Recently, I’ve spent some time evaluating a new piece of software, Virtual Dyno.
To borrow a familiar phrase, “I’ve tested it…..now I test with it”
The whole premise to the program, is to be able to take data that you would normally log during tuning & generate a dyno chart from it. By being able to calculate the rate of acceleration of a known mass, it functions very much like a chassis dyno. Just in this case the known mass is the vehicle & occupants rather than the mass of the dyno’s drum.
I was a little skeptical of how accurate it would really be, but decided to spend the time to evaluate it anyway. Boy was I surprised! I took several of the datalogs I have from customer’s cars & ran them in Virtual Dyno. I then compared the results to what those same cars actually put down on the dyno. I was surprised by the results!
Rob O’s Cavalier Z-24. Virtual Dyno generated results of 126 whp & 126 ft/lbs. Actual dyno result 127 whp & 127 ft/lbs.
Jean F’s Sunfire. Virtual Dyno generated results of 238 whp & 211 ft/lbs. Actual dyno results 239 whp & 204 ft/lbs.
Paul K’s Z-24. Virtual Dyno results were 156 whp & 133 ft/lbs. Actual dyno results were 153 whp & 134 ft/lbs.
As you can see, the results are extremely close. Two consecutive chassis dyno runs would have more variance than the difference between Virtual Dyno & an actual chassis dyno.
Additionally, if care is taken to do your dyno runs consistently on the same stretch of road, starting at the same point on the road, starting at the same speed etc., the results from Virtual Dyno are very repeatable, enough so as to allow evaluation of changes to the tune in the vehicle.
With this in mind we will be using this as a tool in the future to generate dyno charts for our customers. I will also be updating the Customer Rides pages for those where I have datalogs with the appropriate info.
Update Feb. 20.
Took a 2006 Pontiac Grand Prix out & datalogged it to see what Virtual Dyno would have to say about it.
This car is absolutely bone stock. GM rated the Series III 3800 V6 at 200 hp & 230 ft/lbs, so with a 20% drivetrain loss the car should put out approx. 160 whp & 184 ft/lbs.
So what were the results? 155 whp & 183 ft/lbs. Yet another result that appears to be right on the money!
Update June 7,2011
Took a brand new 2011 GMC Sierra (with only 800 kms on the odometer) out today to see what virtual dyno had to say about it. This truck is equipped with a Vortec 4300 V6 that GM rates at 195 hp, & 260 ft/lbs. If you assume a 20% drivetrain loss (this is a 2wd truck), then this truck should make approx. 156 whp & 208 ft/lbs at the rear wheels.
Here are the Virtual Dyno results. 160 whp & 212 ft/lbs.
As a side note, there appears to be quite a bit of power left on the table with the tune in this truck. With any luck we’ll have a chance to see what can be squeezed out of it with a custom tune some time in the near future.
For the details on how the tune for this truck went, click here. http://innovativetuning.wordpress.com/projects/our-2011-gmc-sierra-4300-vortec/
Update Mar. 4, 2012.
We spent some time today with a 2008 Civic LX with an R18 engine & automatic. Originally the purpose of spending some time with this car was to confirm compatabilty of our new software & interface with Honda’s, but we figured if we were doing some runs anyway, we may as well kill 2 birds with one stone. The owner wanted to find out if a K&N high flow filter would be of any benefit. So we did 2 runs with the stock filter in, then 2 runs with the K&N in. As I’ve come to expect,Virtual Dyno was an invaluable tool & worked flawlessly. Our new interface is also working flawlessly with every vehicle we’ve used it with.
Here are the results of our afternoon.
122 whp & 115 ft/lbs. Those numbers are right in line with what this car should run with its minimal mods (cat-back exhaust)
Reviewing the datalogs afterwards revealed that, while the K&N did actually flow more air, the car ran 1 – 1.5 deg less timing with the K&N filter in, negating any improvement in power. The first instance we’ve encountered that a K&N alone offered no improvement.
Update Sept 28, 2012.
Evidently we are not alone in our enthusiasm for this software!
Update Dec. 2, 2012