Honda Power Unit Hardware & Software

[trinidefender]

Wazari confirmed the 2016 Honda PU operated at 4.0 bar, and we mainly agreed that the Mercedes was running 4.5.

I was under the impression that wazari or someone stated that it was around 4 bar absolute and merc about 4.5 adsolute (3 and 3.5 bar boost consecutively)

[Wazari]

I realize that some people are trying to break down the race telemetry and "read" into it. I will say that this "race telemetry" published from the Austrian GP is not entirely accurate IMO and has been altered somewhat.

[roon]

Why? Getting your opponents to spend time analyzing bad data or ideas is certainly a tactic. The McLaren horns in the 00s were rumoured to be such, what you might call, 'intel-drains'. But presumably teams are aware of these red-herring tactics and would not invest time with potentially curated published images & data, instead investing that same time back into their own R&D.

[Far]

http://www.pitpass.com/58210/Alonso-fea ... o-weakness

Looks like Alonso known the engine is going to be down on power compare to Mercedes but only for a few margin but the aero now is the big cuestión.
Brown say he is not that dumb and only hope the chassis to be good enough.
I think Brown needs to hire the aeroteam and chassis team from toro rosso.

[Gridlock]

I think Brown needs to hire the aeroteam and chassis team from toro rosso.

Or perhaps a senior aero guy from the parent team, like Peter Prodromou?

[Far]

I think Brown needs to hire the aeroteam and chassis team from toro rosso.

Or perhaps a senior aero guy from the parent team, like Peter Prodromou?

I know Peter was in McLaren when Adrian was there too and both got to the bulls but many teams including Ferrari are chasing the top aero guy in toro rosso. If McLaren win all this year is because they no need nobody new there.

[mrluke]

Consensus is around 3.5bar boost

Wazari confirmed the 2016 Honda PU operated at 4.0 bar, and we mainly agreed that the Mercedes was running 4.5.

4.0bar abs - 1.0bar = 3.0bar boost
4.5bar abs - 1.0bar = 3.5bar boost.

I see trinidefender has beaten me to it, thanks

[mrluke]

Sorry for the double post and bringing something up from a few pages that is borderline off topic....

I had some time to think about how to communicate my thoughts more clearly.

Turbine blade and scroll change. Interesting. Usually the turbocharger wheel should be the same size as the compressor wheel to aid balance and reduce* spool time. For a lot of street turbos they run. Smaller turbo wheel thinking its gonna spool quick... It normally does. But you also find that you can add a bigger wheel that is similar in size to the compressor, and get a similar spool time with the benefit of less back pressure up top.

I am not sure that this is correct. In fact I am struggling to find much evidence of street turbos coming with equal sized compressor and turbine wheels.

The turbine is sized based on how much air is coming out of your engine (i.e. 3L engine pumps much more air than a 1L) whereas the compressor is dependant upon how much mass flow you want to add to the engine.

Yes and the same mass of air that goes is the same that goes out. Differences in density of course but the two wheels are spinning at the same angular velocity.

Not necessarily true for a balanced setup. Because at the end of the day 500hp worth of air is still the same no matter the size of the engine. Your will be squeezing 50lb/hr of air thru tiny little snail shell. Lotta heat to the bearings a high backpressure. You may have a bit more power mid band... But if that was your aim then use a smaller compressor then.

A 500hp 2l will have tonnes of lag. But up top you will be losing power with a small turbine. With a bigger turbine wheel a lot of people find that they get more area under the power curve without loosing too much spool time.

The same mass of air will go in and out when both engines are up to speed and running full boost. However we are specifically interested in how the turbo spools and in particular the fundamental link between turbine compressor housing sizing, spool time and engine capacity.

Consider we have our two engines, the first is 3L and the second is 1L for argument both make 500bhp at peak.

Lets look at a typical dyno pull from ~1krpm all the way through to peak.

Although initially neither engine will be able to spool their turbos, as the revs increase the 3L engine is essentially providing three times the amount of air mass per rpm compared to the 1L engine. This means that the 3L is going to start spooling up the turbo far earlier than the 1L engine.

To try and even this out a bit we could reduce the volume for the 1L turbine housing by 2/3rds (simplification) to enable the turbo to start spooling at approximately the same rpm as the bigger engine.

The downside here is that we will be increasing the exhaust back pressure at high rpm and effectively we will be reducing the potential maximum amount of energy that can be "used" by the turbine to spin up the compressor.

For the ideal turbine housing sizing you need to balance spool against back pressure (In F1 this is further complicated by the MGU-H).

