[WMWNWMN]

Hey Greg, Think that bearing puller will work on my E30 subframe?

Black/brown interior would be lovely, but make sure it's BROWN not tan! Tan is boring.

 

[93FIM5]

Have you seen the video about the 911 owned by the Chief of design for Bugatti? Your build reminds me of that. You should definitely watch it if you haven't already.

Bugatti Head of Design's Personal 911 Project - DRIVEN - YouTube

Very interesting! I do like his taste and how simple hes made the 911, would be a nice departure from the M5 where you have to keep luxury. 820kg is very impressive would be a blast to drive and very much back to the basics which he points out.

Hey Greg, Think that bearing puller will work on my E30 subframe?

Black/brown interior would be lovely, but make sure it's BROWN not tan! Tan is boring.

For the rear subframe bushings? I doubt it will mount right up but I'm sure we could build plates to make it work pretty quickly. Do you have the subframe out of the car or the new bushings in hand? Text me and we can figure it out, still need to get your radio done as well if you haven't already.

Definitely agree on it being brown and not a tan, on the hunt for leather!

 

[SpecRaceM5]

Very interesting! I do like his taste and how simple hes made the 911, would be a nice departure from the M5 where you have to keep luxury. 820kg is very impressive would be a blast to drive and very much back to the basics which he points out.

I don't think I would go that exact route with the M5, but I agree that fundamentals of his approach are very cool. My ideal 2 car garage would be an older aircooled 911 built similar to that or a Singer, and an E34 M5 built to it's "perfect" form with no expenses spared. Kind of like what you are building. :biggrin:

 

[ericono]

Have you done any more work on your air plenum idea? Just checking.

Great work so far. I love checking in to see what you have done next with this.

Take care,

Eric

 

[93FIM5]

I don't think I would go that exact route with the M5, but I agree that fundamentals of his approach are very cool. My ideal 2 car garage would be an older aircooled 911 built similar to that or a Singer, and an E34 M5 built to it's "perfect" form with no expenses spared. Kind of like what you are building. :biggrin:

Completely agree on the M5 having to maintain luxury since it is a dual purpose car, meant that I really appreciate the simplicity and back to basics that hes shown in his build. As for the garage I would have to agree but maybe with a Road Runner thrown in to have a muscle car :hihi:. Thanks for the complement not sure its perfect for everyone but I'm trying for my ideal M5!

Have you done any more work on your air plenum idea? Just checking.

Great work so far. I love checking in to see what you have done next with this.

Take care,

Eric

I have actually, been working on a lot of the internal flow to make sure every cylinder is equal in my CFD simulator. Required some tweaking of the velocity stacks which is a pain considering I'm trying to maintain the OEM length. I still need to develop the modification for the front subframe a bit more due to the charge pipe, but that will be relatively simple. Thanks its been a fun project!

Managed to get a few things done before I left for Texas last weekend. Finished my press tool for the rear bearings.


Rear_Bearings_4 by 93FIM5, on Flickr

Parts ready to go in with the tool.


Rear_Bearings_5 by 93FIM5, on Flickr

Pressing.


Rear_Bearings_7 by 93FIM5, on Flickr

Installed

.


Rear_Bearings_8 by 93FIM5, on Flickr

New rear e-brake hardware and shoes.


Ebrake_1 by 93FIM5, on Flickr


Ebrake_2 by 93FIM5, on Flickr

All done.


Ebrake_3 by 93FIM5, on Flickr

Picked up a large order of parts for my manual front seat refurbishment.
- New springs
- New handles
- New side covers
- New knobs
- New hogrings, pushpins, screws
- New bushings
- New shocks
- Etc.


Manual_Seat_Rebuild_Parts by 93FIM5, on Flickr

So with that I should be able to swap the black leather over from my electric seats and completely refurbish the manuals to like new. I'm still planning on doing the saddle leather but it will need to be tied in with the door cards to look correct so Im going to put it off to winter and get the car on the road

.

 

[93FIM5]

So ordered in some feel good parts and tied up some loose ends before heading out of town this weekend.


Easy_Engine_1 by 93FIM5, on Flickr

New radiator add on shroud.


