E34 Wider Track Width?

[E34prease]

Just some pondering:

I watched a video where some guys used what they called the rear axle from an E32, but I'm assuming they took the whole rear subframe. From what I understand, they effectively widened the track width of the rear.

Accordingly, some E32 control arms are longer than that of E34s. What I am thinking is using front control arms off of an E32 on an E34, which would widen the lower part of the front wheels (negative camber), and to use camber plates or some other form of strut relocation to balance this, yielding the track width of an E32 on a smaller, lighter (still not very light) car. The point would be to have a better handling car.
I did some quick searching and I could not find much, or really anything on this. I'm looking to get some feedback, whether or not I'm just spewing nonsense or maybe this could be something worth doing.

E32 Width - 1845 mm
E34 Width - 1751 mm
Difference -> 94 mm or 4.7 cm each side.

[AHenry014]

As far as i know, the e32 and e34 front subframe is the same. The control arm inner mounting has two holes, the outer being for the e32. The e32 uses longer thrust arms and tie rods. You already know youll have to compensate for camber. As for the rear, i too have read that the trailing arms are wider, which means youll need longer axle shafts, which might not be available in a medium case flange size. It might require a large case diff swap. Youll run into wheel/tire fitment issues. The tradeoff for track width might be negated due to having to run smaller tires that will still fit in the wells.

[dgoodsy]

As for the rear, i too have read that the trailing arms are wider, which means youll need longer axle shafts, which might not be available in a medium case flange size. It might require a large case diff swap.

The e32 came with a medium case diff in the 6 cyl cars, would those axles not work? Agreed on all other points though.

[AHenry014]

Ah very good point. I didnt think of that. Yes, the 735i axles may work for this. You may need to do some diff and hub flange swapping to make it work (same as the 525i to 535i larger axle swap). Another thing i just thought of is youll need the e32 rear sway bar as well (not sure about the front, it may work with the e34 guy).

[E34prease]

As far as i know, the e32 and e34 front subframe is the same. The control arm inner mounting has two holes, the outer being for the e32. The e32 uses longer thrust arms and tie rods. You already know youll have to compensate for camber. As for the rear, i too have read that the trailing arms are wider, which means youll need longer axle shafts, which might not be available in a medium case flange size. It might require a large case diff swap. Youll run into wheel/tire fitment issues. The tradeoff for track width might be negated due to having to run smaller tires that will still fit in the wells.

Well I'm sure fitment and other details can be arranged but I was curious as whether or not there were any major hindrances. Although I'm not a fan of stance, if I were making a dedicated track car, or even a track-minded daily, I would not mind rolling the fenders or sticking some flares on.

[BleedsBlue]

One major hindrance: longer E32 LCAs in the E34 subframe LCA bolt holes place the wheels too far back in the wells (to the point of rubbing). Source: http://www.m5board.com/vbulletin/e34...dc-photos.html

This would be a sweet idea if it circumvented the need and cost of camber plates, but unfortunately I don't think it will ever work the way we're wishing. As discussed in the thread above, you could probably fix the crazy caster by using E32 UCAs, but then your camber drop will disappear. That would widen the track, though--though I expect longer tie rod ends and sway bar links, and some modification to the strut top mount will also be required in this scenario.

[E34prease]

One major hindrance: longer E32 LCAs in the E34 subframe LCA bolt holes place the wheels too far back in the wells (to the point of rubbing). Source: http://www.m5board.com/vbulletin/e34...dc-photos.html This would be a sweet idea if it circumvented the need and cost of camber plates, but unfortunately I don't think it will ever work the way we're wishing. As discussed in the thread above, you could probably fix the crazy caster by using E32 UCAs, but then your camber drop will disappear. That would widen the track, though--though I expect longer tie rod ends and sway bar links, and some modification to the strut top mount will also be required in this scenario.

As stated earlier, also what I've heard, that there are both holes in the e34 subframe, as in there is an empty hole, where had it been an e32, the control arm would go. Or would this yield the same problem?

[eddycooper]

RealOEM shows that:
- subframe is same for E34 and E32
- upper control arms are different
- the tubular frame that the lower control arms bolt to is different
- lower control arms are same
- outer steering arms (the ones that are bolted to the bottom of the struts) are the same

[straight6pwr]

wider wheel/tire = wider track.
add spacers = wider track.
not sure why you want to go through all that fuss to achieve what is fairly easy already.

[Hofmeister]

wider wheel/tire = wider track.
add spacers = wider track.
not sure why you want to go through all that fuss to achieve what is fairly easy already.

this is what i was thinking. i can see it beneficial at the front to avoid having the steering axis shift

[BleedsBlue]

As stated earlier, also what I've heard, that there are both holes in the e34 subframe, as in there is an empty hole, where had it been an e32, the control arm would go. Or would this yield the same problem?

I'm sorry, you'll have to re-word that one. No comprendo.

[E34prease]

I'm sorry, you'll have to re-word that one. No comprendo.

E34 and e32 subframes are the same, CA placement is different.

[E34prease]

wider wheel/tire = wider track. add spacers = wider track. not sure why you want to go through all that fuss to achieve what is fairly easy already.

Just ideas. Maybe someone wanted to go to the extreme. Like some hill climb cars where the wheel is completely out of the body.

[Hofmeister]

Just ideas. Maybe someone wanted to go to the extreme. Like some hill climb cars where the wheel is completely out of the body.

as he said, e32 rear arms and just move the front ones to the next. Throw a bit of spacer for the extra wide and you have this

[jawnswagg3r]

dont know why i missed this. i run the longer e32 upper control arms with the lower control arms in the outboard e32 holes, instead of the stock inward e34 holes. not super extreme.... but definitely a wider track. e34/32 tie rods are same P/N just have to be lengthened to fit. everything is compatible, suspension geometry is now e32 stock essentially. i run kmac camber plates. only thing i have problems with is fender clearance. lowered on vogtlands, i have severe rubbing with 17x8 et20 style 19s. 235/35/17 i think? hankooks. basically waiting on coils to really figure out fitment... looks and drives good with a healthy few degrees of camber. trying to figure out a clean way to creatively widen the front fenders...

heres where i'm at now tho, virgin fenders. with, of course, e32 control arms

[Layne]

suspension geometry is now e32 stock essentially.

Your shock towers are inboard of where they would be on an E32, so you have much more negative camber.

[ross1]

Your shock towers are inboard of where they would be on an E32, so you have much more negative camber.

And bump steer to boot.

[BleedsBlue]

I'd be interested to see where you are with negative camber, jawnswagg3r. As well as caster. It's crazy the track is so wide now that the super-conservative wheel and tire set-up you have is so close to rub! I guess you'd need to run much higher offsets to get wide rubber up front--which seems like a neutral side-effect compared to just running wider, low-offset wheels with stock track control arms. Unless you're all about that deep dish

[Tre0Tre34]

Who's not about that deep dish?

Sorry, just got the summer set on today... It was a long winter... In which it didnt really snow that much... But when it did, i was glad to have the blizzaks mounted

[Hofmeister]

Just spacing the tire out will cause trouble in the front. Steering feedback can get out of whack, plus scrub radius increases. Thats why you want the tire to turn around the center point. Both ways of increasing width will need the same ammount of fender work, but one will will have better handling. For the rear so long as you compensate with stiffer springs you can get away with it