HELP!! Wheels and using spacers

[whinbush]

Ok Guys and Girls especially those with Technical knowledge of Boxster's.
Are you sitting comfortable? Then we shall begin.....

I am the proud owner since new of a 2.9 Gen II 987 which I have since new in April 2009.
Having gone through two rough winters I decided that this year I would put some winter boots on.
As I opted for the 19" alloy option which Runs 235/35/19 front and 265/35/19 rear
These boots are on the wide side if we see the white stuff.
As when it comes to snow, the narrower the tyre the better.

Now it seems the best I can get down to is 205/55/17 and 235/50/17 so I went on line and after a bit of searching found a set Porsche of 17" rims
Via Porsch-Apart (don't know why the spelt Porsche wrong) anyway they told me that they would fit my car

The fronts are part number 996.362.124.00
The Rears are 996.362.125.05.

The problem is that when I whipped my current wheels off and put just the new Alloys in place the fronts look ok and the clear brake callipers etc.
But the rears although the wheels turn freely they have very little clearance on the inside against the struts so when shod with rubber no chance they will fit [>:]

So not the outcome I wanted.
I was already to pack them back off then I thought what about spacers?

I had a look at design 911 and there are indeed a number available but I have no experience in using or fitting them.

So the few of you out there who know all the numbers can you help?

1) Most importantly are spacers OK to Use will the car be stressed?

2) If the answer above is a yes then what size should I can I use as they are available from 5mm-30mm

http://www.design911.com/Porsche/Boxster/Wheel-Spacers/pt184_-cma81-cmo82/


3) Also Do I need to use on the Fronts as they look like they will fit Or is it Ok just to fit at the rear?


So slide rules at the ready any help will be received and absorbed from an educational stand point. However best to talk to me like Im a 10year old. []

Cheers


Jamie

 

[Mark_Bennett]

Porsch-Apart are good people. It's always worth giving them a call - they may have spacers []
If they spelled it correctly then I suspect Porsche (who are very protective of their name) would get rather upset...

Porsche themselves offer 5mm shims for the Boxster, and others are available depending on the spacing needed.

What are the offsets for these wheels? For the rears it should be 40mm for a 8.5" rim.

 

[whinbush]

I dont have a clue what the offset is on the wheels I have bought.
I was hoping somone might know ?? [8|]


My manual says smallest wheels that will fit are
Front 7J x 17 H2 55mm rim offset
Rear 8.5J x !7 H2 40mm Rim offset

I will try calling them again but as they told me they would be fine from the off, my trust in their advice is low

 

[Mark_Bennett]

OK - the whees you have (the 17" ones) do they have a number moulded each side of the valve hole?

If so (and most Porche wheels do - but not all) then one will be the rim width (8.5 at the back) and the other the offset in mm.

Porsch-apart are a very reputable company - and I suspect that you do have the correct wheels. I was suggesting calling to see if they had suitable spacers.

It's good to see your manual confirms the offset I thought should fit.

 

[Buddy]

If these were the wheels you asked about in an earlier thread then the fronts are ET55 ( 55mm offset ) & the rears ET50 ( 50mm offset ), easy to check the measurements by doing a drop check off the inner rim and calculating relative to the rim tyre bead width provided you can make allowance from the inner tyre rim etc, easier to do than explain without diagrams. Take care to protect the outer face by laying the wheels on a piece of carpet or other thick soft material.

If that confirms the offsets I would expect that they should fit without spacers after all tyres are fitted to Porsche wheels which are close to the same width as the rims and struts don't usually sit vertical but angle inboard at the top.

If you get your tyres fitted you will have a good chance of clearing the struts but don't pull the bolts down until you have confirmed the clearance. If they do trap against the struts then you have some risk of damaging the struts!

For spacers, if you fit 5mm it will usually be ok on standard wheel bolts ( general rule but confirm with supplier ) thicker than 5mm you should be looking at new longer bolts appropriate to the thickness. Remember if you use bolts that are too long they will probably bottom in the holes or if holes are through the flange may contact something behind.[:-]

 

[CLIFFWILKINS]

As Said 5mm shim spacers ok with existing bolts but and wider spacers
you will need longer bolts.

 

[whinbush]

Hi All thanks
Buddy the offset is ET50 for the rears .

My worry is that when I put the alloy on the rear it almost touches the Strut so by the time I stick a 55 profile tyre on it will catch the strut.
So I am gusseing as my new wheels have a 50mm offsett when the should be 40mm I will need a 10mm Spacer?

Also If I do use a spacer do I have to use the same on the fronts even though here the offset is correct at 55mm

 

[Mark_Bennett]

I'd say you only need the spacer on the wheels that you have an issue with.

 

[Buddy]

If the wheels are the correct width but should be a 40mm offset then 10mm will be correct, however, if the rims are say 10mm wider than normal then you would need 15mm thick spacers, do you understand what I am getting at?

 

[whinbush]

I do indeed.
So having checked, it's a pair of 10mm spacer"˜s that is needed and just on the rears.
Next to get the winter boots on and we are off
Many thanks to all for advice and suggestions.
Also sorry on the typo front.
The danger of quick typing on an iPhone.
I did actually go through the schooling system then successfully onto University.
However reading my posts I would wonder if English was even my first language.

 

[Buddy]

Let us know how you find the winter tyres, at present I'm unlikely to need them but in future years...

Don't forget the longer bolts! Probably as expensive as the spacers, if not more!