FUCHS Experts: Difference between 911 & 944 Offset on 8Jx16?

Gunter · Gunter's Garage

Someone offered me a pair of 8x16 coming from a 944. How much difference is there in the offset? For a 911, the numbers should be: 911 361 020 (45 or 99) Offset: 10.6 The numbers on the 944 wheel are given to me as: 951 362 117 Offset: 23.3 I want to put them on the back of my SC. Any problems with that? If it does not work, I can pass them on to someone.

Thanks maxnine, I"ll put them in the "For Sale" section.

maxnine11 · maxnine11's Garage

hi Gunter. here is Sherwood Lee's chart. It should have the answers to your questions (and more) chart . 8 inch 944 wheels are generally used to cram the FRONT fenderwells full of rubber.max

Bill Verburg · Bill Verburg's Garage

911 8x16 are +10.6mm, the 944 8x16 are +23.3mm o/s. The larger the + o/s the further inboard the wheel center line is. This means that the 944 8s or 911 7s which also have the +23.3mm o/s can be used on the front of a 911.

The 911 8s an only be used on the rear of a 911, they stick ouboard too much for use on the front.

stomachmonkey · 03-18-2003, 05:34 AM

Here is a good visual chart that I saved from another post on this board.

Forget who the author was but thanks for putting it together.

You will notice that the 944 8 will not fill the outer wheel well as nicely as the 911 8.

Check the inside for clearence carefully, you do not want the wheel to wear a hole in an oil line.

Scott

panzerfaust · 06-18-2015, 04:59 AM

wow this is a great chart!

i have 8x16F (944)and 9x16R fuchs on my M491. i want to put the 9's up front. has anyone done this?

are there any issues with brake clearance or rubbing on the inside being 5mm more in board of the 944 8x16s?

regards

pf

peon77 · 06-18-2015, 11:22 AM

Sorry, didn't see this is an old post.

KTL · 06-18-2015, 01:32 PM

panzerfaust,

Have you tried to put your rear wheel on the front? I think you will have difficulty fitting a 16x9 Fuchs on the front of the 930 body since your turbolook front axles have extended hubs which is basically a built-in spacer of ~21mm added hub length.

The pre-1981 930 can fit the 16x9 because it has a removable spacer that slips over the wheel studs on the front hub. Removing the front spacer allows the 16x9 to fit. It's a tight fit but it fits.

Here's a picture of a wheel with similar dimensions on my racecar with 930 front fenders and slightly lengthened A-arms. The wheel pictured is a BBS RS 16x9 ET+15mm and 245/45-16 tire, which is basically the same as a Fuchs 16x9. The A-arm is approx. 3/4" longer. My car is basically like a pre-1981 930 with the front spacers removed.

panzerfaust · 06-18-2015, 06:01 PM

hello kevin

yes ive notice the hub differences when i was at a buddys place and they were measuring a 77 930 and a 87 930 for the the braid wheels to be made.

i was hoping to use the stock 9's in front and get 11's in back. so looking at your photo if i added 21mm then take away 3/4" (19mms) it would be roughly 2mm further? i wonder if i can get away with that. I have quite a bit more camber dialed in at the moment with the 944 8's

Bill Verburg · Bill Verburg's Garage

Quote:

Originally Posted by panzerfaust

wow this is a great chart!

i have 8x16F (944)and 9x16R fuchs on my M491. i want to put the 9's up front. has anyone done this?

are there any issues with brake clearance or rubbing on the inside being 5mm more in board of the 944 8x16s?

regards

pf

Glad you like the chart, I put it together years ago, since I've gone to a more sophisticated modeling system
if the base wheel is the 951 8x16 ET23.3 wheel
the 9x16 ET15 wheel has 21mm more front space and 4.4mm more back space
if your car has the removable 21mm spacer then remove it and the 9 fits otherwise not

panzerfaust · 06-19-2015, 07:52 PM

Quote:

Originally Posted by Bill Verburg

Glad you like the chart, I put it together years ago, since I've gone to a more sophisticated modeling system
if the base wheel is the 951 8x16 ET23.3 wheel
the 9x16 ET15 wheel has 21mm more front space and 4.4mm more back space
if your car has the removable 21mm spacer then remove it and the 9 fits otherwise not

Hi bill !

I think it will be close... Depends on the tire size I suppose. I can fit two fingers between the tire and the fender inner flange. I don't know if they have been rolled but they seem smaller than my 86 930 and my buddy's 87 rolled ones.

I'm running -2 camber which helps a great deal though the car is lowered. Great deal of bump steer with the tie rod canted up. I often wonder why folks offer raised spindles and don't modify the steering arm to boot like the RSR cars?

Seems like one can kill two birds with one stone without resorting to a bump steer kit. Elephant seem to have one now but it's seem complicated with extra bracing and spacers.

