Stu wrote: ↑23 Nov 2022, 13:31
I would hope not, but as far as I understand it one of the basic underlying principles of creating downforce/lift is the difference in the distance travelled of the air molecules around the object that is moving through them; which does point to more side-pod being beneficial. I know that this is not 100% correct when the object is in very close proximity to the ground, but creating that pressure differential must still be key?
That's correct in general, but it's not really applicable like that for sidepods. Zero-pods leave too much of the rear of the floor exposed (in front of rear tyres) and this means you have no bodywork to support the downforce created by the floor, something I wrote here
Vanja #66 wrote: ↑14 Jul 2022, 09:54
***
In wind tunnel, W13 might be the fastest car, but the WT model is still just a model and it can't reflect the actual car 100%. With these rules, this showed with very different model floor stiffness compared to actual floor stiffness.
From this perspective, Merc design has a clear disadvantage with such a big exposed surface. This low stiffness, coupled with potentially smaller ride-height operating window (potential suspension problem, but definitely not as big as it seemed early in the season), leaves the car set-up options compromised. Low stiffness reflects on bouncing sensitivity by providing unstable and unpredictable floor sealing and sudden gain and loss of extra downforce. If bouncing is sorted, bumps on track and roll while cornering affect the predictability of downforce, as floor deflection and vibration increase and decrease it. I'm still not convinced Hamilton and Russell crashed in Austria Q because they pushed too far and not because of mid-corner downforce loss.
To take care of this, the only sensible solution are rod stays, since cable stays don't prevent upward deflection (i.e. floor edges are still prone to vibrations, just limited in downward direction). Rod stays are a big drag penalty, unless concealed within sidepod bodywork, which is what RB was doing from day 1. Somehow Ferrari manages things with cable stays alone, but their floor is significantly less exposed in the critical area (ahead of rear wheel) than Merc. And with wide bodywork, you can fit as many stays as you want, which can also reduce floor weight while increasing stiffness.
***
Merc solved this by raising floor throat height a lot with Barcelona upgrade, reducing overall downforce a lot, and have done a number of other improvements since then to get some of that downforce back. Good pace in Mexico was down to smaller drag penalty than usual, while Brazil race win was also down to top contenders for the win being out of the battle for victory. AD was a reality check, as they had quite a lot of drag to compensate floor downforce loss by running the big wing, while RB and Ferrari could rely on floor downforce more than Merc and use far smaller wings. Even if Merc lowered the car (like Ferrari), evident by experiencing bouncing again after a lot of races.
