Boxster wheel dimensions, I searched Options

[914turboford]

I searched and sort of got the answers but am not sure:

1. Is it correct that a 16" Boxster wheel will bolt on a 914 trailing arm without spacer?

2. A 17" front boxster wheel will need (approximately 1") spacers to fit on a 914 trailing arm, right?

3. What size spacer would be needed for a 17" boxster rear wheel (17x9?) to fit on a 914 trailing arm? Some type of fender flair needed, I assume.

4. What is the offset for a standard Fuchs 16x7 and 16x8?

5. Does anyone know of a website with dimensions for all of these wheels?

Brian

[Aaron Cox]

fuchs and older wheels like cookies are as follows
(IMG:http://members.rennlist.com/1976c38/wheel_os_small.jpg)

[jim912928]

I run boxster 16X7 rears on all 4 corners of mine. No spacers required and no fender mods required. Run 205's.

Jim

p.s. if you run the 6" boxster front you'll need a spacer for it to look right (can't remember what size...was easier for me to pick up a pair of rears for the front).

[Porsche Rescue]

Here are 6's on all four corners. While the fronts are a bit farther in than stock (about 10mm), I think they look ok. Tires are 195/55 x 16. As Jim says, 205's will fit but I didn't want to take any chance of needing to pull/roll the rear fenders.

[914turboford]

I am in the process of putting huge flairs on the rear. I already have one side 98% done. I have 16x7 Fuchs on the rear with 225's. I relocated my trailing arms outboard approximately 1.2" and am using factory 944 spacers. I have about an extra 1/2" of space to fill and had planned to mount up a pair of 245's on the rear in which case I would probably get another pair of 16x7's for the front to replace my 16x6 Fuchs. I might end up with 4 16x6 Fuchs to sell. At any rate, I started considering going up to Boxster 17's because I heard they are almost as light as Fuchs 16's and I think 17" tires might be easier to get in the profiles needed. A

Any word on whether big spacers are for sure needed for Boxster 17's?

[914turboford]

By the way, Aaron, thanks for that chart. Very useful.

Also, that yellow 914 looks really nice. I wish mine were that color.

Brian

[Aaron Cox]

QUOTE (914turboford @ Dec 8 2005, 06:57 AM)

By the way, Aaron, thanks for that chart. Very useful.

not mine to take credit for.....

QUOTE

am in the process of putting huge flairs on the rear. I already have one side 98% done. I have 16x7 Fuchs on the rear with 225's. I relocated my trailing arms outboard approximately 1.2" and am using factory 944 spacers. I have about an extra 1/2" of space to fill and had planned to mount up a pair of 245's on the rear in which case I would probably get another pair of 16x7's for the front to replace my 16x6 Fuchs. I might end up with 4 16x6 Fuchs to sell. At any rate, I started considering going up to Boxster 17's because I heard they are almost as light as Fuchs 16's and I think 17" tires might be easier to get in the profiles needed

just increasing track? why not leave your suspension where it is and use WIDE wheels to fill out the flares... BTW 7" with 225 is kinda a stretch. fwiw im running 8" under very sublte rear flares........with 225's

[Demick]

QUOTE (Aaron Cox @ Dec 7 2005, 04:13 PM)

fuchs and older wheels like cookies are as follows (IMG:http://members.rennlist.com/1976c38/wheel_os_small.jpg)

Hey Aaron

Who created that chart? It looks like they calculated the backspace number incorrectly from the generally accepted backspace measurement.

Backspace is normally defined as the hub mounting face to the innermost edge of the wheel (if you laid a wheel down flat on the ground, backspace would be the distance from the hub mounting face to the ground).

But the numbers in that chart look as though they calculated backspace from the hub mounting face to the inside of the tire bead flange (where the wheel width is measured from).

Anyway, the difference is about 9mm. So all of those backspace dimensions should be increased by ~9mm.

Demick

[914turboford]

By moving the trailing arms out less spacers are required meaning less unsprung weight. The brackets I made don't weigh much. Yes the axles are longer and thus heavier. So maybe there is no net savings of unsprung weight or a very small one. Incidentally it turned out that the custom axles I had made before were long enough. I do, however, like the idea of shorter studs and spacers for strength issues. The main benefit is that I'll probably be able to use a stock trailing arm (or at least a less modified and therefore lighter one) on the driver's side instead of the one I cut down to clear my Ford Escort transaxle.

[Porsche Rescue]

I've found that chart to be very helpful. It is on a 1:1 scale. What you see on the chart is exactly what will happen if you switch one of the wheels shown with another. For example, notice that switching from a 6x15 to a 7x15 adds 26mm (1") all to the inside using the 49mm offset wheel. Using 23.3mm offset 7"wheel adds the width entirely to the outside.

[Mueller]

QUOTE (Demick @ Dec 8 2005, 09:13 AM)

Hey Aaron Who created that chart?  It looks like they calculated the backspace number incorrectly from the generally accepted backspace measurement. Backspace is normally defined as the hub mounting face to the innermost edge of the wheel (if you laid a wheel down flat on the ground, backspace would be the distance from the hub mounting face to the ground). But the numbers in that chart look as though they calculated backspace from the hub mounting face to the inside of the tire bead flange (where the wheel width is measured from). Anyway, the difference is about 9mm.  So all of those backspace dimensions should be increased by ~9mm. Demick

Demick, the chart says "backsize", not backspacing (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

Is backsize even a word, it should have been farside instead (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif)

[bd1308]

QUOTE (Mueller @ Dec 8 2005, 11:55 AM)

Demick, the chart says "backsize", not backspacing (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) Is backsize even a word, it should have been farside instead (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif)

or over yonder....

b

[marks914]

I have 17 inch boxter s alloys on my car. 1 inch spacers all the way around.
Mark

[marks914]

heres another...

[Demick]

I think backsize is the correct term for this type of measurement.........

[914turboford]

I think I am going to stick with 16's, either Fuchs or Boxsters. Nice green 914!

Brian