The 2014 engine - a technical evaluation

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The 2014 engine - a technical evaluation Dave Baker 2/23/12 4:46 AM
After reading some of the gibberish in the "2014 fuel flow and low down
torque" thread I thought I'd better post what's really happening with this
engine in a new thread rather than let any comments get lost in the
squabbling.

The mandated engine is a single turbo V6 of 1600cc capacity and a maximum
80mm bore size. This in turn sets the stroke at 53mm if they use the full
bore size allowed and the bore stroke ratio at 1.51 which is not very
oversquare for modern F1 engines. In fact it's not an unusual ratio for
standard road car engines and motorbike ones.

Fuel flow is limited to a maximum rate of 100kg/hr from 10500 rpm upwards to
the 15000 rpm rev limit and below 10500 it decreases in a linear fashion
with rpm down to idle where there is just enough fuel flow to keep the
engine running.

In a normally aspirated engine with unlimited fuel flow the engine's power
is airflow restricted. The better it can breathe, and at the highest
possible rpm the more power it can produce and this is essentially a
function of total inlet valve area. With a turbo engine the addition of
boost pressure can multiply this power up to almost any factor, limited only
by detonation and the physical strength of the engine components. This led
to 1500cc engines producing up to 1500 bhp in qualifying trim in previous F1
seasons.

With fuel flow limited however the engine's power output is also limited and
becomes a function of the Brake Specific Fuel Consumption (BSFC) that can be
achieved. No matter whether N/A or forced induction this bhp limit will be
about the same. A conventional petrol road car engine running stoichiometric
fuel/air mixtures mandated by the catalytic converter can achieve a BSFC in
the low 0.4s lb/bhp/hr. Race engines running richer fuel mixtures at higher
rpm with greater frictional losses struggle to achieve better than about 0.5
lb/bhp/hr.

If by careful design the F1 engine designers can get anywhere close to the
BSFC of a road engine of say 0.43 lb/hp/hr we can calculate that the 100
kg/hr fuel flow limit will limit power to about 510 bhp from 10500 rpm
upwards. If they can't achieve a BSFC that low then obviously power will be
less too. We'll have to see how they get on but clearly they will not be
able to get anywhere near the current 750 bhp as some have incorrectly
surmised.

At lower rpms as the fuel flow limit reduces then the power will also reduce
in a straight line fashion to generate a power curve that looks similar to
that of a normally aspirated engine where power at any rpm is a function of
torque x rpm. This has been done very deliberately to prevent designers
using very high boost pressures at low rpms to create an engine with 510 bhp
everywhere in the rpm range.

We can now calculate the boost pressures that will be required to fully
utilise the fuel flow limit. A normally aspirated 4v F1 type race engine on
conventional petrol is limited to producing about 97 ft lbs of torque per
litre. This indicates about 155 ft lbs from a 1600cc engine at peak torque.
At 10500 rpm this would set power at 155 x 10500 / 5252  = 310 bhp. However
there is sufficient fuel flow for 510 bhp so the turbo boost factor required
will be 510 / 310 = 1.645.

Boost factor = (atmospheric pressure + boost pressure) / atmospheric
pressure or (14.7 + B) / 14.7.

If (14.7 + B) / 14.7 = 1.645 then B = (1.645 x 14.7) - 14.7 = 9.5 psi

At 15000 rpm at the same torque value the N/A power equivalent will have
risen to 155 x 15000 / 5252 = 443 bhp

As fuel flow is still limiting power to 510 bhp the boost factor required
has fallen to 1.151 and we can calculate that the boost pressure required
has dropped to only about 2.2 psi.

All of this ignores some unavoidable flow and efficiency losses created by
the turbo itself and the associated pipework, intercooler etc and by the
need to run lower compression ratios than for a N/A engine. It also does not
account for the fall in torque produced either side of the peak torque rpm
but allowing for everything it is unlikely that a well designed engine will
need to run much more than about 11 or 12 psi of boost pressure up to 10500
rpm and then steadily decreasing from this down to maybe 4 psi at 15000 rpm.
These are not high pressures, even for a road car engine, and will not
require anything very special in the engine design to accomodate. With the
relatively low rev limit of 15000 the engines should be very reliable and
long lasting. It's possible that with development such an engine could go
most of a season or at least well into it. Any loss of power due to wear and
tear can be corrected for by increasing the boost pressure to continue to
use the fuel flow limit to its full.

