## Remarkable finding re 2104 engines

Showing 1-20 of 20 messages
 Remarkable finding re 2104 engines Dave Baker 1/14/13 8:14 AM A year or so ago I posted an analysis of the likely power output of the 2014 engines based on the mandated fuel flow limits. This can be found here and needs reading again first. http://rec.autos.sport.f1.narkive.com/YUJklIQk/the-2014-engine-a-technical-evaluation So fuel flow peaks at 10,500 rpm at 100 kg/hr and below that it decreases in a linear fashion according to the equation (rpm x 0.009) + 5.5 kg/hr. Power at any rpm will be limited entirely by the BSFC (brake specific fuel consumption) that can be achieved and there is obviously no data on that yet for this new direct injection design but I made my own best guess of 0.43 lb/bhp/hr (262 grams/kWhr) and upon that surmised a peak power at 10,500 rpm of 510 bhp. I could be way off on this but the general points that follow won't alter. Indeed there is talk online of peak power closer to 600 bhp but we'll see in due course if BSFC figures low enough to achieve this are even remotely possible. Above 10,500 rpm the power can't increase further because the fuel flow is capped. In fact as frictional losses in the engine must increase as rpm increases then crankshaft power should decrease somewhat. Below 10,500 rpm BSFC should improve slightly and thus power per gram of fuel used should rise a bit as revs drop. The power curve can therefore be drawn as two straight lines, one rising from low rpm to 10,500 rpm and then another almost horizontal line (sloping downwards somewhat) from there to 15,000 rpm. If you want to draw this out in a spreadsheet yourself my calculated data points are as follows: 7,000 rpm - 355 bhp 10,500 rpm - 510 bhp 15,000 rpm - 486 bhp Join those three points with two straight lines and you have it. Clearly this looks nothing like a conventional airflow limited power curve. Regardless of the BSFC figures that the manufacturers achieve the general shape of the curve will stay the same even if the actual bhp numbers are higher. The remarkable thing that results from this curve shape is only apparent once the full vehicle performance is simulated and that's what I've now done. Other things to note are that 8 gears will be allowed, minimum car weight rises to 685 kg and that the ERS system will make 160 bhp available for up to 33 seconds a lap. Twice the power and 5 times the duration of the current KERS system. I've simulated the car performance both with and without ERS. In either case, and regardless of gearing, the computer is adamant. THERE IS NO POINT IN REVVING PAST 12,000 RPM BEFORE CHANGING GEAR! Only in top gear will the engine want or need to go past 12,000 rpm in order to achieve its top speed which will still be close to 200 mph on long straights. In fact I calculate that top gear will need to be selected at about 135 to 140 mph and from then on until 200 mph the driver has nothing to do other than steer and brake and operate the ERS etc. This will lead to a very strange driving experience and probably a similarly strange viewing one. In the slow parts of the lap it will sound like the drivers are short shifting, which indeed they will be, at about 12k rpm and then finally on the straights the engines will howl right round to the 15k redline and not want to change back down a gear until speed drops below 140 mph. At Silverstone for example the cars should be able to stay in top gear without a change all the way from Woodcote, round Copse, Becketts and on to Stowe which is over half a lap. This will be utterly counter-intuitive to the drivers who are used to revving to the red line in each gear before changing up as indeed are all of us in any type of car being driven to the limit. I suspect no one other than the teams, and maybe not all of those yet depending on how far they've got with simulations will even be aware of this anomaly. You heard it here first. The other thing that becomes apparent is that the engines will not want or need 8 gears. In fact a totally flat top end power curve like this is very insensitive to gearing and could manage quite well on the current 7 gears or even 6. We'll see if any teams opt to save weight and complexity with fewer than the 8 gears allowed in the regs. I suspect the winning teams might well do