Indy Rev

This is interesting. I put 18" twists on my 91 S2 without issue or any spacers. I have a buddy that uses 17's for track tires on his 87' turbo and I don't think he uses spacers either.

J Berk

The 86 should be early offset.... 17" late wheels should not fit right (23vs52 offset)

Indy Rev

You are correct. Just rechecked and it is a 87. I was swapping friends and cars.

BobSantos

It would be good if OP could give us the exact specs of his wheels, both new and old.

Zuffenhausener

Front:
Orig. D90: 16x7 ET55
New Boxster: 17x7 ET55

Rear:
Orig. D90: 16x8 ET52
New Boxster: 17x8.5 ET48

If there are any other numbers from the wheels that might be helpful I can go and get them off of the S2 wheels but the Boxster wheels aren't here with me right now.

veleno

You have a couple of options (some already mentioned).

1. Get either a spacer or adapter

2. Have the center of the boxter wheel bored out so the hub fits through the wheel. However, by doing this you may not be able to mount the center caps anymore. Also, check for clearance fitment as you don't want to go this route only to find out the wheels now hit the springs.

Zuffenhausener

OK, went and retrieved the Boxster wheels and I pulled the dust cap off of the hub and attempted to mount the wheel without the dust cap installed. No dice. I can't really tell what's going on behind there but the wheel doesn't seat, even with no dust cap on the hub. Just wobbles.
So how do I determine which spacers I need (assuming that is what it will take to make this work)?
I have the Boxster wheels here now and can relay any pertinent numbers from them if necessary.

BobSantos

This should answer your questions... 1/4" or 7mm...

http://porsche-info.com/porsche-fitment-guide/

veleno

Take the center cap off and see how the hub fits into the center of the wheel. You'll get an idea of how wide a spacer you need to buy. If you do go the spacer route, I would recommend buying extended studs as you will not have enough lug nut turns if used without.

Adapters will eliminate the need for extended studs and quite possibly may fix you issue.

If you have a digital caliper you can accurately measure the outside diameter of the hub against the inside diameter of the wheel hub hole. Then you can measure the length and voila, you'll know exactly how wide of a spacer/adapter you will need.

Zuffenhausener

Well there you go...

"All 986, 996, 997, part# wheels will require a 1/4″ (7mm) for the front hub. This is so the wheels will mount flush on the hub." (thanks BobSantos for the link) http://porsche-info.com/porsche-fitment-guide/

Thanks everyone for the help. (except possibly all of the folks who have claimed these Boxster wheels fit all late 944s.)

**************************mother****ertits!!!!

BobSantos

Don't thank me thank Porsche. Great that they record this information officially.

RSflared72e

Have done this multiple times. Use a thin spacer (say 1/8") and you will have plenty of thread bite left. One approach I took was to cut spacers out of thick gauge steel and stack them til you have the standoff you need. Easy.

Zuffenhausener

So I went and ordered a set of H&R DRS 7mm spacers for the front wheels. The kit arrived and I slapped the spacers on and tried mounting the wheels without replacing the wheel studs as is said to be required. As expected, the lug nuts went only half-way on with half if the threads still left. So with the 7mm spacer it really does need (surprise) about a 7mm longer wheel stud. So I took off the wheels, calipers, rotors and hub and then removed the existing studs and was ready to install the new supplied wheel studs from H&R only to find out the studs they sent are even shorter than stock! I measured the stock studs I pulled off and they're 52mm and the new H&R studs are 45mm. Instead of being 7mm longer to work with the 7mm spacer, they sent 7mm shorter studs! Well at least I got to see how the news wheels look on the car if only for a few minutes.

veleno

As long as you get a minimum 7 full turns you should be good to go, no need to change to longer studs. Another option would be to get tapered lug nuts that thread through the lug nut hole of the rim and add extra grabbing/threading of the studs (see picture). They do offer open ended lug nuts that taper as well.

Zuffenhausener

If you look at the threads inside the lug nut in the photo here you can see the shiny threads that were in contact with the wheel stud and also the duller colored threads that never came into contact with the stud. I think I count 5, maybe 6 turns I got on the stock 52mm studs. Ideally I suppose I'd have 59mm studs to account for the 7mm spacer but I think the only larger size is 66mm.