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| GT3000 |
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I was under the impression that driveline losses are pretty much constant. ie if you have 165 fwkw and 100 rwkw then if you do an engine mod that gives you 110 rwkw you then have 175 fwkw.
_________________ 1970 V6 GT Capri
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| KTASTRPHE |
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Yeah, thats what my understanding was - the driveline takes about the same power no matter what mod you do. I guess about 50kw in falcons.
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| One Drone |
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KTASTRPHE wrote: Yeah, thats what my understanding was - the driveline takes about the same power no matter what mod you do. I guess about 50kw in falcons.
That's what I meant, I was just unable to elaborate.
_________________ There are 10 types of people in this world. |
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| Madxh |
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4.9 EF Futura wrote: Questamation thing.
I guess the one theory we have.... Let's assume the standard EF 4.0L V8 produces 165kw at the flywheel (probably a big assumption). ON AVERAGE, these engines yield 105-110kw at the rear wheels (of course, all dynos are different, different weather etc etc.) with an automatic transmission. So 165fwkw to 110rwkw = 33% loss through drivetrain. So ppl usually assume 30% loss from fw to rw on a standard car. As for modded engines.... anyone's guess. Need some figures to compare... fwkw to rwkw. SO what i wanna know is when did ford produce a 4.0L V8???? 
_________________ The Ute with the Most |
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| data_mine |
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Madxh wrote: 4.9 EF Futura wrote: Questamation thing. I guess the one theory we have.... Let's assume the standard EF 4.0L V8 produces 165kw at the flywheel (probably a big assumption). ON AVERAGE, these engines yield 105-110kw at the rear wheels (of course, all dynos are different, different weather etc etc.) with an automatic transmission. So 165fwkw to 110rwkw = 33% loss through drivetrain. So ppl usually assume 30% loss from fw to rw on a standard car. As for modded engines.... anyone's guess. Need some figures to compare... fwkw to rwkw. SO what i wanna know is when did ford produce a 4.0L V8???? Jaguar is a Ford owned company, they make plenty of 4.0 V8's
_________________ 1998 DL LTD in Sparkling Burgundy, daily, 302W, stereo, slow |
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| madmax |
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data_mine wrote: Madxh wrote: 4.9 EF Futura wrote: Questamation thing. I guess the one theory we have.... Let's assume the standard EF 4.0L V8 produces 165kw at the flywheel (probably a big assumption). ON AVERAGE, these engines yield 105-110kw at the rear wheels (of course, all dynos are different, different weather etc etc.) with an automatic transmission. So 165fwkw to 110rwkw = 33% loss through drivetrain. So ppl usually assume 30% loss from fw to rw on a standard car. As for modded engines.... anyone's guess. Need some figures to compare... fwkw to rwkw. SO what i wanna know is when did ford produce a 4.0L V8???? Jaguar is a Ford owned company, they make plenty of 4.0 V8's And they put them into EF's?? 
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| xr8 dismantler |
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there is no direct conversion for fwkw and rwkw there are to many factors that come into play.
auto or manual, tyre type and size and lots more can all vary the rwkw. on my nissan patrol we work on a 50% power loss down the driveline. i can change tyres and change rwkw,s quite a bit |
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| unclewoja |
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30% is a rule of thumb that most people use and it is wrong.
Losses are in the order of 12-15%... that's including losses in the diff and top gear in the transmission (1:1) Have a look http://toyotaperformance.com/dyno.htm Yes, yes. I know it's a toyota website, but it is the BEST resource I have come across that tells you everything you need to know about engines, transmissions, tuning, fuel, spark, turbo.... anything basically. Where I work we make right angle gearboxes for irrigation. They use spiral bevel gears in them. When we test them, we put about 2Hp through the box and this is enough to heat the gearbox up to about 60 centigrade in about 30mins. This is a 170kg gearbox we're talking about. The bigger ones we make, weighing in at about 300Kg, take about 1hr to heat up. Now, if you are losing 50kw in the transmission to heat, and the transmission weighs no more than 100kg, that's 33 times more heat and 42% less mass to absorb the heat. |
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| 4.9 EF Futura |
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Madxh wrote: 4.9 EF Futura wrote: Questamation thing. I guess the one theory we have.... Let's assume the standard EF 4.0L V8 produces 165kw at the flywheel (probably a big assumption). ON AVERAGE, these engines yield 105-110kw at the rear wheels (of course, all dynos are different, different weather etc etc.) with an automatic transmission. So 165fwkw to 110rwkw = 33% loss through drivetrain. So ppl usually assume 30% loss from fw to rw on a standard car. As for modded engines.... anyone's guess. Need some figures to compare... fwkw to rwkw. SO what i wanna know is when did ford produce a 4.0L V8???? Hehehe - yeah yeah..... 4.9L then.... you know what i meant (i certainly wouldnt be talking about the I6 now would i?  )
_________________ I promise..... I will never die. |
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| 4.9 EF Futura |
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unclewoja wrote: 30% is a rule of thumb that most people use and it is wrong.
