Track on m3??

Post Fri Jul 08, 2005 5:25 pm

anyone know the exact figure as to how much wider the track is on an m3??? from hub face to hub face on front and rear compared to stock e30???

cheers
Karan

Post Fri Jul 08, 2005 5:42 pm

i asked this a few months ago mate
this was kelsons reply

Glenn

Had the rears off this week end to clean inside them, check brakes etc. Measured across the axle, wheel mounting flange to wheel mounting flange with the car supported on axle stands at the beam ends.

I used two steel rules and measured as close to the axle line as possible below and to the rear of the diff at about the 4 oclock position looking from the left of the car towards the right, in a straight line between the two steel rules parallel to the floor (phew). The measurement I got was 1451mm. You will need to allow a bit of variation to allow for camber variation etc but hopefully this will be close enough.

Kelson

Post Fri Jul 08, 2005 5:57 pm

Post Fri Jul 08, 2005 5:59 pm

Simon u r the man!!!!!!!!!!!!!!!!!!!!!!

what a hero

Post Fri Jul 08, 2005 6:04 pm

that equates to .35cm out mroe at the rear and .25cm at the front each side....

not much really.... so i reckon 215rubber over 8.5in rims will fit under the arches nicely with et13...

Post Fri Jul 08, 2005 6:08 pm

Karan wrote:that equates to .35cm out mroe at the rear and .25cm at the front each side....

Other way around I think.

Surprising, I'd have expected a bigger rear increase.

Post Fri Jul 08, 2005 6:20 pm

yeh oops

it is surprising actually

Post Fri Jul 08, 2005 9:30 pm

I have a piece of paper from BMW which states 1424mm for the rear. And on the next page it says 1433.

And 1412mm for the front.

Post Fri Jul 08, 2005 9:41 pm

UweM3 wrote:I have a piece of paper from BMW which states 1424mm for the rear. And on the next page it says 1433.

And 1412mm for the front.

i just realised is track measured from hub face to hub face... or wheel face to wheel face?

Post Fri Jul 08, 2005 9:47 pm

Karan wrote:
UweM3 wrote:I have a piece of paper from BMW which states 1424mm for the rear. And on the next page it says 1433.

And 1412mm for the front.
i just realised is track measured from hub face to hub face... or wheel face to wheel face?

Edit* Total width from outside edge of wheel rims afaik.???

Post Fri Jul 08, 2005 9:52 pm

I thought track was from the centre of 1 wheel to the centre of the other? Meaning the centre line of the wheels width, not it's height. Or from the outside of 1 wheel to the inside of the other. Both of those should give the same result.

Aston

Post Fri Jul 08, 2005 9:53 pm

so that is less than the hub face to hub face measurement...

u mean the actual inside of the rim?

Post Fri Jul 08, 2005 9:57 pm

I thought track was from the centre of 1 wheel to the centre of the other?

So did I, but the Autodata lists different tracks for different tyre sizes, which is why I've edited my post 3 times.

Doesn't use different offset rims for wider tyres? ??

Post Fri Jul 08, 2005 9:58 pm

Simon, what version of Autodata are you running mate?

I get this from the 2004 edition:

I get the same results for the E30 (non m3)

Andy

Post Fri Jul 08, 2005 9:59 pm

yeh id think it would be that....

anyone wanna work out how mich more a m3 hub face is outwards than a stock e30 then.....for me

Karan

Post Fri Jul 08, 2005 10:00 pm

I am not entirely sure but I thought I read it in a book from the police once. They were talking about how much the track could be changed and still be legal and they said the track was measured from the centre of 1 wheel (if you look at it from the top, so you are looking down on the tyre and then find halfway between the edges and across the width, like half of the 215 bit) to the centre of the other. Or the other way I said.

I thought it was about the wheels and not the hubs because if you put on wheels (or spacers) with a lower offset they will stick out further and effectively increase the cars track?

Aston

Post Fri Jul 08, 2005 10:14 pm

Simon, what version of Autodata are you running mate?

I get this from the 2004 edition:

2004.

That's bizarre. We've got the same screen capture (Engine code etc.), with different numbers.????

I'm on a different PC without Autodata, I'll check the other later.

Can you check the track on a 1.8 E36 M42 318Ti Compact on yours for me?

Post Sat Jul 09, 2005 12:12 am

Checked it Andy.

The track I posted is M3 86-87. Yours is M3 88-90.

The later Evo 2/3 is the same track as the 88-90.

Post Sat Jul 09, 2005 5:30 pm

Karan, I measured the rear track on my Compact this morning.

It is deffo exactly 1464 from hub face to hub face.

I've previously tried some E30 M3 hubs/discs which narrowed the track by 20mm each side. (Narrower hub/less disc offset.)

Iirc, the arms/beam are the same width, which would make the E30 M3 1424 from hub face to hub face.

1424 matches the Autodata figure. The only thing that confuses me, is that the Autodata lists the Compact as 1416.

Post Sat Jul 09, 2005 6:44 pm

cheers guys!

Post Sun Jul 10, 2005 12:44 am

Hi Simon, sorry I haven't got back to you before, I hope this is right:

Andy

Post Sun Jul 10, 2005 9:04 am

Thanks Andy, that matches mine.

Must just be the different model year for the M3s that caused the confusion. (Change of wheel rim?)

Post Sun Jul 10, 2005 10:49 am

I wonder what the possability of using M Coupe rear arms are in an E30 M3

Post Sun Jul 10, 2005 11:29 am

I wonder what the possability of using M Coupe rear arms are in an E30 M3

This Compact has a whole rear beam, arms, hubs etc from a Z3M/breadvan.

The hubs are a similar width to an E30 M3, (not as wide as a Compact). They use a huge dish/offset on the wheels which must give the increased track.

The Z3M/breadvan use bigger rear wheel bearings/shaft splines than an E30 M3.