e36 M3 geo settings - what do YOU think?

[GTWayne]

I am writing this post for two reasons really, firstly; I had a fantastic day @ Goodwood on 6.6.09 and went round in circles more rapidly than ever before ( just HAD to tell you that ) and secondly and more pertinent to the above title I guess; After taking the car to Ray West for a hasty geo the day before a shakedown run @ Hullavington on 5.6.09 I came away with 3.5 degrees negative camber on the front and every other parameter stayed unchanged because all bolts necessary to make key adjustments were found to be seized, buggered or broken so it was decided to leave well alone and re attempt at a later more organised date once we had the service items in hand. Point is, the car handled really well with mega sharp turn in, minimal roll ( I don't have an anti roll bar fitted at present ) and the only noticeable down side seemed to be a light-ish back end that skipped a little when pushed hard. I was using slicks but things were nowhere near as finite as I was led to believe they might have been. What do you think I should expect to change and what can be done in any specific area to plant the back end and make it more stable but in doing so, is this likely to offer less of a transition between mega grip and possibly finding myself air born?

[swtmerce]

What suspension are you running? Is it height and damping adjustable? If so, what heights are hub to arch for front and rear?

[dan101smith]

Well....

Firstly, glad you enjoyed the trackday.

Secondly, a wayward rear is fairly common on stripped E36s.

I've already forgotten if you're on coilovers, but if you are, then getting the car corner-weighted is a useful first step.

When did you find the rear most loose - high or low speed corners, or under braking?

[GTWayne]

I have two way adjustable Leda coilovers.
Will measure the hub to wheel arch when I get home tonight or first thing in the morning.
The rear of the car is only really moving about in high speed, long corners; fine under very heavy braking ie. 150yrds from corner @ 130mph and the only slow part of Goodwood is the chicane and the wheels were spining under early acceleration on the way out but it was very controllable which I did not expect from slicks.

[teabagger]

Have read of this:

http://forums.bimmerforums.com/forum/showthread.ph...


I ended up going for:
front:
camber: swopped evo top mount to give aroung -3.0deg each side
toe: 0 toe

rear:
camber: -1deg50min each side
toe: -0deg 10min each side

my car feels good on these settings, tyre wear is also the best its ever been.

[GTWayne]

swtmerce said:

What suspension are you running?

Leda coil overs

swtmerce said:

Is it height and damping adjustable? If so, what heights are hub to arch for front and rear?

Yes, 320mm front and rear ( give or take a mm or two )

[dan101smith]

Have it properly cornerweighted. When you say the back felt loose, was it actually sliding, or just rolling more than the front?

Mine's light at the rear and so the back is very mobile - I quite like that because it's very progressive (you can steer with the brakes, go-cart style).

[GTWayne]

Spoke to Ray West today and am looking at having the car properly corner weighted along with some specific adjustments made to the rear suspension including a limiting kit in a week or so.
The car slides, or tries to but with the slicks it is more like a corner induced skip. This trait needs to be eradicated before I can move forward. I quite like the car feeling loose but I need to be able to get the power down ASAP I am happy with the front end @ 3.5 degrees neg. and 0 toe but am going to have 2.0 degrees neg. and .20 toe put on the rear ( unless Ray thinks this to be a bad idea ) and see how I get on with that. I don't think the car needs to be any lower than it is now and besides how well it handles I also feel that it looks right with the typical nose down attitude that BMW's seem to like.

[swtmerce]

A tried and tested height set up is around 320 at the front and 305 at the rear. What those settings are trying to replicate is to have the front lower arms at horizontal i.e. parallel to the road but it's difficult to do without access to a ramp. The rear is then set a bit higher to give some rake. Go too low and you get terrible geo at the front as the 'beyond horizontal' arms massively effect the camber as the suspension compresses. Overly low also makes for a lot of understeer.

[dan101smith]

I forgot to ask about bushes. The slicks put a massive amount of stress on standard ones. Have you got Powerflex on there? If you're looking at limiting kits then I guess not.

BTW, I'm at Bedford on the 29th if you fancy it? Open pitlane for £129...

[GTWayne]

^^^ I ordered the limiting kit from Simpsons and during the conversation asked about Powerflex bushes and was advised against them; how do you get on with them then Dan? The V8M3 that I have set about creating will have fully rose jointed suspension and every conceivable necessary extra but my current M3 only needs to be as good as it can be within a given investment threshold which I am fast approaching.

