[WEC] Toyota LMP1 Discussion

[cokata]

Originally Posted by TF110

The last we heard about the engine was Wurz saying itd be 'over 600hp'. If they step up to 8mj yet still make that much, then the efficiency must be a good gain in %.

Not possible, even if they drop down to 2mj.

[TF110]

Anything is possible, friend. Dont believe the teams saying they only make "500, 520hp"! Theres a lot of understating going on and most everyone accepts that to be the case.

[cokata]

Originally Posted by TF110

Anything is possible, friend. Dont believe the teams saying they only make "500, 520hp"! Theres a lot of understating going on and most everyone accepts that to be the case.

I don't feel like doing the math, but with the amount of fuel they have to get 600+ hp would require 45%+ efficiency, and that's very hard to achieve even for a diesel, let alone a petrol engine.

[Pandemonium]

It is well possible. But I am not sure. Last year difference with lmp2 pace was not that big. They need more power!!!.

[TF110]

Originally Posted by cokata

I don't feel like doing the math, but with the amount of fuel they have to get 600+ hp would require 45%+ efficiency, and that's very hard to achieve even for a diesel, let alone a petrol engine.

I dont think that target is reachable without the hybrid aspect added to the mix. But for diesel I think its within their grasp.

[Articus]

Originally Posted by TF110

I dont think that target is reachable without the hybrid aspect added to the mix. But for diesel I think its within their grasp.

The combustion engine efficiency is purely a function of the input energy and the output work of the ICE. The hybrid system increases total "system" efficiency (1000hp on petrol alone vs 500hp petrol and 500hp electric) but it plays no role in ICE efficiency.

[TF110]

No difference from what Im saying. Doesn't the hybrid make life easier on the engine especially in acceleration instances? So that would mean the engine isnt working as hard because the electric power is providing a good amount of assistance? Thats how Toyota describe their hybrids for the street.

[Articus]

Originally Posted by TF110

No difference from what Im saying. Doesn't the hybrid make life easier on the engine especially in acceleration instances? So that would mean the engine isnt working as hard because the electric power is providing a good amount of assistance? Thats how Toyota describe their hybrids for the street.

The only real way the Ts040 and say a prius are similar (aside from being "hybrids") is that when the Toyota is leaving it's pit box (i.e on pure electric) it's just like a Prius at low speed.

The Prius and hybrids like it are using it's hybrid system to replace the ICE at certain speeds and rpm ranges. You can do clever things (like in Honda Accord) spin up the motor every time to it's most efficient rpm range and then start injecting fuel spark.

But the TS040 is using the hybrid purely as a power boost. It's energy is additive, not meant to replace the ICE. If you have two "engines" the quickest way down a straight is to utilize both at maximum load and that's how the ERS gets utilized in Audi ,Porsche, Toyota.

They are hybrids sure, but quite different to road cars.

[TF110]

Of course its different from the road cars. But theres definitely reason to think the hybrid helps with engine efficiency by working in conjunction. It would be nice to see the rules open up for things like cylinder deactivation

[GasperG]

Prius is also using hybrid for power boost and I must say it's quite addictive to floor a Prius.

With TS040 maybe there are accessories that are not belt driven by the ICE, but still boosting efficiency (and HP) for 15% from last year is unlikely or better say impossible.

And one could say that under max bursts of acceleration (1000 HP) TS040 is 77% fuel efficient.

[rich07]

Originally Posted by Pandemonium

It is well possible. But I am not sure. Last year difference with lmp2 pace was not that big. They need more power!!!.

I see Jeremy Clarkson has joined ten tenths

[TF110]

Originally Posted by GasperG

Prius is also using hybrid for power boost and I must say it's quite addictive to floor a Prius.

With TS040 maybe there are accessories that are not belt driven by the ICE, but still boosting efficiency (and HP) for 15% from last year is unlikely or better say impossible.

And one could say that under max bursts of acceleration (1000 HP) TS040 is 77% fuel efficient.

Thats 15% if they only made 520hp, right? But I think thats a little conservative(?) or some other similar adjective.

[GasperG]

Yes 15% is from 520 to 600 HP.

If a team states ICE power than you can work out the efficiency from this numbers:
E20 petrol: 39.3 MJ/kg
Fuel flow 6MJ petrol: 89.5 kg/h

It's funny that only Toyota gave us official ICE power, I wonder why?

[TF110]

So what would 41% efficiency equate to? Is it 520hp?

[GasperG]

To lazy to work out the numbers ?
39.3 MJ is 10.917 kWh

at 100% efficiency you get: 10.917 kW*h/kg * 89.5 kg/h = 977 kW

under those numbers "official" ICE efficiency is 383 kW/977 kW = 39.2%

But note that Toyota probably round those numbers to get their 1000 HP figure, and this was also very early (27. march) statement.

[cokata]

Originally Posted by GasperG

To lazy to work out the numbers ?
39.3 MJ is 10.917 kWh

at 100% efficiency you get: 10.917 kW*h/kg * 89.5 kg/h = 977 kW

under those numbers "official" ICE efficiency is 383 kW/977 kW = 39.2%

But note that Toyota probably round those numbers to get their 1000 HP figure, and this was also very early (27. march) statement.

They already said 41+% percent i believe if i'm not mistaken. And that would give them ~540 bhp. Nissan are claiming 550 bhp for their engine which would put it bang on 42% efficiency. I would have expected a bigger advantage for them given that their engine+drivetrain combo is much heavier for the sake of better efficiency, as the general rule of thumb is that if all else is equal higher torque and lower rpm will yield higher efficiency.