Easy_Engine_3 by 93FIM5, on Flickr

New dipstick, other one was a little dirty . . .


Easy_Engine_2 by 93FIM5, on Flickr

Cruise control cable mount.


Easy_Engine_4 by 93FIM5, on Flickr

Also got around to assembling the new calipers before having to call it a night.


M_328_Rear_Caliper_Parts by 93FIM5, on Flickr

All done and ready to be mounted when the Hawk HPS pads make it in, really really like the little "M" on them perks of 328mm rears.


M_328_Rear_Calipers_Assembled by 93FIM5, on Flickr

 

[FLarimer]

You realize of course that showing us "stuff" like this is gonna make us all crazy....

All done and ready to be mounted when the Hawk HPS pads make it in, really really like the little "M" on them perks of 328mm rears.


M_328_Rear_Calipers_Assembled by 93FIM5, on Flickr

 

[93FIM5]

You realize of course that showing us "stuff" like this is gonna make us all crazy....

Haha I think were all a bit crazy anyhow!

Spent the weekend traveling to eastern Iowa to visit the GF's family so I didn't make much progress. Managed to install new trunk shocks which made a nice improvement, I actually went with the spoiler version shock since it has a little more power and should last longer not to mention the trunk easily opens on its own now.


Trunk_Order_1 by 93FIM5, on Flickr

Still need to finish cleaning a few things up and check the trunk over to make sure its rust free and that there are no seams that need patching before installing the new trunk gasket and vents. I cleaned up a little bit of wiring going up the trunk arm and replaced the trim piece.


Trunk_Trim_1 by 93FIM5, on Flickr

That was it for this weekend.

 

[m6bigdog]

...

Just one note on the diff oil, is it LSD oil? I ask because thes diffs require the correct oil or become noisy when turning at low speeds. Castrol syntrax is what was specced and what I used after rebuilding mine.

FWIW, BMW changed the diff lube spec many years ago to SAF-XJ which is 75W-140, GL-5. see attachments.

I love it. From old to new again. BMW restoration is expensive.
I've spent so much at my local BMW dealer that I get better than the wholesale discount.
When my son was a BMW Tech he could get parts at dealer cost + 10%.
That is one reason I like buying a car new, because you can keep it new forever!!!

 

[m6bigdog]

Well it was a productive weekend, managed to check off a few things on the M5s to do list and finished up the E31 X-brace DIY. Here we go.

X-brace modified and ready to be installed.
Installed view from under the car.


X_Installed_Front by 93FIM5, on Flickr

Be aware, the swaybar arm on the E-31 with the X-brace is 5/8" shorter than the early model cars with the tube cross-member, so when the E31 swaybar from a early model with the tube cross-member is fitted on an E-31 with an X-brace the early model swaybar is moved forward enough to contact the lower control arm (arm too long) when the wheels are turned to the stops. It makes for some ugly "U" turns!! .

Therefore, I anticipate installing the X-Brace on the M5 will also move the M5 swaybar forward enough to contact the lower control arm when the wheels are turned to the stops. I assume the M5 swaybar could be taken to a spring shop and 5/8"-3/4" could be trimmed off the arms and reshaped and drilled for the swaybar link.

With that said, I love what you are doing. You are being inventive by retrofitting the best of the BMW parts bins into your build/upgrade.
My kind of guy!!! Thanks, Now I Know the X-brace fits. I'll add that to my list with the EDC suspension and 6-speed

 

[93FIM5]

FWIW, BMW changed the diff lube spec many years ago to SAF-XJ which is 75W-140, GL-5. see attachments.

I love it. From old to new again. BMW restoration is expensive.
I've spent so much at my local BMW dealer that I get better than the wholesale discount.
When my son was a BMW Tech he could get parts at dealer cost + 10%.
That is one reason I like buying a car new, because you can keep it new forever!!!

Thanks for the info on the diff oil!

Be aware, the swaybar arm on the E-31 with the X-brace is 5/8" shorter than the early model cars with the tube cross-member, so when the E31 swaybar from a early model with the tube cross-member is fitted on an E-31 with an X-brace the early model swaybar is moved forward enough to contact the lower control arm (arm too long) when the wheels are turned to the stops. It makes for some ugly "U" turns!! .

