Work Meister S1 3pc

[99turbo]

[QUOTE=Jim Dorociak;9298612]Guys best way to measure and calculate ET. Measure from very outer edge of the rim lip to outer edge of opposing rim edge. Measuring this way adds usually about 1" to the real width of the wheel. Then place a flat edge across the very highest edge of the rear rim and measure down to the back pad of the wheel center. Take that measurement and compare it the the 1/2 measurement of the total width of the wheel.

So lets say rear wheel is 12" across. The 1/2 of that is 6" and how does that compare to the measurement down into the back wheel to the pad area. For sake of discussions - the pad height measurement is 6" ET would be 0. So measurement is 7.5" - 6" = 1.5" and that converts to 24 mm = 1" so 24 + 13 = ET 37.


Hi Jim,

Thank you for the helpful input. Where did you get the +13 in the equation (24 + 13 = ET 37.)

-99

[Jim Dorociak]

24mm = 1" 1/2" is 12/13mm so it is not always an exact science. it really is not 24 but something slightly larger 25.4mm = 1" to be exact. so that ET is calculated based on the 1/2 measurement of the total width of the wheel compared to or subtracted from the actual backspacing measured. In the example 6" was the middle point on the 12" wheel if you had a actual measured backspacing of 7.5" - 6" that is where you get the 1 1/2" and convert to mm to know the ET.

I just built a 10" front wheel -- 4" outer rim, 6" inner rim and low pad height and in the end the measurement was 10 ET 10" as measured. I built a 13" rear wheel. 7" outer rim 6" inner rim and when it was all said and done it was a -24 ET 13" wheel. Jim jdorociak@gmail.com

[PorkerNW]

Hi 99 turbo

Btw are you based in Hong Kong? Just wondering if you know whether this set fits a 964 C2 coupe? Cheers

[99turbo]

Originally Posted by PorkerNW

Hi 99 turbo

Btw are you based in Hong Kong? Just wondering if you know whether this set fits a 964 C2 coupe? Cheers

Hi,

I'm located in Houston, Tx. I don't think these will fit a narrow body 964 c2 with the current set up. However, I do have a extra pair of 1.5 inch works lips
(1.5 inch lips polished) that can be powder coated to match. Swapping the rear lips will make it a 18x8.

18x8 an 18x9 will fit a narrow body.

-99

[99turbo]

Originally Posted by Kaefer

99turbo,

To measure back space did you place a flat edge across the very highest edge of the rear rim (outside edge of barrel lip) and measure down to the back pad of the wheel center? And this is how you came up with 6.75" of back space?

If yes then based on more calculations (this time using 10x18" and 12x18" with 6.75" back space) I'm coming up with wheels that are 9x18" ET+32 and 11x18" ET+6.

Please confirm how you measured back space and we can confirm what the actual wheel offsets are. I'll delete any un-needed data after we confirm back space to clean up your thread and minimize confusion.

Kaefer,

I did..
1. flat edge across the very highest portion (outside edge of barrel lip)
2. tape measure down to the back pad

If you could delete the un needed data I would greatly appreciate it. It seems like there are quite a few different opinions on how to measure the et -offsets and I don't want to confuse a potential buyer.

These fit my 78 930 flush in the rear and about .5 inches inside the fender in the front.

[PcarPhil]

99turbo,

Done.

My unsolicited opinion is that these wheels are 9x18" ET+32 and 11x18" ET+6. These are very nice 930 wheels.

GLWTS!

[99turbo]

Weekend bump!!

[99turbo]

bump!!

[99turbo]

TTT

still for sale!!