DIY VAGCOM Road Dyno

[A4Ade]

Well i got some data out of the butt dyno spreadsheet, i have attached a pic showing the graphs.

Its a little lower on HP than i was hoping for but then its not the best power graph and the logging says the ecu was not reading full throttle either.

Hi phatso,

Thanks for putting up the log. I'll post my graphs for comparison with yours. First though, I need to know what mass you used for your car+you in your calculations.

Cheers,
Ade

[phatso]

I think i used 3600 lbs i will check when i get home, i accounted for Me,, the car and 1/2 a tank of fuel.

My total weight might be slightly off as i dont know if my mods (coilovers, bits here and there, brake conversion) are lighter or heavier than the stock items.

I will try and get the S3 on a weigh bridge if i can and then rework my graphs using the acurate weight, as well as getting a load more runs recorded.

I want to know which power curve from my 1st graph is more to the style of the car, the 2nd one looks like i would expect from a non turbo, the 1st one has the massive torque curve i would expect but it runs out a little early.

I also want to get some higher gear runs, but i dont know of a long enough straight, 3rd gear run takes the entire section i have to coast back down to below the starting speed.

Cant get the s3 on my local rollers as they only have a 2wd setup or otherwise i would do a load of runs on there logging them all to compare to the RR graphs.

[A4Ade]

I think i used 3600 lbs i will check when i get home, i accounted for Me,, the car and 1/2 a tank of fuel.

Ok, well using this weight, I get the following:



The solid lines (and the max values quoted on there) are from you 1st run. The max values from you 2nd run (which is the dashed lines) have max hp: 213.0 and max torque: 236.3

The graphs look a bit different to yours, but the two are pretty close to each other, especially the hp.

Ade

[phatso]

Nice one, thanks for working them out, i must have put something odd in the calculations for my 1st graph.

I take it the figures here are power at the wheels, as the s3 is 210hp (crank hp) stock and mine is running more boost, i have no idea what % of power is lost in drive chain losses on the quatro system.

[Billy Bob]

I have just logged some data for you, i have tried putting it into the butt dyno spreadsheet but it wont draw the graphs for me.

I have attached the csv from my logging session, there is a lot of random data in there as i was doing some test logs while i drove out to the long straight i used for the runs.

I did 2 3rd gear runs upto 6k rpm in the S3, One each way down the same straight. If you could let post up the graphs after working them out that would be great.

The S3 is running 20psi with a MBC with a full custom remap, re circ valve, air filter and miltec full system with sports cats.

Looking at the logged file it says i was only using part throttle even though i was sure it was flat on the floor, I might re cailbrate the TPS, (throttle)

I think the 1st run is roughly lines 1325 to 1555 and the 2nd run is line 1602 to 1793

Did you ever solve that "part throttle at full load" -mystery?