28 replies to this topic

[turssi]

Waiting for Melbourne I was going through some of the rule changes and started to wonder what this 100kg total fuel limit, together with max 100kg/h flow limit and 15k max revs mean. I don't understand engines, but maybe there is someone here kind enough to explain.

In qualifying I imagine the power units to do max rpm and use the max flow?

For a two hour race I imagine ano average 50kg/h fuel flow? Does this mean running at 7.5k (half flow, half rpm?) revolutions? How agressive will the power units be during the races at best and at worst?

Also what about the energy recovery? Do the drivers want to accelerate and brake as much as possible to load the batteries? Or do they get loaded even if driving smoothly taking care of fuel consumption and tires?

What eles is there to consider?

Edit to correct the rev limit, thanks Wuzak.

Edited by turssi, 08 March 2014 - 00:31.

[Wuzak]

The rev limit is 15k.

 

They will run maximum fuel flow when they need maximum power - ie the straights.

 

Much of the time of a Grand Prix will be spent at less than full power. 

 

They could use higher gears for slow corners, which means lower rpm and less fuel used. And hey would still have the power to break traction.

 

They do not want to be accelerating and braking. They want to maintain speed as much as possible. But energy recovered from teh brakes can be helpful in saving fuel. eg on acceleration the driver may demand 600hp. The ICE can do this with fuel fuel flow, or it could be split 500hp from the ICE and 100hp from the MGU-K, which saves fuel.

 

They would also want to maintain speed, since the MGU-H would recover more energy, which could be stored or used directly.

[turssi]

So the traction (can it be broken down into rubber, asphalt, downforce and applied torque?), ICE efficiency, ERS power all mean something. Tracks with the most time accelerating will probably be the ones with most time saving fuel?

What about this ERS-H? You use chemical energy (fuel) to create kinetic energy (rotating turbo charger) to run a turbo and then recover heat energy (hot gases)? What do you do with the heat to 'maintain speed' as you put it?

Edit for an additional question: I read somewhere that from 10.5k revs onwards one has to apply the max fuel flow. Is this true? Does it mean that only with revs lower than this fuel saving is possible?

Edited by turssi, 08 March 2014 - 01:16.

[xflow7]

My hunch is that no one's going to want to be the lead car until the last couple of laps, and we'll see a lot of trying to stay within 1sec then opening DRS, but not to pass - just using the drag benefit.

 

I've said it elsewhere, but in my opinion the 100 kg per race rule is a big mistake.  The 100 kg/hr rate limit is fine and I'm actually in favor of it.  But capping max fuel during the race at such an artifically low value is dumb.

Edited by xflow7, 08 March 2014 - 02:05.

[hollowstar]

My hunch is that no one's going to want to be the lead car until the last couple of laps, and we'll see a lot of trying to stay within 1sec then opening DRS, but not to pass - just using the drag benefit.

I can't see that happening. I mean, wouldn't that degrade the tyres way too fast?

Or do these new regs allow cars to follow each other without such spectacular degradation?

[turssi]

@xflow7: How do yoy know if and how much of the time they'll need to save fuel?

Moving to the topic of the electrical motors: Am I correct thinking that they are superior in accelerating at low speeds and then again at saving fuel at top speed? Does this mean that electrical boost will be used for accelerating for the longest straigths and then again to save fuel when at top speed?

[xflow7]

I can't see that happening. I mean, wouldn't that degrade the tyres way too fast?

Or do these new regs allow cars to follow each other without such spectacular degradation?

 

It's a possibility, but the tires are said to be much tougher in order to cope with the torque loads, so they might take more abuse than we're used to.

[xflow7]

@xflow7: How do yoy know if and how much of the time they'll need to save fuel?

Moving to the topic of the electrical motors: Am I correct thinking that they are superior in accelerating at low speeds and then again at saving fuel at top speed? Does this mean that electrical boost will be used for accelerating for the longest straigths and then again to save fuel when at top speed?

 

I don't really, but the total race consumption for past GP's has been posted various places and the 100kg limit is a drastic reduction at many tracks.

[rooksby]

My hunch is that no one's going to want to be the lead car until the last couple of laps, and we'll see a lot of trying to stay within 1sec then opening DRS, but not to pass - just using the drag benefit.

 

I've said it elsewhere, but in my opinion the 100 kg per race rule is a big mistake.  The 100 kg/hr rate limit is fine and I'm actually in favor of it.  But capping max fuel during the race at such an artifically low value is dumb.

