Sustainable fuels for 2026. V10's will be green!

[Big Tea]

Because V10 engines sound awesome. That's the only selling point for it...

I would think a flat 4 at 20k RPM would be worth hearing

This may interest some https://www.youtube.com/watch?v=WIA7vBx_dvM

Skip to 1.15 if you like

[lucafo]

Can we talk about F2 engine here?
It seems FIA will really go for sustainable fuel and what comes from F2 will guide the decision.
https://www.racefans.net/2022/08/10/fia ... from-2024/

[Gillian]

Because V10 engines sound awesome. That's the only selling point for it...

I would think a flat 4 at 20k RPM would be worth hearing

This may interest some https://www.youtube.com/watch?v=WIA7vBx_dvM

Skip to 1.15 if you like

That's awesome

[vorticism]

The FIA got into the business of aesthetics the past few seasons. The question then becomes where to draw the line: at visual? Or also audible?

The V10 was of course an accident in some sense; it arose iirc out of mandating NA engines and swept volume in the 90s, which led directly to high RPM multi-cylinder arrangements. Whether the FIA intended it or not, they would go on to produce the sound which came to define F1.

[JordanMugen]

Again, as I seem to always ask ( ) why mandate a V10? there is a cost cap.
If someone wants a flat 4 or inline 3 why force them to go the V10 route?

I don't follow what the cost cap has to do with it. Under naturally aspirated piston engine regulations there will be a cylinder count which is best. The actual extra cost of producing an engine with more cylinders is likely negligible, we are talking racing engines built with near unlimited budgets, not Dacia Sandero mass production.

For 1000cc in MotoGP the optimal cylinder count was probably five or six, probably a V6 being the best configuration for power, at the expense of size and weight compared to the V4. But FIM initially set the maximum cylinder at five, so Honda tried the compromise V5 engine instead which was very successful, before FIM reduced the maximum cylinder count to four (temporarily reducing the swept capacity to 800cc in the process).

For Grand Prix cars, under 3500cc regulations ten cylinders proved most promising, while twelve and eight also had merits. Eventually engine makers converged on ten cylinders being best for the capacity which was later reduced to
3000cc. If the swept capacity had been 4000cc however, then twelve cylinders would possibly be best.

Notably Toyota were keen to try again with 3000cc and twelve cylinders for the year 2000, as Ferrari had done in 1995, but the FIA prohibited this before Toyota raced it.

If someone wants a flat 4 or inline 3 why force them to go the V10 route?

Sure, why not. But given three or four cylinders were not optimal for 3000cc in 1995, they are unlikely to be optimal for 3000cc in 2026.

But you are quite correct that the engine with 1000cc per cylinder should have less friction. Even in road car (as opposed to truck) engines though, 1000cc per cylinder is very unusual so I'd be surprised if it proves to be the optimal configuration in a petrol racing engine.

[Big Tea]

Again, as I seem to always ask ( ) why mandate a V10? there is a cost cap.
If someone wants a flat 4 or inline 3 why force them to go the V10 route?

I don't follow what the cost cap has to do with it. Under naturally aspirated piston engine regulations there will be a cylinder count which is best. The actual extra cost of producing an engine with more cylinders is likely negligible, we are talking racing engines built with near unlimited budgets, not Dacia Sandero mass production.

For 1000cc in MotoGP the optimal cylinder count was probably five or six, probably a V6 being the best configuration for power, at the expense of size and weight compared to the V4. But FIM initially set the maximum cylinder at five, so Honda tried the compromise V5 engine instead which was very successful, before FIM reduced the maximum cylinder count to four (temporarily reducing the swept capacity to 800cc in the process).

For Grand Prix cars, under 3500cc regulations ten cylinders proved most promising, while twelve and eight also had merits. Eventually engine makers converged on ten cylinders being best for the capacity which was later reduced to
3000cc. If the swept capacity had been 4000cc however, then twelve cylinders would possibly be best.

Notably Toyota were keen to try again with 3000cc and twelve cylinders for the year 2000, as Ferrari had done in 1995, but the FIA prohibited this before Toyota raced it.

If someone wants a flat 4 or inline 3 why force them to go the V10 route?

Sure, why not. But given three or four cylinders were not optimal for 3000cc in 1995, they are unlikely to be optimal for 3000cc in 2026.

But you are quite correct that the engine with 1000cc per cylinder should have less friction. Even in road car (as opposed to truck) engines though, 1000cc per cylinder is very unusual so I'd be surprised if it proves to be the optimal configuration in a petrol racing engine.

The cost cap would mean there is no scope for some to spend endless on 'niche' engines just to give one particular team an advantage. Any engine built will have to be useable, and preferably transferable.

There could still be some trade off as there was pre turbo where a smaller capacity different type equivalent could be used, weight or fuel. Just a 2cyl 1.5 v a V10 12k rev limited and fuel limited could be attractive if weight was expressed X for car Y for engine. If they could sane 80kg and still meet the minimum weight it could be viable to try Wanker 2 stroke air cooled etc. Even a common straight six could have advantages but not be usable due to 'regs'

[PlatinumZealot]

But much of the efficiency gain is not in the combustion chamber, it's in recovering as much of the energy that comes out of the exhaust ports as possible. A V10 isn't going to be anywhere near the overall efficiency of a current, complicated, hybrid system.

What?!!

The PUs are 50% efficient overall. The ICE part alone isn't. Strip off the energy recover systems and you'd lose a huge chunk of that headline efficiency straight away.

