Mike951

Going to be running a 7mm spacer to fit my BSA wheels. How do you tell if the wheel fitment is safe with a spacer, as far as stud length and catching enough threads goes. I only need to run this in the rear. Car is an 86 951 with stock studs, street only no track.

Thanks
Mike

pontifex4

It turns out that, if you have 45mm studs, 7mm means that you give up too much thread, in spite of what online retailers claim.

Here's a photo of what I mean from mine (stock 45mm studs + 7mm spacers on open steel lug nuts). Note in the photo that all the threads of the lug nuts are not engaged. This is not okay. I started a thread asking this recently, which is why I have the picture handy.

PorscheDude1

From what I've read, 7mm is the max spacer width before you need longer studs.
Also, from what I've read, you need at least 6 full turns of the lugnut.

Mike951

I'm guessing the contruction of the wheel has alot to do with this...depending on how deep the holes in the wheel are recessed and how thick the hub section of the wheel is....

PorscheDude1

Exactley.
The info I gave is from mostly reading about stock wheels.
If you can get 7 full turns, you should be good to go.

Geldfalle 944

I have 4 20mm spacers to put the 928 BBS on a 944. Not to thread hijack but where do you get the studs to fit such a spacer? I am not sure I want to go there anyway. 7mm sounds much more tame.

krystar

http://www.paragon-products.com/Sear...x=0&Search.y=0

http://www.pelicanparts.com/cgi-bin/...31-671-00-M260


guessing 45/50mm is stock.

Potomac-Greg

OEM wheels and OEM studs leave the stud just about flush with the outer face of the lug nut. So any spacer is going to leave lug nut threads uncovered.

pontifex4

Exactly. That is what is illustrated in my photo above. Technically, I did have more than 6 full turns of engagement to torque spec. when I mounted the wheel above as a test, but respondents to my thread seemed to think that the nut isn't designed to hold properly unless all its threads are in contact with the stud.

thirdgenbird

i was in that thread

like already stated, it depends on the wheel. with oem wheels and 7mm spacers i got 5.5-6 turns out of the nut. this is probably enough with steel nuts, but i do not recommend it. my guess is that there are probably lots of cars out there with 7mm spacers, and stock alloy nuts. (with closed ends you may never know)

here is my car with oem studs and no spacers


here is the car with oem studs and 7mm spacers



i found studs from a 911 that had studs that were about 7-7.5 mm longer and now the car is back to stock engagement. (its an easy swap)

FRporscheman

I'm really glad I read this thread, I have some 8mm spacers I was thinking about using, and all this info is great. Pictures are awesome.

ritzblitz

A general rule of thumb regarding thread engagement:

Minimum thread engagement = diameter of screw

1.5X the diameter is better though.

For example- M10, you should have somewhere between 10mm and 15mm thread engagement.

Mike951

Does a spacer smaller then 7mm exist?

My real issue here is not that the wheels don't fit, but the center caps in the rear will not snap in by just a hair, due to the spindle. 7mm was the smallest I could find. I bet if I had something like an 1/8", that would bring the wheel out just the hair I need for the center cap to stay in. Here's a pic of the rear, no spacer:

PorscheDude1

I think there are 3mm spacers available.

odurandina

many people run 4 and 5 mm spacers.

if you have your heart set on these wheel spacers, install 10 mm longer studs.