Therefore, I anticipate installing the X-Brace on the M5 will also move the M5 swaybar forward enough to contact the lower control arm when the wheels are turned to the stops. I assume the M5 swaybar could be taken to a spring shop and 5/8"-3/4" could be trimmed off the arms and reshaped and drilled for the swaybar link.

With that said, I love what you are doing. You are being inventive by retrofitting the best of the BMW parts bins into your build/upgrade.
My kind of guy!!! Thanks, Now I Know the X-brace fits. I'll add that to my list with the EDC suspension and 6-speed

Interesting and I think I noticed that the swaybar was moved slightly forward but I didn't notice any interference but that's most likely due to the suspension not being loaded (on stands). I will double check lock to lock for interference when the car is on the ground. My car MAY be ok due to the bump steer spacers but this could definitely be an issue on cars without. It looks like the E31 swaybars may fit or like you said I can modify the OEM bar, either way not a game changer but definitely something to be aware of and check. Thanks again for the heads up and compliments!

So I was able to cut and then crack the inner races on the stub axles so they will get cleaned up and installed. I also got around to prototyping a fog light switch delete plate to go along with the M Sport fog light delete plates I've been working on.


Races_Removed by 93FIM5, on Flickr


Fog_Light_Switch_Delete_1 by 93FIM5, on Flickr

Need to fix a few more gaps for the switch delete plate but it snaps in place and with a piece of the OEM radio plate cut to fit it will look OEM! So with that I should have a solution to completely delete the fog lights :7:. Now on to building the ducted front brake backing plates.

 

[m6bigdog]

93FIM5,
Not that you need encouragement, however here are a couple of items for the, M5 mission creep!!

An upgrade to Memory seats (w/bolster), memory mirrors (w/passenger side dip) and fully articulating memory steering column (w/up-down, E-34/E-32 just offered telescoping) from an E-31 with 3 spoke air-bag steering wheel.

The E-31/E-32/E-34 seat memory module does not have enough memory ports for the seat bolster and E-31 steering column so I added the E-31 steering column memory module. I reworked the M5 sport driver seat to add the memory components (motors w/memory pots, drive cables and switches) and I made new seat and body wiring harness to implement the memory functions.

 

[93FIM5]

93FIM5,
Not that you need encouragement, however here are a couple of items for the, M5 mission creep!!

An upgrade to Memory seats (w/bolster), memory mirrors (w/passenger side dip) and fully articulating memory steering column (w/up-down, E-34/E-32 just offered telescoping) from an E-31 with 3 spoke air-bag steering wheel.

The E-31/E-32/E-34 seat memory module does not have enough memory ports for the seat bolster and E-31 steering column so I added the E-31 steering column memory module. I reworked the M5 sport driver seat to add the memory components (motors w/memory pots, drive cables and switches) and I made new seat and body wiring harness to implement the memory functions.

Mission creep is already terrible!!

Very nice, hopefully others are taking notes! I personally prefer manual adjustment for seats and the added loss in weight/simplicity but part of that is because my seats were never memory, just heated and electric. That being said your work looks great, any other modifications you care to share?

 

[m6bigdog]

Thanks for the info on the diff oil!



Interesting and I think I noticed that the swaybar was moved slightly forward but I didn't notice any interference but that's most likely due to the suspension not being loaded (on stands). I will double check lock to lock for interference when the car is on the ground. My car MAY be ok due to the bump steer spacers but this could definitely be an issue on cars without. It looks like the E31 swaybars may fit or like you said I can modify the OEM bar, either way not a game changer but definitely something to be aware of and check. Thanks again for the heads up and compliments!

So I was able to cut and then crack the inner races on the stub axles so they will get cleaned up and installed. I also got around to prototyping a fog light switch delete plate to go along with the M Sport fog light delete plates I've been working on.


Races_Removed by 93FIM5, on Flickr

...

I had yet to see someone use your method; I'll have to keep that in mind just incase, I use a bearing separator to remove the inner race on my axles.

