Rules for 2013 - Crank power vs Dyno

[WillM]

Drivetrain
Dyno type FWD RWD AWD

DynoJet (inertia dyno) 0.865 0.855 0.845
Mustang (eddy current dyno) 0.840 0.830 0.820
DynaPack (hub dyno) 0.870 0.865 0.860
Dyno Dynamics 0.769 0.769 0.769

Thanks for sharing Doug!

I once couldn't help myself and hit two dynos in one day.
Two hours after I left a Dyno Dynamics shop, I was strapped down and ready to go at a DynoJet.
The result? Exactly the same. I was blown away.
This was not my track car, and if I remember correctly, the max hp at both dynos was 178.

Results from above table:
Dyno Dynamics = 178/0.769 = 231 hp
Dyno Jet = 178/0.855 = 206 hp

[Chrispy]

So, assuming that dyno plots are not mandatory, and using technology to create an approximation of 'power' is acceptable, given an agreed-upon range of error (10%, 15%?).

Is there a 10-15% acceptable range of error when stating a vehicle's weight?

If not, why the double-standard?

Because HP is somewhat variable and weight is not (aside from fuel burn). There will need to be some acceptable margin defined for weight to account for scales, fuel etc. (Okay technically weight can vary slightly by location on earth due to small variances in gravity 0.5% from pole to equator)

Results from above table:
Dyno Dynamics = 178/0.769 = 231 hp
Dyno Jet = 178/0.855 = 206 hp

There's probably a logical explanation for this such as correction factors, heat soak, increased air temp etc. That's one of the reasons that you need a reasonable margin for error since conditions are not always equal.

[C5toSM]

Please visit the link below to view the current schedule for development of the 2013 rules package. Your board has added an additional board meeting this Tuesday night that will focus on the proposed touring classes and safety. When the job is finished we will hold a member vote by E Ballot to allow members to ratify the package should they so choose. As always: member feedback is encouraged. See schedule for details:

http://comscc.org/rules/2013-proposal/

John Spain, COM President for
The COM Board of Directors