26 replies to this topic

[random]

Steve Matchette revealed during the Monaco practice coverage on SpeedChannel today that Williams is testing a new Active Suspension system. He actually called it "in car ride height adjustment".

It gets around the rules against such things by not being actuated by any in-car sensors. They map the track and control the ride height from the pits using the newly allowed 2-way telemetry. So I suppose it raises the car in the slow and bumpy bits and lowers it in the fast and smooth bits. Pretty neat tech.

My feeling is that they should probably just allow active suspension again if this sort of thing is legal. I'd gather true in-car sensors for an active suspension system would be safer than running everything from the pits.

[Janzen]

I would not really call that active suspension since it is not reacting to the car, it is more an adjustable suspension. But the thing is who knows. Since they are allowed to get information from the car everything that is recorded by the data recorder can be sent to the pits where acomputer can calculate the settings for the suspension. But I do not think the transfer speed is up to the task to get a truly active suspension. I would think that the rule would simply be that you are not allowed to adjust the suspension while on track?

[Ferrari FX]

I believe that the rules says that the suspension geometry cannot be modified when the car is on track.

[Ursus]

I find it difficult to envisage how they will get it around these regulations:

Quote

10.2 Suspension geometry :
10.2.1 Suspension geometry must remain fixed at all times.
10.2.2 Any powered device which is capable of altering the configuration or affecting the performance of any
part of the suspension system is forbidden.
10.2.3 No adjustment may be made to the suspension system while the car is in motion.

On another note, does the regs above mean that adjustable anti-roll bars are forbidden?

[Marco94]

I recall a conversation with a Ferrari engineer some time ago, and he said that they were indeed not allowed. IIRC of course.

[Ferrari FX]

Quote

Originally posted by Ursus
I find it difficult to envisage how they will get it around these regulations:



On another note, does the regs above mean that adjustable anti-roll bars are forbidden?

Nope...

[Pioneer]

Yes, driver adjustable anti-roll bars are forbidden.

The things that are allowed to be driver adjustable.

All electronic engine, gearbox, and differential settings. Also brake balance front to rear. Thats it as far as I know.

[Ursus]

A bit strange that they on't allow adjustable ARB's as it's a feature of most racecars(AFAIK). Probably to avoid any interpretation about what an ARB *really* is and firmly plug any loopholes.

[random]

I can only say that Steve Matchette is usually right on the money when discussing technical issues. I gather he has a good handle on the current rules as well.

Perhaps the suspension stays still and only the bodywork moves. I know, movable aerodynamics are forbidden...

[Pioneer]

Perhaps Williams is testing it in anticipation of it being legalized in the future. It would not suprise me if they were planning to push for legalization even if its several seasons from now.

[Ben]

Hydraulic actuation is still legal, provided it only takes the form of pistons acted on by the pushrods, i.e. you can have the spring/damper mounted remotely (low down near the centre of the car) and connect it with hydraulics in much the same way as the braking system.

The option this gives you is to be able to precisely meter the volume of fluid within this hydraulic circuit and adjust the ride height by simply turning a knob on a fluid manifold, easier than adjusting pushrod lengths during a pressurised qualifying session.

As far as active suspension goes though, it treated the suspension as combinations of four modes; pitch, heave, roll and warp (twist) and assigned individual springing and damping values to each one. There are ways of doing this passively, the third spring being the most basic (partially decouples pitch, heave, and roll modes) so this could be part of it.

Ben

[masterhit]

So, you could map the suspension to the braking system and have a car which lowers the suspension after heavy braking for, say, a corner?

[Ben]

No, because that would entail an energy input, hence active.

What I'm saying would be modal suspension control. You would have a seperate spring and damping rate for pitch, heave, roll, and warp.

This would allow you to set up a very stiff roll rate to keep the floor square to the road, a very progressive heave rate to maintain ride height and a stiff pitch rate that could reduce to absorb big bumps while braking. Finally tou could specify a very very soft warp rate to allow the car to follow road contours (crowning in the road - think the hill down to mirabeau at Monaco).

