lengthen, and by torquing when hot you in effect over tighten the studs causing them to stretch and break prematurely.
When torquing hot, I reduce the wrench setting about 10 lbs from cold. We start @ 100ftlbs cold
We don't re torque at each stop. Read somewhere that when heated, the studs lengthen, and by torquing when hot you in effect over tighten the studs causing them to stretch and break prematurely.
When re-torquing, I reduce the wrench setting about 10 lbs when hot. We start @ 100ftlbs cold and try to check 1 or more times during the race.
It's good practice to check the lug nut torque each time you pit. It can be done while the driver gets out of the car and before fueling begins or afterwards as the driver gets back into the car and belts up.
I just worked at a local car club endure race (10 hours). I observed pits stops for any safety violations and made sure they observed the 5 minute minimum pit stop time if they fueled the car. It was no problem for even one crew member to do this task as I described above in the time needed for the driver to exit and/or enter the car.
Under our rules we even allowed work on the car such as this to be done as long as it was on the opposite side of the car from where fueling was being done. Not Lemons legal.
Just to make sure it's 100% clear, you cannot do this in Lemons in the hot pits. If you are using the hot pits during a Lemons race, you cannot do anything other than take the driver out, add gas, then add ice to the cool shirt and put a driver in. If you want to bring the car into the main pits, or if your track does not use hot pits you may do other work.
My own experience, if you find that your lugs require tightening every pit stop, something is wrong. Most teams I know torque them in the morning, and check them after the day is done once things have cooled down, and that's it. If you find that things are loosening up you either have a mechanical issue with the actual lugs/bolts/studs/wheels/mating surface or you have a problem with your torquing procedure. You should be checking that the mating surfaces of the hub and wheel are clean, that the threads are clean and free of unwanted grease/dirt/other, thread all lugs/bolts on basically by hand to make sure the wheel is seated flat, then torque. It's a really good idea to roll the car a small distance and torque again as when you lower the car the way the suspension moves will try to cock the wheel in like it wants positive camber, which can affect your torquing. By rolling the car you get everything to settle to the natural state and you'll be sure you did torque to the desired spec. We will often torque the wheels on, then drive to the gas pumps to fill for the day, then torque again and it's not uncommon for a few bolts to snug up a little more. Over torquing can lead to problems too. Don't up the torque setting from recommended unless you're switching hardware and the manufacturer tells you to.
In 20 something races We have only had a wheel loosen up once. I felt it happening, on the straights I started to feel a shimmy in the front end. Brought the car in, had the bolts checked and the driver's front took almost a full turn of tightening. We think that wheel wasn't checked in the morning. Otherwise never a problem. We're using OEM bolts/hubs/wheels and torquing to standard 81ft-lbs (saab's spec).
We check them every couple of pit stops. If using hot pits, we check them when we have to add more oil, which is often.
We check them before Saturday's session, and since we usually swap tires after Saturday and before Sunday, they are torqued properly before Sunday's session. Have never had an issue in 35+ races.
We use the hot pits so just torque them before each day. No issues in 10 races so far
Same as most - we check torque Saturday before going out, rotate tires Sat evening (hot, so good and snug but not torqued), and check torque cold on Sunday am before going back out. Never an issue.
I would recommend converting to studs if you drive something that uses wheel bolts rather than nuts, but if that’s done, we have never had an issue with loosening wheels, torque them cold and never give it a second thought.
After 29 Lemons races, we’ve only had one wheel loosened due to improper install. The lug caught on the lip of the rim instead of seating properly.
Lugs coming loose is not a common problem. If they do it’s normally a installation issue.
Your pre-race routine should be to check tire pressure and lug nuts each morning before going on track. Then each time you change tires.
Be sure everyone on the crew knows your desired cold tire pressure and lug torque specs.
Other than that it’s over kill and normally not necessary.
Also,
We used a tire pyrometer on a practice day to determine our correct cold tire pressure. Looking at even temps across the tread and the correct wear pattern or tire “roll over”. Now we know if we set the tires to 31 psi cold, we’ll get the best tire wear, grip, performance and longer tire life.
Some might think this is about winning, but I would say it’s about safety. Taking care of your tires is a vital safety issue.
We actually DID have stud failures... most likely due to re-torq every stop. The studs grow when hot, so a re torque results in an overtight condition when everything cools down. Once we just started doing a pre-race torque only, the failures stopped
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