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?
 
come off the throttle onto the brakes and the rear end steps out instantly, sometimes in a big way
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that really doesnt sound right at all, unless youre doing that agressively as well as adding some more lock.

id expect that sort of reaction in something sharp like a 205 gti (you know the sort of thing i mean) but not a cloud on wheels bmw.

what does
if driving aids are odd
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mean?
 
aaah. just seems there must be a fair bit of rear brake bias for it to react like that when you get on the brakes mid bend. great if youre auditioning for Best Motoring, but Mrs Whoever popping down the butchers aint going to have a clue what to do.

cant be right
 
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.
 
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!
 
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?
 
My only long term experience of the E90 was 1 week in Italy last year in a 320d Touring and I can't say it's ever something I noticed or something that made me take note. I did hussle it a little across the roads of Tuscany (as much as you can a 320d) and it's not somethng that crossed my mind as being and issue so it strikes me you have an issue somewhere, perhaps tyre pressures so worth checking. It's difficult to get a view from a post as the amount of braking applied would have different consequences too as you know but if you were applying a light kiss to remove some speed and settle the car a little in bend I would not expect fireworks. If you were applying heavy braking then yes it might unsettle the arse and require some input from the steering, even with electronic in place.
 
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!
Click to expand...

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.
 
I don't know how this sounds, but my e36 can do this to me depending on the conditions.

You've gone from having throttle on, causing the rear to put more downforce on the road, when you lift throttle the rear becomes lighter but not enough to come out of step.

Yet when you touch the brakes, the front have more bias, and doing so causes the rear end to be even lighter than just lifting off. This could cause the rear to step out.

This can be made worse by road conditions, camber, tyre pressures. You say that you've got brand new tyres, i also find new tyres a bit slippier when new due to some coating to protect the rubber in storage.

Or has it done this even with used tyres?
 
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?
 
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.
 
You might have issues with tyres as said, but it might also be worth checking alignment and even brake distribution, though if there was an issue here I would expect a dashboard light. Does this happen on every bend or just a particular 'test' bend where surface and camber may have some influence.
 
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.
 
Don't forget that RWD is a killer and if you ever switch the engine on and actually drive it then it's a 50/50 if you'll reach the end of the journey.
 
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