Re: How You Measure [was Dyno down the road...] <longish>

[Jim Conforti <lndshrk@xxxxxxxxxxxx>]

SMILLER@domain.elided wrote:

> When making engine modifications, there are 2 questions that one might
> ask:
> 
> 1.  How much power did I gain witht the mod?
> B.  How much faster does the car go because of the mod?

  Of course.. theres the little problem of ..

  ... "How fast do you go in which gear, and where is the motor operating
       in that gear"

> Timed acceleration runs tell you how much faster the car goes as a
> result of said mods.  

  In that gear.. in that particular portion of the engines operating
  conditions.. 

  Example being: 60-100 in 3rd gear (assuming you can get 100 there) is
  going to be a VERY different operating range from 60-100 in 4th or 5th

> Plus, freeway runs save you the cost of the dyno rental.

  Scott.. I dunno about your state.. but most places, 100 in a 75
  will cost you more than $100.. a LOT more.. 

> On a
> dyno, each run should be corrected for temperature, barometric
> pressure and maybe even humidity?  

  Temperature, Barometric Altitude, Vapor Pressure of Water (from BA and Hum.)

> So to recap (hold on, almost done now!), both methods of measurement
> have valid applications.  

  When PROPERLY CONDUCTED sure.. 

  When done wrong, the dyno is just as useless as the timed runs...

  Jim

  PS: There's even more to it than what we talk about above.. but we'll
      save if for another life..

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