Re: <E28> What made M5 Handle (Part 1)

[Richard Nott <gis@xxxxxxxxxxxxxxxx>]

 Scott, Thanks for the Stir  : )     I think I can answer most of them  ;  )

SMILLER@domain.elided wrote:

> Boy, Richard, trying to start a flame war while so many others are still
> going on, that's brave!
> >
> >The E28 M5 had a reputation as a great handling car - WITHOUT the
> >tendency for the back of the car to flick out with no warning in the wet
> >- unlike the standard 535, 528, or the even worse 520.
>
> NO BMW since at least the mid-'60s has had a 65/35 weight distribution,
> that's more like what you'd find in a front wheel drive car.  The E28
> chassis is very close to 50/50.

Sorry Scott, your Wrong!.  To quote Autocar, 20 June 1981:...While we were
witnessing a quick run up the wind tunnel at BMW's Ismaning R and D
establishment outside Munich, a BMW engineer produced figures to show... -
distributed in a virtually unchanged 65/35 front to rear"   They were comparing
it's weight distribution to the recently replaced E12 5 Series.  The
distribution did not change throughout it's life, infact in a much heavier 535
with bigger engine and gearbox, it got worse.  For more information on the
weight distribution and poor wet weather handling buy a copy of "BMW 5 Series
Gold Portfolio (81-87) It's a great book and a real eye opener, well worth the
read.  Lots of articles on the M5, M535i, 535i, 533, 528i, Alpina B10, Hartge,
etc. Quite a few different magazine articles point out the poor 65/35 weight
distribution.

In another article by Autosport, June 20, 1985 regarding the 535i and it's
tendency in the wet, for the back of the car to swing around in front of you
without warning states: "in the wet... instead of going off backwards" (like the
E12) "you find that strong understeer builds up.  Lifting off under such
conditions, however, brings back the good old BMW trait - the tail comes out.  I
suspect this model, like the 3 series of old, could be great fun and quite
spectacular on the track, but by the same token it is a bit hairy for the road."

In the wet the E28 can be dangerous if your unlucky enough to meet an 'unusual'
road condition.  It will bite you before you know it.  This tendency is made
even worse with 225/50/16 tires all round.  In the wet the problem will leap out
in the most dangerous places: Over the crests of hills in the middle of a bend,
or off camber bends especially if there are one or two little bumps.  And it
isn't nice progressive oversteer, it's violent oversteer without warning .  See
the book above.

This is why German Firms like Alpina and Hartge fitted 205/55/16 Front and
225/50/16 in the rear, to fix this problem.  Or for people wanting more grip
225/50 F, 245/45 R.

> I had a 1988 535i with Dinan Stage 3 suspension, so it was lowered and
> had more negative camber than the stock cars.  When the rear broke
> loose, it did so gradually and controllably.  I did not find this to be a
> problem.

Yes, the E28 is great in the dry, very predictable and controllable.  I don't
think I'd like a Dinan Stage 3 though.  A bit too harsh for me.

> >What can you do to make your non-M5 'Touring Car' handle great?:
> >1.  Fit F/R: 205/55/16, 225/50/16 Soft Compound Tyres as done by
> >Alpina.
>
> Larger rear tires will decrease oversteer and increase understeer.  If
> understeer is how you define "great" handling, go ahead.

It depends on whether you want a track car, or a car that can be driven 'very'
quickly and very safely under all conditions.  I think BMW's M3 defines "great"
handling as slight understeer at the limit with the possibility of oversteer
with applied throttle.  Mine is the same, so I'm in good company.

> The Konis I've seen (here in the U.S.) are pretty darn stiff, even when
> adjusted to their softest setting.

I agree. Way too harsh if you use Koni's on sport springs.  I know on a previous
528i I owned I tried this and found the Koni's way too harsh.  The fix was to
have the gas let out of them with the Sport Spring.  But on Standard BMW Springs
they are simply brilliant.

> I'm not familiar with Bilstein "Comforts".  I've seen 3 levels:
> Street, Heavy Duty and Sport.
>  It isn't clear whether your suggestion of Comforts would
> be more like HDs or like Streets.

Yeah, different names, different markets... Sprint, Comfort, etc, etc,
Symantics... what can you do?.
I have one step down from the Sports.  HD's I think you'd call them.  They make
the back of the car firmer, the idea being to reduce understeer a little and
make it a more sporting drive, but not Rock Hard like the Sports.
Continued Part 2...

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