Could anyone advise on where to start re adjusting my 2-way adjustable dynamics suspension for the track and road?At croft I was plagued with understeer.Tried reducing tyre(AO48) pressures initially-down to 21f/23r(hot) which made little difference.Of the 12 settings for bump and rebound started at 4 from hard rebound/6 from hard bump, and by the end of the day got to 3 from hard rebound/5 from hard bump rear and 8 from hard bump front.Understeer was improving but nowhere near right.Poor turn-in.Also getting power down out of corners difficult.Grip from tyres awesome.Geo has been done when new suspension fitted for track day use.Any ideas?Reg no W407 YAL(aluminium) at Croft in case anyone can remember and add (constructive) criticism re my car/amateur driving technique!
What camber/toe are you running front and rear and also what spring rates and tyres?
camber front -0deg 27mins/rear-2deg25mins
toe front -0.03inch/rear+0.09inch
tyres AO48s
eihbach springs-not sure of rate-came as a package as recommended by Lotus.I can find out…
You need camber on the front otherwise it will understeer. I can’t help with the dampers without driving it as I have no experience with dynamics.
This isn’t a comment on your driving, as I don’t recall it. But…
A couple of years ago there was some discussion about how an uncommited driving style didn’t really help the Exige and led to understeer. I was interested as I was getting a lot of understeer in tight bends. It seemed to make sense, as if the majority of the weight is over the back of the car its momentum needs to be controlled/turned in order for the car to handle in a spritely fashion.
DISCLAIMER: Please DON’T take this as an excuse to go trying out carrying more speed in to bends expecting it to instantly cure the understeer (I generally dislike tips regarding going faster posted on the Internet). After all, understeer in fast bends is probably better than oversteer! I’d recommend professional instruction and a large open space to practice.
I suspose the point I am making is you could spend ages trying to set up the suspension to dial-out the understeer and end up with a less than optimum car, when learning a slightly adapted style could help loads.
Ian
IDG
good advice…
out of interest on a scale of 1 to 10 how much do you think the nitrons have helped you/cars handling ?
camber front -0deg 27mins/rear-2deg25mins
toe front -0.03inch/rear+0.09inch
tyres AO48s
eihbach springs-not sure of rate-came as a package as recommended by Lotus.I can find out…
That looks like very little front camber, almost anyone I know runs it closer to 1 deg (and still uses it as road car).
More than that it would become not nice to drive on the road.
And yes, I can see the std settings are 1/2 deg camber front, but those are (I guess) precisely to give some degree of understeer (which most unexperienced drivers seem to prefer).
Also, am I reading the toes right? Toe IN at the front and toe OUT at the rear?
It should be the other way around. slight toe OUT at the front (0.2mm) and slight (1.2mm, sorry don’t have the numbers in deg) toe IN at the rear.
Hmm? I’d say 7.5
It was pretty good before hand, but Uldis still mullered me on std (and only about 20bhp more, although I was expecting him to do that as per usual). With the stiffer springs you have to be quicker to catch stuff (but Benja will testify I’d got better at that by the end of the day ). With the stiffer bushes there’s a lot more info coming through the wheel too, which certainly helps.
The body control is definately much better. Following ‘normal’ road cars on the motorway, you see them hit a bump and pogo slightly, the Exige just eats them now. Although with the stiff springs some pot holes you really feel! All in all though the car is amazing given that its springs are about 3 times as stiff.
Ian
Last year before fitting the dynamics suspension and AO48s I did 2 track days at Cadwell.Turn in was superb and without thinking almost.The car tended to oversteer if pushed.Also-looking at the geo settings, I had it done twice.Once before Cadwell and then when the new suspension was fitted.Looking at the geo print out the settings were identical both times.And yes Uldis the toe in settings are as stated.I was attacking the corners pretty hard at Croft but was definitely limited by understeer compared to last year.I will have a chat this week with Pat Thomas at Kelvedon Motors who did the work.What I would like to know is what settings to try on bump and rebound, and what influence this has on understeer etc.Apparently Nitrons are based on dynamics dampers (the chap who designed them worked for Racing Dynamics beforehand, allegedly!)Noone seems to have experience of them as they are rare as hen’s teeth and v.expensive!In hindsight Nitrons may have been a better idea as so many have experience of them.I was persuaded to upgrade the suspension rather than fit the UCR box and LSD…Thanks for your input.
Do you have any graphs of the Dynamics? In my experience it’s not the make of shock thats important, it’s the setup/valving, common sense really. Without the graphs it’s impossible to comment without driving it.
(but Benja will testify I’d got better at that by the end of the day ).
Agreed, as you put the power down and the back came round, I really thought this one’s not coming back but some very swiftly applied opposite lockery gathered it all up nicely
Which I have a Mr Walsh taught steering technique to thank!
Ian
Marcus,
check that, toe in at the front and toe out at the rear is definitely wrong.
That could be the cause of the understeer you’re having.
Why don;t you spek with Guy, from Nitron.
I’m sure he’ll be happy to tell you.
And if you’re eventually thinking on changing them for Nitrons, send me a PM, I muight be interested in them
agree with uldis, it is wrong.
spoke to Pat Thomas today…The geo is set with less camber to reduce darting/chewing of tyres/ toe settings are to take toe steer off rear so there is no need for as much toe in…Also my tyre pressures were too low and suspension settings not quite right!Think I’ll stick to the day job and put his advice into practice next track day…Hopefully…
Also spoke with him (for other reasons)
Your car was setup with toe out at the front and (slight) toe in at the rear, as it should be. In addition, you have a modified rear setup which takes away the rear bump steer (which is very good, I want that).
But the main problem I guess was the bump settings and tyre pressures.
Oh, well, I guess you need more trackdays
I agree-the main variables to fiddle with are the bump/rebound/tyre pressures.I had the tyre pressures too low/ bump too hard.Next time I’ll start with tyre pressures at 24-26hot with rears 1lb higher than fronts/bump at 6-8from hard and rebound at 4 from hard.(after talking to Pat-he is extremely helpful)When’s the next one?
Whatever you do it will understeer with 0 camber at the front. Doesn’t take long to pull the camber shims so worth a try at your next track day.
Pat told me it wasn’t 0, was 1/2 a degree.
I personally prefer about 1 deg, but maybe they considered the type of use, more road than track?
But even then, I still prefer 1 deg, even on the road. Yes, it’s a bit more nervous and tends to follow ruts or changes on camber, but the upside is much better front grip when cornering hard.
Besides, my tyres are never worn on the inside, more like flat, so 1 deg suits me very well.
I suppose if I used Nylatrons I could bring that down to 1/2 a deg again?
What do you use Randy? I know you have Nylatrons.