Lotus E20 Renault

[matt21]

The caliper is linked directly to the suspension. It isn't fully ridged to the hub. The bolts probably ride in slots, allowing the caliper to move slightly. When you brake, the torque forces the caliper against the suspension system, opposing the car's tendency to dive when braking. This is what Renault is doing and what the Honda anti-dive system (TRAC) does.

A moving caliper would be too risky IMO.. I think there is a simple hydraulic piston that reacts to pressure of the brake fluid inside the caliper. As the pressure increases the piston moves hydraulic fluid that is in a second circuit that is connected to another hydraulic cylinder in the upright.

The unit likely has:
A check valve - to stop the car from braking while the suspension compresses.

A damper built in - to dampen vibrations.

A thermocouple activated valve? As the brakes come up to temperature the circuit is open.

Here are my thoughts in a picture..

I think this one is forbidden by the rules.

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.

[DaveW]

What JA has to say about it

In my view, that is a good way of generating a plethora of interesting problems to solve, including compliance, thermal expansion, friction, & dynamic response. To put it into some sort of context, the compliance of the strut is likely to be significantly higher than that of the front heave spring(s). Being unkind, I could imagine Charlie Whiting laughing thinking, yes they can have that - nobody has made it work yet & in will keep them occupied & out of trouble.

I'm with JT. The front suspension is so compromised now, why not try to do it with geometry?

[dren]

I didn't say Renault were definitely using it, I was just thinking that there could be using it.. haha Yeah the honda system sounds like it can work... so post some pictures for us.

Sorry, I wasn't infering you were saying Renault were definitely using it.

Here is a picture and my translation of the Japanese text. Luckily it "directly" translates to english so I only have to be able to spell it out.

1: Check Valve
2: Check Valve
The text in the middle on the right: Control Piston
Text at the bottom: Orifice Valve

So the caliper here actually physically moves upward when braking due to the rotational torque of the rotor. That pushes against the control piston which generates the needed hydraulic pressure to oppose the diving.

[csponton]

DISCOVERED THE SECRET OF THE LOTUS
The spelling of the structure of the Lotus Renault discovered by Giorgio Piola and put the light through its website and Nugnes http://www.omnicorse.it, the brake system is activated, but not through a pump mounted parallel to the splitter as braking was thought at first and how it was written in previous posts.


The ingenious solution is all concentrated in the upright: to move the strut to the suspension that lifts the car during braking and acceleration and lowers the movement of the floating caliper brake.

This is the solution as already announced in a post this morning is perfectly legal because no one is acting in its operation and therefore can not be held mobile device.

What is the solution?

In essence, the Lotus-Renault would be able to lift the front of the car during the delicate phase of braking, preventing the wing can crawl on the asphalt, providing the ideal F1 ride height for maximum stability aerodynamics in a crucial area that affects the car's load and efficiency of the rest.

http://spontoncristiano.blogspot.com

[triart3d]

And why not a hydarulic suspension system..
http://www.carbibles.com/suspension_bible_pg3.html




more:
http://www.carbibles.com/docs/racecar.pdf

[hardingfv32]

Being unkind, I could imagine Charlie Whiting laughing thinking, yes they can have that - nobody has made it work yet & in will keep them occupied & out of trouble.

This is exactly right:

1) Why wasn't this started the day after they banned active suspension?

2) If motorcycles had this in the 80's, why is F1 only getting to it in the 2000's?

3) Could this be something that Lotus tried and failed with and now they are just creating a misdirection for the other teams by asking for permission to use it?

Brian

[hardingfv32]

To put it into some sort of context, the compliance of the strut is likely to be significantly higher than that of the front heave spring(s).

Can you expand?

Are you saying this is more than just modifying the ride height, that a new (variable?) spring system is being added to the front suspension system?

Brian

[DaveW]

Why wasn't this started the day after they banned active suspension?

It was, before active suspension was banned (I recall). Hydraulic switched ride height devices were used to adjust the platform ride height on track whilst respecting a minimum ride height rule in the pit. These worked at spring/damper motion ratios, were powered by a hydraulic power supply, & were required only to switch between two states. Hydraulic support was required only at low air speeds.

Can you expand?

What is being suggested is rather different (in implementation). In the present case the link is required to support push rod loads directly (motion ratio 2+, spring + damper forces), with a minimized CSA (aero), very high hydraulic pressures (compliance & seal friction), significant temperature variations (brakes), & with no stable power source (I guess). Zero leakage would be a given....

[allstaruk08]

if the anti dive fails will the car just react like a normal f1 car would under braking or will there now be play in the suspension ?

[PhillipM]

A moving caliper would be too risky IMO..

Depends if it's actually moving or just pivoting around a bearing/mount, with the end of the caliper pushing another piston in proportion to the brake torque.

That way would be poor for brake consistancy though, even if it doesn't move far.

[Huntresa]

LOL! http://www.totalf1.com/full_story/view/ ... on_banned/

[mith]

Sad news... Could someone stick this thread?

[ringo]

This could have never been legal.
Driver actuated aerodynamics clear as day.

This works from the driver's input, not from the forces from the road surface.

The driver can modulate it by modulating his pressure on the brake pedal.

In no way is this thing reacting directly to external forces on the tyre surface.

[ESPImperium]

Paul Seaby @Seabs
Details The new Lotus F1 fired up successfully at 1.12pm... All systems good! Bring on the first test!

Always good to hear that the first fire up went well!

[Crucial_Xtreme]