Flywheel HP and WHP adverage difference? Red or Random help.
Thread Starter
Senior Member
Joined: May 2002
Posts: 156
Likes: 0
Flywheel HP and WHP adverage difference? Red or Random help.
This is a general question and probably different for ever vehicle so we'll just say a 4 cylinder engine. What is the adverage % of HP lost from the engine to the wheels with a auto trany? Also with a manual?
[ September 16, 2002, 02:20 PM: Message edited by: d_m_kolb ]
[ September 16, 2002, 02:20 PM: Message edited by: d_m_kolb ]
Super Moderator
Joined: May 2001
Posts: 11,851
Likes: 2
From: Rancho Palos Verdes, CA
Vehicle: 2008 Toyota Prius 2006 Suzuki SV650S
Average with manual is about 15-20%
Average with auto is 20-25%. Some are as bad as 30%.
Average beta dyno's out in the 120's for 5-speed
Average beta dyno's out in the 10x's for auto's.
Average with auto is 20-25%. Some are as bad as 30%.
Average beta dyno's out in the 120's for 5-speed
Average beta dyno's out in the 10x's for auto's.
Thread Starter
Senior Member
Joined: May 2002
Posts: 156
Likes: 0
So lets say one engine makes 130 Crank HP and another engine same size makes 180HP. Will both of these engines lose the same % of 10 to 15 or will the engine that makes more HP actually lose less of a %?
Super Moderator
Joined: May 2001
Posts: 11,851
Likes: 2
From: Rancho Palos Verdes, CA
Vehicle: 2008 Toyota Prius 2006 Suzuki SV650S
They will both loose the same PERCENTAGE, so the higher HP engine will loose MORE HP.
Assuming 15% drivetrain loss.
100 HP ENGINE will dyno out about 85 to the wheels a 15 HP loss
200 HP ENGINE will dyno out about 170 to the wheels, a 30 HP loss.
It's still 15%, but you loose double the HP, by doubling the HP of the engine...
That is why say an 900 HP dyno for a supra or skyline is so dramatic. Again, assuming a 15% drivetrain loss (which any supra/skyline owner would kill for) that means the engine is putting out 1035 HP. If you figure the 25% for the drivetrain loss, the engine is putting out 1125 HP.
[ September 14, 2002, 09:30 AM: Message edited by: Random ]
Assuming 15% drivetrain loss.
100 HP ENGINE will dyno out about 85 to the wheels a 15 HP loss
200 HP ENGINE will dyno out about 170 to the wheels, a 30 HP loss.
It's still 15%, but you loose double the HP, by doubling the HP of the engine...
That is why say an 900 HP dyno for a supra or skyline is so dramatic. Again, assuming a 15% drivetrain loss (which any supra/skyline owner would kill for) that means the engine is putting out 1035 HP. If you figure the 25% for the drivetrain loss, the engine is putting out 1125 HP.
[ September 14, 2002, 09:30 AM: Message edited by: Random ]
Guest
Posts: n/a
QUOTE
Random:
That is why say an 900 HP dyno for a supra or skyline is so dramatic. Again, assuming a 15% drivetrain loss (which any supra/skyline owner would kill for) that means the engine is putting out 1035 HP. If you figure the 25% for the drivetrain loss, the engine is putting out 1125 HP.
Mother whor$ never thought of it that way. There is an 800 HP 10 second Supra in Hawaii jesus. You mean to tell me his engine is putting out over 1000 HP out of a twin turbo 6 cyl, jesus. smile.gif
That is why say an 900 HP dyno for a supra or skyline is so dramatic. Again, assuming a 15% drivetrain loss (which any supra/skyline owner would kill for) that means the engine is putting out 1035 HP. If you figure the 25% for the drivetrain loss, the engine is putting out 1125 HP.
Thread Starter
Senior Member
Joined: May 2002
Posts: 156
Likes: 0
This in my mind doesn't make sense to me. If a engine that makes 100HP is behind the same trany as a 200HP engine it seems the 15HP lose through the trany of the 100HP engine would still be 15HP through a 200HP engine.
This is a quote from a friend of mine
This is a quote from a friend of mine
QUOTE
The TH350 in my car uses about 40-hp to run behind my 330-hp 327. If I replace my 327 with a 660-hp engine you're telling me that the same exact trans is now gonna require 80-hp to run?
Wrong.
It's still gonna take about 40-hp. If I install a 100-hp engine, it's still gonna take about 40-hp to turn.
I'm thinking along the way he is thinking so can anyone really explain this where it makes sense?
Wrong.
It's still gonna take about 40-hp. If I install a 100-hp engine, it's still gonna take about 40-hp to turn.
Senior Member
Joined: May 2002
Posts: 566
Likes: 0
You are too fixated on 40 HP. The other factor that comes in is TORQUE! Why do most people forget that torque is just as important as HP??
Also, it's not just the tranny, there is power lost on the rear end, drive shaft, torque converter, wheels, and gravity. So, my car has a 350ci LS1 V8, if I were to upgrade it to a LS6 with about 400 HP, I would still lose about 15 percent from the crank to the wheels. The tranny doesn't take a certian amount of power to run, it is power that is lost in the the transfers of power from one mechanism to another.
I'm sure one of the more physics savy people here could give you a better explanation.
[ September 16, 2002, 11:53 AM: Message edited by: AllBlackTibby ]
Also, it's not just the tranny, there is power lost on the rear end, drive shaft, torque converter, wheels, and gravity. So, my car has a 350ci LS1 V8, if I were to upgrade it to a LS6 with about 400 HP, I would still lose about 15 percent from the crank to the wheels. The tranny doesn't take a certian amount of power to run, it is power that is lost in the the transfers of power from one mechanism to another.
I'm sure one of the more physics savy people here could give you a better explanation.
[ September 16, 2002, 11:53 AM: Message edited by: AllBlackTibby ]