So the design constraints of this engine will be very different from that of
the normally aspirated engines. Instead of concentrating solely on trying to
maximise airflow through the cylinder head to get more bhp the designers
will be trying to optimise fuel efficiency (minimise BSFC) and minimise
frictional losses as they can get the power they want, or that the fuel flow
limit restricts them to, simply by changing the boost pressure. Using the
highest possible compression ratio without detonation at the required boost
pressures, creating the fastest possible burning combustion chambers and
achieving fuel droplet distributions that burn at the leanest possible
fuel/air ratios will be their challenges.

They should be able to achieve 450 bhp very easily. Whether they can get 510
or even beat that is more doubtful but I suspect that their research will
have valuable knock on effects for road engine design in due course. I'll be
surprised if they haven't hit 500 bhp by the time the engines need to be
used.
--
Dave Baker


Re: The 2014 engine - a technical evaluation News 2/23/12 5:17 AM
Neat and comprehensive tech analysis.  Thanks, Dave!
Re: The 2014 engine - a technical evaluation Bobster 2/23/12 5:26 AM
Thanks for that, Dave.

Now I just have to read it a few times and hope it all sinks in.

Re: The 2014 engine - a technical evaluation larkim 2/23/12 5:49 AM
I think I understood a few words of that, thanks! ;-)

Bbbbuuuuttt; only 510bhp for F1 cars??!?!?!?!?!

Matt
Re: The 2014 engine - a technical evaluation Bobster 2/23/12 7:23 AM
On Feb 23, 2:46 pm, "Dave Baker" <N...@null.com> wrote:

> They should be able to achieve 450 bhp very easily. Whether they can get 510
> or even beat that is more doubtful but I suspect that their research will
> have valuable knock on effects for road engine design in due course. I'll be
> surprised if they haven't hit 500 bhp by the time the engines need to be
> used.

Any estimate of what the energy recovery systems will add?
Re: The 2014 engine - a technical evaluation brafield 2/23/12 8:23 AM
On Feb 23, 4:46 am, "Dave Baker" <N...@null.com> wrote:

Dave, if you write the book, I'll buy it and throw away my Ricardo and
Crouse texts.  Thank you very much for that.
Re: The 2014 engine - a technical evaluation Kerry Montgomery 2/23/12 8:46 AM

"Dave Baker" <Nu...@null.com> wrote in message
news:ji5cf9$rep$1@news.datemas.de...
Dave Baker,
Thank you for the concise and understandable explanation.
Do the regulations require the fuel flow below 10500 to decrease in a linear
fashion, or only monotonically?
Thanks again,
Kerry


Re: The 2014 engine - a technical evaluation Mark Conmy 2/23/12 11:06 AM
Dave Baker <Nu...@null.com> wrote:
>
> After reading some of the gibberish in the "2014 fuel flow and low down
> torque" thread I thought I'd better post what's really happening with this
> engine in a new thread rather than let any comments get lost in the
> squabbling.

As always, very interesting read.  It will be interesting to see how
they get around the reduced bhp - it could be a real spur to innovation.

That's to say, not getting around the lack of power is not something I
want to contemplate too much right now...
;-)
Re: The 2014 engine - a technical evaluation Frank Adam 2/23/12 11:42 AM
Well done Dave. Was wondering when you were to polka in.
I couldn't find the engine specs (like bore/stroke) on the FIA site when i
looked. Did you get this from the mole ?

Btw, i've surmised the 750, because last year they said they wanted to retain
the power level of the current engine. So it was only a theory.
If your claculations come through, i guess what they meant was 120KW + engine
power. Works out about right.

