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it seems that you have been unimpressed by my frequent assertions !! ..........
that the engines will not get anywhere near 15000 rpm because so doing would be unnecessary and disadvantageous
and that the MGUH torque (motoring or generating) will be controlled to manage its rpm and hence boost throughout

They will use the 15000rpm.
The reason why?

The ratios are fixed for the whole season.
There will be no need to compromise on gear raitios, when you have the flexibility of an additional 5000 rpm.
Some races you may see the max rpm, some races you may not. The point is the team can use it to allow better selection of gear ratios that doesn't create a compromise.

Tommy Cookers wrote:it seems that you have been unimpressed by my frequent assertions !! ..........
that the engines will not get anywhere near 15000 rpm because so doing would be unnecessary and disadvantageous
and that the MGUH torque (motoring or generating) will be controlled to manage its rpm and hence boost throughout

Even if rpm is generally kept below 13 or 14,000, there is still a reasonably large reduction in required boost from 10,500. Using MGUH torque to control boost is likely the default option, but it may still entail a fairly large change in back pressure over the engine rpm range. I'm assuming MGUH torque alone cannot fully control boost pressure, but that a change in turbo rpm will be required as well. Does anyone have any info on that?
If the change in turbo rpm causes a change in back pressure, causing a significant loss in total power, I'm just suggesting a more efficient way to keep back pressure constant than using a wastegate.

chip engineer wrote:

Tommy Cookers wrote:it seems that you have been unimpressed by my frequent assertions !! ..........
that the engines will not get anywhere near 15000 rpm because so doing would be unnecessary and disadvantageous
and that the MGUH torque (motoring or generating) will be controlled to manage its rpm and hence boost throughout

Even if rpm is generally kept below 13 or 14,000, there is still a reasonably large reduction in required boost from 10,500. Using MGUH torque to control boost is likely the default option, but it may still entail a fairly large change in back pressure over the engine rpm range. I'm assuming MGUH torque alone cannot fully control boost pressure, but that a change in turbo rpm will be required as well. Does anyone have any info on that?
If the change in turbo rpm causes a change in back pressure, causing a significant loss in total power, I'm just suggesting a more efficient way to keep back pressure constant than using a wastegate.

As the rpm rises beyond the 10,500rpm peak fuel flow the compressor power required will be reduced. However, the turbine power produced will also be less, as there will be less exhaust energy.

Thus I find it highly unlikely that the engines will be faced with excessive exhaust back pressure - unless the engine designers deliberately follow the path of high back pressure.

And, yes, the turbocharger would have to change speed to maintain the same mass flow rate and change the boost.

Well the fuel flow is constant from 10.500 to 15.000 rpm. This means that the airflow has to be the same as well. So the turbo will reach peak rpm at 10.500 rpm and sustain this rpm even though the engine increases the rpm to 15.000 rpm. So when the flow is constant and the turbo rpm is constant from 10.500 to 15.000 rpm the back pressure wont increase. And when the flow volume is the same and the only thing that changes from 10k to 15k rpm is the flow speed wouldn't back pressure actually decrease??

So there is still no need for a wastegate.

forgive me if this is a silly question, if the air and fuel mix is the same from 10,500-15,000 will BHP increase past 10,500? if it doesn't will we see cars changing gear around 10,500-11,000 ?

allstaruk08 wrote:forgive me if this is a silly question, if the air and fuel mix is the same from 10,500-15,000 will BHP increase past 10,500? if it doesn't will we see cars changing gear around 10,500-11,000 ?

Friction increases with rpm. So the power will go down.

They will want the shifts to finish at 10,500rpm at the lowest.

Power above 10,500rpm will be greater than that below 10,500rpm. That is, if the shift ends at, say, 9,500rpm the driver will be losing time.

You could generalize and say that viscous friction increases with square of the rpm, why friction-losses at 15 000 rpm will be almost xactly twice the friction at 10 500. Sometimes I think the rule-makers had a thing for even numbers.

agreed, briefly running somewhat towards the higher rpm would be useful when ripping up through the (non-ideal) gears

the upper gears will have about 16% rpm change/shift, so the worst mismatch could only be 24% (for ?sec in 1 race per season)
because in the upper gears another gear is typically only ever +-16% away
(the 2014 8 gears available to the driver will be very slightly wider spaced than 2013's 7 gears)

so aim for a range for sustained running of 10800-12600 ? as this almost always gives enough margin for mismatch

the turbo characteristics just shown tell me that a 10% variation in turbo/turbine rpm will regulate boost for 'my' narrow rpm range
about 25% seems necessary for the wide 10500-15000 rpm range

wuzak wrote: As the rpm rises beyond the 10,500rpm peak fuel flow the compressor power required will be reduced. However, the turbine power produced will also be less, as there will be less exhaust energy.

