Rolling road v liquid gauge readings

[dippy4000]

I was wondering why there is a difference between the rr and liquid gauge power and torque outputs.

for example the car was stage 1 mapped in june on a hot day, on the rr it came out with 208bhp and 242 lb/ft, the liquid gauge today says 197bhp and 222lb/ft.

I have only done approx 1200miles since the map and the only change on the car since is a n249 bypass. could this be it or is it because the rolling road is just that, rolling with no risistance, not that i could see that would make much difference.

I have no faults on the car. any ideas would be great.

 

[Fl@pper]

5% difference if that by the looks

would you consider a liquid gauge as accurate as a workshop size dyno machine ?

how does it measure it ?

 

[dippy4000]

5% difference if that by the looks

would you consider a liquid gauge as accurate as a workshop size dyno machine ?

how does it measure it ?

I would assume the workshop being accurate yes, though i dont know how it comes to the conclusion. i think the liquid uses the maf, i will look at the instructions to verify.

 

[Fl@pper]

be interested to see what info it uses as i would guess it's all electronic but 5% considering dyno lottery is pretty damn close to be honest

double checked the bypass and pipes just in case ?

try it late night in some fresh air or with a load on and see if it varies ?

 

[dippy4000]

you can toggle between maf method and ecu torque method. I was using the maf one as this is the default on petrol engines.

 

[Fl@pper]

does it record or save any logs like vagcom or anything ?

 

[dippy4000]

double checked the bypass and pipes just in case ?

try it late night in some fresh air or with a load on and see if it varies ?[/QUOTE]


pipework all ok still maintaining 22 on the vac, and 18.5 boost peak down to 13.5 holding, same as before the bypass.

does it make a difference between 3rd and 4th gear?

may give it ago later in the cold clear air

 

[dippy4000]

does it record or save any logs like vagcom or anything ?

No its real time viewing on all aspects.

 

[ibizacupra]

so it replies on a known weak sensor for its figures?
good luck with that, taking it as gospel

same goes for block 120 measurement

its an indication..

 

[james walker]

mines pretty accurate, within 5 bhp. it takes maf readings for bhp output. as bill said, uses a weak point, but only really an indication... why would you want to know all the time, unless theres a fault.

 

[dippy4000]

I know its a guide, I understand how the reading is reached from the liquid, I dont know how its done in the workshop. I dont want to know what it is all the time also. Ihave just got it so was checking out its figures, and was wanting to know why the figures are diffrent. Being as im unaware how the workshop does the figures i wanted to know what the difference is so i know why!

 

[dippy4000]

why would you want to know all the time, unless theres a fault.[/QUOTE]


as map was done on a day that was almost 90 degrees outside, i was told that the figure would be higher when it cools,so was curious, felt a bit gutted when it came up less.

 

[freegeek]

Give your maf a clean and see if that changes the readings.

The liquid relies upon a good accurate maf reading, my readings recently went soft after installing a k&n filetr, I would avoid oiled fiters in future.