However what we can clearly see is that turbine housing is primarily driven by the amount of air/heat/energy omitted from the engine rather than being simply the same size as the compressor.

If we left the big turbine housing on the small engine it may not even be able to generate any worthwhile boost but this housing might be ideally sized for the 3L engine.

The turbine housing on the below is far too big for a car but something with a bigger engine like a bus / lorry it is OEM fitment. But both turbos have very similar sized compressor housings.

[godlameroso]

Ever heard the term don't judge a compressor by it's cover?

[gruntguru]

Consider we have our two engines, the first is 3L and the second is 1L for argument both make 500bhp at peak. Lets look at a typical dyno pull from ~1krpm all the way through to peak. Although initially neither engine will be able to spool their turbos, as the revs increase the 3L engine is essentially providing three times the amount of air mass per rpm compared to the 1L engine. This means that the 3L is going to start spooling up the turbo far earlier than the 1L engine. To try and even this out a bit we could reduce the volume for the 1L turbine housing by 2/3rds (simplification) to enable the turbo to start spooling at approximately the same rpm as the bigger engine. The downside here is that we will be increasing the exhaust back pressure at high rpm and effectively we will be reducing the potential maximum amount of energy that can be "used" by the turbine to spin up the compressor.

The 1L engine will need three times the MAP and three times the Exhaust Absolute Pressure to make the same power so the smaller housing is appropriate anyway.

However what we can clearly see is that turbine housing is primarily driven by the amount of air/heat/energy omitted from the engine rather than being simply the same size as the compressor.

I think other posters were talking about wheel size which ideally is similar for compressor and turbine.

Wheel size has two components - tip diameter which relates to pressure ratio (for both turbine and compressor wheels) and inducer diameter (exducer for turbines) which relates to the volumetric flow rate.

The turbine housing on the below is far too big for a car but something with a bigger engine like a bus / lorry it is OEM fitment. But both turbos have very similar sized compressor housings.

http://i149.photobucket.com/albums/s69/ ... ch2012.jpg

The bigger one would be too small for an F1 engine!

[Brian Coat]

I realize that some people are trying to break down the race telemetry and "read" into it. I will say that this "race telemetry" published from the Austrian GP is not entirely accurate IMO and has been altered somewhat.

Yes and there are no scales either!

You can check some inconsistencies using other known data.

E.g. We already know the rpm and velocity and very approximate acceleration of that car on that circuit from trap speeds, in-car audio FFT and known gearing. Actually, these numbers look relatively consistent
>> but the data has been "smoothed" rather crudely. For usable resolution, YouTube audio will be much more accurate.

Lower down the page things go a bit awry.

MGU-K output is 120kW and the graph sort of implies that the MGU-H is on the same scale, suggesting an MGU-H of >90kW ... very competitive indeed.

However, this is a race lap and (as the ES graph confirms), the total MGU-K/MGU-H net energy flow must be zero or the battery will go flat on the next lap.

If you integrate the MGU-K+MGU-H kW then there is a sizable over-charge, not reflected in the ES lines, which implies the MGU-H output has been flattered by the way the graph is shown.

The energy flows balance when the maximum MGU-H output is 62 kW ...

This is consistent with the MGU-K disabled periods and the lack of aggressive acceleration modes in the race calibration?

All this just a bit of fun. It's like doing the crossword in yesterday's newspaper, but the dog already ate half the clues and someone spilled ink on the rest.

I have not looked at the ICE yet.


EDIT follows >>

[PlatinumZealot]

It would be so nice if Lewis published his telemtry again!
We would see so much!
Or not! Lol
(sarcasm)

Well something sorta satisfying to know: The driver telemtry has driver centric things like vehicle speed, steering angle and brake pressure etc whereas the engine telemtry is whole nother kettle of fish - coolant temps, intake pressures, oil pressure, cltuch temps, turbine rpm, and for these hybrids ERS data. The driver's probably never even see the engine telemetry right?

[Brian Coat]

I'd expect the "own PU" teams' drivers can see PU telemetry, if they want to.
How much use some of it is to them is another question.
Primarily of interest to PU Team track support engineers and Race Engineers?

[Craigy]

I'd expect the "own PU" teams' drivers can see PU telemetry, if they want to.
How much use some of it is to them is another question.
Primarily of interest to PU Team track support engineers and Race Engineers?

Drivers need to manage fuel consumption, temperatures, ES levels and so on, so I'd expect them to see that data at the very least between runs, and in some cases live in the car.

[Brian Coat]

Agreed. From my (very PU-centric) perspective, that's car data.

I believe PZ was referring to the full engine telemetry.