Team Lotus Steering Wheel - Dif setting curious.

[PiB]

http://www.youtube.com/watch?v=58Zkbbfygjw&fea...

From:

http://www.jamesallenonf1.com/

Lotus has two dials for diff settings that are rather interesting. One dial sets the dif for entry settings and one for exit settings. Like brake bias the driver can manually change each dial between corners.

My question is how does the car switch from the entry dial setting to exit dial setting? It would seem to me that this would be a form of an active-dif - through other sensors (steering wheel angle, throttle, etc) the car automatically changes the dif settings for the driver from entry to exit. Perhaps I'm completely off base.

Whatever the case, Lotus has got some clever things up there sleeve. He didn't want to talk about the "wing" button.

[Silent1]

Diff settings under braking and then diff settings under acceleration?

[RedYellowGreen]

I'm pretty sure hi tec difs can have there charecteristics tweaked for acceleration, braking and off throttle. Well thats on my gran turismo console games anyway its supposed to mirror the real thing so I doubt this would be anything special in a high end competion car such such as an F1 car.

[Jungles]

PiB said:

My question is how does the car switch from the entry dial setting to exit dial setting? It would seem to me that this would be a form of an active-dif - through other sensors (steering wheel angle, throttle, etc) the car automatically changes the dif settings for the driver from entry to exit. Perhaps I'm completely off base.

You are.

It's just a form of electro-hydraulic differential and has been used by various teams since the 1990s. The system is not "active diff", because the differential settings are manually set by the driver or pit crew, and the actual differential itself is purely mechanical. Only the adjustment of the diff lock setting is electronic. In many racing cars, you've got clutch-pack LSDs which have different lock settings for when the car is coasting and when power is applied. The electro-hydraulic system retains the mechanical basis of the diff, but allows the lock settings to be changed electronically. For the diff to be truly "active", the torque transfer function would have to be electronically controlled (ie. like the centre diff in World Rally Cars).

The system is not particular clever by modern standards. It's used in pretty non-exotic machinery, like some high-end tractors and 4WDs.

Edited by Jungles on Friday 21st May 02:26

[PiB]

That makes some sense. 'Off' throttle setting and 'on' throttle setting. I guess when they use the terms 'entry' and 'exit' it seems different.

I've seen the diff dials before but never two separate ones.

Jungles, my point was it sounds like the diff is electronically changing the % lock itself from one driver selected setting to another. Of course in the past we've had fully active computer controlled variable diffs that worked in-conjunction with the traction control. (O/T the Ferrari 458 comes to mind.)

The 'CBP' button was suspicious too. Usually, the clutch setting is electronic adjusted/changed manually by driver feel at the parade lap or from other chances to adjust it from data collected. However, having a single 'clutch bite point' button almost sounds like the car will optimize it automatically - for the driver.

And why couldn't he talk about the 'wing' button?

Should I be expecting a knock on the door any second . . . .

Edited by PiB on Friday 21st May 02:35

[stew-S160]

The guy suck at commentary, but his Blog site is pretty damn good.

[Galileo]

Jungles said:

... some high-end tractors...

So, not only have Lotus borrowed their colour scheme from John Deere, but their technology too? Shocking.

[esuuv]

PiB said:

And why couldn't he talk about the 'wing' button?

No idea why he said he couldn't talk about it - but would that not be for the adjustable element in the front wing they are allowed?

[LocoBlade]

PiB said:

Whatever the case, Lotus has got some clever things up there sleeve.

This isn't anything out of the ordinary for an F1 car, just par for the course. Here's the Williams one from last year which seems to have 3 diff dials (the blue ones at the top), one for corner entry, one for mid corner and one for exit

[PiB]

Thanks LocoBlade. That picture makes it clear that it's nothing new. And to be sure, three diff dials is more interesting than two.

[pw75]

stew-S160 said:

The guy suck at commentary, but his Blog site is pretty damn good.

looks pretty damn good compared with legard...blog is excellent

[PiB]

So the Ferrari steering wheel doesn't have any of these multi-dif settings.

http://www.youtube.com/watch?v=T6HFvF-QfTo&fea...

[The Wookie]

PiB said:

The 'CBP' button was suspicious too. Usually, the clutch setting is electronic adjusted/changed manually by driver feel at the parade lap or from other chances to adjust it from data collected. However, having a single 'clutch bite point' button almost sounds like the car will optimize it automatically - for the driver.

Or the driver feels where the bite point is and presses the button to tell the car to use that position as a reference point.

IIRC most F1 cars have a two stage clutch system, one paddle for pulling away which works close to the bite point to control wheelspin, and a second paddle that's released once the car is underway.

[LocoBlade]

PiB said:

So the Ferrari steering wheel doesn't have any of these multi-dif settings.

http://www.youtube.com/watch?v=T6HFvF-QfTo&fea...

Yes it has, look at the video 4m45s in, top left and top right of the wheel there are "dif in" and "dif ex" thumb wheels

[davepoth]

Lotus had three diff dials too...