Lotus's braking attitude compensator is now illegal

[Crucial_Xtreme]

Any thoughts on which the other "front-running" team with a similar device might be?

Ferrari have been working with the Lotus Renault Reactive Ride Height System since December.

[hardingfv32]

Frankly, unless there was some kind of break though of a nature we do not appreciate at this time, this would be a very old idea.

Frame the problem and your limited options become obvious. You need a hydraulic force, tied to the braking activity, to move the push-rod. What are the possibilities?

Using the break line pressure could be tricky if there is feedback from changing suspension loads (bumps?) that could upset the braking effort.

I am not sure what problems a moving caliper might create, but I have no doubt there is room for complications. They are just not presenting to me at this time.

Brian

[timbo]

It seems to be pretty simple in essence. When break pressure is applied a part of the oil goes to a small cylinder which elongates the front suspension strut.

That would render it illegal as it uses driver's movement to trigger pitch attitude change.

[Tim.Wright]

I doubt they would be using brake line pressure for the reasons you suggest. Otherwise it would be all packaged inboard.

What it looks like to me is the braking torque is fed to the lower control arm via a hydraulic mastercylinder which drives a slave cylinder on the pushrod.

There would be some rotational movement on the hub but I dont see this having any effect on the suspension.

What Im interested in working out is why they didnt add more antidive and run with a lower static front ride height. Seems they want to keep the front axle soft in heave for some reason (to keep the front wing in ground effect?).

Tim

[N12ck]

Talk about Lotus living up to there name and being innovative, this thing is almost like active suspension but only under breaking, can anyone give an insight to the aero benefits of this (as apparently its mainly for stability and aero benefits)

[hardingfv32]

Talk about Lotus living up to there name and being innovative, this thing is almost like active suspension but only under breaking

Or is it their current rep that they are good for innovation that does not win races? It could be that the system was just a on the car to send others on a wild goose chase. It could have been complete disable during the test. Lotus might have abandon the idea already.

I still question the dynamics of a caliper that moves. How much movement is required? What would this movement mean to the driver? Does the system's movement have variability or does it stop out very rapidly? Could track irregularities (bumps,et.) feed back to the caliper and cause brake lockup?

This system should have been on the engineer's mind the day after they banned active suspension. Why try it now?

Brian

[Paul]

I would also like to hear expert opinion on how this system could change general suspension characteristics. I imagine this being another compromise of aero ahead of mechanics, and thus problems setting it up for bumps, kerbs and such.

[gridwalker]

How do you think the handling will be affected if the system breaks on one side only? Asymmetrical ride height adjustment can't be good for the balance of the car.

[WhiteBlue]

It seems to be pretty simple in essence. When break pressure is applied a part of the oil goes to a small cylinder which elongates the front suspension strut.

That would render it illegal as it uses driver's movement to trigger pitch attitude change.

No, because the driver pushing the break pedal has a primary legal function. If they just use the original modulation it would be perfectly legal.

[Tim.Wright]

Unless you lock a tyre, braking torque is more or less the same on each side unless there is a delibrate biasing system for left/right.

When you are below the limit of the tyre, the only thing that can affect the braking torque balance left/right is the pad mu which is a function of temperature.

I have read that they have had this cooking since 2010, so there's obviously a few tricks to get around with the left/right dist of brake torque being one of them.

Tim

[Tim.Wright]

No, because the driver pushing the break pedal has a primary legal function. If they just use the original modulation it would be perfectly legal.

I don't think the primary function comes into it. Otherwise you would have wings controlled by the throttle.

The fact that its controlled by the braking torque and not the master cylinder pressure means is reacting to the longitudinal dynamics of the chassis, not a driver input directly.

Tim

[WhiteBlue]

No, because the driver pushing the break pedal has a primary legal function. If they just use the original modulation it would be perfectly legal.

I don't think the primary function comes into it. Otherwise you would have wings controlled by the throttle.

The fact that its controlled by the braking torque and not the master cylinder pressure means is reacting to the longitudinal dynamics of the chassis, not a driver input directly.

Tim

Breaking torque is ultimately controlled by the driver pushing a pedal. It is all the same, just a different way to describe it.

[hardingfv32]

The fact that its controlled by the braking torque and not the master cylinder pressure means is reacting to the longitudinal dynamics of the chassis, not a driver input directly.

1) Maybe Lotus viewed it as a little gray too and that is why they sought official approval. Or, it could still be a rejected system. Going to the FIA for approval just adds to the misdirection.

2) Had not considered brake lockup on one side only. I might be useful to have both sides of the system connected.

3) Don't worry about the legality, that is politics. Figure out how it works and the plus & minus of the system. We have something non-aero to talk about!!!

Brian

[myurr]

Breaking torque is ultimately controlled by the driver pushing a pedal. It is all the same, just a different way to describe it.

Or more accurately it's a consequence of pushing the pedal and not directly controlled by it. That is where they will argue there is a loophole.

By way of demonstration, if the car is stationary then pushing the bake pedal will have no effect to this system (if my understanding is correct). So pushing the pedal does not control it directly.

[waynes]

anyone else think Red Bull and their so called over the top rake might have been found out by Lotus?

i mean, a car pointing towards the ground is going to dig a hole under braking. however, we didnt see that from the RB's.

I think Lotus have seen the rake issue as an area to exploit and come up with this brilliant method

bravo Lotus

=D>