E46 & E90 (non M Power), handling query.....

merlin

merlin

merlin

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Having had both of the above I've noticed a lot of similarities in the handling.

On a couple of occasions however the E90 has put my heart in my mouth and thinking back - I can't ever remember the E46 doing this. Will try to explain what it's doing:

Going round a sharpish high-ish speed bend, if you come off the throttle - rear end lightens up just a touch - very very subtle, nose tucks in - everything is fine and dandy. Exactly I suppose as you'd expect.

However, do the same bend and come off the throttle onto the brakes and the rear end steps out instantly, sometimes in a big way. Nose tucks in, if driving aids are odd - they ping the rear brakes, if driving aids are not on - you're needing opposite lock otherwise you'll be going agricultural pretty quickly.

The E46 never ever scared you, it was always totally planted under braking.

Either BMW have dialled this into the E90, or only other thing is perhaps I'm running the wrong tyre pressures?
 
This only happens at say > 70mph.

I suppose it could just be a handling characteristic, but it's just not something you'd expect in an oil burning rep mobile.

First time it happened I genuinely crapped myself.
 
Matt82 said:
bet you did... the whole world go in slow motion for the duration of the slide?

ask on an e90 board, there ought to be others on there that like to thrash their cars, they seem to be flat out a lot of the time from what i see!
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First time it happened I sorted it out then about 5 seconds later it just hit me that I'd got probably 30 degrees of angle going on at about 80mph with trees everywhere - it wasn't even close to being funny.

Second time it happened I had the DSC on, but still if I'm perfectly honest - it *** me up. :(

TomO said:
i know on the M3 they dialled out some understeer going from e46 to e92 and its quite noticeable in my experience. maybe something similar on the regular versions?
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I think this is a bit different, the balance of the car is spot on:

Take a bend with no throttle and mild understeer, take same bend with throttle and mild oversteer - which is totally relaxed and wouldn't scare a pensioner.

The problem is only when the car is loaded up laterally and has some speed on the go - and then you want the brakes. Suddenly the rear end weighs about 4 kilos.
 
HummuH1 said:
Every BMW I've owned delivers lift-off oversteer. If you know a car/road/track well it can be great fun and in certain circumstances, increase corner speed.

However, what you describe in the second scenario is lift-off oversteer with brakes then applied. At over 70 mph on a tight bend I think you'd find that would throw most cars into the nearest hedge.

Can't comment on the E90 but it was never going to be better that the E46 chassais, particulalry the ///M vairants. I have heard of people saying that the E90/92 is more 'oversteery' than the E46 but I'd say it's probably more of case of finding the balance of the car and that can take time.

Also, When you say you've got Pilot Sports on, I assume you mean PS2's, not the vastly inferior original Pilot Sports?
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Without correction - yes, nearest hedge here we come.

Mine is an M Sport E90 diesel. In many ways it feels like an exact replica of the E46 handling, except as said - under loaded braking.

PS2's yeah, RF's.
 
Tight-ish bends in general & over say 70mph. If i keep the throttle planted - it's fine, it's just when you think umm, maybe I should scrub some speed off here....

Perhaps the two times it happened the roads were a touch off camber and I've not really noticed? Will need to experiment once I've checked the tyre pressures and topped the life insurance.
 
Simon said:
I love the 50/50 claim.

It may be 50/50 but the actual weight is so far away from the centre of rotation that they have a large PMI (Polar moment of intertia)
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Fair old distance between engine and rear diff/rear axle.

Not difficult to get it pointing backwards.
 
Simon said:
Yeah thats what I mean, stick all the weight in the back as far as you can back and you get 50:50 still but a equally heavy back end.
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No what I mean is - would that contribute towards oversteer on braking when under lateral load?
 
Fett said:
Not the fun, progressive type of oversteer, is it?
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Certainly isn't! It feels like someone is lifting up the rear wheels off the road, not fun because it feels like it's going to snap and swap ends and there's nothing you can do about it. It doesn't swap ends - but initially it feels like it's going to because the rear just feels like it's floating. Totally different to power oversteer when you can feel through your backside the rear is down on the deck.
 
BMW sport tyres are always inflated to rock hard levels - you don't run 33psi or whatever in them - you run around 39/40psi in them.

Hence it's not quite as easy to spot a problem......
 
E46 had a dead zone in the steering, E90 no dead zone, feels good, real good.

In terms of pushing it - E46 and E90's behave much the same. Take a bend with no throttle = understeer on the limit, same bend with throttle = oversteer on the limit. DSC on the E90 allows for 15 degrees of drift before cutting in (according to the salesman (which probably means it's utter horse poo :rolleyes: )).

Brakes on the E46 were pretty good, rarely had any fade, no fade experienced on the E90 yet but I've only had it two months.

Suspension feels the same, both cars well sprung, minimal body roll.

Not really relevant but it seems with the new age 3 series things have moved up a notch with performance; E90 325d performs same as the old E46 330d and so on.

I like the gearchange on the E90 a bit better - feels precise but it's very notchy though so if effortless gear changes are your thing - avoid!

Stiff clutch is starting to affect my left leg muscles - I've started walking around in circles. :p
 
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