17 x 9 & 17 x 11 Staggered setup by Rota

[the_dude]

Project: PSD Widebody Wheels

Target Size: 17 x 9 Front 17 x 11

Front Offset: ?

Rear OFfset: ?

Front Backspacing: ?

Rear Backspacing: ?

Style: ROTA PSD or minilites


here's a picture of the your fronts (17 x 9)

we'll be working on the 17 x 11 shortly as soon as we can nail down backspacing and offset.

[DV 993tt]

Dude

Does Rota have other style wheels for Porsche cars? How about 18" wheels?

[Bill Verburg]

Moses asked for my input on the 9 & 11" wheels. I spent over 30 years cramming increasingly big wheels in Carrera wheelwells and know their limits well, however I don't have much confidence that I have a handle on 930 wheel wells.

Here is what I have gathered. For the fronts there is a division
930 front, '75 - '80, discard spacers
9x15 ET+15

930 front, '81 up built in spacers
9x15 ET+36

930 rear, all years
11x17 ET-19

It would certainly be advisable to input from the 930 guys as to what they are currantly using

[Moses]

Thanks, Bill!

[aschen]

I am absolutely in for these, you may get a better responce in the turbo specific forum.....My vote is for use without spacers for ultra deep dish, but will be happy eather way

flat four and drunk on the floor

[the_dude]

if you guys know any mods that can help us move the thread. or just start a new one?

-sd

[gestalt1]

if my calculations are correct, an et of -19 is about 4.75" of backspace for the rear. i think this is to little backspace. i have a set of lindsey 9.5 and 11x17 wheels on my 73 rsr widebody. i had them made with 5.5" of back space front and rear. this is an et of 0 for the rear and et of +19 for the fronts. i am using no spacers. attached is a photo and the fronts are maxed out, so a little less back space is not a bad idea, maybe 5.75". however my fronts are 9.5" wide, not 9". the rears could move out a little more but i would think .375" max per side. this would be a back space of 5.125". i think most would prefer to fine tune with spacers than have fender rubbing problems with no spacers. my opinion is that both 9x17 and the 11x17 should have 5.5" of back space, this would allow for spacers to be used if needed. keep in mind this is for a narrow chassis, not the turbo chassis and that the wheels would have good caliper clearence provided so the spacers are for aesthetics only. i had a set of 9&11x15 fuchs and cashed them in, but the backspace on the fronts and rears was 4.75-4.875". i think the rounded shape of the tire on a 15" wheel allows less backspace than what a 17" tire would.
-matt

[gestalt1]

sorry, forgot the picture. this is at a ride height of 25" from fender lip to ground on all 4 corners.

[Bill Verburg]

Originally posted by gestalt1
if my calculations are correct, an et of -19 is about 4.75" of backspace for the rear. i think this is to little backspace. i have a set of lindsey 9.5 and 11x17 wheels on my 73 rsr widebody. i had them made with 5.5" of back space front and rear. this is an et of 0 for the rear and et of +19 for the fronts. i am using no spacers. attached is a photo and the fronts are maxed out, so a little less back space is not a bad idea, maybe 5.75". however my fronts are 9.5" wide, not 9". the rears could move out a little more but i would think .375" max per side. this would be a back space of 5.125". i think most would prefer to fine tune with spacers than have fender rubbing problems with no spacers. my opinion is that both 9x17 and the 11x17 should have 5.5" of back space, this would allow for spacers to be used if needed. keep in mind this is for a narrow chassis, not the turbo chassis and that the wheels would have good caliper clearence provided so the spacers are for aesthetics only. i had a set of 9&11x15 fuchs and cashed them in, but the backspace on the fronts and rears was 4.75-4.875". i think the rounded shape of the tire on a 15" wheel allows less backspace than what a 17" tire would.
-matt

You may be right, but keep in mind a true 930 has rear hubs that are further outboard then on a 911 w/ 930 flares.

[TRE Cup]

If subydude is looking to produce one part for the 11 x 17, then the following needs to be considered
As others posted above; the 930 has different offset requirements . Also the big brake packages that some fit to their aluminum rear arm cars (74-89 standard 911) may require a different offset as well.
I would recommend the most common size that allows both client groups to realize installation. This will require the use of spacers for some of the applications.
Otherwise at least 2 part numbers will be needed= more inventory= more cost

[Gene Wilkes]

+1 TRE
Once the wheels are produced the adjustments WILL be MADE!