 

Assuming enough cars are still running on track, I'd imagine it could indeed look like a bicycle racing peloton. With total allowed fuel consumption so tight, the advantage of staying in the slipstream, and then running full mix and boost for the last few laps must be too significant to ignore.

 

But if so, surely it won't take long to end up looking more like a bicycle track sprint race. With cars slowing down and playing cat and mouse. That's because of the fuel flow limit. If the car in front can slow down enough to save fuel and then run at maximum legal fuel flow at the end, then it doesn't matter how much extra the guy behind may have saved, he can't use more than the FIA limit.

 

The back of garage spreadsheets will require to be liquid cooled to try and keep up with chasing optimum strategy. It'd be funny if the last ten laps looked like an extended safety car restart.

[Oho]

[Wuzak]

Assuming enough cars are still running on track, I'd imagine it could indeed look like a bicycle racing peloton. With total allowed fuel consumption so tight, the advantage of staying in the slipstream, and then running full mix and boost for the last few laps must be too significant to ignore.

 

But if so, surely it won't take long to end up looking more like a bicycle track sprint race. With cars slowing down and playing cat and mouse. That's because of the fuel flow limit. If the car in front can slow down enough to save fuel and then run at maximum legal fuel flow at the end, then it doesn't matter how much extra the guy behind may have saved, he can't use more than the FIA limit.

 

The back of garage spreadsheets will require to be liquid cooled to try and keep up with chasing optimum strategy. It'd be funny if the last ten laps looked like an extended safety car restart.

 

Rubbish. 

 

In 1988 the cars ran with 150l of fuel that was required to do out laps (of which there could be several), the formation lap and the in-lap. 150l is ~110-120kg. And they didn't have to drive around like a peloton.

 

This year's cars have 100kg fuel allowance from the start to the finish - so that doesn't have to take into account the out-lap, formation lap or in-lap (or any burnouts that may be required by the winner).

 

Some tracks will be tight on fuel and others will be quite comfortable. I would imagine that the fuel saving will be no different to that experienced since refuelling was banned.

[spacekid]

I asked this question in the 'Reanult are a catastrophe' thread, but no one could answer.

Much has been made of the fact the Renault power units probably won't be able to run full power without melting. So I expect them to qualify badly. But how far down are they likely to be in the races? With the fuel flow limits will this mitigate their problems to an extent, or even allow them to run at a pretty similar power output to the Mercs and Ferraris in some races?

[Shambolic]

I've said it elsewhere, but in my opinion the 100 kg per race rule is a big mistake.  The 100 kg/hr rate limit is fine and I'm actually in favor of it.  But capping max fuel during the race at such an artifically low value is dumb.

I think the opposite - The total fuel cap makes sense (it's still not exactly frugal) but the per hour (per second) flow cap is daft. The cars should be limited to 100kg of fuel, but be able to use it as and when they choose. In other words, let them pour it by the bucketload into the cylinders for max power, but have to balance that with barely allowing a sniff of petrol before or after in order to make it to the flag.

[rodlamas]

I asked this question in the 'Reanult are a catastrophe' thread, but no one could answer.

Much has been made of the fact the Renault power units probably won't be able to run full power without melting. So I expect them to qualify badly. But how far down are they likely to be in the races? With the fuel flow limits will this mitigate their problems to an extent, or even allow them to run at a pretty similar power output to the Mercs and Ferraris in some races?

No, because of their problems, probably they haven't been able to integrate the whole PU and therefore won't be making the same amount of energy/torque on track with the same mass of fuel that Mercedes & Ferrari are making.

[Boing 2]

One thing that brings out the pedant in me is this stuff about recovering braking energy, these cars aren't recovering braking energy, they are harvesting the cars momentum during braking.

[turssi]

@boing 2: What about the MGU-H then? Is it a generator run with exhaust gas, doubling as a turbine for the turbo charger?

[demet06]

@boing 2: What about the MGU-H then? Is it a generator run with exhaust gas, doubling as a turbine for the turbo charger?

 

 

Yes it doubles as a motor and generator. At low revs it is in motor mode and drives the turbo, blowing air into the plenum. It effectively reduces turbo-lag. Then at higher revs when the turbo is being blown by the exhaust it reverts to generator mode to charge the battery. MGU = Motor Generator Unit.

[Imateria]

The problem here is that I reckon a lot of the teams are only just starting to get their heads around the best way to run these cars in race trim. Trying to predict how the racing will unfold at this point is utterly pointless.

[BillBald]

I think the opposite - The total fuel cap makes sense (it's still not exactly frugal) but the per hour (per second) flow cap is daft. The cars should be limited to 100kg of fuel, but be able to use it as and when they choose. In other words, let them pour it by the bucketload into the cylinders for max power, but have to balance that with barely allowing a sniff of petrol before or after in order to make it to the flag.

