geometry differences of E36 M3 Spindle to E36 Spindle?

[freeski27]

what are the geometric differences between the two? i.e. - offset, camber, caster, etc.

I have a 5 lug setup with mostly e36 stuff with the exception of m3 control arms and offset CAB's. But I would really prefer a bit more caster, and I'm wondering if the m3 spindles will do that for me.

the other consideration is to do a custom CAB mount...

[freeski27]

anyone?

[Hellabad]

There are two M3 spindles, and one 325/328 spindle as far as I know. (there are different casting numbers with the same geometry)

The main difference between 325 and M3 is in the angle tilted back, which affects where the tie-rod is, which affects bumpsteer. This is where Ground Control builds the e36 on e30 kits differently.

That is the reason how you can inadvertently bolt together e36 parts onto an e30 and it drives worse than before.

There is also a teeny teeny difference in camber from 95M3 to 96M3, but is so small it is hard to measure even in a jig.

The spindle will NOT affect the caster, that needs to be accomplished with the correct lower control arms and bushings.

Jay from GC

[Aptyp]

disregard Jay's post... he's just trying to push his product :)

Differences are very visible there. Because e36 strut towers are more vertical than e30, on M3s e36 pushed spindle forward by moving outer balljoint back. That matched to e36m3 control arms and you get a near perfect caster and camber. In my 5-lug thread, I put up my alignment numbers, so you can see it within specs with factory e30 alignment.


There is a way to make e30 handle worse, though. It is to manipulate strut housing to angle spindle over the ball joint and thereby moving tie-rod lower as well.

[Skafrog]

disregard Jay's post... he's just trying to push his product :)

Can't let this one go. I find it laughable how you have "figured" out the 5 lug swap, and then tell Jay that he doesn't know what is going on. Humility goes a long way, and seems to be something you should practice since what you have posted on your "comprehensive" 5 lug website is nothing but re-hashed ideas which have been floating around race tracks across the country for 8+ years.
Ground-Control makes parts specifically for 5 lug e30 track cars which fix many of the inherent problems of swapped cars, most of which are not listed in the main catalog. Some of these problems I am willing to bet you have never experienced, since I doubt you have never tried to put an 305/645/18 slick on a 5 lug e30 while maintaining stock fenders required by BMWCCA regulations.
Side note: What year e36 m3 spindle did you post in your picture?

[Aptyp]

Jay definitely knows what he's talking about... and those two pics back-up 2 of the paragraphs he wrote, but the spindle does effect caster. Ball joint mounting is 10mm offset for extra caster. That's what pics are trying to show.

All the ideas floating at racetracks for who knows how many years are fine and dandy... Using those "ideas", when I took my rear apart left me scratching my head for answers and decommissioned my car for a few weeks. Because everyone had "ideas" and and every yuppie asshole was happy to add his opinion to a database of untried theories. No rehashing for me, I tried all of the options (e36 and e36m spindles, e30 and e36m control arms, camber plates, control arm bushings). And why would try fitting 305's in the back on 18" rim? EVEN IF it was for the track? I've never had anything bigger than 245 on a 17, and a lot of BMWCCA guys were asking a lot of questions about the setup at VIR. I guess they were the ones that didn't get the "rehashed ideas" memo either.

Spindle shown is the s52 e36m3 (m-roadster/m-coupe). You can see the part number in the pic "907". As Jay was saying there's a small difference in camber between s52 models and early s50 model spindles. Only way I can notice it, is with everything installed. Looking at two spindles, I thought all I saw was a slight manufacturing imperfection.

And there's a lot of humility... I will bow down and order coilovers from Jay, when time comes again, like I did last time. I'd love to one day have their complete setup, without spending hours at home and in the garage figuring everything out for myself by myself.

[xschop]

Hey Guys (and gals) I signed up because I looked everywhere for this spindle difference info and landed here. I saw another post by user Massive Lee stating the e36 M3 caliper mounting ears are 6.9mm "inward" and the mount radii (caliper bolt hole centers to spindle center) are 2mm shorter than non M3. Can anyone confirm this info. I am putting Wilwood Superlites 4-pot calipers and 325 x 28 rotors (2001 M3) on a 1995 318ti and want to make the adapter for the M3 as well for a friend that is swapping in a V8. Thanks for any help.

[xschop]

Bump for confirmation

I dissected the e36 non-M3 spindle today and mic'd everything with dial indicators. The spindle shaft is 37mm, not sure what the e30 is but I heard it was smaller. The caliper mount radii are 100mm exact so I mocked up a 1/4 moon shaped adapter for the Wilwood caliper. After grinding off the squared edges of the top spindle ear, it fits like a glove with the 2001 M3 rotor.....325 x 28