Back on the E-31 x-brace.
So, I have my parts list all together and I decided to do one last parts comparison and measurement check before I placed the order.
I'm very familiar with both since I have the M5 and 850 in my garage.
The E-31 front end track width is 3.2" wider than the E-34 and only 10-20mm (3/8" - 3/4") of that comes from the rim offset.

The only part that the E-34 & E-31 front end have in common is the lower control arm. The E-34 aluminum control arm is the exact same part as the E-31 but without the spherical bearing. The E-34 & E-31 struts (just happen to have them in my parts bins) are dimensionally very similar with no track width added from them.

I took my tape measure under the cars to see if I could find the 2-1/4" - 3" of width in other suspension parts.
Using a tape measure presents its problems however with limited space it is as good as it gets for now.
When I measured the distance between the E-31 & E-34 inner mount points of the lower control arms the 2-3/4" - 3" is the difference.
I measured the lower control arm steering ball join to ball joint distance and the E-34 is approximately 49-1/2"and the E-31 is 52-1/2" which leaves 3" in track width without the wheel offset.
The upper control on the E-31 are approximately 5/8"-3/4" longer (1-1/4"-1-1/2" total both sides) so that leaves another 1-1/2"-1-3/4" in the other parts.

The only place were I saw a measurement that was a cause for concern is the distance between the upper control arm mount points.
Measuring on my back with limited space - I measures approximately 23-1/2" for the E-34 cross member (inside to inside bolt) and 24-1/2" for the E-31 x-brace.
If my measurements are anywhere near accurate that would make the E-31 x-brace too wide at the upper control arm mounts and unusable for the E-34 without rework to move the mounts in board.

Since you have both the E-34 cross member and x-brace in the open please make some more accurate measurements between the upper control arm mount points and advise me of your findings.

Also, the E-31 x-brace swaybar arm measures 12-1/2" from the center of the bar to the link hole where as the M5 bar is closer to 13"
The swaybar mount points are both 31" wide however the spread between the swaybar links is wider on the E-31 swaybar by about 3-1/2".

So that is what I know for now...

 

[93FIM5]

I had yet to see someone use your method; I'll have to keep that in mind just incase, I use a bearing separator to remove the inner race on my axles.

Back on the E-31 x-brace.
So, I have my parts list all together and I decided to do one last parts comparison and measurement check before I placed the order.
I'm very familiar with both since I have the M5 and 850 in my garage.
The E-31 front end track width is 3.2" wider than the E-34 and only 10-20mm (3/8" - 3/4") of that comes from the rim offset.

The only part that the E-34 & E-31 front end have in common is the lower control arm. The E-34 aluminum control arm is the exact same part as the E-31 but without the spherical bearing. The E-34 & E-31 struts (just happen to have them in my parts bins) are dimensionally very similar with no track width added from them.

I took my tape measure under the cars to see if I could find the 2-1/4" - 3" of width in other suspension parts.
Using a tape measure presents its problems however with limited space it is as good as it gets for now.
When I measured the distance between the E-31 & E-34 inner mount points of the lower control arms the 2-3/4" - 3" is the difference.
I measured the lower control arm steering ball join to ball joint distance and the E-34 is approximately 49-1/2"and the E-31 is 52-1/2" which leaves 3" in track width without the wheel offset.
The upper control on the E-31 are approximately 5/8"-3/4" longer (1-1/4"-1-1/2" total both sides) so that leaves another 1-1/2"-1-3/4" in the other parts.

The only place were I saw a measurement that was a cause for concern is the distance between the upper control arm mount points.
Measuring on my back with limited space - I measures approximately 23-1/2" for the E-34 cross member (inside to inside bolt) and 24-1/2" for the E-31 x-brace.
If my measurements are anywhere near accurate that would make the E-31 x-brace too wide at the upper control arm mounts and unusable for the E-34 without rework to move the mounts in board.

Since you have both the E-34 cross member and x-brace in the open please make some more accurate measurements between the upper control arm mount points and advise me of your findings.

Also, the E-31 x-brace swaybar arm measures 12-1/2" from the center of the bar to the link hole where as the M5 bar is closer to 13"
The swaybar mount points are both 31" wide however the spread between the swaybar links is wider on the E-31 swaybar by about 3-1/2".