 

You want to see a Marussia overtaking the entire field, and then running out of fuel.

[turssi]

Heh, that would be great :-D small team doing something totally ridiculous. But I believe it's not possible considering the technical regulations.

Thinking about the max 100kg per race limit, it's not so tough? Was it Bottas who said that most of the time in Bahrain you don't need to give it any consideration?

I mean if by comparison to last year you can run around 5% of the time on electricity (25% of a lap x 20% of the total power) and your motor has 33% less cylinder volume and lower revs, then in total we're saving 40% fuel by definition. So if last year in some race you spent 165kg of fuel then the new power unit would spend that 100kg. Or am I mistaken (as I said in OP i don't know engines)?

[Gorma]

The problem here is that I reckon a lot of the teams are only just starting to get their heads around the best way to run these cars in race trim. Trying to predict how the racing will unfold at this point is utterly pointless.

I don't think teams have any idea on what's the best way to the cars. There are so many questions marks when it comes fuel consumption and temps in traffic Sure you can calculate the fastest strategy for the race and bin it after the first lap. You are running against other people and at some point during the race you might need to go faster than first planned to make up positions. That means that you need to save fuel at some point. 

[turssi]

I'm starting to think that the fuel flow and the max fuel limits are just simple safeguards against supersizing the turbo and/or tweaking the engine so that you have a ridiculous difference in between how the PU operates during qualifying and race. But as the posters say, we will see it during the season as the teams tackle the related learning curve.

[spacekid]

No, because of their problems, probably they haven't been able to integrate the whole PU and therefore won't be making the same amount of energy/torque on track with the same mass of fuel that Mercedes & Ferrari are making.

Cheers mate, makes sense!

[dave34m]

Well it seems like after the first lap they will go right into fuel save mode and try not to stress the engine (PU) and then if we are lucky any cars still running with 5 laps to go we might see some racing, but probably not at full speed.

 

It could be a very ordinary start to the year

[Wuzak]

Well it seems like after the first lap they will go right into fuel save mode and try not to stress the engine (PU) and then if we are lucky any cars still running with 5 laps to go we might see some racing, but probably not at full speed.

 

It could be a very ordinary start to the year

 

They won't need to fuel save that much. Maybe a little more than last year, but not a whole lot.

 

V8s - ~750hp ~150kg fuel.

 

V6s - ~600hp 100kg fuel.

 

Now, 600/750*150 = 120kg.

 

But the 2014 engines are much more efficient than the 2013 engines.

 

And they have the option of using electric power for a portion of the total. 600hp required at any given time could be made by the ICE alone, or 440hp from the ICE and 160hp from the MGU-K, or any combination between. 

[Boing 2]

@boing 2: What about the MGU-H then? Is it a generator run with exhaust gas, doubling as a turbine for the turbo charger?

 

Yes, Demet's explanation sums it up, the MGU-H is the most complex part of the package to understand, the MGU-K is simple as it harvests energy under braking and powers the engine on acceleration after the traction limited phase is over. The MGU-H  (spinning at 100 000 rpm)  harvests energy at max speed and as Demet says, powers up the turbo at low revs to kill turbo lag but it can also feed it's power directly to the MGU-K unit rather than charge the battery so the turbo is powering the engine and the electric motor simultaneously. It can be used to charge the battery to power the MGU-K later (as well as powering itself) and it also seems to have some wastegate functionality (although there's a proper wastegate there too). So it's charging the battery, powering the turbo, powering the MGU-K and protecting the engine, you'd have to guess we're going to see these things fail quite a bit.

Edited by Boing 2, 10 March 2014 - 10:40.

[GVera]

I asked this question in the 'Reanult are a catastrophe' thread, but no one could answer.

Much has been made of the fact the Renault power units probably won't be able to run full power without melting. So I expect them to qualify badly. But how far down are they likely to be in the races? With the fuel flow limits will this mitigate their problems to an extent, or even allow them to run at a pretty similar power output to the Mercs and Ferraris in some races?

 

You're assuming the problem occur within the ICE and not the electric components of the PU, if the problems reside on the electric components, the fuel limits would make things worse for the Renault during races.

[turssi]

Looks like the FIA has posted ano answer to many of my questions!

http://www.fia.com/n...ower-unit-guide

Great direct to the point reading for all of us fans who are a bit technology limited!

[OvDrone]

It's not the flow of the ocean it's the... nevermind.