[MyNameIsNigel]

Originally Posted by GasperG

Yes 15% is from 520 to 600 HP.

If a team states ICE power than you can work out the efficiency from this numbers:
E20 petrol: 39.3 MJ/kg
Fuel flow 6MJ petrol: 89.5 kg/h

It's funny that only Toyota gave us official ICE power, I wonder why?

Originally Posted by GasperG

To lazy to work out the numbers ?
39.3 MJ is 10.917 kWh

at 100% efficiency you get: 10.917 kW*h/kg * 89.5 kg/h = 977 kW

under those numbers "official" ICE efficiency is 383 kW/977 kW = 39.2%

But note that Toyota probably round those numbers to get their 1000 HP figure, and this was also very early (27. march) statement.

Where did you get the energy density figure for E20 petrol from ? In draft V04/V05 of the LMP1 Technical Regulations, a figure of 39.55 MJ/kg was quoted, but the 2014 fuel specifications were not final at that time. This initial hypothesis was then deleted in subsequent drafts.

[Articus]

Originally Posted by TF110

Of course its different from the road cars. But theres definitely reason to think the hybrid helps with engine efficiency by working in conjunction. It would be nice to see the rules open up for things like cylinder deactivation

But even then, what is the point of cylinder deactivation in full throttle a racing application (cylinder deactivation and full throttle are mutually exclusive unless you just like to go slow). I still think you are confusing the needs of motorsport with those of road cars. Like I said before, combustion engine and ERS power is additive, so cutting back the number of cylinders achieves nothing for racing but making you slower.

Now on the highway in your big V8 Chevy Tahoe or your V8 Mercedes going 60mph in the middle lane, yes cylinder deactivation makes perfect sense to boost fuel mileage.

[TF110]

Originally Posted by Articus

But even then, what is the point of cylinder deactivation in full throttle a racing application (cylinder deactivation and full throttle are mutually exclusive unless you just like to go slow). I still think you are confusing the needs of motorsport with those of road cars. Like I said before, combustion engine and ERS power is additive, so cutting back the number of cylinders achieves nothing for racing but making you slower.

Now on the highway in your big V8 Chevy Tahoe or your V8 Mercedes going 60mph in the middle lane, yes cylinder deactivation makes perfect sense to boost fuel mileage.

Im confusing nothing. If you watch F1 at all, there was talk about the off-throttle exhaust blowing in the Red Bulls after the exhaust position rule change. This was said to be done by cylinder deactivation-
http://somersf1.blogspot.com/2012/06...g-via.html?m=1

There are other advantages to it as well, fuel consumption (especially under safety car), braking feel during harvesting etc.

[Articus]

Originally Posted by TF110

Im confusing nothing. If you watch F1 at all, there was talk about the off-throttle exhaust blowing in the Red Bulls after the exhaust position rule change. This was said to be done by cylinder deactivation-
http://somersf1.blogspot.com/2012/06...g-via.html?m=1

There are other advantages to it as well, fuel consumption (especially under safety car), braking feel during harvesting etc.

exhaust blowing is banned. Why would you want to waste fuel blowing off throttle in endurance style racing anyway? Audi was only blowing exhaust on throttle.

[TF110]

Originally Posted by Articus

exhaust blowing is banned. Why would you want to waste fuel blowing off throttle in endurance style racing anyway? Audi was only blowing exhaust on throttle.

Its banned now. As is cylinder deactivation and variable valve timing. Thats my point. Theres rules currently that are banning solutions that would help with engine and aero efficiency. If you recall, Audi's increased fuel consumption wasn't from the exhaust blowing. Your post is taking only one thing, like ebd, and thinking the negatives. But cylinder deactivation cuts fuel usage in areas like slow corners while off throttle use, for blowing a diffuser, would keep the car stable in braking. That would also help with energy recovery, and therefor better hybrid usage. VVT is known to reduce fuel consumption and emissions.

[GasperG]

Originally Posted by MyNameIsNigel

Where did you get the energy density figure for E20 petrol from ? In draft V04/V05 of the LMP1 Technical Regulations, a figure of 39.55 MJ/kg was quoted, but the 2014 fuel specifications were not final at that time. This initial hypothesis was then deleted in subsequent drafts.

Looking back in a different thread We did get accurate MJ/l number from presentation of how ERS initiative does work:
http://tentenths.com/forum/showthrea...kg#post3403689

But from there I calculated with 0,740 kg/l density, not exactly sure where I got that number and if it's correct, but it's very close to yours, so we must be there somewhere

[TF110]

So 29.15 mj/liter = 39.39 mj/kilogram? How accurate is this? Maybe someone can find out the rating of shell's E20 race fuel.

[MyNameIsNigel]

If only Shell could disclose the relevant fuel specifications.

[hcl123]

Exactly the kind of issue that made me 'hot' on discussions on this forum!?...

They publish their factors, seem to have reasons for them, and in principle nobody is opposed at 'balancing opportunities' by the means of 'energy usage'... but they always fail to publish the 'energetic content of the fuels' in some place !!...

Which leads to believe they (FIA/ACO) don't 'enforce' anything on this issue, not even check if values are in accordance with the published, much less if the 'teams' are not using 'special additives' (which they (the teams) are of course, foolish of them if they don't, they are always looking for rule loopholes to gain advantage in every other area, special aeros and wings, this area of fuel additives is simply a no brainier )...

Just a charade !