Wheel with spacers on a road course

[GSpeed]

Hi guys,


Spacers are perfectly safe for track use, to a point. The thicker your spacer is, your wheel and tire exert more leverage and force on your Lugs/studs/hubs/uprights and/or suspension. The heavier your car is, the bigger and stickier your tires are, the harder you accelerate and brake, the greater your cornering force is, the greater the stress on those same components is. Keeping all that in mind, thinner the spacer you can run, and still achieve the fitment you're looking for, the better off you are. In general I try not to run any spacer thicker than 15mm or 5/8in., unless you have really beefy hubs and upgraded studs/lugs already.


The Subaru above is a good example, fairly heavy wagon, all-wheel drive, high horsepower. You may put a spacer on the car and be perfectly fine on the street, go to the track and have a blast. Then you decide to put slick race tires on the car, which amplifies the forces on your equipment, and could shear studs off, break a hub, or even break a wheel. The learning curve on these failures is steep and sudden. On the other hand, take a Miata, light weight, less power, less cornering force. You may be able to run a similar or thicker spacer, and never worry about it at all.


There are also different kinds of spacers. The more "universal" your spacers are, the less safe they are. The more models they can fit, the less precisely they will fit YOUR car. You need to determine whether your wheels are Hub-centric, or Lug-centric. Hub-centric wheels are aligned by the centerbore of the wheel and hub, and normally have a spacer that sandwiches between the two. Lug-centric wheels usually have specially keyed or beveled lug nuts or lug bolts that work together to keep the wheel and hub aligned properly, and will typically have a spacer that is permanently attached or bolted to either the wheel or hub face. When looking for spacers, upgrading your lug nuts and studs is almost always a good idea. If you're a DIY'er and have tools, it can be fairly inexpensive too.


Everyone has to inspect their equipment at a regular interval. Improper torque and over-torqueing can damage equipment, even upgraded equipment. Those guys who bring more than one set of wheels to the track have to watch for advanced wear, from swapping wheels back and forth.


Hope this info helps guys.


-Wally

[GSpeed]

I'd like to add to what Wally said. I think it's important to emphasize the difference between sandwich spacers and bolt-on spacers.

If you look at the individual corner of the suspension as a static load, you can imagine the path the load travels through the contact patch, wheel, stud/lug nut, spacer, and hub at any given moment. In both cases, the compression loads are the same. The spacer is just "squished" between the wheel and the hub, and you're not going to have any issues.

With a sandwich spacer, the wheel studs carry the tensile load from the wheel through to the hub, exactly as they were intended. Assuming your studs are up to the task (ARPs or equivalent) you won't have any issues.

In the case of the Subaru above, you've now added another piece into that tensile load path. The load travels from the wheel, to the studs in the spacer, to the spacer, and THEN into the hub. So if the spacer is not capable of handling the tensile loads being asked of it, you wind up with the wheel beating you to the next corner. Not a good scenario.

So from a racing perspective, sandwich spacers are probably just fine. We run wheel spacers on 1000+hp Vipers so we can use old wheels. The loading is hardly any different than a lower offset wheel. I wouldn't say the same about bolt-on spacers. You're just asking too much of them.

Jake

[boredom.is.me]

Spacers (and lower offsets) will also tend to place more load on bearings.