How much is lost?

[95-stang]

I'm sure its been asked somewhere, but i cant find it, roughly how much HP on a 95 is lost between the motor and the axle?
If say you have a 350HP motor, by the time its gone through an automatic box, just how much is left at the wheels?

 

[Rice_slayer]

I read somewhere that its 20%-25% for autos loss to the wheels then 10%-15% for stick. so a 70hp to 87hp loss im thinking, but dont take my word for it, I just read that somewhere for the stock engine specs ie, car has 215BHP, but dynoed most get 190rwhp with the 5 speed...

 

[Paul]

There is no magic number that can be used. Any comments herein would be speculation at best.

 

[GDTrumbo]

There is no magic number that can be used. Any comments herein would be speculation at best.

Exactly. Even a slight tire size change will affect this. GT

 

[RJayLo]

but there is a such thing as an approximate. Im sure thats what hes asking.

 

[Paul]

But what would be the objective of guessing a rear wheel horsepower number based on an approximation of parasitic losses through the drivetrain?

 

[95-stang]

Well its because people keep asking me at shows, and to tell you the truth dynos are thin on the ground near me.
It was just an aproximation i needed just for my general interest also, it did'nt need to be totally accurate.

 

[LAFENATU]

I would say 20% is a good round-a-bout number..

If it helps you any..

I had a 92 LX 5 Speed that made 276RWHP to the wheels...(Crane 2031 Cam)

I have virtually the same setup in this 95 AOD-E except I have a stock cam in this car. This car made 251RWHP.

Pro-M 75mm
65mm TB
GT40 Intake
GT40 Iron Heads
1.7's
Shorties
3.73's
Prochamber
Flowmaster Catback

 

[Addermk2]

RWHP doesnt mean shit... the only thing that matters is how fast you can get it down the 1/4

 

[Paul]

Well its because people keep asking me at shows, and to tell you the truth dynos are thin on the ground near me.
It was just an aproximation i needed just for my general interest also, it did'nt need to be totally accurate.

Are you guessing the output of your motor as well? Because using an approximate percentage to calculate approximate RWHP based on an approximate engine output seems pretty... well... approximate.

If you want to know how much power you make, go to the track and come back with some trap speeds and the weight of your car - that will be a far better indicator.

Paul.

 

[El_Diablo]

RWHP doesnt mean shit... the only thing that matters is how fast you can get it down the 1/4

and that doesnt mean shit when the road gets twistie.... whats your point? its all subjective and different drivers can do different things with the same car.... thats where numbers come into play in getting a good baseline idea as to where you should set your goals at

 

[Addermk2]

well if you want to get down into it like that... RWHP doesnt count for shit at all. since its a approximated calculation, based on torque, speed, and rpm

 

[El_Diablo]

true, but using those number outputs and a few others you can calculate your projected track outputs, its all a numbers game in the end :thumb:

 

[RJayLo]

But what would be the objective of guessing a rear wheel horsepower number based on an approximation of parasitic losses through the drivetrain?

true, but why stop there. Lets go after the manufactuers for getting us to THINK our motors came factory rated at a certain number. Those are approx as well since we all know no 2 cars will put down the exact same numbers time and time again. I dont think thats really the point here though. We all know vehicles have a built in loss for thier each particular case but as a whole, the question is geared toward the factory "average" for rwhp numbers. If the car puts down a claimed 225hp is it safe to say the wheel hp is about 180? 190? 42? The objective is to get an idea what an average real world horsepower is put down day to day on the wheels since we all know the number on the dealer sticker is just a way to get people to buy the car!