Speedtoys

You mean, don't do it without strengthening the sway bar attachment design first.

Happens in a lot of cars..goes with the territory to do that first.

Randy V

Normal street driving, never tracked. Sounds like you might be having issues.

Yes, but most folks aren't aware of that. They just bolt it on and go.

FredR

Good that you understand this- bolting the Devek bar on and hoping for the best is a definite no no.

I followed Carl's approach for this mod as shown on his website. As I remember you use a steel square section 11 inch long x 1 inch and cut it into two pieces with a 45 degree cut around the centre point. Weld them in and forget about it.

If you would like a photo of my installation just holler as the car is up on the jack stands at the moment or you can visit Carl's website.

Rgds

Fred

RKD in OKC

To set your adj anit-swaybars

Find a flat space your can drive in circles of 100ft radius.
Drive the radius so that you are going around the circle NOT adjusting your steering.
Then slowly increase throttle i.e. speed until the car breaks loose.
As it breaks loose notice whether it is the front or rear that lets go first, i.e. understeer or oversteer.
Stiffen the end that breaks loose first.
If you can't loosen the opposite end.
The test drive the circle again.

Basically it is neutral when it breaks both loose at the same time and makes a larger radius without changing the direction to steer out of the corner.
.
When it is neutral, lifting the throttle it should oversteer. The front will grip better and it will turn back into the corner. Adding more throttle it should understeer, the front will lose more grip and it will turn towards the outside of the corner. But not flooring it or that will cause power oversteer, a whole different animal.

The idea is you will be going thru the apex at slight drift with enough throttle to maintain your speed. You are in a 4 wheel drift. As the car starts to drift out the desired radius you lift the throttle a little so the front grabs more and the car turns in. Then you add the throttle back to maintain both your speed and the 4 wheel drift. You make these adjustments thru the apex or middle of the turn. The is called throttle steering.

When exiting the corner you add the throttle slow enough that the understeer carries the car to the outside of the turn, You can also start removing steering input to straighten out the car, which lets you add more throttle. If you add too much throttle too soon the rear starts coming around. To little and well...it is slower. By the time the front wheels are pointing down the straight you should be back to full throttle.

The radius of the circle you setup the car for should be the size that you want the most control, or your average turn radius. Once setup the tendency it to understeer in smaller radius corners and oversteer in larger radius corners.

Also the Wiessach rear setup makes it a little more difficult to tell what is going on because the car does not rotate as much due to the rear steering. I.E. the rear of the car is not hanging out as much as a car without rear steering. The angle of the car is less than the angle of the rear wheels.

Speedtoys

For the archives, that can be a good thing.

ROG100

I have a blue Devek front sway bar I will part with - Roger

Speedtoys

Already have one on the way Rog, but this is good news for others that may be in the market

The trick, is finding a rear solution to compliment it with, Stan was able to help me out with that

FredR

I suspect that what the Devek crew knew was that as wider rubber is fitted to the front end the 928 tends to go from a chronic understeering vehicle to an oversteering one as if the gains in traction on the front outstripped the gains on the rear. Thus the front end needed more stiffening options.

For the stock 928 I suspect Louie rationalised that some improvement in cornering could be had over the stock understeering setup by having an option to make the rear roll bar a bit stiffer and then re-set it after a track session to something more akin to stock.

In a perfect world it would be nice to have an adjustable system that allows a range of adjustment that fully covers transition from understeer to oversteer.

The entire subject of tuning for such characteristics is rather complicated as other factors are in play such as spring rate front to rear and camber/toe and for most of us continuous rounds of adjustment are just not practical. Even the type of circuit impacts optimisation viz lots of short sharp turns or more sweeping higher speed bends.

In the end I set the rear links on the softer of the two settings and nowadays run the Devek bar somewhere around mid range and that to try and give a neutral type of setup. Either way I am used to the feel of the car and generally do not change settings much.

I also use Carl's lower front frame brace. When I fitted this I doubted I would notice any difference [due to my own lack of ability] but I immediately felt a change much to my surprise and nowinstead of running around 2 degrees of camber up front I use 1.3 degrees all round and it seems to work but to be fair, I am not pushing the car as hard as I used to and am running slightly narrower rubber front and rear.

To quote the late great motorcycle ace Mike Hailwood "the trouble with infinitely variable suspension is that there is one correct setting and an infinite number minus one wrong ones".