Dynolicious

[Petrina Polo]

I think that there is no such thing as a percentage drivetrain loss..

A gearbox uses up X number of Kw, drive shafts same etc etc.. whether you have 100kw or 200kw the gearbox, driveshaft will reduce by the same power..

hence as you up the power... the drivetrain loss becomes less and less as a percentage but the same in real terms of how much it reduces by....

So adding an extra 40kw at wheels is probably only adding an extra 40-45kw at motor. not as some people like to think an extra 40kw +(20-30%) drivetrain loss..

[Timbo]

Interesting theory. So you suggest drivetrain loss is an absolute value rather than a relative proportion. How would you explain that using the the laws of physics, which state quite clearly the relative relationship between force and motion, and the increasing effect of friction to, say, speed?

[Y2008]

as Timbo said it's not quite as simple as that. But I just think there are too many variables and the fact is we can't get out engines dynoed. But anyway who cares about drivetrain loss if we all compare wheel horse power. I think it would be interesting to know a stock polo gti's wheel horse power. I think the one that would make a difference with dynolicous is the weight. We should pick some reasonable weight and stick with it (car+3/4 full tank+75kg driver) just so we can minimise the variables.

[shaneth]

as Timbo said it's not quite as simple as that. But I just think there are too many variables and the fact is we can't get out engines dynoed. But anyway who cares about drivetrain loss if we all compare wheel horse power. I think it would be interesting to know a stock polo gti's wheel horse power. I think the one that would make a difference with dynolicous is the weight. We should pick some reasonable weight and stick with it (car+3/4 full tank+75kg driver) just so we can minimise the variables.

i have it also, get the weights and stuff and illput the same ones in. as for drivetrain loss with this program as i read it if you left it at 0 itll give you atw figures.

off there site.

Enter Weight and Drivetrain loss by tapping on either of these items. These parameters are used in horsepower calculations.

* Enter the weight of your vehicle, including occupants and cargo. The units for this default to lbs, but if you prefer to use kg, this can be selected from the setup screen.
* Enter a value for drivetrain loss. Drivetrain loss is a value which is used to generate an estimated engine horsepower figure from the measured wheel horsepower. This number varies by vehicle and is not generally published anywhere, as it is just an estimate and dependent on many factors.

mounting

The iPhone or iPod Touch must be aligned with the direction of travel. This means the screen must face toward the back of the vehicle, and the device may not be turned left or right. It may, however, be tilted up or down, at any angle from horizontal (screen facing up) to vertical (screen facing towards taillights).

[RoSonic]

Doesn't a dyno measure the power loss in the stage when (after reving up) the car is left without throtle until it stops?
if so, I think a difference in power output wouldnt affect this measure... giving the same power loss at a specific RPM.

[MACCAA]

Stock Polo GTI's generally produce about 95kw at the wheels.
I weighed my car on a weighbridge and it was 1220kg[cloth trim,no sunroof,1/2 tank fuel]
Having said that,anyone who takes seriously the figures from something plugged into their cigarette lighter is on drugs....
Cheers
Len

[shaneth]

Having said that,anyone who takes seriously the figures from something plugged into their cigarette lighter is on drugs...

Taking serious and having some fun are 2 different things.

[Y2008]

"Curb weight (US) or Kerb weight (UK) is the total weight of a vehicle with standard equipment, all necessary operating consumables (e.g. motor oil and coolant), a full tank of fuel, while not loaded with either passengers or cargo.[1][2]

This definition may differ from definitions used by governmental regulatory agencies or other organizations, for example, many European Union manufacturers include the weight of a 75 kilogram driver to follow European Directive 95/48/EC.[3] Additionally, organizations may define curb weight with fixed levels of fuel and other variables to equalize the value for the comparison of different vehicles." courtesy of wikipedia.com

The only weight that keeps coming up for the Polo GTI is the 1190kg figure. So i guess if we round it up to 1200kg + 75kg (driver) that should give us some comparative figures.

[Y2008]

Since i take nothing seriously then that shouldn't be a problem but to justify the 15$ i payed i think the least i could do is minimize the variables.

[pologti18t]

why does everyone get narky when I repeat what is well known. A DYNO is only usefully for comparing cars or comparing modifications to A car.

You can take the same car and run dyno tests on different dynos and literally get quite different results.

So... I have little time for people who say "my car got 126.3kw on the dyno". It means nothing.

If they said...My car recorded 110kw before the mod and 117kw after the mod I would be more impressed. Thats what a dyno is for. Not for silly bragging rights. Its a tuning tool.

[Y2008]

why does everyone get narky when I repeat what is well known. A DYNO is only usefully for comparing cars or comparing modifications to A car.

You can take the same car and run dyno tests on different dynos and literally get quite different results.

So... I have little time for people who say "my car got 126.3kw on the dyno". It means nothing.

If they said...My car recorded 110kw before the mod and 117kw after the mod I would be more impressed. Thats what a dyno is for. Not for silly bragging rights. Its a tuning tool.

Who could disagree with that. And as a matter of fact I don't think i would take my car to get dynoed except as a participation in a club or social event as i don't race it or tune it myself. I don't even have my car modified in any way yet unless tinting and the sharan antenna would have a miraculously given me me wings.....or was that red bull
All i can say is, i love gadgets and i love my car and there is this lovely gadget called dynolicious and it gives me an excuse to play with my lovely car. How can i not be interested in that.

[RhysQ]

get the weights and stuff and illput the same ones in.

We should pick some reasonable weight and stick with it (car+3/4 full tank+75kg driver) just so we can minimise the variables.

i went to the tip in my car with 2 passengers (myself = 86kg, 'the gf' = about 48kg), 1/4 tank of fuel and i weighed in at 1,320kg from memory.

So... I have little time for people who say "my car got 126.3kw on the dyno". It means nothing.

If they said...My car recorded 110kw before the mod and 117kw after the mod I would be more impressed.

what about those that use a dyno for the first time, you couldn't give a rats what figure they get??... pretty harsh really.

I used two different dyno's on two different days in two completely different weather conditions and i got 122.2kW first go and 123.8kW second go. It was a colder day on the latter test and I was first cab off the rank (8am, compared to 2.30pm on the first test in searing heat). I know there are discrepancies but that seems pretty damn close to me.

I know dyno's aren't 100% accurate but if that's all we've got to go off, it seems pretty good to me.

[Y2008]

So i guess 1275kg seems about right.

[Y2008]

Stock Polo GTI's generally produce about 95kw at the wheels.
I weighed my car on a weighbridge and it was 1220kg[cloth trim,no sunroof,1/2 tank fuel]
Having said that,anyone who takes seriously the figures from something plugged into their cigarette lighter is on drugs....
Cheers
Len

I went for a drive and tried to test it. Was quite hard testing in while staying on the right side of the law. Had a few runs where it didn't record the data properly as the car was moving when i hit start but i managed to get on run where i stopped, pressed start and went. And to be honest i was impressed, as the data made a lot of sense.

[Y2008]

seem like its not as hit and miss as i thought it would be.

http://www.youtube.com/watch?v=0-DFbJQbeSY