What will come after the 2.4 V8?

[WhiteBlue]

A Busa tuned to over 700 bhp at 11,000+ rpm.

[xpensive]

I don't agree with ringo that the xtreme 18k high revving pitch is "classic" in any way, the 3.5 V10s didn't rev like that and the turbos before there certainly didn't, it came with the small displavement V8s. If a 1.5 turbo can produce 700 - 800 Hp at 12k, I see no reason to push the development costs and reliability issues beyond that.

Fuel efficiency and emissions should also benefit from the "lower" rpm thru a more complete burning sequence.

[ringo]

what about the sound.
Then there is the reliability challenge. An 11,000rpm engine will surely last the whole season.
The 18,000rpm thing is something that separates F1 from any other racing series. The engineers also have more of a task creating a reliable engine that runs at these speeds.
Fuel efficiency is nice and all, but i don't want to it play a definitive role in devising the formula. It's good yes, but if it takes away from the spectacle, Bernie is going to have more problems filling seats.

800 turbo charged hp can be made at 11,000 rpm, but i think it's better a power target is avoided. All that should be defined are the displacement, configuration and rev limit.
If the engines make 1100hp at 18000rpm from 1.5 or 1.3lt then so be it.

750hp was looking pretty slow to me from they switched to V8s. The cars never seem to tear through corners like they did in the v10 days. The cars no longer dart through the turns from those still head on camera views.


Another thing about the 11,000rpm limit, is the useful powerband for the small engine. Looking at that dyno chart, things don't look so good under 9,000rpm.
Then turbo lag on the slow circuits.
18,000rpm gives a more lofty range, depending on what boost pressures you want to run to control the power.

[xpensive]

@ ringo, I made this draft last week, based on this years 2.4 NA engines;

If a 2.4 produces 760 Hp at 18000 rpm, then a 1.5 should proportionally mean 320 Hp at 12 000 Rpm.

Add a 1 Bar boost and you are at 640 Hp, 2 Bar and you get 960 Hp.

The above numbers should be in the ball-park, why I would suggest a 1.5 Bar boost (2.5 absolute, like in 1988) to land at 800 Hp and I don't think the power-band or lag will be much of a problem with modern technology at such a low boost?

[WhiteBlue]

I don't agree with ringo at all. FOTA has a 700 bhp target for the engine and that is plenty enough if you consider that an open amount of regenerated power will be added to that figure. It is not sensible in my view to organize a development race for more and more horse power and then cut the excess power in a huge cost step of a new formula every 6-10 years. This is what happened in the past. It used to supply viewers and spectators with the delights of a development contest for power, which was adding drama but wasn't without problems for the safety and the stable government of the sport.

The same drama can be achieved by improving the efficiency of the engine as the competitive advantage to win races. A power contest leads to excess power and ultimately increased safety cost for circuit owners and the constructors. An efficiency contest can lead to technical excellence and new technical break throughs that give us lighter and better F1 cars. Perhaps some new technologies can also be used in road cars. It might invert the technology transfer that has been going from aircrafts and road cars to F1 instead of the other way round. Engineering by nature is about efficiency and if F1 is not embracing that, F1 engineering will ultimately never be leading in technology as it should. Today F1 engineering uses very little front edge technology and a mixture of 100 year old technology and other me toos pioneered elsewhere. I want that to change.

Some people think that the pursuit of efficiency will lead to boring racing. They argue that only unleashing ever greater power and performance creates excitement. They argue that efficiency contests are only good for solar racing and low power racing. I think that view is short sighted. On the other end of low power efficiency races you have the power junkies that do drag racing. There you worship unlimited ever increasing power. But is it as exciting as F1 racing? I dont't think so. So for me worshipping power extremes is no guarantee for exciting GP road racing. One needs to strike the right balance which also can and should include an efficiency contest.

If a 1.5L 11,000 rpm engine was good enough in terms of sound in the eighties why should it not be good enough today? I understand that some people need noise to enjoy racing but sound can be engineered as we know. 11,000 rpm at 2.5 bar will give a mighty sound. Of that I'm sure.

Any fear that a new engine will last 20 races is easily dismissed if you look at the challenges of leaner combustion. Running an engine very lean will destroy it equally fast as running it with power beyond its design spec. Engineers will still have to come up with new tricks and inventions to master the reliability and performance requirements of an efficiency contest.

Turbo lag is long gone in modern turbo technology. You have bi turbos and variable geometry turbos to deal with that problem.

[agip]

You've a point WB. But you must admit that the high rev NA engine sound is a trademark of the sport since more than 20 years. Everyone knows how a F1 car sounds.

Im SURE that a lot of people that dont follow the sport will notice that change in 2013 and will ask what happened.

[marcush.]

tbh engine sound was not that awe inspiring in the turbo days....and i will sadly miss the high revving screamers if they have to go..

I remember very well visiting the PRI show in Indy in 1999 and ALL the US petrolheads who never had witnessed a modern F1 racecar raving about the sound of 16k+revs...

[xpensive]

Well, the 3.5 engines of the early 90s were not really screamers either, 12000 to 13000 rpm, the noise you guys are referring to came mostly with the 2.4 V8s, but how fast we forget?

[autogyro]

You cannot hear the exhaust anyway on television.
That is what matters for the future of F1.

[marcush.]

Well, the 3.5 engines of the early 90s were not really screamers either, 12000 to 13000 rpm, the noise you guys are referring to came mostly with the 2.4 V8s, but how fast we forget?

the only things worth taking a note were the v12s ...right.

[Scotracer]

Well, the 3.5 engines of the early 90s were not really screamers either, 12000 to 13000 rpm, the noise you guys are referring to came mostly with the 2.4 V8s, but how fast we forget?

