Virtual Dyno Room

[Billman]

Anyone fancy trying this HP calculator?

It's made for Evo cars but i think it can be a nice tool for estimates/comparison using logs (time vs RPM) something like the FATS database but more fancy.

http://evoecu.logic.net/mirror/VDR/VDR.v5.71.xls

original post was here:

http://forums.evolutionm.net/ecuflas...simulator.html

[Billman]

did some testing and seem pretty good. I will post later!

[Billman]

I gave the data of my old setup with 2.2 stock ADU engine, siemens 630 injectors, small HX40 (56/82mm compressor) with machined K26 housing and 1.3-1.35 bar boost going down to 1.2 at the redline

I suppose that it is not the most reliable rating but it is nice to make a small database or find out a correct correction to give comparable results.

[EspenW]

That is a brilliant find, Billman
With that program and a Vag Com cable (the £8 copy ones will do the job too), anyone can generate real life whp curves free of charge, at anytime they please. It even has weather correction, very nice.
Just go weigh the car first.

[EspenW]

I just tested it, and it sure works
One thing to be aware of is that the EVO datalogs seem to be running at close to 15hz, while Vagcom from our ECU's only sample approx 3 times per second, so 3hz. This can be somewhat offset by running a smoothing factor or 1 or 2, but spikes won't be recorded, as a result, peak torque and peak whp will be lower than if logged at higher resolution. Something like a VEMS log would be ideal, as I suppose thos log at far higher resolution than an OBD1 ECU.
My MR Dyno accelerometer based logger runs at 100hz, so it will log every single peak. I smooth this to around 37 for a smooth graph.

I did some Vagcom and MR Dyno logging last weekend, and put that Vagcom time vs rpm log into the Virtual dyno, along with weight: 3395lbs for my RS2 with half a tank, and 155lbs for me and my laptop. Also entered the gear ratios and FD: 1.32 for 3rd and 1.032 for 4th and 4.11 for FD. Frontal area is 22.4 and Cd is 0.35.
That, along with a 3rd or 4th gear Vagcom (or other logger) log is all that is required.
The Virtual dyno gave me 419hp at the wheels at 5987rpm. That compares rather well to the 418whp at 6050rpm that the MR Dyno gave me
A 4th gear log will be even better, as the rise in rpm will be slower and thus resolution better. Somewhat better results in 4th as well, with 434hp and 457ft lbs at the wheels due to better load on the turbo. I'll do a Vagcom log from 4th as well and see how that compares in the Virtual dyno.

The program is set up so that you can compare graphs from two runs, making ideal for judging the effects of mods, tweaks, etc.

[Mcstiff]

What is the frontal area? Drag coefficient of a Coupé/S2 is 0.36 Cd, right?

[EspenW]

Frontal area should be about the same as the RS2, but probably a little less, due to the deep RS2 spoiler.
I have seen others quote 0.36 for Cd, but that seems a little high, as the coupe body should be more aerodynamic than the wagon.

[S2central.net]

I have been playing with the VDR spreadsheet a little... seems to do a nice job.

Data I got for frontal area on a Coupe was 1.89sqm (20.3sqft) which is good bit lower than the RS2 number Espen sourced... I doubt the RS2 front bumper makes *that* much difference but anyway... what I will do is take an average of those two numbers for now = 21.35sqft

As for Cd - I too have seen 0.32 published here and there but that seems a tad low... maybe true for earliest B3 with skimpy bumpers and thin rubber. Again I will average at 0.34

What is interesting / annoying is that the comparison function doesnt seem to work when using 4th gear option but works fine on 3rd gear selection.

I got 330whp from two logs of a Vstreamed RS2 that I am currently working on...

I am going to try and parse the format of Zeitronix logs (pretty sure its winlog like) as that will give higher accuracy timestamps for RPM data than VAGCOM ever can - although I appreciate its not critical for a useful result from such tools like these as they do a nice job of smoothing and interpolating.

My own ballpark estimate of crank hp on this motor (based on how much fuel it is consuming at AFR=12, though this is very sensitive to BSFC assumptions) from same logs is in 370bhp territory so it is smelling about right.

[S2central.net]

Well ZT s/w can export datalogs to CSV but its really annoying that it doesnt export the complete timestamp - just gives time of day in hh:mm:ss

[Jamo]

Seems some guy swiped the code and made a rival product http://www.bradbarnhill.com/projects/VirtualDyno/

[Billman]

Can you please edit the first post with the actual link so people can find it easy.

[Billman]

Somehow I can't get it to work.

[A80Avant]

you need to have a car selected and our make is not even in there.
if i take your most recent run and put a bmw Z4, you have 850hp and 1100+ ftlbs torque.

not bad for a holset @ 1.3bar!

[Billman]

hahahahha....very nice.....I knew it's very fast! Thanks :-p

[Billman]

I am not able to see the graph