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Old 04-09-2010, 11:04 AM   #208
ichitaka05
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Originally Posted by NESW20 View Post
i'm comparing their ENGINES. both are small displacement 4 cylinder engines currently available on the market. i was showing that Subaru n/a 4 cylinders don't necessarily have more "torque/L" than other engines. BHP is "brake horsepower" as measure at the crankshaft (on an engine dyno, with the engine not installed in any car, only on a stand in a shop/lab). you are thinking of WHP or "wheel horsepower" as measured by chassis dynomometers (the rollers that cars drive on). they are not the same. all car manufacturers list BHP in their spec sheets.



2wd and awd whp are different. bhp is bhp is bhp is bhp is bhp. the reason your example of the FR impreza had a higher HP rating after it was converted was because there was less drivetrain loss, so more of the engine's BHP was converted into WHP.

the only reason i chose the n/a 2.5L subaru engine is because they don't offer a high-output version here in the US, except the 3.6L H6. it has HP ratings of 256hp and 247ft.lbs of torque. that's 71hp/L and 68.6ft.lbs/L. that's their "high end" n/a engine here in the US.

but just to make you happy, here's the breakdown for honda's base level Civic engine: 1.8L I4. 140hp and 128ft.lbs of torque. when you do the math, it's 77.8hp/L and 71.1ft.lbs/L. Subaru still falls behind in the specific power and torque output.

i hope all of this makes sense for you. drivetrain has NOTHING to do with BHP, only WHP. you are getting the two confused.

-Mike
K, I totally mistaken the bhp & whp on that one, sorry.

Still, I've said that, do the current low model AWD/4WD NA Honda i4 engine (in US) vs current low model AWD NA Subaru H4 engine (in US) and compare the hp/l & tq/l. Comparing FF/FR vs AWD isn't really fair comparison.

I'm using current CR-Z, which is 4wd. They have K24Z1 engine inside & pushin' 166hp/161tq (from wiki) do the math and 69hp/l & 67tq/l. Looks to me, it's almost same hp/ & tq/l range as current Subaru engine me.
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