Scangauge and horsepower observations/question (1 Viewer)

[knorrena]

I recently got a Scangauge II. Its pretty neat. I programmed it to read horsepower. On dead cold startup, at idle (1100rpm) , it registered 19hp at -15*C. After being warm, it shows 9hp at 617rpm and 87*C. At WOT, 87*C with a supercharger it showed a whopping 327hp at 4598rpm (that observation was taken by flashing my eyes down at the SG). I know that this is brake hp:


"The horsepower is based on the engine parameters reported in real time by the engine. It is not acceleration based. Also, it is Brake Horsepower, also known as gross horsepower. Your car is probably rated in NET horsepower which takes the losses of friction, alternator, water-pump and other loads off the Brake HP. It is normal to see the indicated Brake horsepower higher than the factory Net rating because of this. If you have your engine dyno'ed, they will usually rate it in Brake HP like the ScanGaugeII reports."

Scangauge II - Toyota Owners Club - Australia

So what I would like to know is what are other folks registering? Does anyone have any idea what parasitic losses in terms of percent a cruiser might have? MY ass dyno is tellinjg me that at best my cruiser puts out 250-265hp at the wheels. Thats about a 37% loss of power though, which seems high to me.

Karl

 

[e9999]

I imagine that the only way they can get this HP info is from fuel or air consumption and then convert it using the fuel heating value (and perhaps air fuel ratio thrown in there too if from air values).

IOW, it's probably not too accurate in absolute terms, but likely OK on a relative basis. So I would take that with a grain of salt.

I'm surprised that they say that the nominal engine HP values usually given as specs are net and not the gross ones though. I thought the latter was the standard. Great, I just got a 100 HP psychological increase in my engine, and didn't cost me a dime!

And yes, the losses between the engine and the ground are huge!

 

[jfz80]

i thought its rated hp at the wheels was 287 w/ the s/c. I have also heard that through the transmission and all wheel drive 30% loss is not to far off a guess, their standard estimate is 15-20% on two wheel drive sports cars. There is a local performance shop here in town that is $45 for three runs but they have to be consecutive in one day, so i want to get some goodies before i go in and find out. Their facility is two wheel dyno only so they said to drop about 12-15% from my #'s for actual hp at the wheels since id have to drop the front shaft for the runs. Kinda uneducatedly backs up the 30% if you count 15% at each end. oh and waiting on my scanguage currently !!!

 

[PKP80]

How do you program the SG II to read HorsePower? Have one and would like to know for when I put it back in the 80.

 

[knorrena]

Follow these instructions:

ScanGaugeII - Add-A-Gauge™