so. Top gear is therefore going to take a real hammering because the cars will spend so much time in it - way more than currently and will need to be made stronger than the other gears. Let's see how many top gear failures plague the start of the season. Engines will only exceed 12k rpm on long straights so they should last for ages compared to the current 18k redline in every gear. I'm dying to see how long it takes people in the sport to realise any of this or start commenting on it. Without access to a comprehensive vehicle simulation program it would never be apparent. I doubt if the rule setters had any clue their fuel flow limits would result in this strange behaviour. -- Dave Baker Re: Remarkable finding re 2104 engines a425couple 1/14/13 9:14 AM "Dave Baker" wrote in message... >A year or so ago I posted an analysis --- (big snip of good stuff) > I'm dying to see how long it takes people in the sport to realise any of > this or start commenting on it. Without access to a comprehensive vehicle > simulation program it would never be apparent. I doubt if the rule setters > had any clue their fuel flow limits would result in this strange > behaviour. Interesting.  (Indeed = "counter-intuitive") Thank you for posting it. Re: Remarkable finding re 2104 engines News 1/14/13 9:17 AM As you pointed out in your prescient analysis a long while ago (which I did recall), this follows directly from the 2014-spec fuel flow taper, the only issue being at what point on each engine/chassis the efficiency and power output are overwhelmed by internal friction, pumping losses and induced drag, net output curve rolls over, and car hits the drag rise.  A bit top fuel dragster-ish. Re: Remarkable finding re 2104 engines AC 1/14/13 12:06 PM Im my Alan Davis role, why not gear it to reach top speed at 10k rpm? Why go through the extra revs at all? -- AC Re: Remarkable finding re 2104 engines alan 1/14/13 12:19 PM Remember that the object of the exercise is to change gears so as to maximize the area under the rmp/horsepower curve. So if power above 10K only falls off slowly, you still want to operate in that regime rather than below 10K where it falls off more quickly. -- Alan Baker Vancouver, British Columbia "If you raise the ceiling four feet, move the fireplace from that wall to that wall, you'll still only get the full stereophonic effect if you sit in the bottom of that cupboard." Re: Remarkable finding re 2104 engines Noj 1/14/13 12:20 PM Dave Baker wrote ... Why am I thinking of go-carts and chainsaws? > > I'm dying to see how long it takes people in the sport to realise any of > this or start commenting on it. Without access to a comprehensive vehicle > simulation program it would never be apparent. I doubt if the rule setters > had any clue their fuel flow limits would result in this strange behaviour. I reckon the engine makers will have sussed out much, if not all, of what you've discovered.  If they pass that info onto the non-factory teams is another matter. Re: Remarkable finding re 2104 engines AC 1/14/13 1:03 PM Ok, so the point being that you can keep going up the revs as long as the power there is higher than the power available at lower revs if you go up a gear? So even though its less power at those +10k revs, its still better than the power at lower revs? Is that it? -- AC Re: Remarkable finding re 2104 engines Dave Baker 1/14/13 1:48 PM "Dave Baker" wrote in message news:kd1ase\$q6m\$1@speranza.aioe.org... Ok, I need to amend the above slightly. It's a most unusual power curve to optimise the gearing for and the program had been trying to tell me something I was not spotting. You don't need to use the revs between 12k and 15k at all, even in top gear. I'd already input a default 15k rev limit simply because that's what the engines are allowed to rev to and I'd worked out the top gear ratio to give 200 mph at 15k before entering the other gear ratios. It's more simple than that. You gear it for 200 mph (or whatever the drag coefficient will let the car run to) at 12k in top, ignore the extra 3000 rpm and change gear at 12k in every gear as before. The engine never goes above 12k rpm at any time. The 15k rpm limit is academic. -- Dave Baker Re: Remarkable finding re 2104 engines alan 1/14/13 4:05 PM > >> Im my Alan Davis role, why not