2014-2020 Formula One 1.6l V6 turbo engine formula

[Tommy Cookers]

The max fuel flow of 100 kg/hr equals 1470 kg of air per hour with an AFR of 1.
For maximum power you have an AFR of around 0.9, what equals 1323 kg/hr of air.

What would your finalised AFR be ?

0.98 ?, ' 0.99 ? , 1.01 ? , 1.03 ?

I'm thinking that with an AFR actually 0.9 there is only 90% of the air needed to burn your fuel.
Surely 0.9 would only be right for an unlimited fuel formula ?

[Ian P.]

1470 kg air and 100 kg of fuel (per hour) should be stoichiometric at 14.7 to 1.
If the 0.9 is a fraction of stoich... it is not likely to be a scenario that you would use for a fixed and limited fuel flow rate.

Not sure why we are discussing this as the current expectation seems lime the engine formula will be tossed in the bin.
These units are not going to have much commercial relevance (nor do the 2.4 V-8s either) and the cost for the entire power train is going to be enormous.
The FIA is rapidly digging themselves int a deep and steep sided hole.

[xpensive]

...
And yes, there will be intercoolers, a boost of 2.0 and a compressor efficiency of 70% (likely on the high side) results in an air temp. of 140 deg C. Right in the range for intercoolers and too high to stuff into the engine without serious additional compressor losses.

A boost of 2.0 Bar, 3.0 absolute, please xplain how you arrive at a number more than twice as high as the rest of us do?

I doubt if an intercooler will be worth the bother packing- and aerodynamic-wise with a boost as low as 0.7 Bar.

[Tommy Cookers]

If the AFR was 0.9 then 11% at least of the limited fuel passes unburnt into the exhaust side.

If air is injected into the exhaust stream ahead of the turbine the fuel burns, making the engine in part a gas turbine.

Do the rules allow this ??

[matt21]

The 2014 regs don't seem to contain any limitations or specification for bore or stroke. Only displacement.

5.3.1 Cylinder bore diameter must be 80mm (+/- 0.1mm).

As I read the 2014 rules I did not find any regulations on exhaust positioning. Welcome back EBD if they don´t specify it more in detail.

[pgfpro]

If the AFR was 0.9 then 11% at least of the limited fuel passes unburnt into the exhaust side.

If air is injected into the exhaust stream ahead of the turbine the fuel burns, making the engine in part a gas turbine.

Do the rules allow this ??

I think the engineers will be all over this, to the point their will be very little fuel left over post turbine.

[matt21]

What would your finalised AFR be ?

0.98 ?, ' 0.99 ? , 1.01 ? , 1.03 ?


I'm thinking that with an AFR actually 0.9 there is only 90% of the air needed to burn your fuel.

Surely 0.9 would only be right for an unlimited fuel formula ?

Following settings were used by Honda back in ´88. There was also a fuel limit of 150l per race.

1. Best power setting
boost 2.5 bar, charge temp 40°C, fuel 25°C, AFR 0.87, 685hp with min FC 231 g/(hp x h)

2. min FC setting
boost 2.5 bar, chagre temp 70°C, fuel 80°C, AFR 0.98, 620 hp with min FC 200 g/(hp x h)

[Tommy Cookers]

Thanks for that !

I presume 150 l of (mostly) Toluene fuel amounted to a lot more energy than the 2014 scheme will have (ie even this amount of Toluene would support high boost bought with rich mixture, weren't these engines giving about 800 bhp race average max power ?).


I am (often) told that in the bad old days when Toluene was allowed, it was cut with Heptane (zero Octane rating) to produce a fuel with road (thus race) legal 101 or 102 Octane.

The current F1 fuel regs (2011) seem to have no limit on Octane rating.

I wonder what the 2014 engine designers have in mind !

A dollop of Triptane perhaps ?
This is the legendary WW2 era fuel, a bit like iso-octane but hugely more sensitive to lead, so allowing huge power increases in (supercharged) aircraft engines and, more usefully, better economy/power combination due to higher CR.
There seems a surprising level of interest today in improved production methods (problematic re WW2)
112 octane unleaded.
How would it work with non-lead but similar octane booster ?

There doesn't seem to be a ban on Toluene as such.

The 2014 rules would seem to have potential for a 'fuel war, presumably the fuel companies don't want that ?'

[matt21]

There is a limit on aromatics of 40%.

For the "rocket fuel. This is what honda used.

[Tommy Cookers]

Interesting !

