Years ago, I was told that a loss of of power of 20 to 30% from flywheel to
rear wheels is quite normal. I don't know if this is right, but my present
LBC engine falls within the given range: At 6400 rpm, my 1970 1558 cc Lotus
Twin Cam has 147 hp (flywheel)/ 115 hp (rear wheels). If my math is right,
that's a loss of 28%.
I don't know much about the 1500, but I remember it as a long stroke engine,
nice and torquey on the street but not exactly a ball of fire (I had a 1979
Triumph Spitfire in England), and that figure of 50 hp sounds right for a
stock motor - power loss somewhere in the region of 30% probably (I don't
remember the 1500 engine specs) from the flywheel to the rear wheels. That
being said, I am surprised a modified engine would not give more power. I
would also be interested to hear from owners of 1500 Spifigets or Triumphs,
and see what figures they get on a dyno.
JLC
PS: just interested - what was the peak torque reading, and at what rpm?
Mike wrote: [snip]they rated my 1500 Midget at max 50bhp at the wheels (4K
rpm). It
was consistent over two runs. How does this compare to bhp at the crank?
Is there a mathematical formula, or a rough estimate as to how much hp is
lost in the drivetrain?
Also, has anyone with a 1500 Midget ever had their car dyno'ed? Was it
stock? I'd especially like to know what the hp was at the wheels on a stock
1500 Midget. Mine is a very modified '78 and I'd like to know if the mods
were worth it.
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