Noob question about hp....

snizzle

newbie to the forum. joined because a buddy of mine let me borrow his 350z while he was out of town the other week, and i had a blast driving it. i loved it so much im now thinking about getting the 370. i love just searching through all the forums and filling my head with all the knowledge.

heres the question: ive been reading in the exhaust and tuning forums looking for ideas about mods and hp figures vs overall cost. i see alot of ppl talking about getting their 370 up to like 285-hp or so with the k and n or whatever their CAI choice was. now nissans website says the '12 370 base comes with 332hp. so why the difference between the stats from nissan, and ppl talking about the increase they received from whatever bolt on they acquired being drastically lower than what nissan says the car comes stock with?

thanks.

Face

332 bhp (brake horsepower) is made at the crank (engine output). Once you transfer that power through the transmission and the drive shaft you're looking at an average loss of 15% hp.

So when people talk about 280 or 300 hp they're talking about rwhp (rear wheel horsepower) The power that actually gets to the pavement and moves the car. With a 15% loss, the 370Z puts out 282.2 rwhp

No worries about the n00b question, the only reason I know is because I asked once.

Advertised horsepower is always brake horsepower.

CC_370z

'09-'12 are all 332bhp (base hp). People who got 285 on dynos are call whp (wheel hp).

You lose hp from the crank to the wheel.

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joshs09slvrZ

That's because the sticker HP is at the flywheel and not at the wheels. A stock 370 has around 270-275 HP at the rear wheels and with the K&N, they are saying they're getting about 10 extra HP at the wheels.

You can never really go by what the sticker says. Best way to know is to get the car dynoed!!

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ZSIZZLE

the factory ratings are from the crank taken with an engine dyno(bhp=break horse power, when we measure we use wheel horse power taken with an chassis dyno. the number is lower after drive train loss, every time the power is transferred you lose power (diffs,tranny)

snizzle

makes sense. thanks for the replies. here is an example of one of the threads i saw that just totally confused me on these figures.......

"i have k&n intake for 370z. i dynoed 4whp gain, forgot how much torque gain. but if you search it up, i posted a dyno sheet. i was on a uncalibrated mustang dyno so readings are extreamly low. stock 370z is dynoed at 218whp.

i didnt go with G3 because filter changes require bumper removal. basically if something wrong with intake you have to take off bumper. and i think i read that G3 intake affect AC lines but the problem was solved."

edub370

now 218 is waaaaaaaaaaay on the low side, but i think u get the diff between crank and whp. most people see anywhere from 275-305

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Vince

In this case, the low horsepower was due to the Mustang dynamometer that was used. Mustang's show lower numbers than say, a Dynojet, would show on the same car.

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-Vince
2012 Nissan 370Z Pearl White/Persimmon Touring/Sport/Nav 6MT
370Z Production Statistics - VIN Lookup Utility

wilsonp

Because dynos are all different, before and after so you see the change (in this case +4hp) is what really matters.

And if you're really picky, the change in the curve and not just peak is what really, really matters.

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