moregrip

iTrader: (8)

most obvoius thing wrong with this sheet is where hp/tq curves cross.

DrX

iTrader: (7)

Excel's graphing probably just messed it up a little. Looks like they cross at 5325 but that's not how I entered the data. Torque and hp actually are identical(318) at 5250 RPM as they always must be(I've been reading).

BigBlackAv

why is that?...I have heard that it was 5500, but still don't understand why.

camcojb

Because you actually measure torque and then horsepower is figured mathematically from the torque numbers.

Here's the formula: HP = torque times rpm divided by 5252
Once the rpm = 5252 then 5252/5252 = 1, canceling it out. That leaves HP = torque. HP isn't measured directly, it's mathematically figured from measuring torque over a period of time (rpms).

Jody

moregrip

iTrader: (8)

a dyno measures tq, hp is just a mathmatical equation.

moregrip

iTrader: (8)

someone finally posts the real number , instead of 5250, good on ya

DrX

iTrader: (7)

You will find a lot of articles on how James Watt came up with this stuff.
Here is one that also relates it to performance at the track:
http://www.vettenet.org/torquehp.html

Did you know that we now have a new horsepwer rating system for 2005?
http://www.sae.org/certifiedpower/details.htm
"SAE-certified horsepower
In 2005, the Society of Automotive Engineers introduced a new test procedure (J2723) for engine horsepower and torque. The procedure eliminates some of the areas of flexibility in power measurement, and requires an independent observer present when engines are measured. The test is voluntary, but engines completing it can be advertised as "SAE-certified".

Many manufacturers began switching to the new rating immediately, often with surprising results. The rated output of Cadillac's Northstar V8 jumped from 440 hp (328 kW) to 469 hp (350 kW) under the new tests, while the rating for Toyota's Camry 3.0 L 1MZ-FE V6 fell from 210 hp (157 kW) to 190 hp (142 kW). The first engine certified under the new program was the 7.0 L LS7 used in the 2006 Chevrolet Corvette Z06. Certified power rose slightly from 500 hp (373 kW) to 505 hp (377 kW)"

zippy

my guess is that the guy wasn't wide open at that point. as was said, he probably rolled into it to keep it from downshifting and that's why the graph is like that. i'm sure by around 3200 or so he was wide open. at that point it was just a brief second to peak the boost and then big power came on.

i agree about the rpm crossline. i'd bet that the torque line is scaled differently and he cut that out. i've seen that many times.

DrX

iTrader: (7)

Yeah, some of the other "unlocked" charts look similar. Probably brought it in gradually-no boost until WOT. Will try a locked 3rd gear pull when/if my EFI Live ever gets here.