So that is what I know for now...

Adversity breeds innovation . . . didn't have a suitable puller and no local auto parts stores did either and I didnt feel like taking the time to build one. So out came the dremmel and the cold chisel lol.

Good info on the possible width difference, I will double check my parts tonight and post my findings. BTW here is a post from member Hugo with his install/driving experience with the x-brace. http://www.m5board.com/vbulletin/e34-m5-discussion/197786-bk01499-new-3-6-track-car-12.html

He mentions refitting the control arms as being harder but its unclear what exactly he means. I BELIEVE its due to the washers required with the Powerflex bushings hes using and the boxed nature of the x-brace mounting point vs the more open design of the standard setup. He does say the improvement is worthwhile and hasn't had any detrimental effects but it would be nice to get an update. I'm really tempted to run the 850csi front bar after a few runs with my current F/R 25/20 setup, kinda makes me hope I have interference issues so I have a legitimate excuse to try lol. I'm getting pretty anxious to get my car back on the ground and experience the changes myself! Thanks again m6bigdog for showing some possible issues to this mod so we can clear it up!

 

[m6bigdog]

...

.... BTW here is a post from member Hugo with his install/driving experience with the x-brace.

He mentions refitting the control arms as being harder but its unclear what exactly he means. I BELIEVE its due to the washers required with the Powerflex bushings hes using and the boxed nature of the x-brace mounting point vs the more open design of the standard setup. He does say the improvement is worthwhile and hasn't had any detrimental effects but it would be nice to get an update. I'm really tempted to run the 850csi front bar after a few runs with my current F/R 25/20 setup, kinda makes me hope I have interference issues so I have a legitimate excuse to try lol. I'm getting pretty anxious to get my car back on the ground and experience the changes myself! Thanks again m6bigdog for showing some possible issues to this mod so we can clear it up!

I read Hugo's post on the x-brace install post.

I hope I just made a measuring error; I've made enough of them over the last 4 years remodeling my house!!<?xml:namespace prefix = "o" ns = "urn:schemas-microsoft-com<img src=" /><o></o>
Until a measurement is made of the tube cross member and x-frame, I can only speculate on my rough measurements if they are correct and if not I apologize for creating the extra work for you.

<o></o>
<o></o>
Unfortunately, the E-31 bars will not fit on the E-34 as the E-31 bars are 3-1/2 inches wider.
Also the x-frame was installed on all E-31's not just the CSi after 4/92.

<o></o>
<o></o>
Reading the part in Hugo's discussion about heavy steering is of concern. That is what I would anticipate if the distance between the upper control arm bushing mount points is increased. The suspension geometry is determined by the location between the fixed suspension mount points and the length of the suspension arms which locate the bottom of the strut/steering arm in relation to the upper strut mount.

Spreading the upper control arm mount points not only changes the normal angle (fixed mount bolts perpendicular to the suspension arm) of the lower and upper control arms it will add caster to the front suspension geometry.
Increasing caster will make the steering heaver and will make the steering return to straight ahead position more pronounced.

Camber is not affected while the wheels are straight ahead however there will be some increase in the camber when the wheels are turned due to the added caster. The total suspension geometry changes would be best diagnosed on an alignment machine. The geometry change will also relocate the front wheel slightly forward of the designed normal position.

<o></o>
<o></o>
I don't have a distance between the lower and upper control arm chassis mount points or I would calculate the anticipated change in wheel location. The caster change will be a little more difficult to estimate because I would need the vertical (plum) location of the upper strut mount in relation to the steering arm. I don't anticipate a forward wheel location change greater than 1/4-3/8 inch. If my memory serves me well 1/4 inch would be close to .6 degree of caster change.

