18 replies to this topic

[Ali_G]

I saw an old pic in Autosport the other day of Jim Clarke at the Indy 500.

One striking thing came to mind when I saw the pic. The lenght of the wishbones etc on the right hand side of the car were considerabley longer than on the other side. I'm guessing this has to do with the continuing left turning.

COuld someone explain to me how you could get a performance advantage out of this.

Also, is this still allowed today in CART or IRL. I know i've never seen a similar set up.

Niall

[Ross Stonefeld]

corner roll. You setup the car so that at maximum cornering force, mid corner, the car is completely level. Even weight at all 4 wheels, because thats where you're making up all the time. If you go into extreme oval racing, like sprintcars and midgets, its even more noticeable. The right front and left rear are similar sized tires, but the left front and right rear are two seperate sizes/compounds. Plus really long suspension on the right hand side.

[DOHC]

There's also another geometric-mechanical effect. Because you only turn left, you prefer to have the car's C of G located as close to the center of the turn as possible. Think of a merry-go-round, the lateral G force is greater the farther out on the periphery you are. So you want to move the C of G towards the turn's center; this is maybe 250 m away though, so the effect will be rather small, on the order of 0.1%. But always on Indy cars when extra masses needed to be carried (e.g. extra oil tanks) these have been located on the left side.

[Jezztor]

Re asymmetrical setups, did you guys see the BAR tyre setup for the race? Need to look for pics, but they ran scrubbed tyres on one side, new ones on the other side - for the race..!

[bs]

Maybe an IRL head (are there any on this board?) can confirm this, but it is my understanding that current IRL Indy Cars carry the radiators on one side only for the very same reason.
The other side pod is AFAIK, empty.

[Ben]

If you think about it, what the Lotus suspension did was make the left wheels support more of the car's weight. This means that as load is transferred to the right hand wheels in a corner the loads on the wheels tends to equalise. This is obviously desirable because the two tyres on an axle generate maximum lateral force when loaded equally (vertical load that is).

Ross is correct - although it is the weight transfer not the roll angle that is the crucial parameter. The roll angle is related to the weight transfer by the roll stiffess of the suspension but it is the load on the tyres that matter as far as generating lateral force.

The thing to consider with roll, is that static tilt is employed such that the car does ride flat in the corners, this ensures the underwing is optimised for generating downforce.

Ben

[Ian McKean]

But why don't they do it now?

[Manson]

There is a rule in the book now that states that the difference in suspension links can only vary by 1 inch, side to side IIRC. Thats why they don't have the big differences in lengths like you see on the Lotus.

I run ovals only with about 67% left side weight. Ross is correct about setting the rideheights so that the car is level at maximum corning load.

[biercemountain]

As far as I know, neither CART nor IRL use asymetrical suspension components like in the past.

They do continue to use "stagger", having different sized tires on the left and right side of the car, however.

From what I've read, Mario Andretti used his knowlege of stagger and other "oval tricks" to help him in F1. Apparently, hardly any of his competitors, or their engineers, had any idea of what he was doing. Even Collin Chapman wasn't very knowlegable about the subject, and just defered to Mario in areas having to do with "set up".

Of course, Collin would then make sure Mario ran out of gas on the next to last lap because he ran Mario on as light a fuel load as possible. I understand this happened alot during the 77 season.

[DOHC]

Originally posted by Manson
I run ovals only with about 67% left side weight. Ross is correct about setting the rideheights so that the car is level at maximum corning load.

Isn't the aero equally important? In 1965, there was no "underbody" and no wings. In your picture, however, the wing appears to be loading both sides the same. Why aren't the wings generating more downforce on the left side for oval racing?

[Manson]

Originally posted by DOHC

Isn't the aero equally important? In 1965, there was no "underbody" and no wings. In your picture, however, the wing appears to be loading both sides the same. Why aren't the wings generating more downforce on the left side for oval racing?

I did have another aero package that would have been better had it not been banned! It was two wings, both within the rules but I got the old "spirit and intent" clause pulled on me. Even though it doesn't say in the rules, the "intent" is one wing per car.

I've been meaning to try a wing mounted more to the left but with all the engine problems I've had the last 2+ years, no wing package will help if you're blown up in the infield. Let you know if I get a chance to try it out.

[DOHC]

Manson -- good luck and best wishes! Great to hear that what I thought of had already been tried!

[Henri Greuter]

To my understanding, Lola has tried asymetric suspension at Indy back in 1991 (we talk about mere millimeters here) but it was banned and there was quite a hassle for some teams to convert the cars back into symmetric setup. That the last time I heard about it being tried.

In the good old Roadster days the trick was to get more weight on the inside of the car, hence the engine & driveline on the left. This to lighten the load on the right tires in the left corners. It was more difficult to do something similar with the rear engined cars introduced in the 60's so instead of moving the engine to the left, the entire chassis was moved to the left, using the asym's.

When the cigarshape made way for sidepodded cars the trick to get more weight to the left was made easier with locating heavy parts to the left of the car.

I can only wonder how stable an asymmetric car would be when built under the current rules allowing ground effects etc. Some aerodynamic balance on both sides must be achieved I think. But that doesn't take away the opportunity to ballast the left side of the car as much as possible.
So it might not even be feasable to do anymore.

Henri Greuter

[ray b]

when indy cars first went roadracing the cars were still asymetic indy setups as thats all they had!!

[BMW FW22]

best thing is to buy NASCAR 4 or 2002 and test ...

wow then youll know

[Kid Prozac]

Originally posted by Jezztor
Re asymmetrical setups, did you guys see the BAR tyre setup for the race? Need to look for pics, but they ran scrubbed tyres on one side, new ones on the other side - for the race..!

another thing i seemed to notice in canada was that the front tyres had substantially differen amounts of camber side to side. is this cos of the layout of the circuit, more left or right hand turns for instance?

[DataFly]

Are such asymetric setups allowed in F1, or must the springs, dampers, etc. all be of the same strength? If it's legal, do any teams use such uneven setups?

[AlesiUK]

It was my understanding that this "staggered" set up was still used on ovals,not to such a great length.as someone said,different sized tyres are common.

i must admit when i saw all those cars losing left rear wheels in that race a few weeks ago my initial thought was maybe they were using some kind of dif set up to stagger the power to the wheels,more on the left and it was causing to much stress.

of course that proved totally wrong,it was just faulty hub assemblies......

there is nothing in f1 rules to stop you using different settings on each damper.

[AlesiUK]

one thing that spring to mind about f1 and staggered setups.Didnt last years ferrari(or maybe the 2000car) have 2 seperate aerofoils on the front wing instead of just one going right across?So theoriticaly they could run diferent downforce settings on each side of the car?it would be a strange thing to do but in F1 you never know.Why else have 2 aerofoils?