Dropping from 16x9's to 16x8's - 15mm adaptor question/recommendations?

[fallingat120mph]

Keeping my 16x7/9 Fuchs already on the car but getting new rims.

Front will remain 16x7 but back is dropping to 16x8. Found these for the back end and wondering if anyone has ever used or heard of:

https://schnellperformance.com/products/porsche-wheel-spacer-adapter-15-mm



For the record I want to replace the studs on the rear and have a traditional set up, but after an hour of reading seems like the above would work for me getting it across country and being able to drive until I have time for extended studs.

I like the thought of being able to bolt these on and being done with it.


Any recommendations or thoughts on spacers/adapters for 16x8's on an 86' coupe is greatly appreciated. Or maybe there is a thread I missed that wasn't from the early 2000's...our host doesn't sell the 15mm adapters like the above just the 21mm for the 16x7 rear set up.




Again, thank you!
Erik

[Bill Verburg]

Originally Posted by fallingat120mph

Keeping my 16x7/9 Fuchs already on the car but getting new rims.

Front will remain 16x7 but back is dropping to 16x8. Found these for the back end and wondering if anyone has ever used or heard of:

https://schnellperformance.com/products/porsche-wheel-spacer-adapter-15-mm



For the record I want to replace the studs on the rear and have a traditional set up, but after an hour of reading seems like the above would work for me getting it across country and being able to drive until I have time for extended studs.

I like the thought of being able to bolt these on and being done with it.


Any recommendations or thoughts on spacers/adapters for 16x8's on an 86' coupe is greatly appreciated. Or maybe there is a thread I missed that wasn't from the early 2000's...our host doesn't sell the 15mm adapters like the above just the 21mm for the 16x7 rear set up.




Again, thank you!
Erik

assuming a 225/50 tire on an 8 ET10.6 Fuchs w/ 15mm spacers, the outer shoulder of the tire will be right on the ragged edge of fitting or not.

ride height supension spec and set will determine yes/no.

[darrin]

Erik -- If I recall correctly, the 16x8 and 16x9 fuchs' offsets are different, with nearly all of the 16x9's additional width on the inside -- in other words the outer edge of a 16x8 is only a "smidge" farther from the rear fender lip than a 16x9

[dg567]

4.4mm difference between the two. Why do you want/need to run the 15mm spacer? Mount the 16x8 as is, no need for a spacer.

[fallingat120mph]

Originally Posted by Bill Verburg

assuming a 225/50 tire on an 8 ET10.6 Fuchs w/ 15mm spacers, the outer shoulder of the tire will be right on the ragged edge of fitting or not.

ride height supension spec and set will determine yes/no.

Thank you Bill always appreciate your take on these matters...

With the price of these adapters I was thinking 15mm might be a good start before I invest in new studs and better, real, spacers for when I want to dial it in for long term usage.


Erik

[fallingat120mph]

Originally Posted by darrin

Erik -- If I recall correctly, the 16x8 and 16x9 fuchs' offsets are different, with nearly all of the 16x9's additional width on the inside -- in other words the outer edge of a 16x8 is only a "smidge" farther from the rear fender lip than a 16x9

Originally Posted by dg567

4.4mm difference between the two. Why do you want/need to run the 15mm spacer? Mount the 16x8 as is, no need for a spacer.

I researched and researched what owners with 16x8's are doing or have done through the years and 15mm seemed like the max. Read also folks with 16x9's even use spacers...

So...looking at how my car is sitting with 16x9's I sill have quite a bit of room left. I know every 911 is different and even with the 9's I feel like there is still room.

So, as I stated in the response up top, I thought for the price I would try the 15mm and go from there...


I have seen where 16x8's end up being near perfect for some, and then for others they have various spacer sizes on different corners to balance the look, etc.



So, I am waiting on shipment (for the rims) and will mount before I order or purchase any spacer or adapters. Guess my biggest concern would be I have never been around adapters - verses spacers and new studs (extended) which I have seen plenty. Still feel like that's the best route but thought I would go down the rabbit hole a bit and try and learn something.


Thank you for the responses - much appreciated!

Erik

[fallingat120mph]

As a side note I may have had the 23.3 offset sticking in my brain vs the 10.6 of the rims I have just ordered.

So, will be mounting before worrying about adapters/spacers.


But...still would like to hear from others who have used adapters.




Erik

[David Inc.]

I have them for my 16x7, I think mine are 21? 22mm?

They work but they're a pain to torque up because of clearances (probably not an issue with the 15mm), and you have to be careful about mounting. If you don't clean all surfaces very well and torque them up slowly and evenly it's easy to leave your wheels in an off-balance condition.

I really need to get the right studs put in with a real spacer. If you're only considering it for one drive and then replacing, don't bother (that is unless you plan on doing little photoshoots across the country, I guess).

[fallingat120mph]

Originally Posted by David Inc.

I have them for my 16x7, I think mine are 21? 22mm?

They work but they're a pain to torque up because of clearances (probably not an issue with the 15mm), and you have to be careful about mounting. If you don't clean all surfaces very well and torque them up slowly and evenly it's easy to leave your wheels in an off-balance condition.

I really need to get the right studs put in with a real spacer. If you're only considering it for one drive and then replacing, don't bother (that is unless you plan on doing little photoshoots across the country, I guess).

I did read a few times regarding the torque and getting them mounted safely and right.



Thanks for this - no, no photoshoots across the country.

[David Inc.]

Originally Posted by fallingat120mph

I did read a few times regarding the torque and getting them mounted safely and right.



Thanks for this - no, no photoshoots across the country.

Hey no problem. And in that case I'd say they're not worth the trouble, and if you accidentally introduce an imbalance then it'll put a damper on the whole trip.

[Bill Verburg]

There is a volume envelope available to tires, it is determined by f/s, b/s, OD and crown radius profile ratio. It ca be expanded bit w/ ride height and camber.

for an SC/Carrera rear tire total width space is ~266mm
f/s is ~114mm(4.5")
b/s is ~152mm(6")
total 266mm(10.5")

widest I've ever fitted is a nominal 275/40 x17om a 9.5 ET19 wheel, this requires work on the trailing arm, lips and ride height alignment restrictions
for this setup tire;
f/s is 121mm(4.8")
b/s is 159mm(6.25")
total is 279mm(11")

w/o ride height restrictions and alignment tricks or additional work
255/40 x17 on 9.5 ET19
for this setup tire;
f/s is 114mm(4.5")
b/s is 152mm(6.0")
total is 267mm(10.5")

a 225/50 x16 in this case an A052 on an 8ET10.6 w/ 15mm spacer has a tire ;
f/s is 120mm(4.7")
b/s is 111mm(4.38")
total is 231mm(9.1")

every tire is slightly different in w/ OD and crown profile so there is some tire variation involved but the above tires are typical

so you tell me if it fits, unlike some I have installed and used the above, no guessing here.