Warm regards

KTL · 06-22-2015, 06:45 AM

I would suggest going with a bump steer drop link kit instead of bending the steering arms. When you effectively shorten the steering arms by bending them, the effort required to steer the car increases quite a bit. I have the bent steering arms on my racecar and the steering effort on my car is quite noticeable at speed. Point being is that w/out power steering these cars obviously require a bit of effort to steer anyway. Bending the arms makes steering the car even harder because you've shortened the lever arm on the steering axis.

I'm not a big strong guy, weighing in at a slim 170 lbs & 6 ft. tall. I feel i'm fairly fit and manage the steering OK. However, when I got away from exercising over the past several years, I could notice the heavy steering effort a lot more. My shoulders were exercised a lot after a day of driving it at the track and i'd have muscle soreness days later, just like I had done a shoulder/upper body workout. Point being is that if somebody's not all that strong in the upper body, your shoulders are definitely going to feel it.

Plus the beauty of these bump steer kits is that you can fine tune the height of the tie rod end with shims. That's a nice feature to get your bump steer as minimal as possible. But it's never going to go away entirely. Bump steer is just the way it is with McPherson strut front suspension.

The front toe curve is the top right graph. Notice how the suspension traveling upward shows toe out occurring. In other words, your static/base alignment is toed-in (where dashed curve crosses the Y-axis on negative side of graph) and toes-out as the suspension travels upward. Eventually it flattens out to vertical/constant, which is good. But then you get beyond that vertical region and the toe continues to change.

So what all that means is that your toe is changing as suspension travels. The goal is to minimize that change with setting the tie rod at a good starting height and reduce suspension travel. Setting the height is pretty straightforward with the drop link kit. Reducing suspension travel = stiff springs which most people care not to do. A stiff front suspension makes for a really unpleasant ride and really physically beats on you in my opinion

panzerfaust · 07-04-2015, 08:20 PM

Quote:

Originally Posted by KTL

I would suggest going with a bump steer drop link kit instead of bending the steering arms. When you effectively shorten the steering arms by bending them, the effort required to steer the car increases quite a bit. I have the bent steering arms on my racecar and the steering effort on my car is quite noticeable at speed. Point being is that w/out power steering these cars obviously require a bit of effort to steer anyway. Bending the arms makes steering the car even harder because you've shortened the lever arm on the steering axis.

I'm not a big strong guy, weighing in at a slim 170 lbs & 6 ft. tall. I feel i'm fairly fit and manage the steering OK. However, when I got away from exercising over the past several years, I could notice the heavy steering effort a lot more. My shoulders were exercised a lot after a day of driving it at the track and i'd have muscle soreness days later, just like I had done a shoulder/upper body workout. Point being is that if somebody's not all that strong in the upper body, your shoulders are definitely going to feel it.

Plus the beauty of these bump steer kits is that you can fine tune the height of the tie rod end with shims. That's a nice feature to get your bump steer as minimal as possible. But it's never going to go away entirely. Bump steer is just the way it is with McPherson strut front suspension.

The front toe curve is the top right graph. Notice how the suspension traveling upward shows toe out occurring. In other words, your static/base alignment is toed-in (where dashed curve crosses the Y-axis on negative side of graph) and toes-out as the suspension travels upward. Eventually it flattens out to vertical/constant, which is good. But then you get beyond that vertical region and the toe continues to change.

So what all that means is that your toe is changing as suspension travels. The goal is to minimize that change with setting the tie rod at a good starting height and reduce suspension travel. Setting the height is pretty straightforward with the drop link kit. Reducing suspension travel = stiff springs which most people care not to do. A stiff front suspension makes for a really unpleasant ride and really physically beats on you in my opinion

Yes shorten arms equals more effort but quicker effective steering ratio. Like everything else it's a trade off. I don't find the steering effort that heavy outside off parallel parking and I'm running 225's. With mcphersons u won't ever get rid of bump str. Most track cars today run much lower than even full blown G series race cars 40 years ago hence the raised spindles. But why not do the steering arm as well like the RSR cars? To me it just makes sense move the arms as well.

KTL · 07-06-2015, 07:45 AM

No argument there. The effort is increased but it's not a night-and-day difference. However when you drive the car hard for a long time, it can become more apparent. that's all I was trying to get at.

Only reason I suggest the drop link solution is because it's easiest for someone to do it themselves. Whereas bending the steering arms requires someone experienced to reshape them properly. By th way, if you have Boge struts? You can have Tangerine raise the spindles and bend the steering arm for you.

Tangerine Racing Suspension Services

panzerfaust · 01:20 AM

I had over dozen older sports cars in the past without power steering. I still have four cars now without with the Porsche by far being the lightest so I guess I'm used to them.

Thank you for the link... Something to think about sending them out. You are right the ER adjustable will be the easiest so I'm not ruling it out. Anyone out there running these that can give me feedback? I've driven a buddy's ER equipped lighten 930 with steam roller tires with the trick rear articulating rear swing arms. Man what a night and day difference from my stock 930. Unfortunately he didn't have bump steer links.