Power loss through drivetrain
Apr 14, 2008, 08:33 PM
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Power loss through drivetrain
Hey guys i was just wondering exactly how much power is lost throught the drivetrain?? I know is quite a bit but how much exactly?
Apr 14, 2008, 08:46 PM
#2
That question can't really be answered untill someone dynos their car, gets the whp, then pulls the motor and dynos that on an engine dyno. And then there's going to be variations between vehicle to vehicle.
But from most stock evo's dynoed I would guess about a 17-18% drivetrain loss. Not really as much as you'd think. The evo's drivetrain is actually pretty efficient. This is MO others might think differently.
But from most stock evo's dynoed I would guess about a 17-18% drivetrain loss. Not really as much as you'd think. The evo's drivetrain is actually pretty efficient. This is MO others might think differently.
Apr 14, 2008, 08:51 PM
#3
Drivetrain losses are functions of mass, friction, speed, heat, pressure, and time. The drive train simply will not produce uniform losses as more pressure/force is applied presenting a problem for people trying to figure out what the engine is doing.
If your just going to approximate the drivetrain loss for bragging rights them 20% should put you in a very broad ballpark.
Apr 14, 2008, 09:47 PM
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Well the only reason i asked is because Mitsubishi claims 286hp or something like that so what would be the number at the wheels?? something along the lines of around 230hp or so??
Apr 14, 2008, 09:58 PM
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It really can't be calculated.
Drivetrain losses are functions of mass, friction, speed, heat, pressure, and time. The drive train simply will not produce uniform losses as more pressure/force is applied presenting a problem for people trying to figure out what the engine is doing.
If your just going to approximate the drivetrain loss for bragging rights them 20% should put you in a very broad ballpark.
Drivetrain losses are functions of mass, friction, speed, heat, pressure, and time. The drive train simply will not produce uniform losses as more pressure/force is applied presenting a problem for people trying to figure out what the engine is doing.
If your just going to approximate the drivetrain loss for bragging rights them 20% should put you in a very broad ballpark.
As for your new question, it's really hard to calculate because the various types of dynos will have different wheel power figures - some might say 240 whp (dynojet, dynapack) while some may read 210 whp (mustang and dyno dynamics). But the user settings can also influence things.
So to answer your question, the main use for a dyno is to show changes in the power - not necessarily the ultimate power figures. Oh, and it's also one of the few safe places to tune a car
Apr 14, 2008, 10:25 PM
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Yeah i understand i just wanted to get a ball park figure basicaly on a stock Evo.
Well i dont have an Evo yet but im trying to learn as much as posible about them that way i know where i want to go with it. There will be several dyno runs for me as soon as i do any serious mods to the car. I really want it for a street/track car so im only really shooting for around 330hp-350hp no more. i don't need anythng crazy. i just want it to handle well and brake even better.
Well i dont have an Evo yet but im trying to learn as much as posible about them that way i know where i want to go with it. There will be several dyno runs for me as soon as i do any serious mods to the car. I really want it for a street/track car so im only really shooting for around 330hp-350hp no more. i don't need anythng crazy. i just want it to handle well and brake even better.
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Apr 14, 2008, 10:49 PM
#8
This is right on... there have been some attempts at trying to formulate losses in SAE papers. I read one where they went through each individual component and created a massive database in order to arrive at a predetermined loss number. However, once you start modifying things, this does not stay a fixed value or even a fixed percentage. Some of the losses will increase and some will stay the same - which makes the net change basically impossible to determine. The only truly accurate way to measure this is to take the motor out and dyno it, then, without changing any settings, put it back in the car and redyno it. That will tell you how much hp is lost through the drivetrain for that particular configuration.
As for your new question, it's really hard to calculate because the various types of dynos will have different wheel power figures - some might say 240 whp (dynojet, dynapack) while some may read 210 whp (mustang and dyno dynamics). But the user settings can also influence things.
So to answer your question, the main use for a dyno is to show changes in the power - not necessarily the ultimate power figures. Oh, and it's also one of the few safe places to tune a car
As for your new question, it's really hard to calculate because the various types of dynos will have different wheel power figures - some might say 240 whp (dynojet, dynapack) while some may read 210 whp (mustang and dyno dynamics). But the user settings can also influence things.
So to answer your question, the main use for a dyno is to show changes in the power - not necessarily the ultimate power figures. Oh, and it's also one of the few safe places to tune a car
Apr 15, 2008, 07:00 AM
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Low as 215 WHP and high as 265 WHP. You can make even the same brand of dynos read anything and every tuner has different setups and calibrations.
I would say ~230-240 is an average stock WHP number.
DynoDynamics are the most accurate IMO, and Dynojet is probably the least accurate...but they do make everyone happy with the graphs.
I would say ~230-240 is an average stock WHP number.
DynoDynamics are the most accurate IMO, and Dynojet is probably the least accurate...but they do make everyone happy with the graphs.
Jan 19, 2018, 03:07 PM
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Power Loss
I'm just wondering is a % of Loss is really the right way to say how much you lose...?
Like wouldnt the number of lose be very simular. i know drag on the gears through the oil etc would increase as more power was applied. but would it be significant enough to cause a change...?
i.e like wouldnt the power loss for a guess say was like 70HP from fly to wheels of a car thats 300HP be a very simular of a car thats 500HP.
Where to say a 20% lose would me that the 500HP car Would loose 100HP to the wheels and the 300HP car would only loose 60HP...
I would have thought the power lose would be very simular for both cars reghaurdless of power level, but i may be wrong.
My personal Evo was 224KW at the wheels which is ruffly 300HP.
a 20% loss would indicate my car was 270KW at the fly which is 362HP.... seems like alot.
i've always been told ruffly a 40KW loss... but that was what i got told based on no info at all....
Like wouldnt the number of lose be very simular. i know drag on the gears through the oil etc would increase as more power was applied. but would it be significant enough to cause a change...?
i.e like wouldnt the power loss for a guess say was like 70HP from fly to wheels of a car thats 300HP be a very simular of a car thats 500HP.
Where to say a 20% lose would me that the 500HP car Would loose 100HP to the wheels and the 300HP car would only loose 60HP...
I would have thought the power lose would be very simular for both cars reghaurdless of power level, but i may be wrong.
My personal Evo was 224KW at the wheels which is ruffly 300HP.
a 20% loss would indicate my car was 270KW at the fly which is 362HP.... seems like alot.
i've always been told ruffly a 40KW loss... but that was what i got told based on no info at all....