Pah! After the end of the Turbo reign many big names in the F1 field (commentators included) noted how much nicer the N/A units sounded. Remember back in the early 90's we had V8s...but also V10s and V12s. These sound far higher pitch than V8s do.

Tell me these boys don't scream:

[youtube]http://www.youtube.com/watch?v=M1InrgZiv30[/youtube]
[youtube]http://www.youtube.com/watch?v=j5zH7wBZgaI[/youtube]

[PlatinumZealot]

Very true. Something else to think about. Assuming that no combustion event occurs at the same time... (I don't know if that happens in a V8, V10 or V12 so correct me if I am wrong)

A V12 has 12 combustion chambers. 1 power stroke per chamber per 2 revolutions.
So at 10,000 rpm the frequency of explosions =

(1 power stroke per chamber per 2 revs) x 12 chambers x 10,000 revs/minute = 60,000 powerstrokes/minute

A V12 = 1000 power strokes per second @ 10,000 rpm
V12 = 1250 power strokes per second @ 12,500 rpm ("redline")

A V10 = 833.33 power strokes per second @ 10,000 rpm
= 1583.33 power strokes per second @ 19,000 rpm

A V8 = 750 power strokes per second at 1000rpm
= 1200 power strokes per second @ 18,000 rpm

A V6 = 500 power strokes per second @ 10,000 rpm

A I4 = 333 power strokes per second @ 10,000 rpm

So even with the lower rpms the V12 can sound really high pitched , even beating the V8's as noted by Scotracer. The I4 you almost irrecoverably loose that high frequency.

[ringo]

Well, the 3.5 engines of the early 90s were not really screamers either, 12000 to 13000 rpm, the noise you guys are referring to came mostly with the 2.4 V8s, but how fast we forget?

Funny enough, the v8s sound very dull compared to the v10s and 12s.

About the efficiency vision. As the engines get more thermally efficient, the quality of the engine sound will decrease. The beautiful sounds we hear from the engines are carried by the wasted power from the exhausts.
This is why turbo cars don't sound as piercing as NA cars. The turbo takes a considerable amount of power and all muddles the notes from the cylinders.

Turbo is the way to go; but i'm quite interested in the turbo sound at 18,000rmp, and also what turbine rpms will be experienced at these high engine speeds.

I wonder if the sound will be affected drastically?...

Sound power or acoustic power Pac is a measure of sonic energy E per time t unit.

It is measured in watts, or sound intensity I times area A:



The measure of a ratio of two sound powers is



where

P1, P0 are the sound powers.

The sound power level SWL, LW, or LPac of a source is expressed in decibels (dB) and is equal to 10 times the logarithm to the base 10 of the ratio of the sound power of the source to a reference sound power. It is thus a logarithmic measure.

The reference sound power in air is normally taken to be 10−12 watt = 0 dB SWL.

Sound power is neither room dependent nor distance dependent. Sound power belongs strictly to the sound source.

http://en.wikipedia.org/wiki/Sound_power

Now assuming the 750hp engines have a 33.3% efficiency, the rest of the power, 750hp going to cooling and 750hp should go out the exhaust pipes.

750hp is about 560,000Watts. using the above formula, referenced to sound power of 10^-12W , we get 177 decibells.

The teams may use this technique to figure out who has the most power, but it assumes the engines all have the same efficiency.

Anyway, as the efficiency increases we have less of that power going to the atmosphere.
Lets say our engine is 42% efficient for argument's sake. 562.5hp both to cooling and to atmosphere. Whitblue mentioned 25% increase in fuel efficiency, I'll tie that to the overall efficiency and add 125% to the 33.3% efficiency.

Thats 572hp, 386,000W going to exhaust. using the formula we get 175.86 db.
177db vs 175.86db Not bad, still loud as hell , the levels are still close.

though this does not take the frequency into account

[xpensive]

I stand corrected, smikle's xplanation is most credible, what we pick up with our ears is really detonations per time-unit,
where an 12k I4 is bound to sound rather dull in comparison.

ringo's discussion over sound power in dB vs the thermal power leaving through the xhausts is equally interesting,
though I wonder if it is really that simple, what happens if you add a muffler?

Being a sucker for cracking numbers, this gave me something to think about, the turbo is also in a way muffling the sound without stealing power to the same proportions, isn't it?

[ringo]

The turbo is literally taking power from the exhaust and putting that power to the compressor; putting a load on the exhaust, which weakens the sound and muddling it.

A muffler takes away some of the energy as well, it's really a restriction so back pressure will increase. But i think it gets detailed as it relates to technicalities of sound such as attenuation and correlations with muffler volume and engine displacement etc.
http://www.icmem.com/icmem2009/PDF/MR22-.pdf

But i think Smikle has a point with the frequencies and how our ears interpret them.
The sound power has something to do with it, but frequencies probably play to our minds more.
http://en.wikipedia.org/wiki/Psychoacoustics
just an article on psycho-acoustics; it explains why 18000rpm is a must

using this chart, an equal loudness contour.


a 4 cylinder at 333Hz has to be 10 decibels louder than the v12, 1000Hz, to give the same sensation; if i'm interpreting this concept correctly.

more on equal loudness contours:
http://en.wikipedia.org/wiki/Equal-loudness_contour

10 decibels difference is a Wattage factor of 10 times the power (logarithmic relation), so it's interesting as to how a 4 cylinder will come close to giving the same feeling as the 12 or 10 cylinders. Muchless one grumbling at a measly turbo muffled 11,000rpm when the V10 was singing like angels at 20,000 rpm.

I like seeing efficiency dynamics and new technology, but to be honest i won't enjoy watching it for 2hrs as a form of entertainment. It loses the novelty after maybe 3 silent races with nothing but tyre noise and kers motor whine.