Checking Track Width, Wheelbase:
Dug out my front control arms and built them up with new Lemforder ball joints.
Click to view attachmentAdded some new Boge inserts into the struts
Click to view attachmentClick to view attachmentAnd we are off to the races to being able to measure track and wheel base directly after adding the front hub/rotor.
To measure front track, it is given at curb height. The suspension as installed ends up in rebound. Therefore, the front suspension needed to be jacked up near curb height to get a decent measurement.
Front track is listed as 1343mm with 5 1/2 x 15" wheels. But, in order to measure track off the rotor surface, we neeed to know the wheel offset. A bit of digging on the internet and PET shows the 5 1/2 x 15" wheel has an offset of 40mm.
So let's roll. Jacked up to near curb height.
Click to view attachmentClick to view attachmentDirect measurement off the trammel is 1420mm. But remember, offset needs to accounted for to get track at the centerline of the wheel and tire.
So 1420mm - (40mm offset x 2) = 1340mm
Looking good.
Next up rear track is listed as 1383mm with the 5 1/2" wheel.
Trammel measurement from rear rotor face to rear rotor face came up 1464mm.
Again accounting for offset 1464mm - 80mm = 1384mm.
Time to throw on some wheel & tires to see how things look.
Driver Side wheel to the sheetmetal fender flange that the rocker panel sits into.
Click to view attachmentand comparing to passenger side
Click to view attachment Right on!
Let's check the wheelbase. Wheel base is listed as 2450mm.
Click to view attachmentDriver side right on the money!
Click to view attachmentPassenger side:
Click to view attachmentClick to view attachmentSo here we have 2445mm. Looks like about 5mm different than passenger side. But, there is no need to panic. Remember that both sides measured the same from front ARB hole to rear hub centeline. I trust this measurement way more since there is only one degree of freedom (where the STA is) vs this direct wheelbase measurement that has two degress of freedom (STA location + position of the front strut spindle).
Even if there were a full 5mm of variance in wheelbase between driver and passenger side, I could live with that but the reality is that wheel base will vary slightly side to side as we do the final alignment to set rear toe-in.
So as a final reality check, I did move the rear wheels between maximum toe in and toe out doing a crude check from tire center line to centerline with a tap measure.
Looks like I can get a maximum toe in 7/16" and maximum toe out of 1/4". As an engineer I love symetry but in this case, we would never want toe out so I'll live with it.
And finally, I wanted to take a rough look at camber gain.
Before doing that recall, that I started out with a smidge more camber on the passenger side due to weld shrink when I put in the outer suspension console. I went back and shimmed passenger side until I had the same 89.9 degrees on the rear hub.
That took 4.3mm of shim. So that answers my previous doubt about how much higer in Z the outer console was. Not terrible. I would have rather been right on the money but I can live with having to have an "extra" 4.3 mm of shim on the passenger side.
So the math does work out (roughly). Per the Russek notes, 1mm of shim = 10' of camber = 0.16 degrees. So knowing that I'm 4.3mm high in Z, I should have an extra 0.68 degrees of camber on the passenger side. I had 0.5 degrees more. I'll chalk the other 0.18 degrees of error up to build variation, measurement error, and accuracy limitation & repeatability of my Husky angle gauge.
I then pushed the rear STA's up to a point where I thought they looked like they were closer to curb height. I then took a quick look at camber gained.
2 degrees on Driver Side
Click to view attachment2.2 degrees on Passenger Side.
Click to view attachmentLoving it.
So at this point, we've verified that camber gain is working properly (increasing as wheel goes into compression), that it is pretty close to symetrical side to side, and that near curb height we have more than enough camber. We would then add shims to take camber out closer to spec at curb.
Feeling really good about proceeding with final welding of the inner suspension console today.