Losses are in the order of 12-15%... that's including losses in the diff and top gear in the transmission (1:1) Have a look http://toyotaperformance.com/dyno.htm Yes, yes. I know it's a toyota website, but it is the BEST resource I have come across that tells you everything you need to know about engines, transmissions, tuning, fuel, spark, turbo.... anything basically. Where I work we make right angle gearboxes for irrigation. They use spiral bevel gears in them. When we test them, we put about 2Hp through the box and this is enough to heat the gearbox up to about 60 centigrade in about 30mins. This is a 170kg gearbox we're talking about. The bigger ones we make, weighing in at about 300Kg, take about 1hr to heat up. Now, if you are losing 50kw in the transmission to heat, and the transmission weighs no more than 100kg, that's 33 times more heat and 42% less mass to absorb the heat. Awesome read and some interesting opinions... link at the bottom of the page: http://www.pumaracing.co.uk/power3.htm Suggests some formulae for calculating drivetrain losses (lol, after explaining that it's impossible to calculate... altho he/she does state they are rough, 'rule of thumb' type calcs). Would be interesting to see some results from FM users: FWD cars - add 10 bhp to the wheel figure and divide the result by 0.9 RWD cars - add 10 bhp to the wheel figure and divide the result by 0.88 4WD cars - add 10bhp to the wheel figure and divide the result by 0.84 To estimate the expected wheel bhp from a known flywheel bhp just reverse the equations FWD - multiply flywheel power by 0.9 and then deduct a further 10 bhp RWD - multiply flywheel power by 0.88 and then deduct a further 10 bhp 4WD - multiply flywheel power by 0.84 and then deduct a further 10 bhp Results in my engine making 265hp altho prolly add a few more on there thanks to the slushomatic (i assume this person talking manual trans).
_________________ I promise..... I will never die. |
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| Choca |
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Cheers Guys for all of that
The reason I made the post was because i have an EF 5 speed and im currently getting 135rwkw after the 10th of feb i should have 160+rwkw what i want know is would i have more power at the wheels and the fly wheel than a BA 6?? sounds stupid but just something i would like to find out.
_________________ EF EL Fibreglass bonnet with BA Bulge Click Here: http://fordmods.com/forums/viewtopic.php?t=54102
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| unclewoja |
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Choca wrote: Cheers Guys for all of that
The reason I made the post was because i have an EF 5 speed and im currently getting 135rwkw after the 10th of feb i should have 160+rwkw what i want know is would i have more power at the wheels and the fly wheel than a BA 6?? sounds stupid but just something i would like to find out. All you need is an extra 30kw @ the fly to equal a BA (185kW if I remember correctly?)... not hard to do at all. EDIT: Also, you can get dissapointed if you overestimate the losses in teh transmission. This is because you get an actual fly wheel kW of less than you calculated. So when you calculate your 160 RWKW as 228 FWKW(30% loss - overestimated) and you only barely keep up with a 185kW BA, you get dissapointed. If you underestimate your transmission losses, you get an actual fly wheel kW of more than you calculated. So if you calculate your 160RWKW as 168 FWKW (5% loss - underestimated) and you barely keep up with a 185kW BA, you get happy. |
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| nicco |
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Usually you can guestimate it at around 20% loss. Which for my brothers commodore works perfectly. But ford measures there flywheel KW differntly from holden.
Holden puts on all the accesories, AC pump, alternator power steering etc. This all drain kW. Ford doesnt, it runs the motor without any accesories. Which is why we lose about 30%. Our fly wheel figures are a tad optimistic. But my brother doesnt need to know that when i rub it in about my EF having more power and tourque than his VY S!!! 
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| data_mine |
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nicco wrote: Usually you can guestimate it at around 20% loss. Which for my brothers commodore works perfectly. But ford measures there flywheel KW differntly from holden.
Holden puts on all the accesories, AC pump, alternator power steering etc. This all drain kW. Ford doesnt, it runs the motor without any accesories. Which is why we lose about 30%. Our fly wheel figures are a tad optimistic. But my brother doesnt need to know that when i rub it in about my EF having more power and tourque than his VY S!!! I always thought it was Holden that were optimistic. Remembering back to when the GT was released, and its 290KW 530NM (I've seen one dynoed with 221RWKW), laying waste to the GTS' 300KW. Anyway, who beats who (your EF vs VY S) down the 1/4, to 100KM/H, 80-120? THATS all you need to know.
_________________ 1998 DL LTD in Sparkling Burgundy, daily, 302W, stereo, slow |
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| nicco |
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Sadly, my brother beat me the only time we raced. He got the start, and was slowly pulling out from there. Damn that short first gear!! But, next time we race i might actually expect him to race, meaning i might actually stall it up...
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