A favor for Cobra'03

[Cobra'03]

Hi Guys!

I need a favor - can anyone steer me to a dyno of a Terminator at or near the 1000 HP level? - I recall seeing something in MM&FF, but I have been challenged on this, and need to know if I was wrong.

 

[dgussin1]

Originally posted by Cobra'03
Hi Guys!

I need a favor - can anyone steer me to a dyno of a Terminator at or near the 1000 HP level? - I recall seeing something in MM&FF, but I have been challenged on this, and need to know if I was wrong.

Click here

That transfers to approx. 1004 flywheel horsepower with 16% drivetrain loss.

 

[Forbidden Snake]

Getting off topic here.....

Why do we use that bogus 12% or 16% loss when calculating BHP or RWHP?

Why would a car with 1000 HP loose more through the drivetrain vs. a car with 500 HP with the same drivetrain?

Powertrain loss on a car should be a fixed value. It doesn't make sense to me that two similar car with different HP would loose different amount of HP through the same drivetrain.

:shrug:

(I know X2C have an auto, but let's assume otherwise any car with a 1000 HP).

 

[akaeric]

Thats allso 125 hp per cyclinder?

 

[dgussin1]

Originally posted by Forbidden Snake
Getting off topic here.....

Why do we use that bogus 12% or 16% loss when calculating BHP or RWHP?

Why would a car with 1000 HP loose more through the drivetrain vs. a car with 500 HP with the same drivetrain?

Powertrain loss on a car should be a fixed value. It doesn't make sense to me that two similar car with different HP would loose different amount of HP through the same drivetrain.

:shrug:

(I know X2C have an auto, but let's assume otherwise any car with a 1000 HP).

Fords svt hotline extimates with the T56 in the 03 cobra that the drivetrain loss is 16%...mercedes AMG hotline told me that the e55 has a 18% drivetrain loss...I know this particular car has an auto...but I used the t56 spec because I cannot speculate the amount of loss with that transmission. I can only assume that there is more loss in an automatic equipt vehicle.

 

[jtfx6552]

Originally posted by Forbidden Snake
Getting off topic here.....

Why do we use that bogus 12% or 16% loss when calculating BHP or RWHP?

Why would a car with 1000 HP loose more through the drivetrain vs. a car with 500 HP with the same drivetrain?

Powertrain loss on a car should be a fixed value. It doesn't make sense to me that two similar car with different HP would loose different amount of HP through the same drivetrain.

:shrug:

(I know X2C have an auto, but let's assume otherwise any car with a 1000 HP).

From a post of mine in this thread:
http://www.svtperformance.com/forum...;threadid=26965

There are several components of driveline loss.

1) I believe the frictional losses do stay relatively constant even when you add more power via mods to an existing car.

2) Losses through gears is proportional (basically, this too is a simplification) to the power that is being transferred through them.

With a 4th gear pull ,with any modern Mustang you are not going through any gears in the transmission(input shaft is coupled to the output shaft in 4th). However, the torque is going through the ring and pinion.

3) There are also losses due to the moment of inertia of all the rotating parts in the driveline . During a chassis dyno pull, the engine has to spin the clutch, pp, trans input shaft, trans counter shaft, output shaft, driveshaft, the pinion, differential, ring gear, axles, wheels and tires from whatever the starting RPM is, to what ever the rotating speed is at the end of the pull. This takes power which is not available to spin the dyno drum, and thus does not show up in the HP number.

If you increase engine HP, you have reduced the time the pull takes. To spin all that stuff to the same ending RPM in less time takes more power, which again, isn't going into spinning the drum. These losses would also be proportional.

So with 2 and 3 being proportional, a percentage is probably the best approximation.

 

[03DOHC]

Originally posted by Forbidden Snake
Getting off topic here.....

Why do we use that bogus 12% or 16% loss when calculating BHP or RWHP?

Why would a car with 1000 HP loose more through the drivetrain vs. a car with 500 HP with the same drivetrain?

Powertrain loss on a car should be a fixed value. It doesn't make sense to me that two similar car with different HP would loose different amount of HP through the same drivetrain.

:shrug:

(I know X2C have an auto, but let's assume otherwise any car with a 1000 HP).

I remember a thread a while back by a few engineers here that stated why the drivetrain loss is not a fixed figure. Something about taking more power to turn the rotating assembly the faster you try to spin it.

I believe one of the posts was by jtfx6552.


On topic: The x2c turbo car made some serious power. That and the strickly(sp) car.

**edit. jt posted as I was typing**

 

[Forbidden Snake]

JT, your explanation makes sense. I wasn't thinking about the proportional power required to spin the same amount of weight faster.

 

[jtfx6552]

Originally posted by 03DOHC
I remember a thread a while back by a few engineers here that stated why the drivetrain loss is not a fixed figure. Something about taking more power to turn the rotating assembly the faster you try to spin it.

I believe one of the posts was by jtfx6552.


On topic: The x2c turbo car made some serious power. That and the strickly(sp) car.

**edit. jt posted as I was typing**

Glad the search feature is back, I was able to find the old post and clean it up a bit..