roon wrote: ↑28 Jul 2019, 20:16
If the current aero and chassis formula remained, and only the engine rules were relaxed, I think we would see a return to NA 4 stroke engines. Likely a vee engine for structure and size, likely small displacement and high operating speed. This is what the engine suppliers are familiar with. In 2005 BMW were making an 82kg V10 with over 900 hp. There is a lot of potential yet with mechanisms and materials.
Exotic engines and systems could be developed, but the immediate, affordable goal, I think, would be something like the above.
I think if the engine rules were relaxed but chassis rules remained the same that it would be unlikely that high rpm N/A 4 stroke engines would return.
Mainly because there is no weight saving in the car (minimum weight being part of the chassis formula), and you would use more fuel.
To get 900hp+, a 3l V10 used roughly 200kg/hr fuel, compared to 100kg/hr under the current regulations.
If the weight limit was reduced you would likely see a V6 turbo, single or twin, or an L4 turbo. With restrictions lifted on the engine rules you would make substantially more power with that setup, considering that they could use a lot of the tricks they have learned in the current hybrids on those. To replace the MGUH they would develop anti-lag systems.
An all up weight of such a V6 turbo ought not be too much heavier than the V10, given the same life expectancy (be that 1 race weekend, as in 2005, or 7).
The turbo engine could run 50% more fuel flow than now and still be substantially less than for the V10, while making considerably more power.
A V6T with 150kg/hr fuel flow, using knowledge from today's V6Ts, could make 1,100 - 1,200hp, or more.
Why does fuel flow matter?
If the races have no refueling, the turbo cars can start lighter, which is an advantage. If there is refueling, the advantage is quicker stops.