Most engine dyno pulls have the bare necessities installed like the water pump ( most times connected to an electric motor and with headers or manifolds) as it takes the minimalist approach to see what the engine's true output is which gives us a reading close to Gross output. This is a beautiful high number. However, we all know adding luxuries like the alternator, power steering, AC and such takes power away. Even adding a belt creates a loss in output. This creates Net output which is going to be lower than the Gross HP figure since the engine will be installed in the car. So take a 500 hp (gross) engine, install the accessories (alt, water, AC, power), I assume the power output is going to take a nose dive in the low 430s or so based on playing the numbers game with quarter mile math formulas. The question is, how much loss is there with each item? I know in the 5.0 mustang era, we used a short belt to bypass the power steering pump. It was worth an honest tenth so about 10 or so HP. So we have: Alternator Power steering AC (6a, 5 , 4 cylinder) Vacuum pump Water pump What else? I am not concerned with driveline losses just accessories.
The alternator drain would largely depend on what amp-load was employed. So to be accurate one would need to figure the average amp-load of your cars running electrical devices and apply that load to the alternator during the pull. Larry
Interesting article (even mentions a Buick), http://www.hotrod.com/articles/ccrp-0311-drivetrain-power-loss/ This article addresses your question, https://www.carthrottle.com/post/how-much-engine-power-is-lost-through-ancillary-components/
Both Larrys.... Thanks. The chassis dyno test was interesting. Yes, alternator drag varies on needs as well as power steering. The weight or drag to turn the accessories is a factor. For bench talk, I rather compare flywheel Net HP over Gross HP. Of course, talking 'wheel' is the current fad. In the end, we don't race dyno numbers. But no doubt, some of the math either computes for Gross, NET, or wheel. Finding each loss would be interesting. I attached for you Mr Wizard .. what I drive during the week..
Awesome! I will be driving for 5 years this year In which I will finally reach Max rate period from there, I suppose I will prob I try to do my 3 best years for the company to match me for my retirement. Plus my deferred Compensation. The Maximum that anyone has made at my station was Nearly $144000. On average, however, it's typically ranges from 93 to 117 K period of course, that's for drivers trying for the retirement plan. I'll probably start this year or next who knows
