Formula One 1.6l V6 turbo engine formula

[xpensive]

Great stuff matt21, you came to almost the same results as me, even if we used completely different methods?

A rather simplistic lazy-dog;

a) A useful equalizer, based on today's 750 Hp from 2.4 liter at 18 kRpm, is 17.5 Hp per liter, kRpm and Bar absolute.
b) Fuel flow for the turbos is limited to 27.7 g/s, which at 47.2 kJ/g and an efficiency of 35% means 460 kW or 620 Hp.
c) Based on a), a 1.6 liter engine with 620 Hp at 12 kRpm would need 1.85 Bar absolute or 0.85 boost to make use of the fuel.

This is of course based on the assumption that each and every input parameter has a proportional impact on output power, where proportionality here means that if one input parameter doubles it's value, so does the resultant output power.

[Rob01]

When the FIA mandates what the bore diameter should be, automatically the stroke is being mandated, a fixed crankshaft axis and chassis/gearbox mounting points, a cap on fuel flow and engine revs limited to 15k rpm, the last bombshell, the engine will produce the same maximum power as the current 2.4l v8 BUT ONLY WHEN THE ENERGY RECOVERY SYSTEMS ARE IN USE, which means the engine maximum power output will be 600 bhp, 150less then the 2.4l v8, and remember this with a turbo super charger. (sunny).

[pgfpro]

There the same numbers I got on my Turbo EFI spreadsheet too running 13.2 A/F at 100*F IAT at sealevel.

[Ian P.]

The 2014 regs don't seem to contain any limitations or specification for bore or stroke. Only displacement.
If the fuel flow is fixed from 10,500 up, and with "normal" boost levels you can get max air flow and hence max power from 10,500 to what-ever, why would you go to 15,000.?? There is no need. 12,500 is more than enough.
Gear boxes are 8 speed. If 1st is good for 100 kph (likely higher in practice) and you run 16% at each shift, then 7th is good for 300 kph. 8th becomes an overdrive to cover DRS, KERS etc without either droppping below max power or hitting the rev limit.
The engine need only run to 12,500. This improves efficiency and will open up some variations on bore / stroke ratios.
It is going to be all about thermal efficiency. The best should be upwards of 40%.
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.

[Tomba]

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.