Bearing in mind the abject failure of the "class of 69" 4WD F1 cars, why is 4WD now (apparently) successful in LMP1 Hybrid cars? Would F1 cars be able to lap faster if they were permitted to drive the front wheels with MGU power as with LMP1Hs?
There is no simple answer to this, and considering it from a hybrid/MGU perspective changes some things.
I remember that I had a discussion about this topic (4WD in F1) back in the mid 90's with someone, and based on the data of the time and taking the then current regs into account, it wouldn't be worth the added weight, complexity and other downsides which would have come with it. ( but this was based on 4WD via the ICE, not via electric drive ).
Things you would need to consider are.
- the weight penality ( a LMP is 850 - 900 kg now ( I think currently it's 850kg for the Hy cars), compared to app. 750kg in F1 ( F1 used to be much lower). If you have a high(ish) base weight, then you would consider to add "meaningful weight" (like a 4WD system), but if not, lower weight will "win the day" more often then not.
- tyres come into this quite heavily, you need a tyre designed around this idea to make it work, both in size (regs) and compound/construction
- aero, trumps many things, so having to change your aero philosophy to account for 4WD is perhaps a hard sell in F1, if anything else remains the same (regs)
- if you force the regs in a certain direction, low(er) bulkhead/nose height, high(er) base weight, mandated weight distribution, tyre sizes etc. you may come to a cross over point, where people will start to considering it. I don't think we are at this point right now.
- how much torque/power/drive you can transmit to the ground via the front wheels at max. acceleration?
That's the critical question, when we did the calculation back in the days we came to app. 15-20%, which wasn't enough to make it worthwhile, back at this time.
- to understand this in simple terms, consider a dragster or motor bike, who will lift the front wheels when accelerating hard, this is the extreme case, but shows the underlying problematic nicely. As harder you accelerate, as more difficult it gets to transmit power/drive via the front wheels to the ground. Where is the "cross over point"?
Track layout and aerodynamics, as well as engine characteristics come into this as well, a F1 car is "grip limited" for only so long ( for speeds of app < 140 km/h, give or take a bit), how often do you accelerate from lower speeds? After the car reaches this point 4WD will not help you accelerating any better/faster, but you may still pay the price for the compromises you made on the aero side and if it means your car is heavier then a non 4WD car, you pay big time, with the extra weight, and a bit for the added friction.
You may gain in low grip conditions, like in the rain etc., but then again on balance over the course of a season, how much/often you gain, and how often you lose out.
I don't think, that it would be a overall benefit for F1 right now, in the given frame work, but this may changes in the future.