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Originally Posted by p76rangie
No, it has nothing to do with what gear it is in, you will always lose around 40% of your power through the drive train.
It is an old 1970's 4.4 rover V8
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Yes it has everything to do with the gear it is in.
When a vehicle is dynoed they strap it down and run it up through the gears.
So yes depending on the vehicle it's not uncommon to get up to 100, 110, 120mph
The run is made in top gear and you get results from accross the operating RPM band. The numbers I was given were from 1500-3500rpms.
These numbers are measured at the rear wheel. Depending on the chassis dyno used to get the flywheel numbers you need to multiply by the axle gearing used and divide by the trany gear if it's not 1:1
Some of the better dynos you enter all of these numbers in and it works it out for you. On the older ones you need to do the math yourself.
Also you are grossly wrong on the 40% inefficiency loss. As a very general rule, rear-wheel horsepower on a manual-transmission car is about 15% less than SAE net, and rear-wheel horsepower on an automatic-transmission car is about 20% less than SAE net.
I suggest you buy this book
http://www.amazon.com/Auto-Math-Hdbk...3364490&sr=8-1
and then try again.