[RallyJon]

So, um, sorry to interject, but what will it take to get 50-55mm offsets made for 964/993/ heck, even Boxsters and 996s if they have any clue that Porsche made cars before 1999.

RSR finish, ducktail, maybe a "Carrera" side script.

Clears big reds and 996 brakes.

My 993 needs these wheels!

[scca_ita]

Well, OK I will say it. Why not just make a nice Fuch center that can have CCW wheels halves bolted to, to suit specific applications? The wheel halves are only $150 each. Easy to assemble too.

[PcarPhil]

Originally posted by Bill Verburg
Here is what I have gathered. For the fronts there is a division
930 front, '75 - '80, discard spacers
9x15 ET+15

930 front, '81 up built in spacers
9x15 ET+36

Geez, I forgot about the differences in the front hubs.

Another thought - Ruf Classic wheels have been fitted to 930's over the years. The Ruf 9" front wheels have an offset of +17.7 and fit all 930's.

Based on this there's a really good chance that the new 9x17 replica Fuchs wheels with +16 et will fit all 930 fronts - we're talking less than 2mm difference in offset.

Does this seem accurate?

Of course the best way to test front fitment would be to bolt up a pair of 9x17 replicas to the front of a later 930.

[PcarPhil]

Originally posted by Bill Verburg


930 rear, all years
11x17 ET-19

Bill -

I was just looking at your wheel page and your above suggestion seems to go along with the entry on your wheel page:

Welded Fuchs 11x17 11.0 -19.1 127.00 165.10 292.10 11.5 930?no spacer?

Do you know whose car this info came from or have any additional info on this entry?

Thanks for the help. I'd love to acquire a set of deep dish Fuchs for my widebody longhood...

[PcarPhil]

One more thing and it's back to work for me...check out 81 930's wheels in this thread:

Anyone have pics of Lindsey racing Fuchs on a 930?

He's running 9.5&11x17 Fuchs on an '81 930. I'm curious what the offset and backspacing of those wheels are.

[RickM]

Would it be helpful to look at other aftermarket Turbo wheel examples.

For years Gotti sold many wheels specifically for turbo and non-turbo wide body 911s. Does anyone know if a common configuration was used for Turbo vs non?

[Bill Verburg]

I would recommend the most common size that allows both client groups to realize installation. This will require the use of spacers for some of the applications

I agree 100%, the safe thing to do is build the highest offset wheel which would be for the '81 up 930 package(both front and rear). High + o/s can always be made lower w/ spacers.

Do you know whose car this info came from or have any additional info on this entry?

No, when I started collecting data i wasn't as careful as I could have been, especially about 930 body cars as I had no interest in them.

Would it be helpful to look at other aftermarket Turbo wheel examples

Yes it would, but you need to know what spacers, if any, were also used. Otherwise the info is useless.

As far as I have been able to determine, '75 -78 used 21mm spacers in front and all used ~25mm rear spacers(early ones may have used even bigger spacers, I just don't have that info)

[gumba]

The earlier turbos used 1" spacers in the front and 2" spacers in the rear, not sure up to what year.
I built a set of 3 pc. fuchs for my '79 930. The fronts are 8x5 x 17 w/5.5" backspacing (255/40/17) and the rears are 11x17 w/6" backspacing (315/35/17 tire). I figured the 6" back spacing would give me some room to position the wheel using spacers, 1/8"- 1". I also use this set up on our '75 Carrera RS look race car. On the race car w/stock trailing arms I use a 3/4" spacer.
I have a pair of 11x15" w/295's on the turbo rear now. The 11x15's have 4 7/8" backspacing. This puts the outside of the wheel flush with the outside of the fender. Also limits the tire size to the 295's.

[RickM]

The 9" & 11" Gotti wheels on my '85 Carrera widebody conversion have no spacers.

However, I don't know if my wheels would be a direct fit for any turbo. If measurements need to be made I can accommodate.