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I finally had some time to lower my car closer to the specs Ron suggested. Having done so, I ran into a problem.

If you look at the pic of the coilover, you can see that with the suspension at rest, the bottom of the shock is touching the coil-over rubber bump-stop. This would of course result in no downward suspension movement.

As I see it, I have 3 choices:

1) Raise the car.
2) Trim some rubber off the coil-over rubber bump-stop
3) Remove the shock and fit a thinner ‘bushing’ (polyurethane??) at the very top of the shock where the threaded rod protrudes through the fender.

Anyone running ROn's setup run into this before?
I’d rather not raise the car since even now, it’s not unreasonably low - not for a track car anyway. How much can I trim off the bump-stop? How much total suspension travel should I allow for? Anyone ever replaced the bushing at the top of the shock with something ‘thinner’ which would increase total shock movement? The setup seemed to work much better before I lowered the car – but it was way too high at the front previous to this.

Cheers,

That doesn't look right at all, have you mailed these pics to Ron?

The helper spring should be compressed when the car is resting on it's wheels (it's only there to keep the spring from rattling about when you jump over curbs) and it should be compressed even if you lift the front end about 1" from curb height as I see it. Or is the kit designed as a progressive setup?

If the suspension rides the bumpstops when cornering is might as well not have a suspension at all, totally useless. It is disastrous for the handling and wil cause sharp/sudden bouncing and understeering.

Contact Ron, he will surely know what's wrong.

I removed those rubbers in my car, and I also changed the front springs for longer ones because:

1.- I removed the torsion bars, so then the car dropped a lot and with that spring, the highest ride height was far too low.

2.- As Mats says I was worried with the fact that the thin springs were not fully compressed when the car stood on the four wheels. I prefer the certainty of having some preload on them.

I think you'll find that rons kit is not happy on 17". the raise the car too much, so when you lower you run out of travel.

ALL of his ring cars run 15" and the kit was developed for these cars.

Have you lowered the torsion bar correctly before fitting the dampers?? you need to drop one notch off the front wishbone to really lower the standard torsion bar (bout 2 or 3") then use the coilover spring to set the correct height. It looks to me like you haven't set the torsion bar low enough to start with.

If this is still no good, my suggestion would be to drill another mounting hole for damper much lower in the steel mounting bracket that attaches to the lower arm.

Check with ron also.

these cars handle much better on 15" wheels on the track, so why go to 17"?? lighter, sharper, and faster. Unless you get to full race car specs and big slicks, and i'm sure ron could help you there also. But one kit can't do it all.

Andrew.b

Is it my imagination or did Michael find yet another use for red silicone hose? I like what he did with it in that last picture that I am going to copy that idea!

I'd start by asking Ron.

After this we can speculate for days. The amount of suspension travel looks a bit tight for me.

BTW, I drove two Ron's cars and neither had 15" tires. One had 195/60R14 (his std size) and the other 205/45R16

Thanks for all the responses.

The car was lowered by one tooth at the front of the torsion bar, effectively dropping it a few inches - the coil-over is jacking the car back up ... but I did not realize that the lighter coil was supposed to be in coil-bind (fully compressed) with the suspension bearing weight. I can certainly crank down on the adjuster springs some more which will lift the front...

The wheels are not 17" - they at 16" and the tires are 40 profile --- probably not much larger in radius than a stock 15" Alfa wheel with stock tyre.

I have emailed Ron - but not heard back yet.

It seems like the coilover is too long - I had a hell of a time just getting it into position before bolting it down for these tests. I resorted to compressing the coilover in a large hydraulic press and using wire to temporarily bind it in this compressed position for installation. I’m not looking forward to removing it

Greg - well spotted! That is some left-over silicone hose

Cheers,

Ciao!

Concerning the RS setup, I would like to know how much of a bump travel there is and how much the coil spring is preloaded. It seems like there is very little of both. Good point of the design is that the roll stiffness is increased without too much load on a chassis.

Is there any side effects of having rapidly changing spring constant (in point where the coil steps in), if the coils are barely preloaded? In theory, when turning, the inside wheels should have better grip due to less stiff suspension. How about on a bumpy road or when the outside wheel is driven on a curb?

What kind of spring constants N/mm or lbs/in are you using and in which purpose (track / road)?

Jarno, as I wanted to be sure to have some preload on the springs, I removed the soft ones. I also removed the torsion bars, because I didn't like the combined behaviour of coilsprings and torsion bars.

I had the following springrates: 125 N/mm (700lb/in) at the front and 60 N/mm (335lb/in) at the rear. With this setup it was damn fast over very good roads or tracks, but absolutely undriveable over bumpy roads or as a daily driver. I've been trying different springrates, but i haven't found the balance I need.
Anyway, I've been told that for street use it's ok with a spring rate between 80 and 100 N/mm at the front and between 40 and 50 N/mm at the rear, although in my opinion the 80/40 N/mm setup is too soft. I'm about to fit a 100/50 or 110/50 N/mm setup.

Guys you are forgetting something!
The soft (helper) springs only make sure your main spring doesn't float when the suspension is unloaded (driving over a bump, curb etc...). Like Mats already said.
It should always be there, suspension travel is more then the unloaded main spring length.

As far as torsion bar vs coil spring, there is no difference in function or feel. Calculated to the wheel they both have a linear springrate. It is just another way of using material to flex!

Saluti,
Maurizio

Right, then we're back to the old problem of loading the chassis in the wrong place when the torsion bars are removed (unless the roll cage also covers the shock mount points properly, as it did in factory racers).
For what its worth, I have set up the RS kit for~10mm of play, before the real front springs come into effect. This allows for reasonable street manners. When cornering hard, I have very little body roll and then everything works.
Jim K.

Yes, chassis is designed to work with torsion bars!

Jim's setup will give a progressive stiffness, is suspension travel > 1 cm the coil spring will start to assist.

My car is mainly track use (coil-over, not RS, but basically the same):
I did lower the car about 1~2 cm to deep for what I wanted and then turned, by adjusting the coil, the car up to the desired height. A standard torsion bar has a 30 N/mm stiffness calculated back to the shock absorber mount. So, the most of the car weight does the torsion bar (static load).
But suspension travel during driving (dynamic load) is on peaks mostly taken by the coil over, because of the much higher (3,3x) stiffness of the coil-over spring.

The clue is to make sure the coil-over assists and not take the whole load, else there is stiffening of the chassis needed.

Saluti,
Maurizio

As this and other topics are very often discussed in the forum, it would be nice to be able to form some kind of data base where clear views and explanations/instructions will be retrievable and easy to find! In the end, a very informative alfabetical glossary will be formed, greatly facilitating readers! Just an idea guys!
Jim K.

The beauty with this forum is the Search button, you might wanna try it sometimes..

oooh, why am I on the internet at 11 PM, got a race tomorrow... :/

Search....duuuhhh , spoke too soon, this damn technology is way ahead of me
What I was truly thinking about is an encyclopedia-like thing, not with articles but with member-input descriptions of the topics, like for example:
"Lowering car": Lowering can be accomplished by acting on ......

In other words it would only deal with the item specifically, again:
"Torsion bars": The front elastic suspension elements in transaxle Alfas are not the usual coil springs but......
I don't know how practical this is, but in the end it would amount to an Alfa encyclopedia! Am I dreaming or what
Jim K.