Originally posted by Keith
Interesting discussion ... I don't think the relationship between HP and BHP is right. This is what I think is going on...

HP is simply a measure of rate of work. It equals 33,000 lbs-feet of work done in 1 minute. BHP is saying that HP is measured against a brake - i.e. the system is running at a steady state. There may be a different amount of work being produced by the same system under acceleration than in a steady state so there can be different power ratings depending on how it was measured. However, they are all using the same definition of a HP.

Talking about HP without the "B" in the front is saying the power was measured but is not saying HOW it was measured. BHP says how it was measured so two people testing the same engine should have the same BHP. There is no meaningful conversion between HP and BHP. Someone who refers to BHP as HP is not being wrong - they are just dropping the reference to how it was measured. However, quoting power measured under acceleration as BHP is wrong.

I think all of this is correct. I am sure someone will comment if it is wrong!

http://kennedyp.iccom.com/pat/what_is_hp.htm

Umm, "All the B means is "brake". The old word for a dyno - because the engine torque was measured by applying a brake to the flywheel rather than a torque converter or electrical motor which is how it's done nowadays. There's no other difference between the two and they both just mean horsepower." One's just at the flywheel

Originally posted by Grinder


http://kennedyp.iccom.com/pat/what_is_hp.htm

Umm, "All the B means is "brake". The old word for a dyno - because the engine torque was measured by applying a brake to the flywheel rather than a torque converter or electrical motor which is how it's done nowadays. There's no other difference between the two and they both just mean horsepower." One's just at the flywheel
I Googled several references and I don't think either Bhp or hp implies measurement at the flywheel. As this reference says, "brake horsepower says how you measure the power, not where you measure it": http://www.landsharkoz.com/tt/tthp.htm
Wheel hp on a dyno is still Bhp.

This one talks about the difference between the steady-state Bhp rating and acceleration hp: http://www.grapeaperacing.com/GrapeApeRacing/tech/miscpower.cfm

Grinder's link says it all:

"BHP and hp are not necessarily the same
So, the measurement method doesn't determine whether it's BHP or hp, yet we see many times that European BHP figures are often different from the hp specified in the USA. Unfortunately, each country has different "standards" -- that is, different definitions of the size, weight, mass, etc. of things. Through international agreements, some things have been agreed upon. One of those is the Watt. One which has not been agreed upon is the horsepower. One US horsepower for machinery is 745.6999 Watts. [Note, US horsepower figures for water and boilers are different.] One metric horsepower is 735.499 Watts, while one UK horsepower is 745.7 Watts.

So both BHP and HP don't say anything about where the power is measured. They're just different units for power (determined under different engineering standards like DIN or SAE). Comparable with the two " types" of gallons we know.

1 HP (DIN) = 0.98632 BHP (SAE)

Nice topic



:)

Odd question for you guys, but what is the proper pronunciation of "Hartge"? Is it pronounced "Heart-gey" (the "gey" being "goat" - "oat" + "key" - "k")? Or "Heart-guh" (guh as in "duh" with a "g")? Or is it even different than either of those two ways?

Grinder Asked
Odd question for you guys, but what is the proper pronunciation of "Hartge"? Is it pronounced "Heart-gey" (the "gey" being "goat" - "oat" + "key" - "k")? Or "Heart-guh" (guh as in "duh" with a "g")? Or is it even different than either of those two ways?Grinder it is the "Heart-guh" (guh as in "duh" with a "g"" which is correct.

alan fae bonnie scotland

Got word today that the John Cooper Works Conversion for the Cooper S will be a Dealer available option kit.I work for Bmw/Mini.Cannot give any further info at this time but will keep you in formed.Cant wait.