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camber, caster & toe

Posted: Wed Jun 23, 2010 7:21 pm
by e21-Mark
I was hoping those of you with experience in setting up e21 suspension could give me some advice on settings for my car now that the rear is adjustable for camber and the front top mounts are in etc?

Although I am hoping to do some track days it is a road car primarily so I want it to be a compromise between handling and comfort.

Anyway, your advice / suggestions would be much appreciated please guys.

Posted: Wed Jun 23, 2010 7:28 pm
by tommi_e21
i think you will get a massive amount of different opinions buddy

im all for lots of negative camber as it gives better cornering but gives uneven tyre wear.

others will say that having a zero camber offers better traction round corners and there are arguments for both sides. zero tolerence will give a better straight line traction.

the only way really is to take it on track and find out what you prefer the best and what gets you the best results.

really what it all boils down to is how often you use your car on the road.

e.g. if i had it my own way my car would be 3mm of the floor which gives the best handling but useless for daily use.

its the same really for suspension geomety set ups in other ways

(roll on the arguments from other members :) )

Posted: Wed Jun 23, 2010 9:03 pm
by e21-Mark
It's not opinions I'm after, more peoples experience.

Nothing wrong with a bit of negative camber but excessive ( over 3 degrees ) does nothing to aid handling. Especially with BM's were the negative camber increases as the springs compress.

Posted: Wed Jun 23, 2010 11:28 pm
by murran
id go 1 degree neg on the back. slight toe in (couple of mms).

half/.75 a degree on the front. very slight toe in.
castor wise..... unless your unhappy with the self centering effect (too fast or not fast enough) i wouldnt go changing it from standard.
*edit* yours has that new fangled power steering thingymebob doesnt it? in which case id be tempted to stick a bit more castor on it as power steering tends to numb the steering feel.

if id bought those top mounts...... id have put more castor on mine to aid the self centering as thats what you want when drifting! let the car do the opposite lock work for you, yove just got to initiate then (clutch kick, flick or shift lock, even a good tug on the handbrake) let go of the wheel and catch it before it corrects itself, control it on the throttle and smoke 'em up on the exit.

i need another drift day!

Posted: Wed Jun 23, 2010 11:35 pm
by e21-Mark
Cheers for that.

I don't have flower steering though. :wink: I much prefer the feel of non-assisted.

Jason has given me some suggestions too. I'm confident that the guys at RPM will set things up but its a big help to get input from those of you who track or compete in their cars.

Posted: Thu Jun 24, 2010 12:30 am
by --ALPINA--
RetroBeemer wrote:It's not opinions I'm after, more peoples experience.

Nothing wrong with a bit of negative camber but excessive ( over 3 degrees ) does nothing to aid handling. Especially with BM's were the negative camber increases as the springs compress.
LOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOL, need a breather ..... LOOOOOOOOOOOL

oh and LOL :D


J

Posted: Thu Jun 24, 2010 4:09 am
by Madhatter
I firmly believe a lot of people put adjustible components on cars with no real intent on racing, so what is the point in varying from the factory setting? if you are worried about tyre wear at all, then you dont really have any reason to be adjusting your alignment outside of factory.

Front

Camber: -3.5 to -4 degrees.

Caster: As much as physically possible.

Toe: Zero. even slightly toed out.

Rear

Toe: Toe in slightly, 0.5-1mm is more than enough.

Camber: As little as possible. Negative camber increases under compression of the IRS rear in the bmw's, you dont need to add more to the situation.

Caster: wont be adjustible.

Otherwise, stick with the factory alignment specs, reduce the rear camber a little and run as much caster as you can in the front.

Posted: Thu Jun 24, 2010 8:05 am
by e21-Mark
I can't speak for anyone else but I wanted to change / improve my car for track days aswell as road use. If that means some extra tyre wear, so be it. Quality part worns can be bought for just a few quid anyway.
There's no doubt that my cars suspension & handling is far better than it was anyway and I enjoy my car all the more for it. In fact, I think the fun factor and enjoyment of my car are the biggest factors, or else I'd drive something totally stock or modern. If it was just about ultimate performance I could have bought an e36 M3 Evo far cheaper! :)

Posted: Thu Jun 24, 2010 9:58 am
by Madhatter
Yes, but the problem is, small changes dont really do a whole lot. If you want to set it up for the track, then the trade off is that its going to be twitchy on the road and its going to wear tyres. Otherwise, like i said, you are better off just sticking with the factory settings, there isnt anything wrong with them.

Only thing that you are really going to benefit from is fixing up the rear camber which will be way out of whack now and running some more caster in the front to help it turn in. You should leave all the other specs factory and just enjoy it. Improved suspension, brakes and tyres are going to result in bigger gains in grip and handling than altering the alignment settings.

Posted: Thu Jun 24, 2010 2:17 pm
by Duracel79
Mark,

As mentioned above, best to run two setups. One for the road and one for track.

What I set mine to all at the same ride height of ~100mm to the chassis rails.

Road:

Front
Camber -1°
Toe In slight

Rear
Camber -1.5°


Race:

Front
Camber -3.5°
Toe Out slightly

Rear
Camber -3°

I don't have caster adjustment or rear toe adjustment mind.

Ben

Posted: Thu Jun 24, 2010 9:06 pm
by PeteK
On the e21 323i which is road with some slight track we have:
Front
Camber - 1 deg
Caster : Standard
Toe: 0

Rear
Stock

On the e12 which is track only we have:
Front
Camber: -3.5 deg
Caster: standard
Toe: Out 1 mm
Rear
Stock

The more camber you get at the front, the better corner grip. 3.5 is as far as the e12 will go without doing some cutting and welding. Toe-in gives you stability and toe-out gives you better turn-in (reduces understeer as inside wheel has tighter turn radius). We adjusted the rears to standard as they gain so much camber when we lowered it.

I've not done anything with caster as I'm still working through ride height, spring rates, sway bar rates, camber, toe in, tyre pressure options.

With the adjustable set ups, it's to get the different settings, not so you can change it between track and road. That would drive you nuts. I ran -2 deg camber on the e12 on the road for years and it was fine. You need some neg camber on the front at the track or you'll destroy your tyres to fast.

Cheers

Posted: Thu Jun 24, 2010 9:35 pm
by e21-Mark
Thanks for the input guys.

Posted: Thu Jun 24, 2010 11:15 pm
by drjim
My car just has the suspension how it bolted together and goes fine!

Re: camber, caster & toe

Posted: Tue May 10, 2011 8:31 pm
by e21-Mark
Am planning to get the car corner weighted prior to Crystal Palace and might run stiffer springs than the road one's as opposed to just winding the dampers up. I was also wondering if everyone running coilovers still runs their ARB's?

Re: camber, caster & toe

Posted: Tue May 10, 2011 8:46 pm
by PeteK
I've still got the anti roll bars on. I went stiffer front and rear. I have coilovers on the back and lower & stiffer springs on the front.

The rear ARB was good, but reduces traction and creates wheelspin. Need to get an LSD!