Power consumption of Active Suspension?

[g-force_addict]

Back when Active Suspension was allowed by the rules
Are there any figures for an active suspension oil pump power consumption during varying conditions?

Was it better to slightly pre-incline the car just before the corner as the power required to compensate for body roll is much greater once centrifugal force began acting and the car already rolled?

Same for pitch when braking. Was it better to pre-raise the nose just before the braking point?

Maybe power consumption wasn't too important as not all engine power is used while braking or cornering?
How did they reduce the Active Suspension oil pump drag during straights? Did they restrict (choke) the oil flow to the pump or something?

[xpensive]

Not much as we are talking very small flows, a constant-flow pump for 200 Bar and 2 liters per minute is less than a kW.

[-Felix-]

I am really trying to remember where I read it to check it, but I am sure it was in the region up to 10hp on bumpy tracks to run the whole hydraulic system for the active suspension. I think the statement was from Peter Warr, the fw14b may have needed less..?

[riff_raff]

While the control frequencies required by the systems were fairly high, the overall power consumption (pressure x volume) was modest. It provided huge returns in terms of power consumption versus gains in aero performance.

[xpensive]

I am really trying to remember where I read it to check it, but I am sure it was in the region up to 10hp on bumpy tracks to run the whole hydraulic system for the active suspension. I think the statement was from Peter Warr, the fw14b may have needed less..?

Right, if you double the stand-by flow to 400 Bar and 4 liters per minute for good measure, that's about 3 kW,
then add 4 kW for the electronics needed and you got 7 kW or 9.5 Hp.

[basti313]

I am really trying to remember where I read it to check it, but I am sure it was in the region up to 10hp on bumpy tracks to run the whole hydraulic system for the active suspension. I think the statement was from Peter Warr, the fw14b may have needed less..?

I also have something in mind with 10hp, but I think it was only the computer to operate the system which took these 10hp. This was said in the National Geo Doku about Senna's accident I think when they were comparing the cars of the different seasons.

[DaveW]

Right, if you double the stand-by flow to 400 Bar and 4 liters per minute for good measure, that's about 3 kW, then add 4 kW for the electronics needed and you got 7 kW or 9.5 Hp.

Mmm... The Lotus System, which I know a little about, was designed around a nominal supply pressure of 210 Bar. My best guess (I have been unable to unearth the records) is that it was powered by a gear pump (using a total loss pressure regulation) coupled directly to the cam shaft. The pump was probably a Dowty 3008 (or equivalent), so would be expected to consume around 5 HP at 4000 RPM. I think the max engine speed was 12000 RPM (so the pump was over-driven by 50% - sounds about right for F1), implying a maximum power consumption of 7.5 HP.

Your guess at electronics consumption was rather high, I think. The first system we designed (1983) ran on an uncharged dry-fit lead/acid battery weighing around 1 kg. It was designed to run for two hours, and it achieved that, completing two races. The system used for the '99 was more power hungry, but my recollection is that it ran happily in the lab driven by a 5 A, 12 V supply. That would imply 60 W maximum.

Hence I think your overall guess is not far away, perhaps between 6 & 8 HP, depending on engine RPM.

Incidentally, there was a big difference between the Lotus & Williams systems. Roughly, the Lotus system required no power to control attitude, but road inputs did consume power. The Williams hydro-pneumatic system required no power to respond to road inputs, but did consume power to hold/control attitude.

Edit: Here is an "arty" image of the '99 system. The pump is in front.....

[-Felix-]

Thank you for your answer Dave!
I find it awesome how much knowledge lies in this forum. You can get answers for questions you hardly would find facts in literature or the like..

[Kiril Varbanov]

Active suspensions may be back in 2017 - http://www.autosport.com/news/report.php/id/113465

[PlatinumZealot]

The suspension can be used to charge the batteries if small MGU-K's were attached.