are Carrera rear 7's the same as 930 fronts?

[John Brandt]

I'm referring to Fuchs for my '84

It just occured to me that I might only need some 9 x 16s

[Bill Verburg]

Yes, the best Fuchs upgrade path is to move the 7" rears to the front and buy some 9x16 for the rear.

[John Brandt]

Hot Diggity Dog!

thanks Bill

[rfuerst911sc]

On the same subject,I assume all 9 inch Fuchs are considered turbo wheels?I have a 83SC that currently has 6 and 7 inch Fuchs and my plans are to move the 7s upfront and put either 8 or 9 in the rear,on a mostly street car is there an advantage going 8 or 9?Thanks

[Bill Verburg]

From a performance perspective the 9 is a more desireable wheel. It is more expensive, so those on a buget will often go w/ an 8. There is little visual difference between them.

[Joe Bob]

On an SC about the biggest tire you can fit on the rear without rolling a fender is a 245.....the 8s can use them....so a 9 in my opinion is a waste.....but some people like the look of the sidewall with the 9s....taste....

[Decolliber]

Originally posted by Bill Verburg
Yes, the best Fuchs upgrade path is to move the 7" rears to the front and buy some 9x16 for the rear.

Doesn't the Carrera have a higher offset on the front wheels (36mm for 16x6"?) than on the rear (23mm for 16x7")? So if you move the rear wheels to the front they would stick out too far? Or is the offset just a function of rim width, irrespective of whether its on the front or back?

[89911]

All 7 by 16" fuchs have the same offset, (except for the 944 fuchs, but I'll avoid these to avoid confusion). This does not change when mounting front or rear. A "Turbo" fuch came standard on 930's but early turbos had 8" rears so it does not have much usable meaning. On the subject of 8 vs 9" in the rear, the 8" weren't much cheaper then the 9"s if buying new. If you already have an 8" in the back, it doesn't change much. I sold my 7's and 8" and now have 8"s and 9"s for $500 more.

[Bill Verburg]

so a 9 in my opinion is a waste.....but some people like the look of the sidewall with the 9s....taste....

Not a matter of taste at all, a wider wheel, remaining within the spec range, will offer performance benefits in the form of better handling and acceleration due to the effects of the rim on a given tire carcass.

Doesn't the Carrera have a higher offset on the front wheels (36mm for 16x6"?) than on the rear (23mm for 16x7")? So if you move the rear wheels to the front they would stick out too far?

A 6 does have a 36mm o/s, a 7 to replace it will have ~23.3mm o/s, the o/s changes because the width changed, you want some of the D inboard and some out.

Look here and here for more wheel info.

All 7 by 16" fuchs have the same offset, (except for the 944 fuchs

All Fuch 7s do have the same o/s, +23.3mm.

There are 2 different o/s Fuch 8s +10.6mm for the 911 and +23.3mm o/s for the 944. The 944 +23.3mm 8 may be used on the front of a 911 to replace a +23.3mm 7 which may be used to replace a +36mm 6

I agree w/ Mike(89911) 8 & 9 is even better, but does get into fitment issues that the more casual users may not wish to deal w/. For that matter 8 & 9.5 or 8.5 and 10 is even better but also even harder to fit.

[ttweed]

Originally posted by 89911
All 7 by 16" fuchs have the same offset, (except for the 944 fuchs, but I'll avoid these to avoid confusion).

No need to except the 944 7x16" Fuchs wheel. It has the same 23.3mm offset as the 911 7x16". The difference is only in the countersunk lug nuts and the caliper overhang clearance on the back of the spokes, which actually matches the 9x16" wheel better. It's the 8x16" 951 Fuchs that have a different offset than the 911 8 x 16".


TT

[jbripps]

Hi all,

So, if I wanted to move my 7x16's up to the front, and I bought 9x16's for the rears, would I need to "roll" fenders? I have an '85. If not, would I need any spacers? How much room will I have left in the wheel wells. I would love that look where there is a tiny space between tires and wells. Please advise.....I hope I'm not stepping on any toes.

regards,

[Bill Verburg]

would I need to "roll" fenders?

Depends on the tires, 205/55 or 205/50 fit fairly easily on most cars. There is some variation and some of the Carreras came from the factory w/ rolled lips.

245/45 on the 9s is no propblem at all.

[89911]

I can't see anyone having problems with 9" in the back unless they have their car extremely low and a soft stock suspension. Then, you may rub above the fender lip. If you have no negative camber in the back, this may also be an issue but generally you would like 1.5-2.5 in the back. This tucks the tire under the rim preventing the fender edge cutting the tires.

[911jon]

I would be inclined to either fit 7's on the front and 8's on the back, or (951) 8's on the front and 9's on the back.

My view is that the tyre width differential for Fuchs on a Carrera should be a nominal 20mm (i.e. 205 on fronts, 225 on rear, or 225 on front, 245 on rear). The two-inch difference between 7's and 9's will cause sidewall distortion on the smaller front rim if 225's are used. This is acceptable, but not optimal.

In my experience/opinion, a larger width differential than 20mm will induce understeer, and the most appropriate rim width combinations are those stated. I think there is a certain kudos associated with the widest 9 inch rim which induces some Fuchs envy....

In general, it is not too difficult (though not cheap!) to get hold of either 8 or 9 inch 911 Fuchs, but the 951 offset 8's are in very short supply, and require significant suspension geometry changes (negative camber) to accomodate them. This can have an impact on tyre life, relevant for a primarily road car. If yours spends as much time on the track, then fine!

I run 7's and 8's on my car, fwiw, and find this to be an ideal combination for a fairly stock car.

[KTL]

Originally posted by jbripps
Hi all,

So, if I wanted to move my 7x16's up to the front, and I bought 9x16's for the rears, would I need to "roll" fenders? I have an '85. If not, would I need any spacers? How much room will I have left in the wheel wells. I would love that look where there is a tiny space between tires and wells. Please advise.....I hope I'm not stepping on any toes.

regards,

Here's a picture of 16x7's up front, wearing 205/55 Yokohama AVS ES100 tires.



You can see they stick out a tiny bit, but still have no clearance problems. The wheel pictured has no neg. camber (0 degrees). So with stock alignment settings, you definitely would not want to toy with any spacers when using a 16x7 Fuchs wheel up front. As an aside, with -1 deg. of camber, my 17x7.5 wheels (+15mm offset) with 225/45 tires fit inside the wheel opening easily. But my fender lips are shaved down to almost nothing ~1/8 inch.

To get that tiny space between the tires and outer fender lip, 7's and 9's do the job perfectly.

[Bill Verburg]

Way back I ran the 7x16 205/55 combo w/ 8mm spacers for brake clearance. It worked but I was also running lots of negative camber in those days. the 944 8x16 w/ 225/50 also worked fine w/ the same suspension settings.

Currently running 235/45x17 w/ less neg. camber w/ no issues(shaved lips)

Next set will be 235/40x17

[zzwhm]

I run 8s/9s with 225/245. The 951 8s are less of a rubbing problem on the front of my Carrera than 7s were. Perhaps because they pull the tire inward and reduce the sidewall bulge.