gear it to reach top speed at 10k rpm? > >> Why go through the extra revs at all? > > > > Remember that the object of the exercise is to change gears so as to > > maximize the area under the rmp/horsepower curve. So if power above 10K > > only falls off slowly, you still want to operate in that regime rather > > than below 10K where it falls off more quickly. > > > > Ok, so the point being that you can keep going up the revs as long as > the power there is higher than the power available at lower revs if you > go up a gear? So even though its less power at those +10k revs, its > still better than the power at lower revs? Is that it? Basically. Horsepower combines the torque and RPM into a single number that reflects (less frictional and some other driveline losses) how much torque you can deliver at the wheels. X torque at y RPM is equal to x/2 torque at 2y rpm. So when you shift up, you do so because the HP at the high RPM now matches the HP at the RPM you'll have in the next higher gear. The short of it is that you don't shift AT the power peak, you shift AROUND the power peak; maximizing the power delivered at all times. If you've got a curve that ramps up at a high rate to peak power at 10,000rpm, and then that ramps down only very slowly, your going to maximize total power by shifting well beyond 10,000. Re: Remarkable finding re 2104 engines alan 1/14/13 4:08 PM In article , Questions? What is the horsepower you calculate for 12k? What is the horsepower you calculate at the new RPM after each upshift? Imagine for a moment that the curve above 10K stayed perfectly flat. You'd want to run it right to the rev limit and then only let the revs drop back to 10K (if that's possible with an 8 ratio gearbox, that is). Re: Remarkable finding re 2104 engines Bobster 1/14/13 7:08 PM On Jan 14, 11:48 pm, "Dave Baker" wrote: > It's more simple than that. You gear it for 200 mph (or whatever the drag > coefficient will let the car run to) at 12k in top, ignore the extra 3000 > rpm and change gear at 12k in every gear as before. The engine never goes > above 12k rpm at any time. The 15k rpm limit is academic. But the drag coefficient will change with DRS, so you'll go a bit past 12k and not have to worry about hitting the rev limiter. Interesting thing I read somewhere is that with the life of these engines they'll be usable at Le Mans. Re: Remarkable finding re 2104 engines Mark Jackson 1/15/13 4:37 AM On 1/14/2013 7:05 PM, Alan Baker wrote: > In article , AC wrote: >> Ok, so the point being that you can keep going up the revs as long as >> the power there is higher than the power available at lower revs if you >> go up a gear? So even though its less power at those +10k revs, its >> still better than the power at lower revs? Is that it? > > Basically. > > Horsepower combines the torque and RPM into a single number that > reflects (less frictional and some other driveline losses) how much > torque you can deliver at the wheels. X torque at y RPM is equal to x/2 > torque at 2y rpm. So when you shift up, you do so because the HP at the > high RPM now matches the HP at the RPM you'll have in the next higher > gear. > > The short of it is that you don't shift AT the power peak, you shift > AROUND the power peak; maximizing the power delivered at all times. Years ago I saw (in /Road & Track/ I think) a graph of torque at the driven wheels versus road speed - separate curve for each gear.  The curves overlap (low gear peaks at low speed, higher gears peak at higher speeds but lower torque values) and one shifts up when the curve for the current gear crosses the curve for the next.  This is also the point where HP in the two gears are equal. Note that with a CVT (not allowed under the F1 regulations) one would run the engine continuously *at* peak power. -- Mark Jackson - http://www.alumni.caltech.edu/~mjackson         Education is what survives when what has been learnt has         been forgotten.                - B. F. Skinner Re: Remarkable finding re 2104 engines Dave Baker 1/15/13 5:27 AM "Alan Baker" wrote in message news:alangbaker-C12E86.16082414012013@news.shawcable.net... > Questions? > > What is the horsepower you calculate for 12k? You can interpolate from the data I supplied but clearly just a bit less than the 510 bhp peak at 10.5k. > > What is the horsepower you calculate at the new RPM after each upshift? Obviously exactly the same bhp as before the change if acceleration is to be maximised. > > Imagine for a moment that the curve above 10K stayed perfectly flat. > You'd want to run it right to the rev limit and then only let the revs > drop back to 10K (if that's possible with an 8 ratio gearbox, that is). Not quite, and this is what the computer had been trying to tell me and I'd been too stupid to appreciate despite having written articles on the very same phenomenon many times in the past. If the bhp curve goes perfectly flat i.e. 510 bhp everywhere from 10,500 rpm to 15,000 rpm then "at a given speed" it makes no difference whereabouts on that bhp line you are because the torque at the wheels will always be the same once gearing has been factored in. So you still ideally change up a gear to drop the rpm in the new gear back to 10,500 rpm i.e. at about 12k to 12.5k which maintains a constant 510 bhp but uses as few revs as possible. Better for BSFC and better for engine life. Lowering the gearing and revving out to 15k won't actually make the car any quicker. It will just use more revs to maintain the same 510 bhp. -- Dave Baker Re: Remarkable finding re 2104 engines Dave Baker 1/15/13 5:28 AM "Alan Baker" wrote in message news:alangbaker-06172B.16054114012013@news.shawcable.net... > Horsepower combines the torque and RPM into a single number that > reflects (less frictional and some other driveline losses) how much > torque you can deliver at the wheels. Almost. Horsepower combines the torque and RPM  "and gearing" into a single number that  reflects (less frictional and some other driveline losses) how much torque you can deliver at the wheels. -- Dave Baker Re: Remarkable finding re 2104 engines Mower Man 1/15/13 2:49 PM Shame we won't be here to see it. In 2104 I doubt there'll be F1 anyway. :-) -- Chris 'Fashion is a form of ugliness so intolerable that we have to alter it every six months.' (Oscar Wilde.) Re: Remarkable finding re 2104 engines Dave Baker 1/15/13 3:17 PM "Dave Baker" wrote in message news:kd1ase\$q6m\$1@speranza.aioe.org... > > The other thing that becomes apparent is that the engines will not want or > need 8 gears. In fact a totally flat top end power curve like this is very > insensitive to gearing and could manage quite well on the current 7 gears > or even 6. We'll see if any teams opt to save weight and complexity with > fewer than the 8 gears allowed in the regs. I suspect the winning teams > might well do so. My friend at McLaren has pointed out that the 8 gears are mandatory and indeed the ratios for the whole season must be nominated and fixed before the first event of the season. For 2104 only you are allowed to change the nominated ratios once during the year. Technical Regs rule 9.6. So whether at Monza or Monaco you're stuck with one set of ratios that are going to have to cover a massive range of top speeds and corner speeds. The availability of at least 2,500 of unused rpm capability between say the normal 12,500 rpm change point and the redline at 15k will therefore come in handy and might be part of an overall plan by the FIA rule setters although I don't usually expect them to be that smart judging by past performance. So probably 7th will be the normal top gear for slow and medium speed circuits and 8th will be reserved for fast circuits. -- Dave Baker Re: Remarkable finding re 2104 engines Bobster 1/15/13 7:31 PM On Jan 16, 1:17 am, "Dave Baker" wrote: > My friend at McLaren has pointed out that the 8 gears are mandatory and > indeed the ratios for the whole season must be nominated and fixed before > the first event of the season. For 2104 only you are allowed to change the > nominated ratios once during the year. Technical Regs rule 9.6. Well the regulations published on the FIA web site say different. 9.6 Gear ratios : 9.6.1 The maximum number of forward gear ratios is 7. 