Wheel Stud Ft/lbs. Torque?

[KRZTACO]

How much Ft/lbs of torque on my lug nuts?



I was thinking 65 ft/lbs of torque on my wheel studs.





KRZ

[98Boxster98]

MY2003 user manual says 94 ftlb (130Nm).

[KRZTACO]

Sweet thanks,

KRZ

[cyclocross]

Hi. My 2001 Owner's Manual also states 130 NM.

[Tool Pants]

The shop manual says 130 newton meters or 96 foot pounds. Something got lost in the translation because if you do the conversion 130 newton meters is 94 foot pounds. There are lots of little mistakes like this in the shop manual.

I have always use 96 foot pounds. The difference between 94 and 96 is nothing.

[limoncello]

Got a question - shortly after I got the boxster I checked with the local club folks, all pointed to the same tire dealer as the best in town for Porsches (all types). Went to the tire man to get a set of fronts, and asked what torque he used. Said he used 80 ft-lbs., always had, and cited numerous boxsters specifically. I've seen a number of cautions on OVER torquing. What about UNDER-torquing? My wheels haven't fallen off, and the nuts are always tight.
Track day is friday, and I will take along a torque wrench & check periodically through the day.
The tire man uses a pneumatic wrench - are they imprecise and he's staying on the safe side?
My owners manual says same as everybody else.
Open for any thoughts or comments.

[Brucelee]

Candidly, I would trust the owners manual for obvious reasons!

[donv]

And definitely trust a torque wrench over an impact wrench for accuracy.

[Perfectlap]

I'd call a place like Ruff NA in Texas or Brumos Porsche in Florida if you are really curious. Both prep allot of cars for track duty. 96 always sounded a bit high to me but I'm no mechanic. My fear is putting too much pressure on the wheel bearings as opposed to not enough. $600 per wheel is not a cheap repair.

[Cold Warrior]

The reason torque values are specified on wheel bolts is not to keep the wheel snug against the hub. The specified torque is applied to the bolt in order to establish an axial preload that will not be overcome by fluctuations in the load appled to the bolt due to external forces. Load reversal leads to fatigue failure, hence the desire to prevent load reversal. The reason this may not be important in a stock car race is that the axial loads on the bolts don't change that much or often during the course of a race. Load fluxuation in a road car is much more dramatic and happens with a much greater frequency. Hence the desire to establish the correct preload (torque) on the wheel bolts.

(Edited to remove the sarcasm)

CW