Flywheel HP to wheel HP

[andries]

Originally Posted by cleong

If we assume that the engine puts out its claimed horsepower, then its about a 15% loss through a manual transmission when you compare it against what is measured at the wheels. 106hp vs. 90whp.

That sound nice. Today I measured with my ScanGauge 167 HP.
If the loss is 15% this means that I have 142 HP on the wheels.
I have the 1.8 2ZR-FE engine (stock 133 hp). The only engine mod is a K&N stock replacement air filter. (that's gain more power for less money)

Whether conditions, during the meeting, are optimal. Outside temperature was two degrees celsius what means the engine got optimal cold air.

[CASTREX]

Originally Posted by andries

That sound nice. Today I measured with my ScanGauge 167 HP.
If the loss is 15% this means that I have 142 HP on the wheels.
I have the 1.8 2ZR-FE engine (stock 133 hp). The only engine mod is a K&N stock replacement air filter. (that's gain more power for less money)

Whether conditions, during the meeting, are optimal. Outside temperature was two degrees celsius what means the engine got optimal cold air.

Those numbers are way off!!!

I've seen a few dyno charts of the 1.8 2ZR-FE

Stock this engine puts out between 118-120 WHP

A K&N drop in filter will net you 1-2 extra hp if anything at all...

[09TRD]

Originally Posted by andries

If the loss is 15%..

"15%" has no basis in fact.

Here, read this:

http://www.sportcompactcarweb.com/pr...t_4/index.html

"...Paulsen also believes that drivetrain losses are neither an absolute percentage nor a fixed number. Instead, he feels the crank-to-wheel relationship is far more beguiling. From his considerable experience, Paulsen suggests that low horsepower (100-200 hp) cars may suffer from as much as 15 to 20 percent of drivetrain loss at the rear wheels. For more powerful cars (200-400 hp), the figure is around 12 to 15 percent. And for mega-powered cars (above 400 hp), the drivetrain losses can reduce to 10 percent or less. What's going on? Getting into the physics behind this complex relationship is worthy of a project in itself. (Engineering editor, Dave Coleman says he's working on it.)"

The type of dyno is also a factor. Two different types of dynos will likely yield two different results - even when all other variables are identical.

Chassis dynos are tuning tools; they do not nor were they ever intended to be used to somehow "calculate" flywheel power.

[ddongbap]

Originally Posted by 09TRD

"15%" has no basis in fact.

Here, read this:

http://www.sportcompactcarweb.com/pr...t_4/index.html

"...Paulsen also believes that drivetrain losses are neither an absolute percentage nor a fixed number. Instead, he feels the crank-to-wheel relationship is far more beguiling. From his considerable experience, Paulsen suggests that low horsepower (100-200 hp) cars may suffer from as much as 15 to 20 percent of drivetrain loss at the rear wheels. For more powerful cars (200-400 hp), the figure is around 12 to 15 percent. And for mega-powered cars (above 400 hp), the drivetrain losses can reduce to 10 percent or less. What's going on? Getting into the physics behind this complex relationship is worthy of a project in itself. (Engineering editor, Dave Coleman says he's working on it.)"

The type of dyno is also a factor. Two different types of dynos will likely yield two different results - even when all other variables are identical.

Chassis dynos are tuning tools; they do not nor were they ever intended to be used to somehow "calculate" flywheel power.

The 15% is meant to be a guide. It isn't fact.