pgfpro wrote:Tommy Cookers wrote:pgfpro wrote:
Its just a guess based on that twenty year old four valve engines are running .37 BSFC numbers with a ton of fuel still being used for thermal management so one would think that F1 could come up with a much better BSFC value with the modern tech. that they will be using?
The engines that have been running around the .37 to .38 BSFC are the GSR 1.8L Honda and the DSM 4G63 2.0L from the early 90's making over 1000HP.
I think today's new injector extreme high flow, atomization technology will be a major benefit for F1 compared to the mid 80's era. This will be the biggest contributor in BSFC numbers. The combustion chamber design of today's engines will also have a decent advantage.
I agree that as the rpm increases you will see the torque numbers drop off big time due to the fuel rule.
Example:
344 ft.lbs/ tq @ 8000rpm 76 kg/hr limit .32BSFC
344 ft.lbs/ tq @ 9000rpm 86 kg/hr limit .32BSFC
344 ft.lbs/ tq @ 10000rpm 95 kg/hr limit .32BSFC
344 ft.lbs/ tq @ 10500rpm 100 kg/hr limit .32BSFC
268 ft.lbs/ tq @ 13500rpm 100 kg/hr limit .32 BSFC abs/kpa 200 or 1.0 bar = 689hp
You're sure that the .37/8 BSFC are with a rich mixture for thermal management (not with AFR close to 1) ?
Sorry,I got the max rpm wrong, now I think 12000 or 12500 max would prevent falling below 10500 on upchanges at max power, and when the car is below 10500 only in situations when it couldn't use more than the lower fuel rate associated with these lower revs
(also the power at max revs would be lower than at 10500 due to the greater mechanical losses at higher revs)
I still think the potential of the super performance DI is for 'partial power' operation with lean mixture (and compression ignition only at extreme PPs), this is seen as the future for road engines (by those who don't like 'Twin/Multi Air' or VVT ?)
...... that is the gains at AFR close to 1 are less IMO
If/when the fuel rate is reduced a lot it would take us down some PP road (weird for F1), if the engines were still 1600cc
The F1 way to deal with a big reduction in fuel rate would be to stay at AFR around 1 and make smaller engines
Anyway, we should all see this future soon enough !
BTW .... regarding your compound turbo, 99% of turbocharged aircraft engines also had a mechanically driven centrifugal supercharger