Outside of comments from Andy Cowell which counter your beleifs.. Simple comparisons can be done to shoe that the combustion/heat managment is THE big differntiator...

The strongest F1 V6 Hybrid started life at 42.5% thermal efficiency... It was adverstized the the electrical machines were greater than 97% efficent. ICE horsepower was calculated at 760hp or so.

In the efficiency of the engines increased year on year... 45%... 47.5%... 50%.. And above. The elecrtical load has not changed.. The MGUK is limited in its output. The ICE Power is now around 850hp. Thats 90hp gained through combustion...

How much did they gain from. Their already 97% effecient electrical machine? Not much.

Ferrari had one of the strongest hybrid systems. They were proud of their strong traction. Then their combustion magic was taken away....

Remember advancing of the ERS is important. It does help "long haul" racing which is great! You save more on fuel over a number of laps and this important for running lighter in the race.

But you are mixing up fuel mileage and thermal efficiency. With fuel mileage the strategy of manging the engines and recovering energy come into play more than the peak efficiency.

[mendis]

What?!!

The PUs are 50% efficient overall. The ICE part alone isn't. Strip off the energy recover systems and you'd lose a huge chunk of that headline efficiency straight away.

Outside of comments from Andy Cowell which counter your beleifs.. Simple comparisons can be done to shoe that the combustion/heat managment is THE big differntiator...

The strongest F1 V6 Hybrid started life at 42.5% thermal efficiency... It was adverstized the the electrical machines were greater than 97% efficent. ICE horsepower was calculated at 760hp or so.

In the efficiency of the engines increased year on year... 45%... 47.5%... 50%.. And above. The elecrtical load has not changed.. The MGUK is limited in its output. The ICE Power is now around 850hp. Thats 90hp gained through combustion...

How much did they gain from. Their already 97% effecient electrical machine? Not much.

Ferrari had one of the strongest hybrid systems. They were proud of their strong traction. Then their combustion magic was taken away....

Remember advancing of the ERS is important. It does help "long haul" racing which is great! You save more on fuel over a number of laps and this important for running lighter in the race.

But you are mixing up fuel mileage and thermal efficiency. With fuel mileage the strategy of manging the engines and recovering energy come into play more than the peak efficiency.

+1.

Even the low range road cars have gone through enormous change in combustion efficiency to give higher throughout for lowering fuel intake. Afterall F1 is pinnacle of efficiencies and in that sense, the V10s created on the platform of current F1 efficiency + ERS + sustainable fuel and lower car weight, can be the better future of the sport once again.

[Tommy Cookers]

Even the low range road cars have gone through enormous change in combustion efficiency to give higher throughout for lowering fuel intake....

no
what you are all talking about isn't combustion efficiency

CE is just what % of fuel eg 95% is burned in the combustion chamber - that hasn't really been changed

what systems like TJI enable is satisfactory combustion of leaner mixtures than would be possible otherwise
plus F1 architecture (presumably) can have some post-cylinder combustion upstream the turbine

[johnny comelately]

Even the low range road cars have gone through enormous change in combustion efficiency to give higher throughout for lowering fuel intake....

no
what you are all talking about isn't combustion efficiency

CE is just what % of fuel eg 95% is burned in the combustion chamber - that hasn't really been changed

what systems like TJI enable is satisfactory combustion of leaner mixtures than would be possible otherwise
plus F1 architecture (presumably) can have some post-cylinder combustion upstream the turbine

"Otherwise impossible"
There would only, if ever, be post cylinder combustion if there was a particular map. For these efficiencies they could not afford to lose that energy from BMEP (despite partial recovery via the H)
MFB will now be higher again to get these efficiencies they could not afford to lose that energy from BMEP.
IMHO.

[Tommy Cookers]

in the insulated exhaust pipe hot unburnt fuel vapour is dwelling at pressure surrounded by hot gas that includes oxygen
won't it oxidise aka burn ?

there will always be some such unburnt fuel there - combustion in-cylinder will never be complete

[johnny comelately]

in the insulated exhaust pipe hot unburnt fuel vapour is dwelling at pressure surrounded by hot gas that includes oxygen
won't it oxidise aka burn ?

[johnny comelately]

in the insulated exhaust pipe hot unburnt fuel vapour is dwelling at pressure surrounded by hot gas that includes oxygen
won't it oxidise aka burn ?

Looking at the: efficiency, RPM vs EVO, BHP I dont think so.
That use of a burn in the pipes was from earlier eras which was a consequence of overly rich mixtures (on turbos) to partially control knock. That was a bonus then to spin up the turbo, no need now with the E.
With higher coolant temps and precombustion pressures, partial HCCI (maybe) and TJI they have IMHO virtually got rid of boundary layer quench, the biggest contributor to the unburnt MF.

[Tommy Cookers]

you seem to be saying that combustion is complete in-cylinder

but combustion is incomplete due to inconsistency - with lean mixtures
inconsistency of combustion is what sets the limit to leaning

inconsistency can have gas burning while leaving the port - to continue if conditions are then suitable oxygenwise ?

[johnny comelately]

you seem to be saying that combustion is complete in-cylinder

but combustion is incomplete due to inconsistency - with lean mixtures
inconsistency of combustion is what sets the limit to leaning

Almost complete
Successful combustion of these new lambdas has not been done before (went very close in the 2 strokes as you set the jetting correctly), so the degree of inconsistency was true before these new parameters such as TJI etc, like you stated.
So that (lean problem) is what used to " set(s) the limit to leaning"