--

Regards, Frank
Re: The 2014 engine - a technical evaluation Mower Man 2/23/12 2:30 PM
On 23/02/2012 12:46 PM, Dave Baker wrote:
> After reading some of the gibberish in the "2014 fuel flow and low down
> torque" thread I thought I'd better post what's really happening with this
> engine in a new thread rather than let any comments get lost in the
> squabbling.
>
> The mandated engine is a single turbo V6 of 1600cc capacity and a maximum
> 80mm bore size. This in turn sets the stroke at 53mm if they use the full
> bore size allowed and the bore stroke ratio at 1.51 which is not very
> oversquare for modern F1 engines. In fact it's not an unusual ratio for
> standard road car engines and motorbike ones.

No, it's more like a late 60s short stroke Anglia based engine... how
exciting!!! Not.

<Massive snip>


> Fuel flow is limited to a maximum rate of 100kg/hr from 10500 rpm upwards to
> the 15000 rpm rev limit and below 10500 it decreases in a linear fashion
> with rpm down to idle where there is just enough fuel flow to keep the
> engine running.

And that's where I object - not that my objection will have any
meaning/effect/whatever - why? A blatant attempt to restrict a good
spread of torque over a wide rev. range.

Just the sort of power/torque we need in road vehicles?

Grrrrrrrrrr!


--

Chris

I am not young enough to know everything.
Oscar Wilde (1854 - 1900)

Protected by www.Spamjab.com {2oILbxoxMTlPIgpNKG}
Re: The 2014 engine - a technical evaluation Frank Adam 2/23/12 3:45 PM
On Thu, 23 Feb 2012 22:30:42 +0000, Mower Man <chris...@nospamf2s.com>
wrote:

>On 23/02/2012 12:46 PM, Dave Baker wrote:
>> After reading some of the gibberish in the "2014 fuel flow and low down
>> torque" thread I thought I'd better post what's really happening with this
>> engine in a new thread rather than let any comments get lost in the
>> squabbling.
>>
>> The mandated engine is a single turbo V6 of 1600cc capacity and a maximum
>> 80mm bore size. This in turn sets the stroke at 53mm if they use the full
>> bore size allowed and the bore stroke ratio at 1.51 which is not very
>> oversquare for modern F1 engines. In fact it's not an unusual ratio for
>> standard road car engines and motorbike ones.
>
>No, it's more like a late 60s short stroke Anglia based engine... how
>exciting!!! Not.
>
I'm not quite old enough to remember, but how did the Anglia do at around
15000 revs on full boost ? ;-)

--

Regards, Frank
Re: The 2014 engine - a technical evaluation brafield 2/23/12 5:51 PM
On Feb 23, 3:45 pm, Frank Adam <f...@notthis.optushome.com.au> wrote:

>
> >> The mandated engine is a single turbo V6 of 1600cc capacity and a maximum
> >> 80mm bore size. This in turn sets the stroke at 53mm if they use the full
> >> bore size allowed and the bore stroke ratio at 1.51 which is not very
> >> oversquare for modern F1 engines. In fact it's not an unusual ratio for
> >> standard road car engines and motorbike ones.
>
> >No, it's more like a late 60s short stroke Anglia based engine... how
> >exciting!!! Not.


Ducati's new Paginale street bike has a bore and stroke of 112mm x
60.8mm (1.84 ratio) and testers report it behaves very sweetly and
mildly.

If you like "nerding" among such data, this is a handy page:
http://users.erols.com/srweiss/tablersn.htm

Re: The 2014 engine - a technical evaluation AC 2/23/12 6:00 PM
Not bad, usually they would bend time and space.

--
AC
Re: The 2014 engine - a technical evaluation George 2/23/12 9:32 PM
Frank Adam <fa...@notthis.optushome.com.au> wrote:
>On Thu, 23 Feb 2012 22:30:42 +0000, Mower Man <chris...@nospamf2s.com>
>wrote:
>>On 23/02/2012 12:46 PM, Dave Baker wrote:
[...]
>>> The mandated engine is a single turbo V6 of 1600cc capacity and a maximum
>>> 80mm bore size. [...]
>>
>>No, it's more like a late 60s short stroke Anglia based engine... how
>>exciting!!! Not.
>>
>I'm not quite old enough to remember, but how did the Anglia do at around
>15000 revs on full boost ? ;-)

Spectacularly - if your standard for comparison is a hand
grenade.
Re: The 2014 engine - a technical evaluation build 2/23/12 10:15 PM
On Feb 24, 6:42 am, Frank Adam <f...@notthis.optushome.com.au> wrote:
I'll bet you a slab that they beat that estimate by at least 100 BHP!