Thus I find it highly unlikely that the engines will be faced with excessive exhaust back pressure - unless the engine designers deliberately follow the path of high back pressure.

And, yes, the turbocharger would have to change speed to maintain the same mass flow rate and change the boost.

There wont be less exhaust energy.
Why would you make that assumption?
The turbine will have even more available power. More so than is need by the compressor, so that energy will either go to the generator or out the exhaust.

wuzak wrote:

allstaruk08 wrote:forgive me if this is a silly question, if the air and fuel mix is the same from 10,500-15,000 will BHP increase past 10,500? if it doesn't will we see cars changing gear around 10,500-11,000 ?

Friction increases with rpm. So the power will go down.

They will want the shifts to finish at 10,500rpm at the lowest.

Power above 10,500rpm will be greater than that below 10,500rpm. That is, if the shift ends at, say, 9,500rpm the driver will be losing time.

Formula 1 engines are very funny things. The increase in friction is not linear, neither can we assume if it increases at all at certain speeds.
There are many different contributors of friction, that have different behaviors at speed so i myself wont guess if there is an increase, or if it levels of, or increases minutely, or if it reduces.
What we can say though is that above 10,500 rpm is a steady level of horsepower, which my be useful when accelerating down a straight, if we compare to changing gear and engine speed drops a few thousand rpm into a lower power level then has to climb again. So i do see where excess engine speed can be helpful.
That's ignoring consideration for engine life though.

Subaru’s new FA20DIT is being developed into a highly efficient racing engine for Le Mans Prototypes. The apparently radical eLMP R engine from Revolutionary Technologies United (RTU) is a 1.6 turbo charged short stroke boxer engine based on a standard Subaru block, it was revealed for the first time at the PMW Expo in Cologne, Germany.

It is expected that it will produce in excess of 550bhp and can run with very little cooling indeed due to its use of a patented ‘Pseudo Adiabatic’ combustion process. This the team behind the project would make a car using it not only highly fuel efficient but also highly aerodynamically efficient due to significantly reduced cooling demands. However the engine is on the heavy side at 130kg.

The man behind the project, Al Solari has something of an interesting past in sportscar racing but claims that this technology has already been proven on a five cylinder Audi engine which developed in excess of 800bhp. Certainly if the technology works as claimed then the engine would (aside from its weight) be highly competitive in a fuel flow restricted formula.

Performance figures and verification of the RTU claims will be announced at the Autosport Engineering Show in January on stand E1162.


[youtube]http://www.youtube.com/watch?v=vVnM8z1nX4k[/youtube]

What is a PSEUDO ADIABATIC ENGINE? How is the exhaust temp half as a regular engine?

Adiabatic condition is usually assumed for most engines. It really means that no heat energy is transferred over a system boundary, such as a cylinder wall. Obviously this is not the case, as cooling water flow takes a lot of heat from the engines.
So psuedo adiabatic would suggest that RTU have selected cylinder wall materials that have very good resistance to heat transfer and are stable at the resulting high temperatures.
Basically it's a high temperature engine, that doesn't need much cooling because it can live with high temperatures.

It's something i think we will see with the new F1 engines as well. Just that a hotter engine maybe won't last as long, and it will be very expensive with the selection of materials.

ringo wrote:Adiabatic condition is usually assumed for most engines. It really means that no heat energy is transferred over a system boundary, such as a cylinder wall. Obviously this is not the case, as cooling water flow takes a lot of heat from the engines.
So psuedo adiabatic would suggest that RTU have selected cylinder wall materials that have very good resistance to heat transfer and are stable at the resulting high temperatures.
Basically it's a high temperature engine, that doesn't need much cooling because it can live with high temperatures.

It's something i think we will see with the new F1 engines as well. Just that a hotter engine maybe won't last as long, and it will be very expensive with the selection of materials.

Ringo these guys are using a stock block with no radiators not some new material. RTU has a patent for the intake manifold,

Fresh cooled air is manipulated so as to allow the engine to run in a lean burn condition further cooling the engine. These superior properties allow for extreme power and efficiency.

Scientifically, an adiabatic process means no energy xchange with the enviroinment, an ICE always has a vast such xchange.

As for the friction vs speed discussion above; As long as there is a viscous film involved, resistance force is proportional to speed and power is always force times speed, why powerloss is squared to the rpm. 15 over 10.5 squared is very close to 2.0.