The qualities of Toluene seem essentially that it's about 25% denser than petrol (iso octane).
That made it perfect when the rules tried to reduce turbo engines power by reducing the volume of fuel, leaving the weight of fuel unregulated,(for 2014 the regulators are to control fuel by weight).
In other circumstances it might avoid having to redesign a car for greater tankage engendered by rapid increases in turbo pressure and power.

Otherwise it's not remarkable, ie proportionate to the air massflow of the engine the heat content no better than petrol's

IMO of course. Other views are available, as they say !

There's quite a difference betwen MON and RON, this might suggest better detonation resistance ie higher boost and power in racing (MON and RON tests are at 600 and 900 rpm respectively)

Thanks, anyway

[Speng]

I guess nobody is a fan of the 2014 rules. I did a quick reading of the rules and here were my high points:
- No VNT, VGT or variable exhaust allowed. Assume wastegates allowed. As the rules allow means to control boost pressure but don't specifically say a waste gate so if you know of some way to do so that's not variable turbine geometry...
- one single stage compressor driven by one single stage turbine but this is no big deal because the pressure ratios you looking at nobody needs multiple stages of turbomachinery.
- No VVT or lift allowed. I assume this is the same as today but it really sucks because if they have as aim to make the engines more relevant to production car engines this should be part of the package because isn't the enabler for variable cycle engines like Miller and Atkinson cycle where the expansion and compression ratios aren't the same *and* vary with various engine parameters? I suppose in the 80s when VTEC was only a gleam in some Honda engineer's eye this could have been thought to be complex expensive tech but VVT is so common today.
- Variable induction/Variable intake geometry (as far as I can tell) is not forbidden. Interesting...
- Even though variable turbine geometry is disallowed they mention nothing about the compressor side of the turbo in this respect. I haven't seen anything in the literature about using IGVs but there are some other interesting control ideas for centrifugal compressors that might be applicable. BTW I would expect the compressor efficiencies to be 85+% unlike other people here who've been quoting numbers like <80%. Maybe I've been reading too many aero-engine references but that is pretty typical now for centrifugal compressors in jet engines with pressure ratios of 4+ (i.e. 3atm+ boost).
- Engine ancillaries must be engine driven. I haven't seen to many race engines with electrically driven ancillaries but with all the electricity going around these cars it could have been a fertile place for development because electric driven ancillaries wouldn't have counted against you ERS discharge allowance so you could essentially drive your ancillaries for free (I'm assuming you could recover more than the allowance given to drive the wheels). Also this is a direction in which production cars are going AFAIK.
- Camshafts and poppet valves are implied but not required by my reading but my guess is a rotary valve would get the serious ixnay. At least they don't require valve springs - that would be so 1990s of them.
- of some actual relevance to current trends in turbos they don't disallow foil bearing in the turbos. This is good from the point of view of them requiring the engine to be shut down in the pits as it eliminates coking of lubricated bearings.
- Inside the V exhausts are not allowed, which is strange as it goes pretty well with the single turbos close to the crankshaft axis that they're requiring (see latest Audi racers for example) but I guess this is an experiment they didn't want the engine makers to bother trying. IIRC at least one V6 from the previous turbo era had the exhaust in the V.
- Interestingly there is no max fuel octane. They do have a lot of requirements on the fuel but I would be surprised if there isn't some fuel experimentation.
- Even though it's going to be delayed the the TERS/MGUH is interesting relative to the KERS/MGUK as the TERS is not limited in it's charge or discharge rates unlike the KERS and the TERS can drive the turbo. I doubt if lag is problem today with shifts being so fast but it might help bump boost at low RPM. I think in the future they'll probably allow more overall ERS capacity and higher discharge rates and this TERS could well be interesting as I reckon even after driving the turbo there's still going to be a whole lot of energy in the exhaust to harvest. The rules say one turbine driving a compressor on the same shaft but they say nothing about a whole nother turbine driving the TERS...
- The last interesting thing I noticed is that there's no limit on boost. I think most people are assuming close to stoichiometric F/A ratios (sorry I'm a turbine person and we say F/A not A/F) but I would assume with DI that you'd be running lean at some engine conditions. I would love if someone could discuss the tradeoffs of a lean DI, Atkinson engine with turbos. Just came to me that the rules don't require spark ignition at all times so I suppose some amount of compression ignition would be allowed at various operating conditions. I wouldn't be surprised to see these things running a lot like a TDI at some point.

