Interesting ScanGaugeII HP reading...

[pacodiablo]

I got a ScanGaugeII for my truck. I added the HP gauge following the directions on the ScanGauge website.

I took the truck out to give it a try, and the HP gauge got to a high of 179 HP. I did multiple WOT runs to see if it was a fluke, but each time the HP gauge had no problem going into the 160s-170s. Does anyone know how the ScanGaugeII determines HP, and why it might differ so much from Ford's 154 HP rating for my truck? The truck is bone stock mechanically.

 

[fixizin]

I don't know anything about this particular brand of OBD-II scanner, but since REAL measurement of HP requires the REAL PHYSICAL MASS loading (and UNloading) of the engine (checkout a REAL dynomometer), I have to conclude that your SG-II is just "making it up".

e.g. based on reading the firmware version # and vehicle type from the PCM, and using that to index into some limited/inaccurate lookup table of HP curves for various engine families, then using your realtime RPM (and maybe manifold pressure) to find a point on that curve and thus "report" it as your HP.

Pretty much useless... sounds like something their mktg. dept. forced their engineers to put in there, to make customers "feel good". I hope that's NOT why you bought this scanner. (How much $$ was it, BTW?)

 

[pacodiablo]

$160.

I got it for real time fuel economy, a trip computer, trans temp gauge, etc. Didn't even know I could add an HP "gauge" until last night.

From looking around online, the HP will read high on any vehicle. It isn't really clear how the ScanGaugeII comes up with its number.

However, the ScanGaugeII can read torque into the torque converter. It gets this data from the truck's own computer, so it should be fairly accurate. With that, it's easy enough to get actual HP.

 

[fixizin]

Oh... the dreaded AUTO tranny... that's gonna steal even more HP from where the rubber actually meets the road... you're gonna need that "extra" 20 HP at the flywheel... lol.

But you say the A4LD actually has sensors which can determine effective torque applied... veddy intuh-resting... probably a pressure vs. RPM thing... hmmm...

With that, it's easy enough to get actual HP.

Well then, I guess FoMoCo just made YOUR 3.0 a little bit special... a little bit better than the other 3.0 Rangers... yep, pulled it off the mass-production line, and ran it through the SVO shop... maybe twice... that must be it... yes, that would eh-splain it.

 

[fixizin]

Dude, I'm just funnin' with ya a bit. Enjoy your new diagnostic tool, but don't let it become a toy... be wary of the add-on bells and whistles is all I'm sayin'...

 

[pacodiablo]

No A4LD here...5R44E. Related, but far from being the same.

The torque going into the torque converter is a normal data item on many OBDII Fords, and probably many other vehicles. I'm not making that up at all. It's amazing what a modern vehicle can tell you if you have the right tools. ScanGaugeII is not using this to determine HP though...it's a Ford specific data item (the gauge I added will only read it from PWM Fords), whereas the horsepower gauge is a generic one that works on all makes. That's why I can't figure out how it is coming up with its numbers.

http://www.scangauge.net/features/

And if a ScanGaugeII won't cut it...
http://www.autotap.com/enhanced_parameters_ford.asp

With that, it's easy enough to get actual HP.

Well then, I guess FoMoCo just made YOUR 3.0 a little bit special... a little bit better than the other 3.0 Rangers... yep, pulled it off the mass-production line, and ran it through the SVO shop... maybe twice... that must be it... yes, that would eh-splain it.

I was saying it is easy enough for me to calculate HP ((torque x rpm)/5252), not the ScanGaugeII. It's HP gauge is clearly wrong...like I said it reads high on any vehicle. However, assuming the torque # from the truck is correct, you can plug it into the HP formula.