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      04-09-2013, 04:05 PM   #248
GuidoK
#buildnotbought
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Drives: Z4 3.0i ESS TS2+
Join Date: Jul 2012
Location: Tinkering in the garage

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Quote:
Originally Posted by Finnegan View Post
Again, two separate issues here. 1st to 2nd, 3rd to 2nd.
Yes I know as I displayed my reaction on them seperately


Quote:
Originally Posted by Finnegan View Post

For 3rd to 2nd, the gate is located to the left of the furthest point of the shifter travel under high load and lateral G. That means it's not accessible.
Woot?
Even reverse is situated next to that fork, and then there is about 1" room.
No way the engine/gearbox assembly can rotate/shift that much!
Between 2nd and the shift gate edge is about 3,5cm space (I can only extract form your post that the lever can't access 2nd because it's limited by the shift gate edge). I've just measured the height between shift gate edge and the mount rubber is about 30cm, and the width between both rubber transmission mounts is about 25cm.
The width between the engine mounts is about 65cm. (I'm sitting here next to my z4 which is on the carlift, so I'm measuring these numbers as I type )
That means that when the shift lever moves 3,5cm, the compression (push pull difference) of the transmission mounts is (3,5/30)*25=2,9cm, but the same push pull difference in the engine mounts has to be (2,9/25)*65=7,5cm
No way that the transmission mounts are that much compressed.
As the engine is about 55cm of height above the engine mounts, it would mean that the engine would have to shift (3,5/30)*55=6,4cm sideways in order to get the corresponding effect on the shift lever. (remember it's a rotational force, both the high load and the G force yanking on the engine block)
The edge of my ESS supercharger assembly is situated about 3cm from the chassis suspension strut well, so in order to get that amount of gear lever shift (for 2nd gear not to be accesible) the supercharger assembly would have to ram itself 3,4 cm through the chassis...
That's just plain ridiculous imho.
Whatever it is that some people can't get the lever into 2nd: I doubt it's that.
I hope you can follow and picture the math I displayed.

Also there is another effect that even further limits the movement of the shifter in relation to movement form the gearbox, and that is that the shifterball is situated in the shift arm. The shift arm is a connection between the gearbox and the chassis. That means that the shift arm hardly moves. What happens when the gearbox underneath moves to the left (so that 2nd would eventually become inacessible), the shift stick itself will bend to the right. Look in TIS for the exact layout from the components.
So I think that it is even sheer impossible for the shif lever to even touch the side.
And as always: 2nd is about 2cm to the left from 3rd, but than down in stead of up

So the only thing you gain with stiffer engine and transmission mounts is a more stable platform. Not that that's a bad thing; the transmission and engine mounts are soft (normal car style), so you can feel the mass wiggle beneath you when you corner and on bumpy roads.
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Z4 3.0i | ESS TS2+ supercharger | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | Powerflex/strongflex PU bushings | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers/KW camber plates | Sachs race engineering clutch | tons of custom sh#t

Last edited by GuidoK; 04-09-2013 at 04:30 PM..
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