Comments/corrections welcome.

[Holm86]

I dont understand why theres all the fuzz about the cost of developing this new engine for 2014.

Just watched the Le Mans 24h race this weekend and came to think of that in the prototype class engine regulations change allmost every year. Often they only race the same engine configuration af few years before changing to at new one.

So i dont get why its all that hard for F1 manufactures to create an engine where there is allmost no design freedom. The LMP engine regulations are much more free.

[Tommy Cookers]

Good stuff, Speng !!!!

.......a few spot opinions before I forget !

compressor efficiency would be lowish due to its small size (tip losses) ?

rotary valves not allowed ? (Ilmor tried a few years ago, then RVs ruled out ?)

2014 rules dictate boost by fixing capacity and rpm, but intend to reduce fuel year by year ?, this would tend to reduce boost and exhaust energy levels ?
(low boost has been convincing in US)

turbo enthusiasts think the turbo is already a more-complete-expansion engine ?
(why would one ever have a turbo synthetic Atkinson ?, although a naturally aspirated (larger) syn. Atkinson has potential ?
the 'flat' fuel regime suits it ?, and other ways of realising super-compression that wouldn't need VVT)

other approaches to petrol engine efficiency are improvements at partial power, so the rules don't cater for them

do the rules allow wide-open-throttle, eg to 'disconnect' some cylinders sometimes ?

the turbo is burdened with the MGU inertia, it needs the MGU to drive it quite a lot ?

a turbo-compound functionality (still looking like a turbocharger) is plausible if the rules allow a second turbine, especially with reduced fuel allowance ?

much of the 'TE' of TERS will not be TE, as much of the KE in KERS is not KE, but it's good advertising, for the FIA and others
(turbines are pressure driven, heat is good for heating/boiling water, ask BMW)


BRM had vortex-throttled 2 stage centrifugal 5 bar supercharging 60 years ago !

[Kiril Varbanov]

Good observations, Speng, I assume that FIA will close or clarify some of the exposed loop holes by then.

My personal obsession is with sound, being ex-sound engineer. When PURE announced CGI for their 2014 competitor, at Scarbs blog I made some calculations and thoughts.
Remember this glorious video of Senna’s Q Monaco, 88? That should be very close to the sound we are going to get in 2014.

A while ago I made an analysis from Vettel’s lap from Monza – the result was 1200 Hz at full rev (18,000 RPM). The math is simple: 18,0000 rpm are 300 rps per cylinder, with 4 stroke engine = 150 ignitions per second, x 8 cyl = 1200 ignitions per second (1200 Hz.)
The race revs that we’re likely to see are around 13,000 (my average guesstimate), which would mean, following the math from before = 750 Hz. That’s not really bad at all, still, it won’t be V12, we better forget about them being reintroduced.
The 4 cylinder would have been awful, however.

I'm interested to what extent the turbo will alter the sound, having all of his specific elements in mind, etc, but in general turbo technologies aren't my best strength, so I will appreciate if someone could shed some more light.

[Speng]

Good stuff, Speng !!!!

.......a few spot opinions before I forget !

compressor efficiency would be lowish due to its small size (tip losses) ?

rotary valves not allowed ? (Ilmor tried a few years ago, then RVs ruled out ?)

2014 rules dictate boost by fixing capacity and rpm, but intend to reduce fuel year by year ?, this would tend to reduce boost and exhaust energy levels ?
(low boost has been convincing in US)

turbo enthusiasts think the turbo is already a more-complete-expansion engine ?
(why would one ever have a turbo synthetic Atkinson ?, although a naturally aspirated (larger) syn. Atkinson has potential ?
the 'flat' fuel regime suits it ?, and other ways of realising super-compression that wouldn't need VVT)

other approaches to petrol engine efficiency are improvements at partial power, so the rules don't cater for them

do the rules allow wide-open-throttle, eg to 'disconnect' some cylinders sometimes ?

the turbo is burdened with the MGU inertia, it needs the MGU to drive it quite a lot ?

a turbo-compound functionality (still looking like a turbocharger) is plausible if the rules allow a second turbine, especially with reduced fuel allowance ?

much of the 'TE' of TERS will not be TE, as much of the KE in KERS is not KE, but it's good advertising, for the FIA and others
(turbines are pressure driven, heat is good for heating/boiling water, ask BMW)


BRM had vortex-throttled 2 stage centrifugal 5 bar supercharging 60 years ago !