Ya gotta use the right method and the right numbers.

beers,

Re: The 2014 engine - a technical evaluation Yousuf Khan 2/23/12 10:27 PM
On 23/02/2012 7:46 AM, Dave Baker wrote:
> They should be able to achieve 450 bhp very easily. Whether they can get 510
> or even beat that is more doubtful but I suspect that their research will
> have valuable knock on effects for road engine design in due course. I'll be
> surprised if they haven't hit 500 bhp by the time the engines need to be
> used.

Is there a limit to how much boost they can let the turbocharger achieve
in the rules? If there isn't, then couldn't they just boost the boost
upto whatever the engine can handle? Even with fuel flow restricted,
running a slightly leaner mixture with that much air pressure should
still get more power out of the engine, shouldn't it?

        Yousuf Khan
Re: The 2014 engine - a technical evaluation build 2/23/12 11:26 PM
On Feb 24, 5:27 pm, Yousuf Khan <bbb...@spammenot.yahoo.com> wrote:
>
> Is there a limit to how much boost they can let the turbocharger achieve
<snip>
>         Yousuf Khan

No.

Re: The 2014 engine - a technical evaluation News 2/24/12 6:37 AM
Had light-seeking connecting rods well below that pace.
Re: The 2014 engine - a technical evaluation Mower Man 2/24/12 7:07 AM
Boost was not an option unless via a supercharger back then - as
distinct from a turbocharger, which were usually fitted to trucks and
railway locomotives.

However, the Broadspeed Angle boxes did very well at 8,500 - 9,000 rpm.
For a modified production engine at that was remarkable in the 60s.
Re: The 2014 engine - a technical evaluation Dave Baker 2/24/12 10:47 AM

"Frank Adam" <fa...@notthis.optushome.com.au> wrote in message
news:k25dk79lo26cbib0lu7i4r8fkqtio7bjcr@4ax.com...
> Well done Dave. Was wondering when you were to polka in.
> I couldn't find the engine specs (like bore/stroke) on the FIA site when i
> looked. Did you get this from the mole ?

The bore limit is on the web somewhere. I can't remember where.


Re: The 2014 engine - a technical evaluation Dave Baker 2/24/12 10:49 AM
build wrote:
> I'll bet you a slab that they beat that estimate by at least 100 BHP!
>
> Ya gotta use the right method and the right numbers.
>
> beers,

What limit? My bhp estimate?


Re: The 2014 engine - a technical evaluation Dave Baker 2/24/12 10:56 AM
Mower Man wrote:
> On 23/02/2012 12:46 PM, Dave Baker wrote:
>> After reading some of the gibberish in the "2014 fuel flow and low
>> down torque" thread I thought I'd better post what's really
>> happening with this engine in a new thread rather than let any
>> comments get lost in the squabbling.
>>
>> The mandated engine is a single turbo V6 of 1600cc capacity and a
>> maximum 80mm bore size. This in turn sets the stroke at 53mm if they
>> use the full bore size allowed and the bore stroke ratio at 1.51
>> which is not very oversquare for modern F1 engines. In fact it's not
>> an unusual ratio for standard road car engines and motorbike ones.
>
> No, it's more like a late 60s short stroke Anglia based engine... how
> exciting!!! Not.
>
> <Massive snip>
>
>
>> Fuel flow is limited to a maximum rate of 100kg/hr from 10500 rpm
>> upwards to the 15000 rpm rev limit and below 10500 it decreases in a
>> linear fashion with rpm down to idle where there is just enough fuel
>> flow to keep the engine running.
>
> And that's where I object - not that my objection will have any
> meaning/effect/whatever - why? A blatant attempt to restrict a good
> spread of torque over a wide rev. range.
>
> Just the sort of power/torque we need in road vehicles?

