HP loss between motor and wheel

[WuzzaCBXRider]

I was watching Dave Kindig’s tv show and an engine they tested had 840 ponies at the crank but only 650 at the wheels. Granted, that power has to go thru an automatic transmission, driveshaft and a posi rearend, axles hubs and wheels but man, a 190 dead ponies? That means that the first muscle cars (that were so cool) that ran the quarter in the 13-14 second range, which was really quick, had only 200 ponies or so at the wheels. The three HP only dyno runs I had my Busa do around 2009 or so gave up two @ 159.+ something and one 160.+ something. What was the motor making?

 

[Red05]

I'm guessing around 188 at the crank? I would think much less HP dropped than the cars.

 

[WuzzaCBXRider]

I'm guessing around 188 at the crank? I would think much less HP dropped than the cars.

Yeah, the car’s loss was around 22% so I’d figure the bike’s loss would be closer to 10-15%.

 

[Red05]

Pretty good output for a stock gen 1!

 

[Berlin Germany]

I was watching Dave Kindig’s tv show and an engine they tested had 840 ponies at the crank but only 650 at the wheels. Granted, that power has to go thru an automatic transmission, driveshaft and a posi rearend, axles hubs and wheels but man, a 190 dead ponies? That means that the first muscle cars (that were so cool) that ran the quarter in the 13-14 second range, which was really quick, had only 200 ponies or so at the wheels. The three HP only dyno runs I had my Busa do around 2009 or so gave up two @ 159.+ something and one 160.+ something. What was the motor making?

the hp-loss at a standard bike ! usually is around 10-12%
so ,
what ever u meassure at the rear wheel (testbench) add this percentage and u have estimated ur engine power .

bike and car u can´t compare .

 

[sixpack577]

+1
around 10% for motorcycles.
A stock gen1 engine makes close to 180 hp at the crank, and a gen2 is almost 200 at the crank.

 

[HayaWakened]

+1
... and a gen2 is almost 200 at the crank.

+1 Gen 2's!

 

[jellyrug]

I was watching Dave Kindig’s tv show and an engine they tested had 840 ponies at the crank but only 650 at the wheels. Granted, that power has to go thru an automatic transmission, driveshaft and a posi rearend, axles hubs and wheels but man, a 190 dead ponies? That means that the first muscle cars (that were so cool) that ran the quarter in the 13-14 second range, which was really quick, had only 200 ponies or so at the wheels. The three HP only dyno runs I had my Busa do around 2009 or so gave up two @ 159.+ something and one 160.+ something. What was the motor making?

The only accurate way to measure engine output, is at the crank. In a building where conditions are controlled.

A rear wheel dyno has a lot of variables, being the heat (hp) you are putting into the tire, the dyno drums, the amount of slip between tire and dyno drums, etc. Tire pressure makes a difference, the strap tension holding the bike on the dyno makes a difference, the humidity and temperatures makes a difference.

Not all that hp is lost in the vehicle, some is lost in the dyno itself.

Dyno’s are great for tuning, but that is where it stops.