dyno calculations.

[mark kibort <mkibort@xxxxxxxxxxxxxx>]

Message text written by INTERNET:bmw@domain.elided
>Rob,

I didn't see anybody spit out the magic number which is 21%.  So an M3
with 200 at the r.w. has, 200 x 1.21 =3D 242.

Now something that I haven't seen anyone mention is playing around
with the coolant temp.  The person at the dyno when I had my car
checked, had me play around with the radiator fan to cool the coolant
down.  <

>>>>>>>>>>>>>>
did you not see my "divide by .84 " post??  It happens to be really close=

to multiply =

by 1.21.?
Where did  this magic number come from?     On most dyno runs, the =

gear train efficiency is at its worst at the higher rpms.  (friction will=

go up
with the  square of the speed)   anyway, in most dyno runs, 10% is just t=
he
rolling
friction .  so your multiply by 1.21 or my divide by .84  is only valid a=
t
6000 rpm or so.
have that and the efficiency goes up.  , especially at the max torque ran=
ge
of 4000 rpm, =

as torque may be even closer to the flywheel figures.  =


Also, yes , the cooler runs quite often are the most HP runs.  (wow, that=

means the e-RAM
is even more powerful as we did the cool run  first and then the hot run
with e-RAM connected )

Just a comment.

mark Kibort =

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