Gerhard.Wiederholl wrote (slightly edited for character translation and
usage):
> It's hard to estimate the number of HPs of a modified engine but you can
check
> Kastners competition preparation manual to see the power gain that comes
> only from a 10:1 compression and a S2 cam.
>
> However I found the formula to calculate the HPs on the clutch of a TR6.
All
> you need to know is the exact top speed of your TR6. You can also use it
to
> calculate the HPs you need to get a desired top speed.
>
> HP on the clutch = (speed in kph) EXP 3 / 37 EXP 3
>
> (37 is the product of all the drag factors of a TR6 with cw, front area,
drag
> from tires, gearbox and wheel bearings etc. considered . Ragtop up.)
>
> Example for a TR6 PI:
>
> POWER (HP) = 193 kph EXP3 / 50653 = 7189057 / 50653 = 142 HP
>
> In a motor magazine a 1969 TR6 (German version) was measured 193 kph or
> 121 mph and the claimed HPs were 143.
>
> Example for a US TR 6:
>
> POWER (HP) = 174 kph EXP3 / 50653 = 104 Hp
>
> (R&T Feb.1969 measured a TR6 109 mph or 174 km/h and the HP number they
gave
> was 104)
>
> Regards
> Gerhard Wiederholl
> =============
To use Gerhard's formula for miles/hour, you need to multiply both factors
by .62:
HP = (.62 * top speed in kph)^3 / (.62 * 37)^3
HP = (top speed in mph)^3 / (22.94)^3
In the above example for a US TR6 (to 2 decimal places):
HP = (.62 * 174kph)^3 / (.62 * 37)^3
HP = (107.88mph)^3 / (22.94)^3
HP = 1255517.62 / 12072.03
HP = 104
Jim Hill
Madison WI
|