I am at Silverstone on 26.6.09 having a days tuition so it may be a good idea to visit a venue soon after to evaluate what I hope to have learned, I will give it careful consideration; what is the noise limit?, I am currently at 102db

[GTWayne]

swtmerce said:

...320 at the front and 305 at the rear...

Thanks for that, I will relay the info to Ray West and if he agrees we will put it into practice

[dan101smith]

I actually don't have Powerflex bushes, I've got standard ones plus a Turner limiting kit (also from Simpsons, but done by the previous owner). That's one reason why I haven't run slicks on mine - I even bought a set but sold them unused.

I'll probably go for Powerflex Blacks, unless the regs allow for solid anywhere in which case those.

I don't think it's the bushes on mine that make the back end so mobile. I think it's the fact the stance is like this:



Even now it isn't much better:



But I'm yet to replace my coilovers, so I've not got round to adjusting the rear ride height / corner weighting.

[GTWayne]

Took Spot II over to West Tuning yesterday and tried to adjust the geo on the back. The NS carrier is bent it would seem ( there is evidence of some body repair on that side of the car so maybe that is where it originated from? ) and only .75 neg. camber was achievable so this was duplicated on the OS too. We dropped the car at the back by 4 turns of the adjuster rings ( coil overs ). I had said to Ray that I wanted the car corner weighted and he said that he would be happy to do it for me but in his opinion was a waste of money as with tin top road/track cars it is just overkill. To be honest I was in two minds but the car felt little different on the trip home ( I know it is road, not track ) and I found myself pondering the benefits of such race tuning pertaining to this type of car at this level for ME
Something worth mentioning is that when Ray saw my wheel studs ( screw in type ) he saw fit to mention that if using slicks these would very likely fail do to the increased load put on them. As I intend to replace the above damaged carrier using donor parts from Spot I, I will also take the opportunity to recon the hubs drilling them out and fitting proper MS rolled studs along with ali bolts ( just ordered from DT @ £200 ) and fit new bearings whilst I at it. I am now getting to the stage where new parts that I am buying for Spot II are only being purchased with a mind to use them at a later to upgrade Spot III. I have just bought some plastic headlamps, so things are getting serious

Dan101; I managed to find a Z3 2.8 rack and as I need new steering arms and TR ends thought I would do it all at once but I must say that if I did not know better, I would never have noticed the difference, but maybe I am just not sensitive enough?
I happened to notice on another thread that you are going the full Suprsprint route - I am also using this system but beware it is loud - like 102db @ Goodwood ( although apparently they are tighter than most and do tend to read a little on the high side )

[dan101smith]

GTWayne said:

Dan101; I managed to find a Z3 2.8 rack and as I need new steering arms and TR ends thought I would do it all at once but I must say that if I did not know better, I would never have noticed the difference, but maybe I am just not sensitive enough?
I happened to notice on another thread that you are going the full Suprsprint route - I am also using this system but beware it is loud - like 102db @ Goodwood ( although apparently they are tighter than most and do tend to read a little on the high side )

The Z3 2.8 rack is the wrong one - you need one from a 4-cyl model (1.8/1.9).

I've got the Supersprint decat, but will be getting a custom backbox to keep the sound below trackday limits for now.

[GTWayne]

dan101smith said:

GTWayne said:

...The Z3 2.8 rack is the wrong one - you need one from a 4-cyl model (1.8/1.9)....

:headbang: B*ll*Cks,st and FnckiN Ar5E Bags, cntin w@nK FnckER!!!
But on the bright side, maybe I am not as insensitive as I first thought

[scz4]

I fitted a rack off the 1.9 and it made a huge difference, turn in is much improved. Struggled with it for the first coulpe of days, kept almost mounting kerbs on sharp turns

[dan101smith]

scz4 said:

I fitted a rack off the 1.9 and it made a huge difference, turn in is much improved. Struggled with it for the first coulpe of days, kept almost mounting kerbs on sharp turns

They are good aren't they


(sorry to rub it in!)

[MarkM3Evoplus]

GTWayne,

There is a website S14power.com with a sub section for E36 track cars.

A guy on here sometimes, TrackM3, went to great lenghths to sort the handling on an E36 M3 track car, so may be worth a look for you/ posting there too.

Cheers,