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Old 04-28-2009, 08:27 AM   #55 (permalink)
miguez
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Quote:
Originally Posted by Forrest View Post
My question is why are we making times same as a c5 vette with 350 hp 360 lb-ft and weighing less th an us?
Hey Forrest,

It could be down to a lot of different things. For example:
  • Suspension geometry, which will determine how the power is transferred from wheels to ground
  • Power loss to the drivetrain. Stated horsepower is usually at the flywheel. For that power to make it to the wheels, it needs to go through the drivetrain. This induces losses, and these losses can vary quite a bit between cars, but usually average about 20%. For example, in the 370Z, the stated horsepower at the flywheel is 332. A lot of people have dynoed their cars stock, which will measure horsepower at the wheel (whp) and obtained around 270-280 whp. I am not sure what the C5 had at the wheel.
  • Torque curve, not just the overall torque number you see advertised. These can vary dramatically between engines
  • Car weight and weight transfer. The more weight on the traction wheels, the more power they can put down before exceeding the traction limit. Weight transfer can also be very different between chassis, and that will alter how much weight is placed on the traction wheels during launch and acceleration

All that being said, it could be none of these, and could be simply down to how the tests were performed, and the differences between these tests.

Last edited by miguez; 04-28-2009 at 08:30 AM. Reason: Added power loss due to drivetrain
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