Michelin's OPT suspension for Formula 1

[GregLocock]

http://www.geocities.com/greglocock/

Click on Gallery, then there's a link at the top of the page.

Any ideas what the fundamental idea is behind this? It seems like a rather complex way of providing a way of mixing and matching a swing arm and an SLA Cheers

Greg Locock

 

[GregLocock]

Here's a much better idea, reminiscent of the X link suspension. I'll model it tomorrow.

http://locost7.info/mirror/dax.php

Cheers

Greg Locock

 

[NeilRoshier]

Greg have you had a look at the rear suspension on the radical as well? Also I believe that the sylvia clubman is using a 'semi beam SLA' (damned if I know what exactly that is) according to an owner.

 

[GregLocock]

I agree that having a tunable suspension is a good idea, it just seems a lot of hoo-ha for the limited advantage you would see on a vehicle whose total suspension travel is about 10 mm.

Anyway, apparently Renault F1 are not using the OPT system, that was just a rumour.

I modelled the DAX system last night. In a camber vs jounce and roll sense it perfectly mimics a beam axle. Not a bad thing in its own right, but a very complex way of duplicating the performance of a simple system.

Cheers

Greg Locock

 

[NeilRoshier]

Ah perhaps that was what the sylvia owner was refering to?...can you see any performace advantages greg?

 

[GregLocock]

Yes, a beam axle is a very good solution for smooth circuits, since the wheels are held at the correct camber (or nearly) for both bounce and roll events.

The DAX system has the advantage that you can dial in negative camber at design, and I suspect with some tomfoolery with the geometry that you could get a neat curve so that both wheels are always at a slight outward lean with respect to the road in roll.

Of course, the way we generate negative camber on a live axle is to heat the axle tube with a welding torch. !
Cheers

Greg Locock

 

Greg,

I'm not sure, but I believe the DAX system may have an advantage at the front as a way to eliminate steering geometry problems that may occur with a solid axle in the same location. There may also be some packaging benefits or chassis structural benefits too. What do you think?

Sean

 

[ubrben]

The key thing to bear in mind is that the OPT is dependant on the lateral force at the tyre contact patch to operate correctly.

If this aspect is ignored, and simulation of the system is flawed. It is this aspect of OPT that makes it much more useful than the Dax system.

Oh, and BTW they have run it on the Renault in testing (at the rear).

Ben

http://www.ubracing.co.uk

 

[LMP900]

Yes - the description in R-E differs from the patent in that the articulation due to lateral force, which is what keeps the tyre normal to the road, happens at the outboard end. What defeats me is how they control the system's normal and lateral reaction forces in every circumstance, and counteract the moment about the bottom BJ which usually tends to give you camber knock-off on the outer tyre in a corner, which is the reverse of what they want to achieve. I mean, you can imagine the system working as designed under one combination of normal and lateral load, but not every combination. Any ideas? And the other thing is that presumably, this self-righting deflection is undamped - not a good thing I would have thought, for a racecar anyway.

Andy

 

[Jreyenga]

Does anyone happen to have the recent racecar engineering article on the OPT suspension. It seems to explain it fairly well(much better pictures than I've seen elsewhere).

Unfortunately my dog ate that one page last weekend.... I hope to get another good look at it so that I can look into developing something like that for my school's fsae program.

Anyone have a copy of the article they can scan? I don't know how legit it is to do that, so....

 

[LMP900]

see also US patent application 2003/0071430 A1, filed recently, and looking like two SLA systems in series, one as normal and the other rotated through 90deg.

Andy