I have a KERS question/hypothesis -

I believe that it was David Hobbs during Australia opining that some weird engine revving going on during downshifts was an ECU algorithm to help charge up the KERS -

This made me wonder: What if you programmed the engine/transmission to declutch the drive wheels during deceleration and then rev the engine to make charge with the KERS motor/generator set? Then, your brake action would be fully by the friction brakes (probably more reliable & controllable) and maybe even more KERS charge could be obtained more quickly than by a true form of dynamic braking.

The downside would be a little more fuel consumption, and of course that the intellectual dishonesty of "fuel economy via KERS" goes totally out the window. As if the sanctioning body really cared about intellectual honesty of these devices in the first place.

 

Well, to expand on what I was saying...engine braking is pretty minimal on these cars anyway as they can pull down at something like 4g maximum. The brakes are already more than powerful enough to haul the cars down at the full limit of traction anyway - and of course most of the brake action comes from the fronts.

My conjecture was that it might actually be easier to modulate the rear brakes alone and use a decoupled engine blip for enhanced KERS charge. So, I don't think they would have to brake earlier at all.

 

I would assume that they have a charge manager (sort of like a voltage regulator) that should be preventing the above.

Whether it actually WORKS is of course another question.

These high charge/discharge rate batteries can be pretty unstable even at the nominally correct rates - being under vibration, heat stress, maybe water splashed on them while hot, etc. Most everybody who has run R/C airplanes or cars has sooner or later seen a big-time battery meltdown.

 

Probably you are right, I was assuming the KERS motor was connected to the front of the engine (unclutched) and that the clutch paks (no idea if single or dual) were part of the gearbox.

Not that it matters much as it looks like KERS was totally valueless this year as opposed to the diffuser.

 

Ha! The engine put in the inertia to be braked down in the first place.

I am Mr. smartypants now! All others are imposters!

 

Well, at least you just about have me talked out of the disconnected wasted revs theory...

 

He knows - Far Out and myself cannot go more than 3 days without a nice friendly science rumble.

Without weapons, of course.

 

First of all, Florian is a German and can probably fence far better than I can. We stick to the .45 automatic here, and that is obviously outside the pale between men of science.

The deal is that the wheels are spinning the engine up when no fuel is squirting (thus engine braking). The electronic modules let the generator in these engine braking moments charge the batteries. In "normal" KERS, the generator would not suck power from the engine (controlled electrically without a clutch) except under braking, letting the wheels turn the engine and charge the KERS.

In "James KERS", the autobox would declutch the engine and let it rip up to full RPM (using fuel) against the KERS while the wheels depend only on the disk brakes. It was just a whimsical idea, after all...