Ben

[masterhit]

The Williams cars were noticably better at riding the kerbs at Canada.

Interestingly, Johnny Herbert was moved to say that the Williams cars were riding the kerbs like active cars in Canada. I'll find the exact quote......

[desmo]

Didn't Tyrrell do that very thing or something similar some years back?

[AndyM]

Desmo, IIRC Tyrrell had a Hydro-active (or something like that) system in which they intended to link the front and rear suspension systems hydraulically. I don't think the development got as far as that, but they did have some system running similar, in I think '95. I read about it when they interviewed Mike Gascoyne after he moved to Benetton.

[Ben]

It was called hydrolink, and was well on the way to being the basis of a modal system by all accounts.

I suspect it only ever ran with a third spring style modal decoupling of pitch/heave and roll.

Ben

[Billy Gunn]

Benetton had a system which I believe had the wonderful acronym of BALLS .....
Benetton Active Load Levelling System. This was around '92 IIRC. I also seem to think it was canned by 'Farm Yard' when he arrived.

BG

[desmo]

'Farm Yard'

I thought I remebered a passive system whereby the pushrods acted on a master cylinder and a slave cyl translated the pushrod pressure into spring/damper travel, essentially replacing the rocker. This, theoretically frees one from the geometric constraints imposed by a rocker system- you can mount many of the components looking at other packaging issues. It will certainly always be heavier and less reliable than a well-done rocker linkage. Would the potential upside of a hydraulic link between front and rear suspensions be worth the cost in weight and complexity? Apparently the current group of engineers think not.

[Ben]

I wouldn't be so sure. An interview with Gascoyne a couple of months ago suggests he's still interested in the idea, and I think he said Renault are (or thinking about) testing a system.

Ben

[Jezztor]

Indeed, article in Racetech mag. I personally like the idea of the "Hydrolink" system. I don't think it would weigh much more, and aside from the mass, you can place the central reservoir anywhere you want on the chassis which will inevitably lead to a lower CoG. I recall Gascoyne saying that it would probably be more useful in sportscars where there is a bit of a limit in terms of rockers, SD's etc. I know Arrows do not like the idea, they feel that a) it is not reliable enough and b) it is hard to balance L&R movements. I'd like to run some tests on the system.

With regard to the active suspension, insider @ Arrows told me that they also run active suspension but it is used solely at tests for ride-height evaluation and rake angle effectiveness. Instead of coming into the pits, they just raise the car from the pits thanks to bi-di tel.

[desmo]

The use of active ride height control in practice and testing would greatly facilitate aeromapping.

Might passively linking the F-R suspensions potentially control pitch motions sufficiently to make some of the aero design compromises currently used to make the cars less pitch sensitive unnecessary? One might be able to realize incrementally better L/D this way.

[Marco94]

desmo,

IIRC front/rear linking is not allowed by the regulations. But maybe I already spreading outdated info.

[desmo]

I am not aware of any regulation, now or ever, that would forbid linking F-R suspensions.

[Ben]

I was always under the impression that such a rule existed, but I think Desmo's right in saying that there isn't.

Ben

[Jezztor]

I concur. With that Racetech article that you also read Ben, the Hydrolink, I recall Gascoyne commenting on possibly linking F&R...maybe that was R&L...can't remember, but there are no rules ATM that forbid it, to my knowledge at least.

[scarbs]

I also do not beleive that link Front rear susp has been regulated against. At the moment it is thought so impractical to acheive that no regs cover it.

But ealier this year, I did hear a very accurate whisper that one British F1 team has approached a German springdamper manufacturer to produce a part for exactly this purpose. I would not be told what supplier or what team was involved. At the time I presumed it would be Gascoyne as he came from Tyrell and was also inlvolved with hydro link project.