understeer - oversteer

[billgatese30]

i've heard that e30's understeer quite a bit before they oversteer(as long as your smooth) however other people(mostly arses that i have had the unfortune to meet) have said that they just overster like mad. i would have emagined that they understeer quite alot before going sideways because of all the wieght up front entering the bend, and then breaking away under sharp power or sharp decelaration.

just trying to sum up the sport(standard suspension) before i take it out on the roads.

any help is welcome, cheers

[Dom]

depends on the road surface/tyre pressures etc... I haven't managed to make mine understeer yet!

[Jhonno]

i've never really had terminal understeer from mine, but it does understeer slightly, altho that can be adjusted..

[billgatese30]

i know that they can be quite good for oversteer(on purpose) plus yours is a four pot, and therefor carrying less nose wieght into the corners, making it less likly to understeer. plus i'm not talking about making it oversteer on purpose, i.e. stabbing the throttle mid corner. i was meaning gently powering through the corner whilst keeping everything nicley balenced and smooth. so with that in mind does any one have any experience of understeer or does it just oversteer pretty much from the start.

cheers dom and any one else who adds to this.

[Jhonno]

in terms of that then i've never had understeer from mine in that situation, its on M-tech sus and balloon tyres..

i have notice the light back end tho when brakin in anything other than a straightline

[Dom]

coming through a sweeping bend with the power mine steps out but if you know it's coming you can keep the throttle down a tad it won't.

If you asked the same question in the summer I'm sure you'd get different answers

[billgatese30]

i know, talk about the wrong time to buy a sport.

hope it doesn't get too

not yet any way.

[Dom]

drive it with respect and it won't bite

[billgatese30]

don't worry, i plan to respect it as it should(if i don't simon might come looking for me )

have to get some practice in in an abandoned car park preferably with no stones, (do any of the northern lads no of any near me by any chance???)

[johnono]

small blocks (s14, 1,6-8is) are lighter and i suppose with fat tyres they would hold but i guess with a 2 or 2,5 like yours, it could slide a little in a constant tight turn ( trying to start a dounut the wrong way )

i have done this myself and scared my passenger a fair bit, i have 215 front and back

[Demlotcrew]

Wider tires dont give more grip!
Now the M3 is a heavy car, it wieghts more than a 325i. It has 50/50 split thats why it handles so well.
ARB's will sort out over/under steer.

Andrew

[jmc330i]

Ive only ever had mine understeer noticeably in a car park with a naff surface in the wet.

Ive always found in the dry, mine steers in pretty well through sweeping corners and then powers out the otherside in a fairly controlled manner. I guess because of the LSD - Ive never driven a RWD without an LSD so cant compare.
On some corners it can drift out slightly but nothing to worrying.

It probably depends on your tyres too. Having better tyres on the front and worn tyres on the back should make it easier to oversteer.

[calder]

i think your first two posts have it pretty much right - given that you're taking the car round a fairly constant corner on balanced throttle and progressively increasing throttle the car will power understeer.
I won't claim to be an expert on this and it does all depend what suspension set up is on the car (i know you said standard sport) as to where the balance is but it's all a matter of degree.
My experience is limited to race car on track only - so i can't really say about the roads.
I suspect that most peoples road experience will come from provoking the car by blipping the throttle on or off to get over steer rather than reaching the limit smoothly to understeer.
Engine power and road condition (wet/dry) will have effect how the car behaves if you nail the throttle in the bend but that's provoking. If you're on a track or airfield then of course you can put in simultaneous brake and throttle inputs to make the car do anything you like but that's something I'm still working up to.

[Widge]

Hi,
My 325i SE is under steering like a pig in slow ish corners at the mo, but it's only cos the front tyres are quite flat and I'm getting a lot of slip with the big 6 pot up front. Note to self put some air in the front tyres, probably goo dto have it over steering as they say snow is on the way

PS billgatese30- haven't you discovered the car park on the north bank of the river Tyne just past the level of the Baltic? going out to sea. Suppose it depend where in T&W you are

[billgatese30]

i live in washington, usually go to makro overflow carpark but it is starting to get full of stones and blown ovre bits of trees, not to mention the crap the gypsy's leave behind.

