FUN WITH NUMBERS

[ivanhoew]

hi chaps,

reading the jereze thread got me thinking ,thanks to the graph put up on fuel flow , I
thought hmm, that could be grossly reinterpreted to give the bhp that flow could supply etc etc...

note, first off ,this takes into account no frictional losses ,no harmonics , or any other part of engine design , its purely to do with what if you could use the fuel they give you to its max .

I used 3 different bscf( basically how much power an engine can make for a set amount of fuel) I used .55 a fairly normal turbo engine output trying to be economical ,.45 a reasonable na engine and .35 a very low figure indeed .

I am imagining the f1 engineers are playing with stratified charge,induction and chamber turbulence, multi spark and everything else they can to run lean (average)as possible .hence the use of the .35 figure .



so first I did the bhp calc..





then the torque..






then added 147.5lbs/ft (200nm) to the torque all the way along the rev range,since the regs allow 200nm with no mention of rpm limit .(I have probably missed it and its only allowed between 5600 and 6400 rpm!)







then did the same for bhp ,at this point I thought hmm, this seems a bit of a big gain ,and then made the assumption that they probably cannot make 200nm all through the rpm range and at some point the system would melt,blow a fuse,fall off the car,sieze,or just go flat forever .if they can make it make 200nm at 15k rpm things look rosy !







and then all the data on one graph.





note ,this entire mass of data is a gross oversimplification .but it will be fun to see how close it all is ,also anything under 5k or so would probably be off cam and redundant.i imagine the real world bsfc is going to be around .45.

regards
robert

[stevesingo]

I would expect BSFC in the 0.40 lb/hp/hr.

The MGU-K is limited to 120kW or 161hp.

The Honda RA168E of 1998 was 0.467 lb/hp/hr at 611hp.

http://www.grandprixengines.co.uk/Egs_69_70_71_Hon...

[ivanhoew]

stevesingo said:

I would expect BSFC in the 0.40 lb/hp/hr.

The MGU-K is limited to 120kW or 161hp.

The Honda RA168E of 1998 was 0.467 lb/hp/hr at 611hp.

http://www.grandprixengines.co.uk/Egs_69_70_71_Hon...

im hopelessly unable to find that bhp limit in the regs steve ,i have been looking here

http://www.formula1.com/inside_f1/rules_and_regula...

got a link to a more detailed set of regs ?

[Justaredbadge]

Quick question, where does the fuel flow-meter sit? Is it specified? Or is it all monitored by the ecu?

[ma9mwah]

ivanhoew said:

im hopelessly unable to find that bhp limit in the regs steve ,i have been looking here

http://www.formula1.com/inside_f1/rules_and_regula...

got a link to a more detailed set of regs ?

appendix 3: http://www.fia.com/sites/default/files/regulation/...

[ivanhoew]

thanks ma9, I see it now ,

i'll modify my figures .I wonder where the 200nm bit comes in , I don't see it in app3,maybe its a trq limit applied until kw reaches its legal limit .

[550M]

I really, really should've tried harder at school....

[550M]

I really, really should've tried harder at school....

Edited by 550M on Sunday 2nd February 20:02

[ivanhoew]

update ,with the 161 bhp added to both graphs ,the bhp one is pretty predictable






the torque one I found interesting , I added the unassisted trq line ,and the 200nm .45 bsfc line to show the crossover point , in case both limits are used .




looks like around 5600 rpm is the crossover point , would be fun if they used a 200nm limit all the way through,but there certainly is some serious torque going on in the lower rpm range, unfortunately well off cam and unlikely to manifest in a real world engine .

id very very vaguely guess best possible is going to be around 425 lbs/ft .

regards
robert

[G0ldfysh]

So will this make starting cleanly harder to achieve with all this excess torque would think the engines will be pretty ruthless on a slipping clutch and the differences between hooked up and full traction launch to bogged down more noticable.

Or will the extra torque off cam reduce the chance of a poor start and then bogging down as with so much torque the tyres would struggle no matter what?

[stevesingo]

Interesting read for some facts and figures…

http://www.renaultsport.com/IMG/pdf/rsf1-moteur201...

50k rpm limit on the MGU-K

I wouldn’t like to guess the speed at which peak power is made, but 161hp @ 50000 rpm is only 17lbft torque.

[RealSquirrels]

electric motors give full torque from basically 0 rpm.

ps - great thread OP.

[ivanhoew]

RealSquirrels said:

electric motors give full torque from basically 0 rpm.

ps - great thread OP.

thank you rs ,appreciate it .

[ivanhoew]

Justaredbadge said:

Quick question, where does the fuel flow-meter sit? Is it specified? Or is it all monitored by the ecu?

JRB, I think there was bit on the regs that specifies the fuel components . would be nice to be able to fool the flow meter with a big tube somewhere after it acting as a reservoir to be emptied suddenly and get an illegal bit of flow ;-)

[slinky]

Intriguing stuff..

Would you mind sharing your sheets, to save me re-inventing the wheel?

[ivanhoew]

no problem slinky , just bung me a pm and ill mail them to you .

robert

[johnfm]

Shouldn't all the related BHP and TQ crossover at 5252 rpm?

[ivanhoew]

johnfm said:

Shouldn't all the related BHP and TQ crossover at 5252 rpm?

yes they jolly well should ...are there sets of bhp and trq that don't john ? maybe I made a muckup somewhere .


robert

Edited by ivanhoew on Friday 7th February 18:01

[Blayney]

ivanhoew said:

yes they jolly well should ...are there sets of bhp and trq that don't john ? maybe I made a muckup somewhere .


robert

Units?

BHP and lb.ft will, I think.

[ivanhoew]

juss seen 441 lbs ft at 5k rpm quoted ,which would fit in well with the .45 bsfc .