car setup & weight adjustment

[campbellju]

im surprised that having a large rear track and narrower front will make it understeer more though, would have thought it would have been the other way round! as on hard turn in the back would try to kick out due to the narrower turning angle on the front.
ie imagine say a trike lol, it would be impossible to make it understeer because the rear is much wider, but i could well be wrong?

INteresting idea but lets look at it another way ;-)

Put a 5kg weight on a 1m pole attached and centred to a 2m base so the pole and base makes an upside down T shape on the floor. If you push the weight it'll probably be stable but if you half the base width to 1m, it'll probably be unstable. If you changed the weight to 10kg and pushed it might be unstable again. Change the base to 4m and its stable. Change the pole to 4m and its not again..... blah blah

What does all that mean.... If the car is unstable you need to lower the centre of gravity or broaden the track. To simplify, the end that is unstable will generally lose traction first and over/under steer.

This is why a rear engineed car has a wider track at the back and front engined cars have a broader track at the front. The heavier bit needs more track to give front and rear the same stability. The other option of lowering the ride height at one end is impractical on most cars.

2 howevers...

1. Changing your front track will change your ackermann angle which can mess up the way the car steers and cause torque steer
2. Life is not simple and with low grip conditions you want extra weight transfer so a smaller track can help. Think of it like digging in with one foot in a tug of war. This is why a slightly higher ride height helps when its raining...... see previous post about ride heights ;-)

 

[pulsarboby]

thanks jim, ive read that 3 times now, and kind of understand what you are saying:der: but if im honest all this stuff is out of my depth, as one thing seems to contradict or upset something else, then your back to square one again, (not what your saying lol, but refering to adjustments that are made). if i start boogering around with everything then i can see me making things even worse, ie i was sure that a wider rear track would have remedied understeer! so that would have been my first glaring error that could have sent me and the car steaming into the tyre wall.
ive always been taught that if you dont fully understand something then dont mess with it, and from what ive said so far in this thread, that is clearlly the case with myself here.

tbh i just want to drive the car, its been sitting round for far too long now and my time is ltd if i hope to get racing this year, so i may have to take it in and just get it setup as best i can, and then drive car to the best of my ability. its not just the car thats gonna need setting up here! its me also after being off the track for so long you tend to get very rusty and lose tracksense, and its a car that im unfamiliar with (as ive never really driven it) lol, so what im saying is that maybe i best familiarise myself with a pretty standard setup first, then i will be in a position to make changes once i know how the cars going to react to my driving style, then i can look into what changes need to be made to rectify that particular problem (whatever it may be) if you get my meaning!

i can set the suspension and tracking to where i think it should be with my substitute weight in car and take it from there. does that seem like a good idea to you jim or do you think i would be better paying first off to get car setup correctly, your opinion is very much valued:-D

 

[campbellju]

i can set the suspension and tracking to where i think it should be with my substitute weight in car and take it from there. does that seem like a good idea to you jim or do you think i would be better paying first off to get car setup correctly, your opinion is very much valued:-D

If you pay someone then chances are you'll get a very accurate but sub-optimal setup. I can give you a few ideas but the only way to setup a car is to do it yourself or be able to explain to someone else what's going wrong. My car understeers too much won't cut it.

Once you do it yourself you start to learn how the car changes and you realise the accuracy is less important than how the car feels. You can setup 80% of how a car reacts on the road without breaking any speed limts or being dangerous.

I have got into a lot of the Maths of suspension but nowadays I tend to visualise the components more rather than calculating everything. Its a bit like using a sniper scope on a sawn off shotgun for most cars

 

[Keira]

crikey :shock:,

im glad im only going in a straight line otherwise i'd have to be all anal and boring like you fookers :lol:

 

[kirko]

as one thing seems to contradict or upset something else, then your back to square one again

thats exactly what happens bobby you can never find a perfect set up for all conditions all you can do is find a set up which suits the majority of your driving ;-)
different drivers also prefer different set ups
i personally had mine set for fast road /track work so it had quite aggressive camber settings and set pretty stiff (which i usually softened for the road)

 

[bracpan]

So true there is never a perfect setup, other wise why do F1 cars fine tune and adjust at every track and still not get it right with all there technology?
What we can do is get a good base to run the car then try and do things like adjust tyre pressures, shocks, anti-roll bars etc on the day. Taking into account wet or dry running, or how bumpy the track is, not much else you can do with only about an hour between runs and no way of re-tracking, corner weighting etc. Even then its only a part of getting the car to corner/handle good. Many other things can be sorted before you even beging to align the car etc...your right Keira going in a strait line does sound easyer..lol
Phil

 

[Odin]

I'm just going to get my car set up for the road and then drive it as hard as I can on track taking into account those limitations, I don't think I have to be the best handling car out there to be having a good time.

And seeing as I'm not going to be doing any proper racing I think that is a good overall compromise, If I can get it back to handling as well as it did on my old gab set up I'll be a happy bunny.


Rob

 

[pulsarboby]

thanks for all the input gents8)
rob thats exactly what im gonna do now! just set it up the best i can, and drive it as hard as i can, and try things out if i get the time.

i really aint got the time for too much dithering about, so we'll see what she can do on my wacky setup, if all goes well then happy days:-D but the opposite will see me and the car, spiralling off the track or bedded in a tyre wall, afterall if you dont push to the limit then you dont know where the limit is!
thats how i found out when racing bikes, throw the bike in, knee down and powerout, if i did not come off then that means i could go quicker untill i reached the stage where either the front washed out and slid or worse still highsided the thing:lol: then you know the limits of the bike and setup, its a painfull way to find out though lol.

 

[campbellju]

Fit a roll cage... that should at least make it leass painful ;-)

 

[pulsarboby]

all ready to go in jim lol

 

[bracpan]

Fit a roll cage... that should at least make it leass painful ;-)

Its also helped the handling as much as anything as the car is now much stiffer.
So I have other improvments planned because of this.
But above all have fun
Good luck
Phil

 

[alexpulsar]

im 6ft 3 and 22st i wang mine round bends like ive stolen it and it dont budge sod the science lol

 

[bracpan]

im 6ft 3 and 22st i wang mine round bends like ive stolen it and it dont budge sod the science lol

lol good for you. keep it up
Phil
PS if its not budging your not going fast enough..its only when the car starts breaking away, then you know if your hadling is OK...or NOT!!!
PPS To be fair you do have to be off track to find its true limits, on the the road is not the place.

 

[pulsarboby]

lol good for you. keep it up
Phil
PS if its not budging your not going fast enough..its only when the car starts breaking away, then you know if your hadling is OK...or NOT!!!

very very true phil! you then know your at the limit and time to make adjustments