Speedyellow993

Does anyone know if it is safe to run Spacers on the track?

Cheers,

Al

Irksome

assuming you mean high-quality, hub-centric spacers, designed for our cars, with appropriate replacement bolts, yes.

every day

ditto

Crazy Canuck

yup.

I run 'em.

every day

I have a set of Eibach wheel spacers (7mm front, 14mm rear) and bolts for sale for $300 if you're interested.

Thundertub

I have Techart spacers on my '99 996. No problems. Lots of events. Like they said, get quality parts and you will not have any issues.

MichaelL

Just be careful to keep the wheel bolts torqued properly, the longer bolts are subject to higher stresses . The book says 96 foot-pounds.

David in LA

are these for 996s or will the work for earlier Porsches (ie do the 14mm have studs)?

Reddy Kilowatt

I'm curious what you mean when you say the longer bolts are subjected to higher stress. How so?

Bklyn964Turbo

I believe since they are longer they have a greater chance than the shorter ones to get damaged or weakened due to track activity....I believe the longer the bolt the more likely that it would bend or break under pressure.

anders44

yes agree Ive abused mine hard, works like a charm, FVD spacers.

Apex996

>> longer bolts are subjected to higher stress. How so?

Even though spacers are hubcentric not all the vertical force gets imparted through that section. Also there is some 'slop' there otherwise you'd have to press the spacers on with a tight interference fit.... so given that they're 'loose', the bolts do take quite a bit of the load... and the longer the bolt the more leverage your wheel has against it...hence the 'higher stress' comment.

PS - If you're going to use spacers on the track you may want to start looking at a track stud conversion kit.

Ed Newman

Buy BBS hardened steel studs & nuts from CDOC... do not use the stock lug bolts or other aftermarket long bolts. I have seen these break a number of times already.... it can be quite ugly.

MichaelL

Stresses are transmitted in two different ways from the wheel to the hub: friction between the mounting surfaces and direct shear through the body of the bolt. The friction force is generated by tensile force in the bolts, by torque in the bolt. Shear force is from direct contact between the parts. The friction force is larger than the shear and more reliable. The shear force from direct contact also causes more bending moment in the bolts and is subject to a large range of stress from fluctuating wheel forces. High stress ranges cause fatigue and fracture in the bolts.