It would be completely impractical to build an engine with very high boost
at low rpm and low boost at high rpm. The compression ratio reduction to
cope with both would make the engine very inefficient, the fuel economy
would be terrible, especially at cruise, the torque loadings on clutch,
gearbox and other parts of the drivetrain would be ridiculous which would
add extra weight and complexity. The fuel restriction measures that have
been set are not only sensible but in fact necessary if the F1 engines are
to bear any resemblance to road ones and for there to be technology transfer
at some future time.
--
Dave Baker


Re: The 2014 engine - a technical evaluation Dave Baker 2/24/12 10:57 AM
No.


Re: The 2014 engine - a technical evaluation Mower Man 2/24/12 12:41 PM
Not what I meant - sorry if I wasn't clear. My complaint was that fuel
flow is restricted at low rpm. So no high torque low rev engines on the
menu. OK, Chunky Chapman wasn't an engine man, nor Jim Hall - they were,
however, innovators. I think it's very disappointing that in future no
aspect of F1 might be said to be truly innovative. I wish CanAm was
still here!
Re: The 2014 engine - a technical evaluation Dave Baker 2/24/12 12:50 PM
You were very clear but maybe you haven't understood the implications of
what you said. The whole point of restricting fuel flow at low rpm is to
limit boost pressure and therefore bhp at low rpm. If fuel flow were
unlimited then so would boost pressure be. Alternatively if fuel flow were
limited to the same value at all rpms then bhp would potentially be the same
at all rpms but only with ridiculous boost pressures at low rpms. Only by
reducing fuel flow limits as rpm falls can bhp be limited to a normally
shaped power curve and a single maximum boost pressure value which can be
accomodated with a compression ratio of a normal value.
--
Dave Baker


Re: The 2014 engine - a technical evaluation Mower Man 2/24/12 2:12 PM
On 24/02/2012 8:50 PM, Dave Baker wrote:
> Mower Man wrote:
>> On 24/02/2012 6:56 PM, Dave Baker wrote:
>>> Mower Man wrote:
>>>> On 23/02/2012 12:46 PM, Dave Baker wrote:
>>>>> After reading some of the gibberish in the "2014 fuel flow and low
>>>>> down torque" thread I thought I'd better post what's really
>>>>> happening with this engine in a new thread rather than let any
>>>>> comments get lost in the squabbling.
>>>>>
>>>>> The mandated engine is a single turbo V6 of 1600cc capacity and a
>>>>> maximum 80mm bore size. This in turn sets the stroke at 53mm if
>>>>> they use the full bore size allowed and the bore stroke ratio at
>>>>> 1.51 which is not very oversquare for modern F1 engines. In fact
>>>>> it's not an unusual ratio for standard road car engines and
>>>>> motorbike ones.
>>>>
>>>> No, it's more like a late 60s short stroke Anglia based engine...
>>>> how exciting!!! Not.
>>>>
>>>> <Massive snip>
>>>>
>>>>
>>>>> Fuel flow is limited to a maximum rate of 100kg/hr from 10500 rpm
>>>>> upwards to the 15000 rpm rev limit and below 10500 it decreases in
>>>>> a linear fashion with rpm down to idle where there is just enough
>>>>> fuel flow to keep the engine running.
>>>>
>>>> And that's where I object - not that my objection will have any
>>>> meaning/effect/whatever - why? A blatant attempt to restrict a good
>>>> spread of torque over a wide rev. range.
>>>>
>>>> Just the sort of power/torque we need in road vehicles?
>>>
>>> It would be completely impractical to build an engine with very high
>>> boost at low rpm and low boost at high rpm. The compression ratio
>>> reduction to cope with both would make the engine very inefficient,
>>> the fuel economy would be terrible, especially at cruise, the torque
>>> loadings on clutch, gearbox and other parts of the drivetrain would
>>> be ridiculous which would add extra weight and complexity. The fuel
>>> restriction measures that have been set are not only sensible but in
>>> fact necessary if the F1 engines are to bear any resemblance to road
>>> ones and for there to be technology transfer at some future time.
>>
>> Not what I meant - sorry if I wasn't clear. My complaint was that fuel
>> flow is restricted at low rpm.
>
> You were very clear but maybe you haven't understood the implications of
> what you said. The whole point of restricting fuel flow at low rpm is to
> limit boost pressure and therefore bhp at low rpm.

