Even if the rack/diff clears i think the passenger CV will hit the subframe with stock firewall.
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man, i didn't expect you to be up so early. i guess we need to consider the sway bar too since its on the front side of the rack. i think both axels will hit the back of subframe equally since they are the same length.
i am visualizing the subframe under the oil pan looking like a piece of angle iron.
i wouldn't worry about the tie rods too much. e36 inners are short and rwd e30 outers are short. a combination of those should make it work out fine.
our constraints are: geometry, axles against the rear subframe, and sway bar. will is a smart fucker so i think after research and with everyone's input, we can come up with something more than acceptable.
maybe the hole for the control arm an be moved forward a tiny bit? we can always use m3 control arm bushings to compensate for the castor change.Last edited by flyboyx; 03-24-2014, 06:29 AM.sigpic
Gigitty Gigitty!!!!
88 cabrio becoming alpina b6 3.5s transplanted s62
92 Mtech 2 cabrio alpinweiss 770 code
88 325ix coupe manual lachsilber/cardinal
88 325ix coupe manual diamondschwartz/natur
87 e30 m3 for parts lachsilber/cardinal(serial number 7)
12 135i M sport cabrio grey/black
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pffft, I slept in. I'm usually at work for 2 hours by now. :p
I'm not convinced that they will hit but nisse's the only one who's put one in the car so far.
there's that little "notch" in the frame for the CV shafts just beyond the subframe, how far apart are they? if you move the diff forward an inch, the shaft at that point is going to move some fraction of that value.
I'm not sure if you're being literal but I wouldn't use angle iron for constructing a subframe. tube steel would be much better.
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Originally posted by flyboyx View Posti wouldn't worry about the tie rods too much. e36 inners are short and rwd e30 outers are short. a combination of those should make it work out fine.
E36 and E30 tie rods are homo. (giggity)
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Originally posted by nando View PostAs in the same?
Might pick up a cheap set on ebay to play with. I got some cheap ix ones and they honestly seem fine.
When i did the rwd e36 rack swap on my rwd e30 i noticed the bmw had swapped the inners and outers from male to female so i couldn't use half of each as you would have two males or two females. It sounded like all rwd components were being discussed, excuse me if one was awd and is different.
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When i tested the front axles it looked like it was more space on the drivers side for some reason but i might be wrong here. I wont say anything 100% untill i have the engine bolted down for good :)
But i dont think the swaybar will cause any problems if we use the stock cross member.E30 325ix M50 turbo 7 spd DCT 4wd 840awhp @ 31 psi.
E30 M50 6 spd 764whp @ 24psi.
E30 M20 6 spd 675whp.
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Originally posted by nando View Postpffft, I slept in. I'm usually at work for 2 hours by now. :p
I'm not convinced that they will hit but nisse's the only one who's put one in the car so far.
there's that little "notch" in the frame for the CV shafts just beyond the subframe, how far apart are they? if you move the diff forward an inch, the shaft at that point is going to move some fraction of that value.
I'm not sure if you're being literal but I wouldn't use angle iron for constructing a subframe. tube steel would be much better.
the center of the notch is about 1" behind the rear subframe ears. i agree with your assessment of the axle being forward only about half that amount. i think there will be some minor interference.
no, i am not being literal about the shape. i am simply saying that to make the rack work and keep the sway bar in line, the sub frame under the oil pan will probably need to be pretty skinny. maybe rectangular tube stock. schedule 40 1 3/4"x1" perhaps?
Originally posted by LJ851 View PostE36 and E30 tie rods are homo. (giggity)sigpic
Gigitty Gigitty!!!!
88 cabrio becoming alpina b6 3.5s transplanted s62
92 Mtech 2 cabrio alpinweiss 770 code
88 325ix coupe manual lachsilber/cardinal
88 325ix coupe manual diamondschwartz/natur
87 e30 m3 for parts lachsilber/cardinal(serial number 7)
12 135i M sport cabrio grey/black
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I'd like to get ahold of some FEA software and maybe work with Will to build a model. I can get any Bentley product I like for free through my instructor license and I think they have some good stuff. :)
1" tube sounds small to me but I'm used to working on stuff that's a few feet in diameter and 1" thick. lol
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Originally posted by nando View PostI think it's also a question of which is worse - bump steer increase from moving the rack, or from changing the length of the rack? however the E46 xi rack has the advantage of being a lot quicker/more responsive than the E30 ix rack. And also if we can get tie rods that will work.
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I hope the bump steer is a non issue, hell maybe it will improve with the rack moved !
One reason to make the rack adjustable would be if optimizing the bump steer for standard ride height and a lowered ride height required a different rack location.
I think shims would be a simple, quality solution for vertical adjustment.
Are you going to mock this up physically or simulate it on the computer? I was thinking of a simple way to create a fully adjustable prototype to do it on a chassis. Attach a stout piece of metal plate to the bottom of the subframe extending underneath the rack location with slots cut in it to achieve all possible front to rear locations. With the plate being too low, spacers can be used to shim the rack up to the desired height.
Should be easy to make and template off when finished.
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I was going to start with CMM data package from the crossmember and build a fixture according to the modified dimensions. BMW's original bump steer curve is a great starting point. Lowering doesn't change the shape of that curve, just where the suspension operates on it.
I'll have to get further along in the process to figure out what I have room for in terms of shimming or adjustment. In moving the rack down, the structural section of the crossmember gets pretty thin, while moving it up is going to depend on oil pan clearance.
A rack like the E46 xi unit with the mounting tabs in front is nice, but I'm not sure it's necessary. The mounting tabs on the stock rack straddle the E53 V8 oil pan, and have different clearance considerations than the center body of the rack itself. I'll have to get a Z3 rack to see what the mounting situation is with it. It might be that the mounting points are far enough apart that they can straddle the pan... or maybe not.
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Originally posted by The Dark Side of Will View PostI was going to start with CMM data package from the crossmember and build a fixture according to the modified dimensions. BMW's original bump steer curve is a great starting point. Lowering doesn't change the shape of that curve, just where the suspension operates on it.
I'll have to get further along in the process to figure out what I have room for in terms of shimming or adjustment. In moving the rack down, the structural section of the crossmember gets pretty thin, while moving it up is going to depend on oil pan clearance.
A rack like the E46 xi unit with the mounting tabs in front is nice, but I'm not sure it's necessary. The mounting tabs on the stock rack straddle the E53 V8 oil pan, and have different clearance considerations than the center body of the rack itself. I'll have to get a Z3 rack to see what the mounting situation is with it. It might be that the mounting points are far enough apart that they can straddle the pan... or maybe not.sigpic
Gigitty Gigitty!!!!
88 cabrio becoming alpina b6 3.5s transplanted s62
92 Mtech 2 cabrio alpinweiss 770 code
88 325ix coupe manual lachsilber/cardinal
88 325ix coupe manual diamondschwartz/natur
87 e30 m3 for parts lachsilber/cardinal(serial number 7)
12 135i M sport cabrio grey/black
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