Motor HP vs RWhp???

[balderman]

If the Motor is pumping out about 35HP.. what would the RWHP be.. is there an average 15% that is lost through the tranny?

What is it for AODE and what for 5-speed

Just curious...

Thanks

 

[law]

Well from what I have read and what I have learned, for a mustang the average lost is about 15% for 5-speed and for an automatic I heard it is as much as 20-25% if not more. So if you have 215 HP then you would multiple 215x.15=32 then subtract 215 from 32 and it would roughly be 183RWHP. Someone correct me if I am wrong.

 

[Joes95GT]

Well from what I have read and what I have learned, for a mustang the average lost is about 15% for 5-speed and for an automatic I heard it is as much as 20-25% if not more. So if you have 215 HP then you would multiple 215x.15=32 then subtract 215 from 32 and it would roughly be 183RWHP. Someone correct me if I am wrong.

Thats right. Typically, on an AODE that has no aftermarket torque converter the loss seems to be closer to 25% if not slightly higher.

Joe

 

[Babyduck]

I wonder if this drivetrain loss percentage is linear... for example, if your car (aode) is making 250h/p at the flywheel, thats roughly 188h/p at the wheels, if you use the 25% rule ( which i find alittle on the steep side).

Now if you take a 700 flywheel horse motor, you come out with about a 175h/p loss through the drivetrain. ( agian, an aode)
(525rwhp) Doesnt seem logical. Then again, your probably going to have an aftermarket convertor on this 700h/p motor, which would bring the drivetrain loss down to what?, 20% or less? Still though, a 175h/p loss through the drivetrain on a high h/p motor vs a low h/p motor shouldnt make a diference. Maybe im missing somthing here?
so in reality, when we say the blocks are splitting at 500 h/p, really its more like the block can take about 600-670h/p before it becomes unstable??

Anyone know, im curious?

 

[Numbles]

Babyduck you said it before I could. Ive wondered the same thing about the drivetrain loss percentage. It seems a little wrong.

Plus in my opinion, a 700hp motor aint gonna have a hard time turing over a transmission and a set of tires so how does it lose more than a low hp motor.

 

[S/CBlack95GT]

Babyduck you said it before I could. Ive wondered the same thing about the drivetrain loss percentage. It seems a little wrong.

Plus in my opinion, a 700hp motor aint gonna have a hard time turing over a transmission and a set of tires so how does it lose more than a low hp motor.

You must remember that dynojets record power based on how fast the engine rotates the tires, they do not record based on load or brake power. So a high horsepower engine will rotate the tires faster, which creates a greater power loss. It takes more power to turn the drivetrain from 50-120mph in 5 seconds than in 8 seconds, therefore the engine will appear to lose more power even though it is still 15% of the engine's total power.

I once heard an engineer from Holley say they found from their research with Mustangs that manuals lose about 18% and the autos lose about 23%. I like to stay conservative and use a 16% loss.

 

[flewthecoupe]

Read all about it here....Horsepower loss