Exactly. So, in 2014 engines will have to operate at the rev limit -
15,000rpm. No place for an engine at,say, 8,500 rpm as it won't get
enough fuel/calories. This is a long way from the Duckworth fuel formula
I've always admired.

I wasn't arguing with any of this - just trying to point out that it's
boring if like me you might think innovation is actually better than a
Formula Ford version of Formula One.

> If fuel flow were
> unlimited then so would boost pressure be. Alternatively if fuel flow were
> limited to the same value at all rpms then bhp would potentially be the same
> at all rpms but only with ridiculous boost pressures at low rpms.

How much boost at, say 9,000 vs 15,000?


Only by
> reducing fuel flow limits as rpm falls can bhp be limited to a normally
> shaped power curve and a single maximum boost pressure value which can be
> accomodated with a compression ratio of a normal value.

Will inter-coolers be permitted under the 2014 regs? That might help my
appreciation of what compression ratios could rise to - given "pump"
fuel, of course.  What do you reckon is a "normal" compression ratio? In
my lifetime they have varied between 6:1 up to 14:1! (The latter USA
fuelled 'Vettes, etc.)


--

Chris

I am not young enough to know everything.
Oscar Wilde (1854 - 1900)

Protected by www.Spamjab.com {2oILbxoxMTlPIgpNKG}
Re: The 2014 engine - a technical evaluation Geoff May 2/24/12 2:51 PM
On 24/02/2012 18:47, Dave Baker wrote:
> "Frank Adam"<fa...@notthis.optushome.com.au>  wrote in message
> news:k25dk79lo26cbib0lu7i4r8fkqtio7bjcr@4ax.com...
>> Well done Dave. Was wondering when you were to polka in.
>> I couldn't find the engine specs (like bore/stroke) on the FIA site when i
>> looked. Did you get this from the mole ?
>
> The bore limit is on the web somewhere. I can't remember where.
>

Technical regulations has this bit:

5.3 Engine dimensions :
5.3.1 Cylinder bore diameter may not exceed 98mm.
5.3.2 Cylinder spacing must be fixed at 106.5mm (+/‐ 0.2mm).
5.3.3 The crankshaft centre line must not be less than 58mm above the
reference plane.

Cheers

Geoff
Re: The 2014 engine - a technical evaluation David Melville 2/24/12 2:54 PM
On Fri, 24 Feb 2012 18:47:42 +0000, Dave Baker wrote:

> "Frank Adam" <fa...@notthis.optushome.com.au> wrote in message
> news:k25dk79lo26cbib0lu7i4r8fkqtio7bjcr@4ax.com...
>> Well done Dave. Was wondering when you were to polka in. I couldn't
>> find the engine specs (like bore/stroke) on the FIA site when i looked.
>> Did you get this from the mole ?
>
> The bore limit is on the web somewhere. I can't remember where.

Try any thread where the major contributors are me, Bird, and Build.

:-)



--
Cheers,
      Dave

Still Crazy After All These Years
Re: The 2014 engine - a technical evaluation build 2/24/12 3:42 PM
On Feb 25, 9:51 am, Geoff May <GeoffMay_do_not_spam...@nospam.com>
wrote:
> On 24/02/2012 18:47, Dave Baker wrote:
>
> > "Frank Adam"<f...@notthis.optushome.com.au>  wrote in message
Geoff,
The 2014 regs:
5.3.1  Cylinder bore diameter must be 80mm (+/- 0.1mm).

beers,

Re: The 2014 engine - a technical evaluation brafield 2/24/12 5:09 PM
On Feb 24, 2:12 pm, Mower Man <chrislov...@nospamf2s.com> wrote:
 What do you reckon is a "normal" compression ratio? In
> my lifetime they have varied between 6:1 up to 14:1! (The latter USA
> fuelled 'Vettes, etc.)