<o></o>
The quickest way to anticipate the upper control arm locations on the tube cross-member vs x-brace is to measure the distance between the inside bolt holes on the upper control arm bushing mount. Since the E-31 uses both the tube cross-member and x-brace I anticipate the location of the frame mount to upper control arm mount is located in the same place for the E-31, so the question is are the E-34 upper control arm mount points the same as the E-31.
<o></o>
<o></o>
The best comparative diagnostic would be to hold both suspension members with an alignment rod through the frame mount holes and install a bolt through the control arm bushing mounts on both cross members and do the comparison of the control arm bolts location and bolt angle.<o></o>
<o></o>


Patiently waiting your results.<o></o>

 

[ericono]

I'm confused (not the first time), but I thought he already has the e31 X brace installed on his e34. Are you saying that if it is installed it will throw his suspension geometry out of wack, or are you saying that it should not be physically possible to install on an e34. Sorry for my confusion, just trying to understand.

Eric

 

[m6bigdog]

I'm confused (not the first time), but I thought he already has the e31 X brace installed on his e34. Are you saying that if it is installed it will throw his suspension geometry out of wack, or are you saying that it should not be physically possible to install on an e34. Sorry for my confusion, just trying to understand.

Eric

I think it is important to wait for 93FIM5 to post his measurement findings on the distance between the upper control arm bushing mounts on the E-31 x-brace compared to the E-34 tube cross-member. I was hoping he would have posted his findings by now, so my concern and any controversy doesn't just hang on my single point observation alone. I would like nothing more than to be in error as I also would like to put the x-brace on my M5 also!!!

So maybe I will re-measure the distance between the upper control arm bushing mounts today using better methods and post my findings.

As 93FIM5 and Hugo have demonstrated the E-31 x-brace does mount on to the E-34 frame without modification.
My concerns are based on my rough (tape measure) measurements indicate the x-brace has the upper control arm bushing mounts further apart (1 inch +/-) than the stock E-34 tube cross-member. Should my measurements be correct, that will add to the E-34's front strut caster, move the steering arm (tie rod lever) forward, change the normal angle (perpendicular to the mounting bolt) of the upper & lower control arms and reposition the front wheel slightly forward of the original engineered location.

In an earlier post used the term "unusable" and that is opinionated and too subjective, I apologize and that is not what I meant. I should stay with an objective explanation; of the anticipated suspension geometry changes if the E-31 x-brace spreads the distance between the upper control arm bushing mount points.

 

[93FIM5]

I think it is important to wait for 93FIM5 to post his measurement findings on the distance between the upper control arm bushing mounts on the E-31 x-brace compared to the E-34 tube cross-member. I was hopping he would have posted his findings by now, so my concern and any controversy doesn't just hang on my single point observation alone. I would like nothing more than to be in error as I also would like to put the x-brace on my M5 also!!!

So maybe I will re-measure the distance between the upper control arm bushing mounts today using better methods and post my findings.

As 93FIM5 and Hugo have demonstrated the E-31 x-brace does mount on to the E-34 frame without modification.
My concerns are based on my rough (tape measure) measurements indicate the x-brace has the upper control arm bushing mounts further apart (1 inch +/-) than the stock E-34 tube cross-member. Should my measurements be correct, that will add to the E-34's front strut caster, move the steering arm (tie rod lever) forward, change the normal angle (perpendicular to the mounting bolt) of the upper & lower control arms and reposition the front wheel slightly forward of the original engineered location.

In an earlier post used the term "unusable" and that is opinionated and too subjective, I apologize and that is not what I meant. I should stay with an objective explanation; of the anticipated suspension geometry changes if the E-31 x-brace spreads the distance between the upper control arm bushing mount points.

I've had family in town this past weekend so didn't have a chance to make it to the car (Its about 70 miles from where I live) but I am headed there today to measure. I hope people understand I don't think m6bigdog is trying to be negative in anyway hes provided very constructive analysis of the x-brace modification. The fact is that its totally possible/probable that the front suspension geometry has been changed, now we just need to determine to what extent so we better understand the mod. If we have moved the upper control arm points further outward from the center we have added more caster due to the control arms being a fixed length and it moving the steering arms forward. This has pluses and minuses:

(+): By moving the steering arm forward weight distribution is affected since you have effectively made the wheelbase longer, very very slight improvement.

(+ or -): Steering will be heavier which some will like and some wont.

(-): Turning radius will be increased slightly, never good.

(+ or -): Steering will tend to be more "darty" so turn in will be easier but the car will also tend to follow ruts and irregularities in the road more.

