Question on offset for Fuch wheels

[bajamar]

I am looking at buying a pair of 16 X 8 fuchs, my current wheels have a 123mm offset. The pair I found are a 951 fuchs with a 23et offset and trying to findout if these would work on my car

[LIRS6]

... your car being a modified '74?

[bajamar]

It still has torsion bars but set up strictly for track events

[bajamar]

Also it is a Targa Carrera so has the wider rear flares

[75 911s]

The 951 16” have the same offset as you noted. They do however sit 1/2” inboard due to the design of the face of the wheel which was changed to accommodate bigger brake clearance on the 951. Should be a great wheel for a Carera flared midyear.

[darrin]

wouldn't the 911 part number 16x8 sit a bit farther out than its 951 part counterpart? If I recall correctly, the face of the 951 offset 16x8 Fuchs will sit "out" and look the same visually as a 16x7 911 offset Fuchs wheel

[bajamar]

When I start looking at the difference in offset, the 951 shows an offset of 125 mm, my current 16 X 8 has an offset of 112mm. So the 951 offset will put the wheel closer to the caliper, is that correct? If that is the case that will be to close to the caliper but I guess I could get a spacer. Any feedback would be appreciated. I apologize to the seller for all the back and forth but I also see he has a standard pair of 8 X 16's for sale although much more expensive so just trying to see what works best for me.

[dwelle]

Fuchs wheel all the part numbers and offset

check the offset chart in the first post, it will all make sense.

the 951 8's will fit under a narrow body, you might need spacers on carrera flares to make them look right...

[darrin]

bajamar -- what are you looking to accomplish with the new 16x8 fuchs? on my '86 (with standard flares -- not a turbo-look), I bought 16x8 911 offset fuchs to replace my original 16x7 911 offset fuch rear wheels and run the same 225/50-16 tire size on the 16x8 that I previously ran on my 16x7 rear fuchs -- this both let the tires sit a bit wider on the wheels AND brought the outer edge of my tires closer to my rear fenders (but plenty far enough away to avoid rubbing) sounds like you already have 16x8 911 offset fuchs -- is there any issue with their fittament? Would be a pain to have to swap on/off spacers whenever swapping wheels?

[Bill Verburg]

Thre are only 2 different physical spec Fuchs 8x16

ET10.6 which is for 911 SC/Carrera rear
ET23.3 which is a 944 wheel but some squeeze it into the front of a 911, the ET is off just enough for this to be a really unhappy fit

for your car use 8ET10.6 w/ spacers from 28 to 54mm depending on what trailing arms and what flare spec is installed

[KTL]

Originally Posted by dwelle

Fuchs wheel all the part numbers and offset

check the offset chart in the first post, it will all make sense.

the 951 8's will fit under a narrow body, you might need spacers on carrera flares to make them look right...

The image dwelle mentioned is SUPER helpful in seeing how different wheels fit the car relative to each other. The vertical line in the middle is the mounting surface of the suspension/axle hub. The horizontal lines are the width of the wheel. Left side of the image is the inboard/wheel well side of the wheel and the right side of the image is the outboard/fender side of the wheel

So all you have to do is look up or down along the listing of wheels and take notice of where are the endpoints of the lines relative to others. Then you'll see how they sit differently on account of width and offset.

In the case of these 16x8 wheels, the difference is very simple. The higher offset +23.3mm wheel sits further inboard ~12mm on both sides of the wheel. 23.3 minus 10.6 = 12.7

If you compare the 16x7 wheel and the 16x8 +23.3mm wheel, you'll see the difference is simply the extra inch of width is split evenly on either side of the wheel. This is because both wheels have the same +23.3mm offset.

In terms of appearance, the 16x8 +23.3mm wheel face looks almost exactly like a 16x7 wheel. The sharp eye difference is in the countersunk lug holes and the deeper hub behind the face. The 16x8 +23.3mm wheel is a better fit than the 16x7 in terms of its appearance relative to the fender flare, since it sits a 1/2 inch further outboard. The 16x8 +10.6 wheel is the best look due to its deeper face and it sits another 1/2 inch further outboard.

[Bill Verburg]

Originally Posted by KTL

The image dwelle mentioned is SUPER helpful in seeing how different wheels fit the car relative to each other. The vertical line in the middle is the mounting surface of the suspension/axle hub. The horizontal lines are the width of the wheel. Left side of the image is the inboard/wheel well side of the wheel and the right side of the image is the outboard/fender side of the wheel

So all you have to do is look up or down along the listing of wheels and take notice of where are the endpoints of the lines relative to others. Then you'll see how they sit differently on account of width and offset.

In the case of these 16x8 wheels, the difference is very simple. The higher offset +23.3mm wheel sits further inboard ~12mm on both sides of the wheel. 23.3 minus 10.6 = 12.7

If you compare the 16x7 wheel and the 16x8 +23.3mm wheel, you'll see the difference is simply the extra inch of width is split evenly on either side of the wheel. This is because both wheels have the same +23.3mm offset.

In terms of appearance, the 16x8 +23.3mm wheel face looks almost exactly like a 16x7 wheel. The sharp eye difference is in the countersunk lug holes and the deeper hub behind the face. The 16x8 +23.3mm wheel is a better fit than the 16x7 in terms of its appearance relative to the fender flare, since it sits a 1/2 inch further outboard. The 16x8 +10.6 wheel is the best look due to its deeper face and it sits another 1/2 inch further outboard.

I made that chart 15-20 yrs ago, at the time I thought it might be useful but time and tech march on

there are 2 primary limiting constraints for and wheel/tire fitment and yes you need to consider the whole package when evaluating a fitment and several secondary constraints that relate to the cars suspension spec and setup

the first primary constraint is backspace


all 911's have pretty much the same spec here, there are some differences particularly in back wrt the oil line but in general a b/s of ~5.75" or 146mm in front and ~6" or 152mm in back

the front space is more complicated not only because of different flares and lip specifics but also because ride height, camber spec, tire specifics, and suspension travel specs
for 911s front/space max is ~3.5"+/- in front and ~4.5" +/- for SC/Carrera rear.

n/b rear(ie pre 78 911 which are no Carreras) f/s max is ~3.5"+/-

the wheel width and ET and the tire width and OD place the wheel/tire assembly w/i the available envelope defined above

930 is more problematic because 911 and 930 trailing arms will have different b/s max and the 930 flares actual f/s varies significantly depending on who installed them.

A 930 fitment might look like this