A few years ago at either a SEMA or ASTMS conference, a NASCAR engine
builder admitted that some of his engines ran incredible compression
ratios up to 20:1 on certain cylinders, ie not all 8 cylinders had the
same c.r.   This related to having a big fat carburetter on a big
manifold, and the need to counter G force on gasoline mist on the big
ovals.    The same guy commented that unless his drivers gad a burned
right foot after a race, they weren't going fast enough!  Roush or
Childress, I forget which now.

Re: The 2014 engine - a technical evaluation John 2/24/12 5:58 PM
>The mandated engine is a single turbo V6 of 1600cc capacity

How lameeeeeeeeeee.........................   LOL
Re: The 2014 engine - a technical evaluation Bill Smith 2/24/12 7:19 PM
On Thu, 23 Feb 2012 12:46:21 -0000, "Dave Baker" <Nu...@null.com>
wrote:

>After reading some of the gibberish in the "2014 fuel flow and low down
>torque" thread I thought I'd better post what's really happening with this
>engine in a new thread rather than let any comments get lost in the
>squabbling.
>
>The mandated engine is a single turbo V6 of 1600cc capacity and a maximum
>80mm bore size. This in turn sets the stroke at 53mm if they use the full
>bore size allowed and the bore stroke ratio at 1.51 which is not very
>oversquare for modern F1 engines. In fact it's not an unusual ratio for
>standard road car engines and motorbike ones.
>
>Fuel flow is limited to a maximum rate of 100kg/hr from 10500 rpm upwards to
>the 15000 rpm rev limit and below 10500 it decreases in a linear fashion
>with rpm down to idle where there is just enough fuel flow to keep the
>engine running.
>
>In a normally aspirated engine with unlimited fuel flow the engine's power
>is airflow restricted. The better it can breathe, and at the highest
>possible rpm the more power it can produce and this is essentially a
>function of total inlet valve area. With a turbo engine the addition of
>boost pressure can multiply this power up to almost any factor, limited only
>by detonation and the physical strength of the engine components. This led
>to 1500cc engines producing up to 1500 bhp in qualifying trim in previous F1
>seasons.
>
>With fuel flow limited however the engine's power output is also limited and
>becomes a function of the Brake Specific Fuel Consumption (BSFC) that can be
>achieved. No matter whether N/A or forced induction this bhp limit will be
>about the same. A conventional petrol road car engine running stoichiometric
>fuel/air mixtures mandated by the catalytic converter can achieve a BSFC in
>the low 0.4s lb/bhp/hr. Race engines running richer fuel mixtures at higher
>rpm with greater frictional losses struggle to achieve better than about 0.5
>lb/bhp/hr.
>
>If by careful design the F1 engine designers can get anywhere close to the
>BSFC of a road engine of say 0.43 lb/hp/hr we can calculate that the 100
>kg/hr fuel flow limit will limit power to about 510 bhp from 10500 rpm
>upwards. If they can't achieve a BSFC that low then obviously power will be
>less too. We'll have to see how they get on but clearly they will not be
>able to get anywhere near the current 750 bhp as some have incorrectly
>surmised.
>
>At lower rpms as the fuel flow limit reduces then the power will also reduce
>in a straight line fashion to generate a power curve that looks similar to
>that of a normally aspirated engine where power at any rpm is a function of
>torque x rpm. This has been done very deliberately to prevent designers
>using very high boost pressures at low rpms to create an engine with 510 bhp
>everywhere in the rpm range.
>
>We can now calculate the boost pressures that will be required to fully
>utilise the fuel flow limit. A normally aspirated 4v F1 type race engine on
>conventional petrol is limited to producing about 97 ft lbs of torque per
>litre. This indicates about 155 ft lbs from a 1600cc engine at peak torque.
>At 10500 rpm this would set power at 155 x 10500 / 5252  = 310 bhp. However
>there is sufficient fuel flow for 510 bhp so the turbo boost factor required
>will be 510 / 310 = 1.645.
>
>Boost factor = (atmospheric pressure + boost pressure) / atmospheric
>pressure or (14.7 + B) / 14.7.
>
>If (14.7 + B) / 14.7 = 1.645 then B = (1.645 x 14.7) - 14.7 = 9.5 psi
>
>At 15000 rpm at the same torque value the N/A power equivalent will have
>risen to 155 x 15000 / 5252 = 443 bhp
>
>As fuel flow is still limiting power to 510 bhp the boost factor required
>has fallen to 1.151 and we can calculate that the boost pressure required
>has dropped to only about 2.2 psi.
>
>All of this ignores some unavoidable flow and efficiency losses created by
>the turbo itself and the associated pipework, intercooler etc and by the
>need to run lower compression ratios than for a N/A engine. It also does not
>account for the fall in torque produced either side of the peak torque rpm
>but allowing for everything it is unlikely that a well designed engine will
>need to run much more than about 11 or 12 psi of boost pressure up to 10500
>rpm and then steadily decreasing from this down to maybe 4 psi at 15000 rpm.
>These are not high pressures, even for a road car engine, and will not
>require anything very special in the engine design to accomodate. With the
>relatively low rev limit of 15000 the engines should be very reliable and
>long lasting. It's possible that with development such an engine could go
>most of a season or at least well into it. Any loss of power due to wear and
>tear can be corrected for by increasing the boost pressure to continue to
>use the fuel flow limit to its full.
>
>So the design constraints of this engine will be very different from that of
>the normally aspirated engines. Instead of concentrating solely on trying to
>maximise airflow through the cylinder head to get more bhp the designers
>will be trying to optimise fuel efficiency (minimise BSFC) and minimise
>frictional losses as they can get the power they want, or that the fuel flow
>limit restricts them to, simply by changing the boost pressure. Using the
>highest possible compression ratio without detonation at the required boost
>pressures, creating the fastest possible burning combustion chambers and
>achieving fuel droplet distributions that burn at the leanest possible
>fuel/air ratios will be their challenges.
>
>They should be able to achieve 450 bhp very easily. Whether they can get 510
>or even beat that is more doubtful but I suspect that their research will
>have valuable knock on effects for road engine design in due course. I'll be
>surprised if they haven't hit 500 bhp by the time the engines need to be
>used.