(+): Allows you to run less negative static camber which improves braking performance but during a turn the car will have additional negative camber due to the increase in caster. So caster allows the tire to maintain a better contact patch through a turn.

(+): Steering will tend to self center more.

(-): If there is too much caster you can get bad weight jacking.

Now I have the ability to adjust a lot more than a stock car can since I have a coilover setup with camber/caster plates and bump steer plates installed so its going to be pretty hard for me to get a back to back comparison alignment with just the x-brace being the modification which is what we really need. As for the swaybars I'm not going to worry too much at the moment since they can be easily modified as was mentioned. Mine will eventually be replaced all together for a Schroeder type setup so for the time being they'll stay. I will post my measurement a little later today guys, again sorry for the hold up! Thanks again to m6bigdog for bringing all of this up so we can dig deeper!

 

[m6bigdog]

I've had family in town this past weekend so didn't have a chance to make it to the car (Its about 70 miles from where I live) but I am headed there today to measure. I hope people understand I don't think m6bigdog is trying to be negative in anyway hes provided very constructive analysis of the x-brace modification. The fact is that its totally possible/probable that the front suspension geometry has been changed, now we just need to determine to what extent so we better understand the mod. If we have moved the upper control arm points further outward from the center we have added more caster due to the control arms being a fixed length and it moving the steering arms forward. This has pluses and minuses:

(+): By moving the steering arm forward weight distribution is affected since you have effectively made the wheelbase longer, very very slight improvement.

(+ or -): Steering will be heavier which some will like and some wont.

(-): Turning radius will be increased slightly, never good.

(+ or -): Steering will tend to be more "darty" so turn in will be easier but the car will also tend to follow ruts and irregularities in the road more.

(+): Allows you to run less negative static camber which improves braking performance but during a turn the car will have additional negative camber due to the increase in caster. So caster allows the tire to maintain a better contact patch through a turn.

(+): Steering will tend to self center more.

(-): If there is too much caster you can get bad weight jacking.

Now I have the ability to adjust a lot more than a stock car can since I have a coilover setup with camber/caster plates and bump steer plates installed so its going to be pretty hard for me to get a back to back comparison alignment with just the x-brace being the modification which is what we really need. As for the swaybars I'm not going to worry too much at the moment since they can be easily modified as was mentioned. Mine will eventually be replaced all together for a Schroeder type setup so for the time being they'll stay. I will post my measurement a little later today guys, again sorry for the hold up! Thanks again to m6bigdog for bringing all of this up so we can dig deeper!

I went under my M5 and 850 again with some better measurement techniques to sort out the distance between the upper control arm bushing mount points.
What I found confirms my earlier measurements; the E-31 x-brace does increase the distance between the upper control arm bushings by approximately 1 inch (bummer). I guess I'll put my X-brace parts list in a to-be-determined folder.

A review of the E-31, E-32 and E-34 all have different track widths and the front suspension parts will yield only a single part that is common between all three and that is the aluminum lower control arm with the E-31 being the only one having a spherical bearing on the lower control arm.
The E-31 & E-32 have the longer upper control arm in common and the E-32 & E-34 have the front axle support in common (this axle support has 2 sets of holes to mount the lower control arm for the application). None of these vehicles share the tube cross-member, as I anticipate while they all may have common chassis mounting dimensions I anticipate the location of the upper control arm bushing are different for all three and that is where each has a different track width with common parts.

The first thing I would look for is a shorter upper control arm. The E-24/E-24 has a narrower 56.2 inch track width, uses the same diameter bushing and I anticipate the ball joint taper will fit the E-34 steering arm and if I remember correctly the control arm has a similar shape to the one on the E-34.
So the question; is the E-24/E-24 upper control arm 3/8-1/2 inch shorter and shaped correctly for use on the E-34 with the x-brace?

So, I need to get back to R&Ring the transmission on my 98-740 (making an old car new again) so while I have all the dimensions necessary to calculate the suspension geometry changes when the X-brace is installed on the E-34 it will be a while before I get to that task.

With that it will be up to others to investigate the full impact the X-brace will have on the E-34's suspension geometry, safety and performance.