Tire sizes on my 914 with all 911 suspension Options

[Downerman]

5 lugs with all 911 rotors, brakes etc, etc,

So here's the million dollar question. Right now the car came with 928 rims that use a 1" spacer for offset (I only had the rears off but assuming the fronts do too). Here's the tire size: 205/55 ZR16 BTW they fit and no rubbing or nothing. Fenders all look stock to me but definately no flares.

Can I assume the Fuchs 7 X 16 running the same tire will be exactly like these? I mean maybe the offset needs to be adjusted but there are SO many people with opinions on what will and will not work. I would love to hear your thoughts.

Dave

[ClayPerrine]

16x7 944 offset Fuchs fit the front and rear of a 914 with no problem I run 225/50-16s on the front of my flared 914. 205/55-16s should fit a non flared car.

[Downerman]

Great info... BTW I took off one of the 928 wheels... inside says 7J so it's a 7" but I do get this.... the offset has everything to do with this. Had a line on some 7 X 16's off a 911 but now I'm thinking otherwise. Anyone else??

Dave

[mskala]

Great info... BTW I took off one of the 928 wheels... inside says 7J so it's a 7" but I do get this.... the offset has everything to do with this. Had a line on some 7 X 16's off a 911 but now I'm thinking otherwise. Anyone else??

Dave

I think the info being presented from both sides is not directly to the point.

First, you say 928 wheel. There were a lot of different wheels, some look
the same but are not. You have to go by the part number or info stamped
on the back.

What you really need to know will be stamped on the back of a wheel. For
example, you said "7J" so it is a 7" wheel. Also check the front, it could
be 6". After the 7J it will have "ET" followed by a number. That is the
offset in mm.

Offset is key. Higher offset (more positive) means the wheel
will sit deeper in the opening. So, if you have a larger offset than you can
fit, it is possible to add a spacer. If you have to low an offset, you are
screwed.

Also, if you have, for example, a 6" wheel with 36mm offset, then a 7"
wheel with a 36mm offset would stick out 1/2" further on both sides.
But if it is a 7" with 23mm offset, then the back side would line up and
the outside would be 1" further out.

All cars are slightly different, but in my view the optimum offset to get
the widest tire or wheel to fit the rear is 35mm. Depending on the
tire and/or camber and springs, you could vary from this. It pays to
check your own car yourself. The front is almost never an issue, but
you have to avoid too much offset on wide wheels to keep from hitting
the shock dust cover.

I once put the 6" 52mm offset phone dials on the car with 205/60 tires
(I had a 924S), they rubbed on the inside rear.

Good luck

[Downerman]

My head is going to blow up. Here's the details.

the 928 rim is 7JX16 928.361.016.00 ALSI12MG
It has a 23 mm spacer that is between the hub and rim (Captain obvious I know) so it fits perfectly with the wheel well.
The data on-line says backspace is 111mm and offset is 65mm

This combo works perfectly with stock 914 fenders. No rubs at all with decent clearance.


Now the 944 rim mentioned above that the guy said works on his stock 914 is: 951.362.115.00 Backspace is 138mm and offset is 23.3 can anyone explain how to figure this out? I flunked math in high school.

Dave

[Downerman]

So using the attached pic as a reference and trying to just think about this as simplistic as I can is this logic sound? All I really care about is my current 928 backspace which is 111mm and add my spacer which is 23mm for a total of 134mm. At that measurement all is well on the inner side AND can I assume because their both 7" rims that the outer is as well?

So, my simple mind is telling me this is my bench for what fits.

That being said is I take the 944 wheel and use the backspace of 138 well shoot, don't I just need 4mm spacers and I'm good to go?


Dave

[mskala]

So using the attached pic as a reference and trying to just think about this as simplistic as I can is this logic sound? All I really care about is my current 928 backspace which is 111mm and add my spacer which is 23mm for a total of 134mm. At that measurement all is well on the inner side AND can I assume because their both 7" rims that the outer is as well?

So, my simple mind is telling me this is my bench for what fits.

That being said is I take the 944 wheel and use the backspace of 138 well shoot, don't I just need 4mm spacers and I'm good to go?


Dave

I don't like to deal with backspace, people measure it wrong and it depends on rim
material thickness. I use the offset values, which are definitely available with the
part numbers you gave.

928 7x16 ET65 with 23mm spacer is equivalent to 65-23=42mm offset.

According to my chart, that 944 rim is 23mm offset. There is nothing you can
do with spacers to make that equal to the 928 wheel you have. It is already
farther outward by 3/4".

Mark S.

[Downerman]

So I have found several of these testimonials along with one right here on this post who are doing it with the 944 Turbo 7" on the rear of a stock 914. I'm going to take the plunge. I do appreciate everyone's input and I mean that sincerly.

Dave


http://forums.pelicanparts.com/porsche-914...-fit-914-a.html