How accurate is the Cobb Horsepower estimated?

[Brickell FIST]

All,

Just wanted to see how accurate this monitor is. Also, does anyone know what the LTFT STFT should be when running E30.

Thanks

 

[Ltsprty15]

Where do you find the estimated horsepower gauge? I only see torque on mine.

 

[felopr]

All,

Just wanted to see how accurate this monitor is. Also, does anyone know what the LTFT STFT should be when running E30.

Thanks

"while tuned, is not really all that accurate, only stock" someone at cobb say so, way back, i dont remember
LTFT and STFT shouldnt be look per one type gasoline, if your tune is on point , it should always be 0, but realistically is never going to be 0 ,is going to swing back and foward
if you have a e30 tune you should be close to 0 but if you have , lets says, e20 on a e30 tune stft and ltft are going to go up to compensate, i hope this helps

 

[Brickell FIST]

Ltsprty, you might need to update your Cobb’s firmware.

Felopr, thanks! When would the values above be dangerous. Would one be able to see if they should add more E85 if the values are off?

Is turbine exhaust flow more of a accurate estimate on hp when on the move?

 

[felopr]

Ltsprty, you might need to update your Cobb’s firmware.

Felopr, thanks! When would the values above be dangerous. Would one be able to see if they should add more E85 if the values are off?

Is turbine exhaust flow more of a accurate estimate on hp when on the move?

A good rule of thumb is that +10 and - 10 should be ur max /min values at wot

 

[MitchsFiesta]

You can make them say pretty much whatever you want. It takes the Load Actual, puts it in the weighted Load to Torque table and uses torque and RPM to calculate HP (this is at the crank). The OTS Cobb tunes are more accurate for the Fiesta than say the focus, where cobb went and simplified them, whereas the Fiesta LTT tables are stock in the COBB OTS. Im not positive but there might also be scaling based on how far timing is from MBT and AFR. I don't really use estimated HP when tuning.

LTFT should stay in the plus or minus 10% range. The STFT is going to be a little more wacky but during non transient states (no change in pedal) it should also be within 10%. e30 or gasoline, shouldnt matter. They will most likely be a little more wacky on e30 as your ethanol content is usually not exact, so its making up for ethanol content on top of your normal fuel trims.

 

[brbauer2]

brbauer2

Decided to test it out.

Here is a V-Dyno of a 3rd and 4th gear pull.

Here are the Peak HP and Torque on the 3rd gear pull from the logs uploaded to datazap.

COBB estimates were 10% lower HP and 6% lower Torque from the V-Dyno results.


And the 4th gear pull.

COBB estimates were 4.5% lower HP and 4% lower Torque from the V-Dyno results.

Take these results with a grain of salt...it's only 2 data sets for something that has lots of variables.

 

[Brickell FIST]

Thanks for testing it out! Great post. Much appreciated.

 

[Kalter]

Decided to test it out.

Here is a V-Dyno of a 3rd and 4th gear pull.

Here are the Peak HP and Torque on the 3rd gear pull from the logs uploaded to datazap.

COBB estimates were 10% lower HP and 6% lower Torque from the V-Dyno results.


And the 4th gear pull.

COBB estimates were 4.5% lower HP and 4% lower Torque from the V-Dyno results.

Take these results with a grain of salt...it's only 2 data sets for something that has lots of variables.

Basically, from your experience, we can probably conclude that Cobb's reading is under estimating WHP and WTQ.

I thought it was over estimating because I'm running Cobb stage 2 and I usually over around 220 estimated HP (seen as high up as 230) and 260 estimated TQ (seen as high up as 280).

As you said, everyone results may vary, but I find it interesting that it would under estimate by as much as 10%.