[Widge]

U R better at Makro cos they've started pulling this one up to build somthing. It used to be HUGE, cos it was where all the workers in one of the ship yards would park during the day so at night it was empty and no railings kerbs etc. used to be a good 500 by 100 m. only wished they hadn't pulled it up before I got a Beemer. I go round an industrial park in benton now cos it's gort roundabouts.

[billgatese30]

makro is ok, but the largest bit is full of inch deep pot holes which are about a foot in diameter and is full of stones, and the smaller bit is...well...small. i need to find somewhere else as all the good industrial estates in washington eithter have cops pulling little gits trying to rob B&Q or they all have trucks moving deliveries on nightshift.

[CaesarBob]

The E30s were originally set up to mildly understeer and then oversteer. BMWs of this era did earn a rep for oversteering wildly but that was usually because owners didn't show any respect in poor weather conditions.

On greasy roads my iS will understeer first and then wag it's tail on the exit of a bend if your committed. Obviously when you mash the loud pedal mid bend (especially on off camber bends) the back end will slide quite a lot.

[mrLEE30]

My cab understeers if pushed hard into a roundabout but to get the front end to grip a bit i use a touch of left foot braking (a technique you need to practice with no one around) then once front end settled controled power should get the rear end out a touch. I race karts so similar principles.

[nwmlarge]

i find my 316 understeers but it has basic tyres on it and it has no power to oversteer properly even lift off oversteer is tricky.

i need more practise on quiet roads

[TVRTASMIN]

Wider tires dont give more grip!

Andrew

? So why do 300+ BHP sportscars have wide tyres. Not to mention F1.

[nwmlarge]

Wider tires dont give more grip!

Andrew

? So why do 300+ BHP sportscars have wide tyres. Not to mention F1.

thats down to a combination of excess of power therefore requiring a greater surface area. also they tend to benefit from smooth surfaces to drive on therefore the wider tyres are gripping all the time rather than on the road where they tend to get bumped around in turn decreasing the contact patch.

the best way to increase grip is to maximise useable contact patch

this is a combo of suspension set up
centre of gravity
and tyre choice.

why else would you use thinner tyres in the winter

[Simon]

Now the M3 is a heavy car, it wieghts more than a 325i.

Same weight 1200kg

[billgatese30]

i thought the sports were about 1350kg

[Simon]

i thought the sports were about 1350kg

Not sure..poverty spec 325i with full tank is 1200kg. It's that bodykit that probably weights it down!

[billgatese30]

couldn't say for definate exactly what the wieght is, just 1350 sprung to mind for some reason.

[Simon]

Deffo not 1350kg!! Just had a look now and a 325ix touring weighs 1350kg!

[Andy335Touring]

2dr 325 1180kg
325 sport 1202kg
M3 1168kg
325 Touring 1270kg
325 Cab 1310kg

[Simon]

2dr 325 1180kg
325 sport 1202kg
M3 1168kg
325 Touring 1270kg
325 Cab 1310kg

Where did these figures come from Andy?

[billgatese30]

must of been one of those then, just sprung to mind for some reason.

cheers guys

[Andy335Touring]

2dr 325 1180kg
325 sport 1202kg
M3 1168kg
325 Touring 1270kg
325 Cab 1310kg

Where did these figures come from Andy?

From the hand book and from a book i borrowed called Gold Portfolio,it's full of old E30 road tests and specs'.

[Simon]

From the hand book and from a book i borrowed called Gold Portfolio,it's full of old E30 road tests and specs'.

Ah OK, I got the owners handbook here too and mine quote different!! Strange

[M3RAGS]

those weights are not correct

[billgatese30]

simon, what does the hand book for the port say???

[Simon]

simon, what does the hand book for the port say???

Handbook doesn't mention the sport, it lists everything else though.