Nice piece of work, thank you.

 If this was an attempt by the governing body to make things a bit
less expensive, they should know, by now, that all rules do is
redefine where indecent amounts of money are spent.

I think they should set a displacement limit (turbocharged), a maxim
width, a maximum length, a minimum weight limit, certain driver
protection standards, and a spec ti(y)re supplier, no wings or visible
aero at all, and let 'em go at it.

                                           Bill Smith

                                       

Re: The 2014 engine - a technical evaluation Dave Baker 2/24/12 11:28 PM

"Mower Man" <chris...@nospamf2s.com> wrote in message
news:ji9217$bci$1@speranza.aioe.org...
>
> How much boost at, say 9,000 vs 15,000?

The equations are in my article.


Re: The 2014 engine - a technical evaluation Dave Baker 2/25/12 2:32 AM
Just as a quick addendum I'll show the approximate boost pressures which
would be required to achieve 510 bhp at lower rpms than the 10500 at which
maximum fuel flow first occurs. Obviously this would require the same fuel
flow limit at these lower rpms. The calculations take account of how N/A
torque would likely drop at rpms so far from the peak torque rpm.

RPM....PSI
4000.....80
6000.....43
8000.....27
10000...13

So even to achieve 510 bhp at 8000 rpm would require double the boost
pressure, and consequent reduction in compression ratio to avoid detonation,
as at 10000 rpm and would significantly alter the required turbo design and
flow capability. At lower rpms still it's clear the problem becomes
insurmountable, or at least ridiculous to pursue.

In any event the engine will only need to operate at full power at rpms
determined by the gearbox and the spacing between each gear. An engine that
revs to 15000 rpm with a 7 speed gearbox will be unlikely to need to operate
at much below the 10500 rpm that the rules have set the fuel flow limit at.
It would be somewhat pointless to try and achieve 510 bhp at rpms much below
that if the engine never operates there.
--
Dave Baker


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