9.6.2 The maximum number of numerical change gear ratio pairs a competitor has available to him during a Championship season is 30. All such gear ratio pairs must be declared to the FIA technical delegate at or before the first Event of the Championship. Those are the regs as published early last month. I keep on seeing comment on F1 sites that seems at odd with the published regs. James Allen ran a report that said with a single, central exhaust outlet diffuser blowing is going to be made difficult. Thing is the regs allow for TWO exhaust outlets, once each side of the car's centre line. Either the regs published in the public domain are not what is being made available to the teams and certain people in the media, or people aren't reading them properly. Re: Remarkable finding re 2104 engines Bobster 1/15/13 7:45 PM On Jan 16, 5:31 am, Bobster wrote: > On Jan 16, 1:17 am, "Dave Baker" wrote: > > My friend at McLaren has pointed out that the 8 gears are mandatory and > > indeed the ratios for the whole season must be nominated and fixed before > > the first event of the season. For 2104 only you are allowed to change the > > nominated ratios once during the year. Technical Regs rule 9.6. > > Well the regulations published on the FIA web site say different. > 9.6 Gear ratios : > 9.6.1 The maximum number of forward gear ratios is 7. > > 9.6.2 The maximum number of numerical change gear ratio pairs a > competitor has available to him during a Championship season is 30. > All such gear ratio pairs must be declared to the FIA technical > delegate at or before the first Event of the Championship. > > Those are the regs as published early last month. Forgot the URL. Many appy polly loggies Latest downloadable copy is at http://www.fia.com/sites/default/files/regulation/file/2014-F1-TECHNICAL-REGULATIONS-111212.pdf or http://tinyurl.com/a363dtj Re: Remarkable finding re 2104 engines alan 1/15/13 7:46 PM In article <8aec5eed-a01a-44bb-b572-3c9dac25c977@gu9g2000vbb.googlegroups.com>,  Bobster wrote: > On Jan 16, 1:17�am, "Dave Baker" wrote: > > > My friend at McLaren has pointed out that the 8 gears are mandatory and > > indeed the ratios for the whole season must be nominated and fixed before > > the first event of the season. For 2104 only you are allowed to change the > > nominated ratios once during the year. Technical Regs rule 9.6. > Well the regulations published on the FIA web site say different. > 9.6 Gear ratios : > 9.6.1 The maximum number of forward gear ratios is 7. > > 9.6.2 The maximum number of numerical change gear ratio pairs a > competitor has available to him during a Championship season is 30. > All such gear ratio pairs must be declared to the FIA technical > delegate at or before the first Event of the Championship. > > Those are the regs as published early last month. And those aren't the regs for 2014... ...because these are: > > I keep on seeing comment on F1 sites that seems at odd with the > published regs. James Allen ran a report that said with a single, > central exhaust outlet diffuser blowing is going to be made difficult. > Thing is the regs allow for TWO exhaust outlets, once each side of the > car's centre line. > > Either the regs published in the public domain are not what is being > made available to the teams and certain people in the media, or people > aren't reading them properly. Re: Remarkable finding re 2104 engines Bobster 1/15/13 9:37 PM On Jan 16, 5:46 am, Alan Baker wrote: > In article > <8aec5eed-a01a-44bb-b572-3c9dac25c...@gu9g2000vbb.googlegroups.com>, > > > > > > > > > >  Bobster wrote: > > On Jan 16, 1:17 am, "Dave Baker" wrote: > > > > > My friend at McLaren has pointed out that the 8 gears are mandatory and > > > indeed the ratios for the whole season must be nominated and fixed before > > > the first event of the season. For 2104 only you are allowed to change the > > > nominated ratios once during the year. Technical Regs rule 9.6. > > Well the regulations published on the FIA web site say different. > > 9.6 Gear ratios : > > 9.6.1 The maximum number of forward gear ratios is 7. > > > 9.6.2 The maximum number of numerical change gear ratio pairs a > > competitor has available to him during a Championship season is 30. > > All such gear ratio pairs must be declared to the FIA technical > > delegate at or before the first Event of the Championship. > > > Those are the regs as published early last month. > > And those aren't the regs for 2014... > > ...because these are: > > -REGULATIONS-111212.pdf> Yes. Which is what I thought I was working from. Anyhoo... got that one wrong. Please erase my post from your memories, folks, and let normal service resume.