SamGrant951

Are you speaking to all bolt-on spacers? I have ran spacers for going on 10 years now without one issue. Auto-x, track, street, etc. I mean 930's had factory bolt-on 1" spacers didnt they?

I know its not "optimal", and I do plan on swapping at the very least my front axle to late offset this year. BMW guys use slip on spacers with longer studs or bolts until a certain limit, like 18-20mm, after that they go to bolt-on. Isnt there a limit to a slip on spacer with longer studs? (I run 25mm all the way around, hubcentric, T-7075 aluminum)

Just curious as my car has passed tech with both NASA and multiple PCA groups without anyone saying a word.

MAGK944

You are right there, maybe I have been confused all these years. The PET definately lists the Fuchs for the 1986 turbo as 7x16 23.3 front and 8x16 23.3 rear. The fuchs for the 1986 na are 7x15 23.3 front and 8x15 10.6 rear. I measured both of mine last night and that is the way they are.

And I thought I had this figured out ...it's a learning experience I suppose.

You might find this useful, just enter you old and new sizes and it does the calcs... Wheel Offset Calculator

.

PorscheDoc

Front and rears of an 86 are 23.3mm, there is no difference. It is also stamped on the back of the rims.

PorscheDoc

The 930's used a 1 inch slide on spacer, using longer studs. I know a ton of guys that run bolt on spacers at the track and I have never seen, nor heard of a failure. I've contributed that phenomenon to "well my uncle's cousin's step dad's wife once knew a guy that had a failure"......If the studs holding the bolt on spacer can sheer off and the wheel fall off, then the same can happen to a slide on spacer with a longer stud. The only failure I can forsee happening with a bolt on spacer, is that the lug nuts holding the spacer to the hub come loose if they have not been torqued on a regular basis....which they should be checked, especially at the track. Yes though, they are typically heavier, which isn't ideal.

SamGrant951

Ah...good to know, I was unaware they were a slip-on style spacer. Thanks Doc.

PorscheDoc

FWIW, I would be far more concerned about spindles and hubs breaking than the spacers causing any issues. I have seen dozens of early spindles break, as well as hubs, both early, late, and M030.

TonyG

Wheel spacers that slip over longer studs are fine. The key here is that they install over longer studs. Your wheel is still bolted directly to the car.


Wheel adapters (which is exactly what they are) bolt to the stock studs. These adapters have their own little studs which the wheel then bolts to. Your wheel is not directly bolted to the car.



TonyG

PorscheDoc

But what is the difference if the stock studs break versus the studs breaking on the wheel hub. The result is the same....the wheel comes off.

TonyG

The difference is with one type the wheel is bolted directly to the car. With the other the wheel is not.


Your argument assumes that the only thing that could fail is the stud itself.


The bottom line is that they are not legal for track use anywhere, are ridiculously heavy, and the inferior method of spacing out a wheel.


And I just don't understand why anybody would use wheel adapters when you can change out the wheel studs so quickly and easily and use the proper slip on wheel spacers. Longer studs cost about $75 per axle (two wheels).


Maybe you should start a thread on the pros/cons of wheel adapters?



TonyG

95ONE

Guys, I value all your opinions. They have merit.
Tony, I think you were a bit harsh on the adapter/spacers though. I do that sometimes about other topics too.

The problem with the Adapters/spacers is that there is no way to check the torque on the lug nuts that hold the spacer to the hub. They are covered by the wheel. If these come loose, there is no way to know unless you take the wheel off.

I do have this set up and am aware of it's shortcomings. So I triple check torque on those nuts before installing wheel. - actually a little difficult since there is no wheel with the weight of the car holding it in place while torquing. I lock mine in at 92ft lbs. I've only run 4 or five events like this. All held fine after being checked every time.
Just knowing and checking should prevent any future issues.

Spindles and hubs on the other hand...

95ONE

My main reason is that they "adapt" my bolt pattern to a much more common bolt pattern. Allowing me to run all sorts of wheels at a much cheaper price. With many more offset options.

It is also two fold as they push the wheels out to the edge of my widebody fenders.

That said. I will eventually purchase some crazy light magnesium centered jongbloed wheels Here
That will do without the spacers as they are just a pain to keep up with as far as torquing them down, and yes. they are extra weight I would rather not have. !!!

Not trying to be argumentative Tony in any way. I respect much that you have done and say. I'm just throwing out my very specific reason for these spacers that others may not have realized before.

2bridges

so vdubvortex I am curious how it is you keep buying wheels that are not even in the ballpark of the offsets you need. Seriously dude you are good entertainment. Good luck with the wheels

Stuttgart996

2 bridges thanks for the input but please know your facts before you try and make me look stupid. I currently have original Bbs rss and the only reason I'm buying these wheels is for carshows where some don't always appreciate origninality

MPD47

I'm confused how BBS RS = originality?

TonyG

Sam,

Yes, I'm referring to "bolt on spacers" (wheel adapters is really the correct term).

930's use a slip on spacer, which requires that you have studs that are longer-than-stock installed.


PCA/NASA tech: If the techs at PCA or NASA could see that they were bolt on wheel adapters, they would not have allowed it. Typically you cannot visually see the difference between slip on spacer and a wheel adapter with the wheel bolted to the car. They look the same looking through the spokes of the wheel.

Do you get your car tech inspected trackside?


TonyG