To any NAM member that can help me out !

What I'm trying to do is force oversteer in the MCS, as to have the control and ability to have throttle steer in any high speed turns. Just like a rear wheel drive car.
I've been doing track days for 19 months with my MCS/Works, have about 4,050 track miles put on the car and feel very comfortable with the set up I presently have, but like anything I need/want to take it to the next level.

The MCS presently has FRONT tire pressure hot 34 lbs wheels set at negative 2.25 degrees camber with 0.5 negative caster with stock swaybar, struts set at midway from firm. The REAR tire pressure hot 37 lbs. wheels set at negative 2.00 degrees camber with a 22mm sway bar, struts set at one click from full firm.

The MCS is presently handles very netural neither understeers or oversteers, this is at extreme speeds 125-130 mph sweepers, OR with a decreasing radius entry at 125mph exit at 110mph.

What I'm trying, is to be able throttle steer thru a sweeper rather than skuff tires, and lose speed. I've been told that a zero toe setting in the rear wheels induce oversteer. Is that true in a front wheel drive car such as a Mini ?

Please help me out !!

MCS4Roy

 

I've been told that setting rear sway bar to the firmest position will induce oversteer. But i'm no pro...

 

Phobol,
Thanks I've already done that

 

Your hot tire pressures seem low to me - have you had a pyrometer to check out the pressures and your camber settings? Did you corner weight your coilover settings?

I've got the same tires and wheels, Alta rear swaybar, stock springs; I can get my car to rotate pretty well. Although high speed sweepers are probably the one place where it's the most difficult to get it to oversteer.

 

I'm currently running a Spax suspension with Hoosier tires (One Time on Toyo RA1's) and have not had much trouble in inducing oversteer though it does depend on the size of the sweeper and how hot the tires are running. If I'm coming down a long straight into a sweeper, Oversteer is easy to induce. If coming out of a series of switchbacks, it seems much harder to induce oversteer.
To induce oversteer I'm using one of two methods. 1- turn wheel, tap brakes or 2 - full throttle into turn then lift. 1 works well on turn entry and 2 works well when in mid turn. ! also works well when the brakes start to fade to provide extra stoppong poser on corners and really freaks those other drivers out. (Reccomend practicing this without an audience the first few times!)

 

Hopefully I can be of some help. I have had some experience tuning suspensions for racing purposes.

First, I would do as ColoradoMark sugested and use a pyrometer to check your temp gradients across your tires. This will help give you a better idea of what is actaully going on. But, be carefull. Don't rely primarily on temp readings of your tires. Things like acceleration and braking will affect the temps and may fool you into thinking something else is going on during cornering.

As for throttle oversteer. You need significant TOE OUT on the rear to give you throttle oversteer. BUT ( a big butt here) be careful. Toe out on the rear will make the car very unstable under braking. This might not be something you want if you're running through 130 mph sweepers. This was an issue with the Audi TT when it was first released. People were spinning out of control when they would tap their brakes at 80 mph. Audi claimed no fault because the car was designed to meet certain handling requirements (ie throttle induced oversteer). Consequently, this one of the drawbacks. But to meet cutomer demands, changes were made to the suspension to stabilize it.

Alternatively, you can try tuning the shocks to give you the desired oversteer. I'm assuming that your shocks are like most aftermarket externally adjustables. When you turn the ****, you're only adjusting the rebound damping. If this is the case, you want to make the front shocks MUCH SOFTER. This will give the front tires more bite and help bring the rear end out when the weight transfers as you hit the throttle.

On a related note. Many people assume the the stiffest setting on the shock is what is need for racing purposes. Quite the contrary. A stiff shock slows down suspension movements and makes the car slower to respond.

If you have any more questions, feel free to send me a PM.

 

I agre with the comment about the tire pressure being low. We are runing about 40 in the front and 38 in the rear cold out at Willow Springs. Also noticed you run more pressure in the rear which is unsual for our group. I haev Kw coil overs, H&R sway bars front and rear , moss mini adj lower rear arms and front and rear strut tower braces from BMP and Pilo for the record.Page Title maxmini home site

 

I would be Very cautious with the rear alignment settings if you are racing at 130mph. What may work for an autocross setup to increase rotation most likely would be too much at much higher speeds. Swapping ends at 130 can be unsettling. I did it in a 700+hp RUF modified 930......once.

 

Rts -

1. Are your GAZ's adjustable? If so what are your settings? A very firm rear and a soft front will significantly aid rotation over the stock shock setup.

2. I have the same wheel/tire combination as you do. I am running cold mid summer pressures about 10 lbs higher than you. If you want more rotation lower the rear pressures.

3. I set front toeout at 1/8" total and the rear at 1/4". This will greatly increase turn in and rotation at the expense of high speed stability. If nothing else rotates the car this will.

4. How much negative camber are you running in the front? Depending on the diameter of your springs and which camber plates you are using you could be getting anywhere from 2 to almost 4 degrees of negative camber. You may have to increase your rear camber to compensate and balance the car.

These settings along with some other things have caused me to start backing off as the car was over rotating. I have found that the mini is highly sensative to toe, shock settings and tire pressures and less so to camber changes.

And every track is different. At the end of the season I was getting close by the last session of every event. I intend to do better this coming year.

BTW, on which track/turns are you doing 130mph sweapers and 110 exits? If I hit it just right I couldn't do much more than 115 in 5th down the back straight at the Glen with a 15 pulley and a 2700 lbs car. Are we talk'in Talladega here? :smile:

 

You say your Front camber is -2.25 and your rear camber is -2.0

Try making your rear camber at least 1 degree less than the front, or about -1.2