Mclaren MP4-31 Honda Speculation Thread

[j.yank]

I believe that is correct - they couldn't get it working at the desired RPM which meant they would never have the power required to be competitive and compounded the issue of ERS recharge and using more fuel.

In the last laps of Abu Dabi Alonso demonstrated speed that was a nearly match to Mercedes and Ferrari. Something similar happen in Canada when Alonso kept Vettel behind him for two laps. So, probably they had the competitive power but they cannot use it for more than a lap without big risk for the whole PU.

[PlatinumZealot]

The reason why Honda chose a higher rpm turbo first time out is for reasons of spool time and efficiency... Yes. Efficiency.

The faster the turbine spins the more exhaust pulses each blade can capture. You get a better use of the pressure pulses. If you design your turbine for a higher operating speed you can be sitting pretty if everything else is perfectly aligned. You see the exhaust pressure pulses are many times faster than the rotor and some of that energy is wasted as reversibility when the hit the rotor. Honda was probably hoping that they could achieve a steady turbine loading throughout the lap and run the turbine at a higher rpm reaping these efficiency benefits. Their turbine map is designed around this high rpm range too. Real world problems obviously put fire to their concept though. The MGUH was not strong enough - poor charging to the battery.. high back pressure from the small turbine.. leads to higher combustion chamber temperatures.. not a flat enough compressor map coz the compressor is small... a whole bag of problems. I think now they realize that the pulse usage efficiency of the turbine is a secondary importance to the efficiency the MGUH and a larger turbocharger can make up for.

[DarkAlman]

I assume that placing the compressor wheel and MGU-H in the V of the engine also causes heat bleedthrough from the engine?

This would heat up the oil in the compressor and MGU-H as well as increasing boost air temperature making it more difficult to cool the engine overall.

Does it make sense to position the MGU-H shroud in or near the plenum chamber to use the intercooled boost air to help cool it down? or at the very least keep it in a cooler ambient temperature?

[j.yank]

The MGUH was not strong enough - poor charging to the battery.. high back pressure from the small turbine.. leads to higher combustion chamber temperatures.. not a flat enough compressor map coz the compressor is small... a whole bag of problems. I think now they realize that the pulse usage efficiency of the turbine is a secondary importance to the efficiency the MGUH and a larger turbocharger can make up for.

Which one of these cannot be catch before season?

[hemichromis]

The reason why Honda chose a higher rpm turbo first time out is for reasons of spool time and efficiency... Yes. Efficiency.

The faster the turbine spins the more exhaust pulses each blade can capture. You get a better use of the pressure pulses. If you design your turbine for a higher operating speed you can be sitting pretty if everything else is perfectly aligned. You see the exhaust pressure pulses are many times faster than the rotor and some of that energy is wasted as reversibility when the hit the rotor. Honda was probably hoping that they could achieve a steady turbine loading throughout the lap and run the turbine at a higher rpm reaping these efficiency benefits. Their turbine map is designed around this high rpm range too. Real world problems obviously put fire to their concept though. The MGUH was not strong enough - poor charging to the battery.. high back pressure from the small turbine.. leads to higher combustion chamber temperatures.. not a flat enough compressor map coz the compressor is small... a whole bag of problems. I think now they realize that the pulse usage efficiency of the turbine is a secondary importance to the efficiency the MGUH and a larger turbocharger can make up for.

I understood that the major problem was that when the turbo was spun to the high speeds it was designed for it caused vibration?!

Where did you get this information?

[godlameroso]

If their civic engine is anything to go by, they may have the turbine cooled by the water jackets in the head.

[Wazari]

Spooling up the turbine with the MGU-H requires energy from the battery.
So the less time you spend spooling up the turbine the more efficient the system will be overall.

I assume that a smaller turbine would require less energy to get spinning initially but would it require more energy at Max RPM?

Yes, this is definitely one issue. More energy drained from the ES to keep the turbine spooled than recovered overall. MGU-H performance lacking in generator mode due to a host of issues as mentioned previously.

Wastegate is needed during transition phases for very short periods but also if MGU-H malfunctions or is disabled.

I don't know how many exhaust exits.

[George-Jung]

I believe that is correct - they couldn't get it working at the desired RPM which meant they would never have the power required to be competitive and compounded the issue of ERS recharge and using more fuel.

In the last laps of Abu Dabi Alonso demonstrated speed that was a nearly match to Mercedes and Ferrari. Something similar happen in Canada when Alonso kept Vettel behind him for two laps. So, probably they had the competitive power but they cannot use it for more than a lap without big risk for the whole PU.

Ok.. but than please explain their poor qualifing form..

[siwillems]

I believe that is correct - they couldn't get it working at the desired RPM which meant they would never have the power required to be competitive and compounded the issue of ERS recharge and using more fuel.

In the last laps of Abu Dabi Alonso demonstrated speed that was a nearly match to Mercedes and Ferrari. Something similar happen in Canada when Alonso kept Vettel behind him for two laps. So, probably they had the competitive power but they cannot use it for more than a lap without big risk for the whole PU.

Ok.. but than please explain their poor qualifing form..

Everybody else is in qualifying mode so the difference between the cars is held rather be than closed as it was during The race when the other cars were probably not in as high performance mode relative to the maclaren

[Andres125sx]

Also, if your engine suffer some damage in qualifying your race is finished and you´ll miss important mileage, while on last laps of last GP, specially when you´re 17th, it really doesn´t matter if your PU break apart so you can push it futher to see what´s your real perfomance when you don´t care about reliability

[Gridlock]

You might also be running 2016-spec aero/chassis/engine parts that you wanted to carry into the Pirelli test? Anyone got any pics of the Macca's rake on those final fuel-light laps?

[ollandos]

Guys any news for car unveil date?

[Thunder]

Guys any news for car unveil date?

Nothing as of yet. But i wouldn't expect it to be 2 Weeks ahead of the First Test at the earliest. McLaren always was one of the First to reveal the Car in the Past Years, but i wouldn't be surprised if we just get a short Presentaion at Barcelona an hour befor the Test starts.

[bauc]

Guys any news for car unveil date?

Nothing as of yet. But i wouldn't expect it to be 2 Weeks ahead of the First Test at the earliest. McLaren always was one of the First to reveal the Car in the Past Years, but i wouldn't be surprised if we just get a short Presentaion at Barcelona an hour befor the Test starts.

Mclaren always have the launch of the new car at the end of January, I'm expecting the same with the MP4-31. Just for reference below are the launch dates for the last 3 cars.

MP4-28 31st of January
MP4-29 24th of January
MP4-30 28th of January

[Thunder]

True, but this Year winter Testing starts later. And i don't know if PP pulls a Newey and wants to develop until the very last second.