What have you done to your E89 today

Vanne said:
Nice calcs. :) how similar to the e85/86 is it?
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The front end is pure E90 so very different to the E85, the rear is a copy of the E85 with some very minor changes to motion ratio maybe and spring / damper rates..


The track difference is offset, not arms

Track goes 1521 → 1562 mm, up 41 mm. But rim offset goes ET47 → ET29, which pushes each wheel 18 mm outboard — 36 mm of the 41 mm right there.

So only about 5 mm comes from anything else. The arm geometry is essentially unchanged between the two cars.

Which means the spring seat sits at the same place on the same arm, swinging about the same pivot. The E85’s rear motion ratio should be close to the E89’s measured 0.670 — probably a shade higher, since the E89’s wheels sit further outboard and a longer lever arm lowers the ratio. Call it 0.68–0.69,
 
Makes sense, quite interesting that they changed the offsets. wow didn't realize that the track went up /that/ much.. how does the weight vary between both? i guess the roof prob ads a few extra pounds to the chassis. That said, its a proper nice roof, much nicer than the e85 or the new z4 has. wow just looked it up, only around 100-200 kgs heavier, that's pretty awesome, i would have thought much more than that.
 
Vanne said:
Makes sense, quite interesting that they changed the offsets. wow didn't realize that the track went up /that/ much.. how does the weight vary between both? i guess the roof prob ads a few extra pounds to the chassis. That said, its a proper nice roof, much nicer than the e85 or the new z4 has. wow just looked it up, only around 100-200 kgs heavier, that's pretty awesome, i would have thought much more than that.
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The roof parts are only 20kg -50kg extra depending on your accounting…most of the weight is a stronger body shell, bigger engines, bigger brakes, bigger wheels, more electronics…
 
Adjusted perches to try and level the car…just about anything and everything that could go wrong did…I’ll drive it lopsided to Zedfest..

Suspect the rear H&R ARB is bent …IMG_2701.jpeg
 
Vanne said:
Have you got pre load set on the bar? If that's off, that will do it.
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Yes I do the proper pre load but looking at a witness mark looks like one side of the arb was trapped by the left thrust camber arm when both trailing arms were unbolted from their dampers…..
 
An annoying one today. Started up the car to take it out for its first spin in a few weeks and was greeted with a steering issue. I turned the thing off and back on and all was well again. It didn’t present any issues throughout the drive or after re-starting again. Given what I’ve read from @B21 in other posts, I suspect my 2011 30i is probably starting to see rack failure. Scanned for codes and there was one related to communication failure.

I will see how I get on but I’m relatively comforted by the price of reconditioned units available on eBay.

I think my plan of attack for the remainder of this year will be to:

  • Get a reconditioned rack fitted
  • Get the water pump replaced
  • Have an oil change
  • Have M3 arms fitted prior to rack swapping and the necessary suspension re-alignment
IMG_1072.jpeg
 
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