7 replies to this topic

[muz]

Do F.1. cars have anti dive and squat built into their chassis???
If not why?, is the wheel travel to little to make it work,or is shifting the tyre contact patch going to up set some other suspension geometery, hence handling.
Saloon cars run a A arm at an angle to length wise ground line to acheive this. Sports cars dont appear to have this. But their A arm inner mounts are uneven to the chassis centre line. Front arm mounting points angle out from chassis c/l, rear the opposite. Top and bottom arms look as if they travel in similar paths, so maybe this is just for strengh.

Cheers muz.

[Yelnats]

I don't see any evidence of this geometry in F1 suspensions and I think, as you suggested, this is because the combination of stiff, short travel suspensions and low G/G renders this unnecessary. Anyone out there familiar with this topic from the inside?

[Greg Locock]

I must confess my first question would be : what /objective/ advantage is there in either antidive or antisquat?

I could even see an advantage in pro-dive, thinking about it, and pro-squat might not be all bad.

[jpf]

I'm not sure about this year, but I thought a few years ago Jordan was running anti-dive at the front, and had adjustability in the geometry to vary this aspect at different tracks.

[jpf]

Greg, it's really about pitch-sensitivity and the peakiness of the aero maps. The diffusers are very ride-height and rake sensitive, plus the front wing is still working in ground effect so even moderate changes in pitch can have serious implications for grip and stability.

[Greg Locock]

That's where I wondered if it could be used to tune the downforce under braking. As the car pitches nose down the wings will be more negative, so generating greater downforce and drag. Whether this is offset by the loss in downforce from the floor/diffuser is the question.

Anti dive increases the effective spring rate of the wheel, which will tend to reduce its grip on bumpy surfaces, so using anti-dive is not without disadvantages

[Formulaben]

Amateur Engineer 2 cents: If your CG (center of gravity) is in between or exactly between your wishbone suspension pivot points, then no anti-squat/anti-dive geometry is needed. Given that modern F1 cars are very low and the upper suspension wishbones are above the CG, the need is limited. The application is much more useful in road cars though.

[Ben]

Originally posted by Formulaben
Amateur Engineer 2 cents: If your CG (center of gravity) is in between or exactly between your wishbone suspension pivot points, then no anti-squat/anti-dive geometry is needed. Given that modern F1 cars are very low and the upper suspension wishbones are above the CG, the need is limited. The application is much more useful in road cars though.

You need to know where your pitch centre is. If the wishbones are parallel to the road, the pitch centre's on the ground. You then have a pitch moment equal to the CG height from the track multiplied by the longitudinal force.

Just having the CG between the pivot is irrelevant without more info.

Ben