wheel spacer/adapters on track

Scott Johnson · **Posted:** Thu Mar 18, 2004 9:41 am

I'm looking at some billet aluminum spacers for the old car. They are 30mm thick, and will bolt to the hub, the spacers contain pressed in lugs, that will then get the wheel bolted to them.

This would allow me to convert from my 4x4.5 bolt pattern to a 5x100 bolt pattern, and I could start using the same wheels on my autocross car as my track car.

So, the big question is, "are these things safe at any speed?"

This is a representative image:

Scott

Dale Schendel · **Posted:** Fri Mar 19, 2004 12:47 am

I don't know about that. I know they use things like that in the mini trucking world and have problems with them breaking at just highway speeds.

DickRasmussen · **Posted:** Fri Mar 19, 2004 8:40 am

Scott,

Are you looking at the H&R Springs version? http://www.hrsprings.com/site/frameproducts.html
If so, I would expect high quality.

I've read lots of discussions about wheel spacers and it appears that the "answer" depends on the quality of the "execution". Obviously the attachment bolts need to be kept torqued . . . just like the wheels do. For track use you may want to check them between sessions just like you do for the wheel lugs. The biggest concern is the bearing loading from the offset change but that is no different from buying wheels with that amount of offset.

SimonWright · **Posted:** Fri Mar 19, 2004 10:07 am

I'm no expert but wouldn't they affect the geometry of your steering a little? In a turn the inner wheel turns more than the outer wheel and I would think the amount of difference is related to the distance between the two front wheels.

Simon

Scott Johnson · **Posted:** Fri Mar 19, 2004 10:34 am

stock wheel offset is about 8mm, new wheel offset will be 38mm, spacers are 30mm.

That puts the centerline of the wheel at the exact same place as it was before the spacers.

It does change the bearing loading somewhat. I'm mostly concerned with durability.

Scott

Adam Ligon · **Posted:** Fri Mar 19, 2004 10:37 am

Well first about the bearing and steering issues. As long as the finish offset with the new wheels+spacers is the same as before without them neither would be affected.

Please don't mention mini truckers in the same sentance as any serious car hobbiest. Those things are about as pointless as a hole in the head.

Porsche and varoius porsche race teams have been using spacers on the street and track for probably longer then most of us here have been alive. I would agree than construction and the rep of the manufacturer are very important.

DickRasmussen · **Posted:** Fri Mar 19, 2004 10:42 am

Scott,

I suspected that you would end up with the wheel/tire centerline at approximately the same place as with oem wheels/offsets.

Based on the H&R website which talks about all the great things they do for durability it looks like that probably isn't an issue with theirs. Note that they sell theirs for Mustangs so I suspect your much lighter car would be fine . . . especially for someone like you who will be checking them and will likely feel any impending problem!

Mark Vitacco · **Posted:** Wed May 26, 2004 2:03 am

Scott:

I would rather re-drill the hubs and use ARP extra thick and
extra long wheel studs to hold everthing together than have
two sets of studs and double the opportunity for the studs to
flex. IF you have a problem with on track you should notice
that they losen more than before. The down side is you
have to remove the tire to re-torque the inner stud. Agan, another
reason to drill the hub and go for ARP bolts.

I've seen plenty of race cars with .50 to .75 inch wheel spacers
so that in itself is not un-common. As far as mucking with scrub
radious, in my experience it will not degrade handelilng with SLA
RWD configuration as it would with Strut type suspensions but as
you are partially compensating for the spacer with the wheel offset
and the net change will be less than 30mm I would not lose sleep
over it.

VIR-P would be a great place to test this, lots of loading and short
sessoins to check it over frequntly. I don't think I would want to
be thinking about this in turn 3 or 9 at Roebling Rd however......

Charlie Guthrie · **Joined:** Thu Aug 28, 2003 8:14 pm **Posts:** 832

These things would make me feel better if the hub side was "hub centric" and the outboard side fit inside the wheel hub. That would accomplish two things: 1.) in the event of loosening, some of the load would be carried by the hub instead of just the bending load on the fastners. 2.) It would better assure that the wheel was running true to the hub, reducing the vibration loading.
I have seen an ad somewhere for such an adapter that had the extended center hub that entered the wheel. I have run flat 3/8" spacers on the MG, and without the centering of the hub, it is tough to get the wheel running true (so no matter how well it was balanced on the tire machine, it will be out of balance on the car).
Regarding fastners remaining tight/torqued. It was common practice for the BMW Spec E30 guys to replace the OEM wheel bolts with wheel studs. The wheel studs threaded into the hub and were secured by Locktite (or other locking means). I have seen several accounts of wheel loosening due to the wheel studs vibrating or heat cycling loose.
Regarding the engineering considerations of the spacer respective to bearing wear and steering geometry, if the final offset is near the stock dimension then there is no real difference.
If you use the adapters, just be prepared to remove the wheels at least one or two times during the first 200 miles to recheck the torque. This is also a good idea with any new wheel because the mating surfaces will seat after some loading and heat cycling. I had wheel tightness/ torque problems with my new Kosi wheels last year (as did several others).
Charlie Guthrie

DickRasmussen · **Posted:** Wed May 26, 2004 10:40 pm

Charlie Guthrie wrote:

These things would make me feel better if the hub side was "hub centric" and the outboard side fit inside the wheel hub. I have seen an ad somewhere for such an adapter that had the extended center hub that entered the wheel. Charlie Guthrie

The H&R spacers (or at least some of them) appear to be hub centric. See the link I posted above.

Charlie Guthrie · **Joined:** Thu Aug 28, 2003 8:14 pm **Posts:** 832

I knew that I had seen the hub centric style somewhere. Dick's link to H&R is just what you need. I would trust that type. I would also put a little faith in Locktite for the primary atachment bolts. The down side to Locktite is that you'll want to use the high temperature stuff so that brake temp's don't weaken the bond and if you ever want to remove the hub attachment it will require heating with a torch (or a really big wrench).
Charlie G

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