OK, I understand that a stock Viper looses about 12% to 15% from the crank to the rear wheels. For example, a stock GTS came with 450 HP, using the 12% figure equals 396 rwhp or a 54 rwhp loss (so it takes 54 RWHP to move the drive line). Heres the part I don't get....say you S/C it like some of us have done and you get 835 rwhp. Using the 12% drive line loss, this means crank HP is about 949 (949 x 12% = 835, or simply a loss of 114 rwhp) My question is this, what would cause the increase in loss if nothing changes other than HP going up. I'm simply looking for the answer to this question. Does my GTS have 949 crank HP or 889 crank HP. I'm betting on the latter but just want to know the correct answer and why.
OK, I understand that a stock Viper looses about 12% to 15% from the crank to the rear wheels. For example, a stock GTS came with 450 HP, using the 12% figure equals 396 rwhp or a 54 rwhp loss (so it takes 54 RWHP to move the drive line). Heres the part I don't get....say you S/C it like some of us have done and you get 835 rwhp. Using the 12% drive line loss, this means crank HP is about 949 (949 x 12% = 835, or simply a loss of 114 rwhp) My question is this, what would cause the increase in loss if nothing changes other than HP going up. I'm simply looking for the answer to this question. Does my GTS have 949 crank HP or 889 crank HP. I'm betting on the latter but just want to know the correct answer and why.
Thanks in advance, Joel
The force on the gear faces increases with torque. There are three losses that I can think of, two of which remain constant. You have the friction between gear faces and bearing losses (probably the biggest factor), the windage losses, and the inertial losses. So basically one changes and the other two stay the same. It would be interesting to see what those percentages are.
Because when you increase your horsepower, the Mexicans see this and steal that much more from you. This is what living in Los Angeles has taught me. Physics can kiss my ass.
Because when you increase your horsepower, the Mexicans see this and steal that much more from you. This is what living in Los Angeles has taught me. Physics can kiss my ass.
LMAO...ohhhh I remember it out there...I saw on the damn news where some damn MAP company is printing Maps w/CA included as part of Mexico..
The force on the gear faces increases with torque. There are three losses that I can think of, two of which remain constant. You have the friction between gear faces and bearing losses (probably the biggest factor), the windage losses, and the inertial losses. So basically one changes and the other two stay the same. It would be interesting to see what those percentages are.
Agreed. This is why some of the old tricks is to run different type of lubricants or synthetics in the drivetrain. Straight cut gears, Micro Polishing the gears etc.
All of it helps in my opinion. Auto will pull a greater % than a manual transmission.
Agreed. This is why some of the old tricks is to run different type of lubricants or synthetics in the drivetrain. Straight cut gears, Micro Polishing the gears etc.
All of it helps in my opinion. Auto will pull a greater % than a manual transmission.
I am all about microniting your gear sets. Lube wise, I like Amsoil or Redline.
The force on the gear faces increases with torque. There are three losses that I can think of, two of which remain constant. You have the friction between gear faces and bearing losses (probably the biggest factor), the windage losses, and the inertial losses. So basically one changes and the other two stay the same. It would be interesting to see what those percentages are.
Quote:
Originally Posted by The Former PFR
I am all about microniting your gear sets. Lube wise, I like Amsoil or Redline.
Me too..been doing that for years..def. helps. We use Redline.
Sean Roe ran a World Challenge GTS one season. He had the engine dyno'd on a stand, then bolted that same engine in the car and ran it on a DynoJet. His measured driveline loss was right at 12.5%.
Sean Roe ran a World Challenge GTS one season. He had the engine dyno'd on a stand, then bolted that same engine in the car and ran it on a DynoJet. His measured driveline loss was right at 12.5%.
Thanks man, that really helps. I guess that the engine HP is closer to 949 then...not that it matters but I just wanted to know.
that i dont know but it does take HP to drive the S/C it just creates more power than what it takes to drive it, unlike the loss that happens when you run your air conditioning
that i dont know but it does take HP to drive the S/C it just creates more power than what it takes to drive it, unlike the loss that happens when you run your air conditioning
It takes power to drive the supercharger, but you don't see it at the crank. Its all subtracted before your dyno takes the reading.
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