Virtual Dyno

[JoRoW99]

Anyone use this before? At first i thought it would be good for tuning to see if you gained power, but after doing back to back to back runs without changing anything...well ill let the picture talk for itself.


But heres a comparison between me before and after E85, holy crap lol.




These guys seem to think its accurate
http://innovativetuning.wordpress.co...-virtual-dyno/

[matt5112]

Repost?

Also if the road isn't level, and the speed is over 50 mph, all bets are off.

You can create similar charts in HPT using dyn air calcs and so on.

[JoRoW99]

Well you dont really want to do it in any other gear than 2nd, and i think it does account for drag somehow since its listed. My only problem is i dont know the weight of the car so i just put in 3700 + 200lb driver. This was also on a very flat nebraska road. I have also checked my HUD speedo vs one of those radar speed signs and its pretty spot on.

Its really more of a toy or a comparison for big mods, i.e. changing power adder, maybe cam or something. If you put it on 0 smoothing it just looks awful. Thats why i did 3 back to back runs to see how consistent it was, but whos to say that wasnt just my car.

[matt5112]

356 virtual HP vs 267 WHP STD.

[JoRoW99]

I think youre referring to the other thread, but i really never know what youre referring to half of the time lol.

[JoRoW99]

In that link, those guys have been within 5 hp on multiple cars. I think one of the reasons for the variance in my runs were that all of them were done on different stretches of road. They are on the same road, just one going one way, one going the same way about 1/8 mile down, and one going the opposite way.

[matt5112]

Sometimes its in the right area (267 WHP STD, what I dyno'd at) and other times its way off.

In one run it claims 400 HP.

In another 376.

In another 244.

[JoRoW99]

Did you have correct weight, temp, baro? multiple runs?

[matt5112]

Yes, yes, yes, tried both ways.

[JoRoW99]

Maybe the dyno was off, LOL jk.

[matt5112]

I've checked using my own math and the dyno was dead in the middle of my estimates.

[Fivefingerdeathpunch]

1 million hp here.

[Explicit_Spade]

[bbarnhill]

I see you guys are using the software so I registered on the forums ... Im the creator of Virtual Dyno and just wanted to say hi and clear up anything I could.

I promise you its accurate. Its as accurate as the logger thats logging the logs (now Ive learned that some loggers are HORRIBLE and give the user data thats just flat wrong [ex. RomRaider with fast logging enabled] ). It has been proven over and over again. Ive tested it on numerous vehicles and its been tested by critics with dynos. Its awesome even with a dyno to do street tuning after you get a dyno tune. Dyno tunes need to be touched up on the street under real world conditions as can be told to you by some of the largest tuning companies out there (I know I used to work for one).

NOW ... it does rely heavily on the user to get good logs on a good road. Some loggers require much more smoothing than others. Oh and the smoothing 0 will be horrible on every logger pretty much. Its only in there to find massive spikes that are hidden by smoothing. So if someone has a large gain in power in the graph that looks a little suspicious you can always flip it on smoothing 0 to see the massive spike. Im betting thats what FiveFingerDeathPunch encountered. Those can be caused by wheel spin or a slipping clutch or any drive train slippage of any kind. With that in mind keep in mind that torque converters come into play here.

Im here if you need help or if you need me to look at something that you think is a problem.

[silvapain]

I'm a new guy to this forum, so take my opinion however you want, but I use VD when tuning my other car (2007 MazdaSpeed 3) and Brad's software is very good and very accurate, providing you input accurate parameters and you log on a flat, level road with minimal head/tail wind.


Tapadatass

[matt5112]

I take it this only calcs acceleration then works back to torque required back through gear multiplication then using engine speed calc hp?

[mechguy]

Show us the "0 Smoothing" plots. I wonder how often it samples data during the run.

[JoRoW99]

Thanks for registering bbarnhill. Is there any way to get the dyno to have more data points? it seems to have maybe half or less of the data points that i got from HPTuners.

Also, as i said i did 3 runs back to back and got a somewhat wide variance in HP (these were not on the exact same stretch of road, but the same road) what else could cause this? maybe i should try doing it on the same stretch of road 3 times. It would probably help if i was on smoothing 2. Im also wondering where you got the drag coefficients and weights from, because IMO 3450 seems low for a GP.

[bbarnhill]

It trims the data rate to about 1 sample per 100 rpm so its RPM based not time based.

Any difference in road can show differences in power. Id repeat comparable tests on the same stretch of road.

If there is a concern with the curb weight of the vehicle show me a place on the internet that has the correct ones and Ill make sure they are correct. Thanks for the help and the feedback.

[matt5112]

No smoothing:



Smoothing factor of 1:



Smoothing factor of 10:



Remember the car made 267.

I can provide screen shots of the vehicle speed curve which clearly shows acceleration falls off near the top of the gear as you would expect for a car with an M90 and rockers. This also suggests torque is falling off, yet this program suggests the opposite.

Here are the same graphs with third gear pulls as well:







If all you're looking for is change in performance, just calculate average acceleration.

Also which tire diameter is this thing supposed to use? Actual or theoretical? Doesn't specify and automatically selects theoretical.