Just how accurate is the AP's reported "estimated" HP/torque numbers?

[danbfree]

I completely forgot that they were available and just now tried them for the first time... just a couple little acceleration got me 262.6ft/lb's of torque but with just a drop in and Stratified tune that seems a little high! LOL... I mean, I know there is a big spike at the beginning and goes down from there anyway, but still...

 

[redmoe]

I have only used vdyno to compare tunes. If it wasn’t a full 3rd or 4th pull I doubt it gives a reasonable output. I would assume that the Cobb calculation uses the same input parameters as programs like vdyno using rpm, gear ratios, tire size, weight and drag to calculate hp and torque.

 

[danbfree]

I have only used vdyno to compare tunes. If it wasn’t a full 3rd or 4th pull I doubt it gives a reasonable output. I would assume that the Cobb calculation uses the same input parameters as programs like vdyno using rpm, gear ratios, tire size, weight and drag to calculate hp and torque.

Well, I hit 213 HP and 278 torque on the way home from work where I get some nice country roads for full 3rd gear pulls... Is it safe to assume that this is crank HP and not wheel ratings? It must use all the engine monitoring inputs to come up with this figure... interesting to see with AC on at idle that torque is higher as more is needed to be made, but I turned off AC before my pulls.

 

[Beans]

It would all depend on the dyno. The estimated tq numbers are just about bang on(within 2% or so) with what my car has put down on my local dynojet.

 

[Sakel]

my stage 1 car with an OTS tune has gone as high as 270 lbs of torque which I find hard to believe.

 

[brbauer2]

I can't find a post I made in my local Facebook group, but iirc HP and TQ were within 5-8% between vDyno and the AP values.

 

[Beans]

my stage 1 car with an OTS tune has gone as high as 270 lbs of torque which I find hard to believe.

It's just a big torque spike. My car did that, too. You can see it on a dyno, as well.look through the dyno thread and you'll see lots of people with this going on. Usually it's in a higher gear (such as 4th) under high load, probably around 3000rpm.

 

[ProDigit]

Correct values need to be measured at 1:1 ratio. The closest to this, is 4th gear at a 1.03:1 ratio.
3rd gear will get you a higher torque readout; since 3rd gear is at a 1.36:1 ratio.
You'll have to divide the 262 by 1.36 to get the right torque, which is about 193 LB ft of torque; which sounds about right.

If you would have measured torque in 4th gear, the values might be a little higher due to higher efficiency.

 

[redmoe]

The ap is using the current gear data from the ecu so the denominator should be correct. Fuel level and passenger weight coupled with aerodynamic assumptions and road variations will play into the inaccuracy. 4th will be more accurate as like mentioned before it is closer to a 1:1 ratio. The 1:1 helps to reduce the compound error from the other variables.

 

[danbfree]

Interesting, I think I will try accelerating gently up to fourth gear then give it the beans and see what I get then, I had no idea it could be that close to accurate, I wonder what they assume loaded weight to be...

Sent from my SM-G930P using Tapatalk

 

[redmoe]

Vdyno will give you a more reasonable result as you can account for temp and weight. It’s a free windows utility. The preset ap data log pids should get you the necessary items to load into vdyno.

 

[koozy]

this topic seems to reappear often, the answer hasn't changed since 2014.

http://www.fiestastforum.com/forum/...AP3-torque-gauge?p=45213&viewfull=1#post45213


"The torque monitor is an estimation based on the calibrated torque to load and load to torque tables in the ECU. There are several compensations and modifiers that are integrated into the model, so it will only be as accurate as the model itself. Since there are so many other functions that rely on the accuracy of this model it can be challenging to maintain the accuracy without doing extensive calibration with the right tools. We've found that the stock model values work well on the stock turbo but will not be accurate on upgraded components. At that point it's better to ignore this value and tune the speed density system to ensure accurate fueling and load calculation.

Cheers,
Braden @COBB"

 

[Brickell FIST]

http://www.fiestastforum.com/forum/...-Cobb-Horsepower-estimated?highlight=Brickell

Hope this helps

 

[danbfree]

http://www.fiestastforum.com/forum/...-Cobb-Horsepower-estimated?highlight=Brickell

Hope this helps

Yeah, that's interesting! I JUST got my updated Stratified tune and I'm curious now... I need to not be so lazy and just use vDyno and it the back roads late at night to get a fairly accurate picture.