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-   -   Torquing Wheel nuts... (https://www.miataturbo.net/race-prep-75/torquing-wheel-nuts-66725/)

mx5-kiwi 06-22-2012 11:28 PM

Torquing Wheel nuts...
 
I have a set of 949 Racing wheel nuts and finally bought a torque wrench.

A couple of questions,

- What torque setting is recommended with these aluminium nuts...

- How many of you track guys do actually torque to a pre determined value as opposed to just cranking on it and deciding physically how tight is tight enough...?

Have my first evening (dark) track day in 4 days time so trying to get things sorted ahead of time. Having read about Emilio losing a wheel in one of his posts I figure wheel nut torque should be one of them...

Lokiel 06-22-2012 11:52 PM

From the website http://949racing.com/6ulfaqsandfitmentinfo.aspx

"70~80 ft-lbs ( 94Nm~108Nm)"

You really need to use a torque wrench to get the feel for how "not tight" this torque setting is (ie. I'm betting that you're over-tightening them massively if you're "guess-timating" - I certainly was).

GAMO 06-23-2012 12:09 AM

80ft-lbs. Don't torque your wheels down after getting off the track; do it cold.

TorqueZombie 06-23-2012 12:54 AM

I torque with the wheels off the ground. Just have someone hold the brakes for 2 min and go in a star pattern.

Mobius 06-23-2012 01:03 AM

I have always torqued my wheels. My rechargeable impact wrench gets them to about 40-50 ft/lbs, I snug them in a star pattern. Then lower the car to the ground and tighten them in a star pattern to 80 ft/lbs with the wrench.

mx5-kiwi 06-23-2012 03:26 AM

Lokiel your right, that doesn't seem 'especially" tight...why is that.

Why wouldn't the tighter the better, be...short of shearing a stud.....or is that the reason..?

curly 06-23-2012 04:01 AM

Quote:

Originally Posted by mx5-kiwi (Post 894453)
Lokiel your right, that doesn't seem 'especially" tight...why is that.

Why wouldn't the tighter the better, be...short of shearing a stud.....or is that the reason..?

Before you torque a fastener, you enter it's plastic range. The hope of a proper torque is to keep a fastener in it's elastic range, so the spring of the metal keeps it tight. If you enter it's plastic range, it stretches without counteracting with any spring force, and just past that you'll torque it off.

P.S. You used the term "shear" COMPLETELY incorrectly.

Lokiel 06-23-2012 04:11 AM

Additionally to Curly's comments, you must be extra careful not to over-tighten aluminium lug nuts since they will crush/deform against the wheel and you risk rounding them off.

triple88a 06-23-2012 04:25 AM

I torque them down with my weight :P

1 foot long wrench sitting at about 30 degrees incline.

I weight about 170 So my max force i can put down is 170 assuming the wrench is at 90 degrees and i'm standing on the tip of it. More commonly i put down about 150lb-ft. I hold my self up while i'm standing on the wrench so i'm putting about 100-120ft-lb.

wannafbody 06-23-2012 08:27 AM

Quote:

Originally Posted by TorqueZombie (Post 894425)
I torque with the wheels off the ground. Just have someone hold the brakes for 2 min and go in a star pattern.

It's hard to do a star pattern with 4 lugs:fawk:

Handy Man 06-23-2012 09:10 AM

Also, with AL nuts its a good idea to use anti-seize to avoid galling, but be aware the it will lubricate the threads which means you shouldn't torque them as much. Typically you torque lubricated nuts to 15% less than dry, so around 70 ft-lbs.

aaronc7 06-23-2012 09:10 AM

Quote:

Originally Posted by Mobius (Post 894427)
I have always torqued my wheels. My rechargeable impact wrench gets them to about 40-50 ft/lbs, I snug them in a star pattern. Then lower the car to the ground and tighten them in a star pattern to 80 ft/lbs with the wrench.

exactly what I do. After I torque them all in 'star pattern' I go once more around to make sure they're all good to go at 80.

triple88a 06-23-2012 04:45 PM

Quote:

Originally Posted by wannafbody (Post 894477)
It's hard to do a star pattern with 4 lugs:fawk:

He torques them in a swastika pattern.

mx5-kiwi 06-23-2012 05:47 PM

Sorry curly, shear WAS the wrong term. Perhaps I should have used stretched beyond material tolerance...;)

Maybe "snapped" which is what I thought I typed or at least intended.

I think I will use 70 ft/lbs and use anti sieze on the thread.

Further to the aluminium nuts, do these have a recommended life span, for example a season or are they good for ages like a steel nut?

curly 06-23-2012 06:53 PM

Actually, I have no idea what the proper technical term is for tightening a fastener so tight it snaps off. Snapped is certainly not it. I thought torqued would work, but in the context of the thread's subject, that could be confusing.

miikeec 06-23-2012 07:21 PM

torque stick at 80ft lbs is ideal

rleete 06-23-2012 07:48 PM

Quote:

Originally Posted by curly (Post 894623)
Actually, I have no idea what the proper technical term is for tightening a fastener so tight it snaps off.

Tensile failure. Exceeded material specifications.

Snapped off works, too.

flounder 06-23-2012 08:21 PM

Always recheck the torque on brand new wheels/nuts after about 25-30 miles. After that 2nd retorquing, they are good to go until the come back off.

chpmnsws6 06-23-2012 09:50 PM

How about normal lugnuts (like Gorilla lugnuts) with ARP studs?


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