those sounds like a lot of variables to have to get right in order for this thing to be accurate. I stick by my original anticipation of failure.

 

This. How close can a free phone app really compare to a 50 thousand dollar dyno?

 

probably comparable to any 50'000$ dynos since all dynos give different numbers for the exact same car.

 

Here is a better question...Why do the $50k+ dynos all read different? For $50k which is the cheap model or 2WD you would think that they would read within a few HP. $50k for testing equipment that is not really accurate, kinda sucks. Remember a Dyno is just a tool, the number it spits out is irrelevant. The curve of the power band is much more important to look at, but really your just using the dyno to hold the engine at a certain load so that fuel and spark can be adjusted. Time slips are a 1000x better comparison, car to car IMO even though drivers are all different.

 

exactly what I thought but didnt want to write it all up. Dynos are tools to help you fine tune your car. Hps and trq numbers are irrevelent. One dyno will say 350hp and the next one 395hp.

 

Yep, my big wheel made 700whp with a correction factor of 160 and smoothing set at 140.

 

I see a lot of people don't understand how dyno's work. even a real dyno has hundreds of variables that can change the results if even one of them changes. everything affects everything else. that's not the point. the point is that a dyno on a given day, with a given set of controlled variables will produce a similar result, and give you an accurate measure of what your car is doing given those variables. a free phone app given the same set of variables will most likely not give you anything accurate because of the amount of variables that you have to guess, and hope you get right in order for it to work.

also, dyno's are used to show gains in power when you mod. the number's are not important. the increase over baseline is. also, all dyno's read differently because not only are their variables with the car, weather, atmospheric conditions at the time, etc, but also with the dyno and how it's calibrated. whether it's a load, or no load dyno, and how it's parameters for measurement are setup for a given run. '

back on topic, phone apps are failures. if you want a pretty accurate measurement of power, take it to a real dyno, or use your evoscan logs to plot a chart on virtual dyno.

 

I don't know about others, but I can assure you, I don't need a lecture on how dyno's work. Yes there are other things such as atmospheric pressure, rolling resistance, load bearing, humidity, altitude, location etc. Id like this not to turn into another "dyno" war. Unless you're a tuner it would be nice if you weren't regurgitating information from others. I have read a lot of forums where these apps have been with in 10whp of their dyno sheets where they have done multiple runs with the app. There are values that you have to guess, but tuning the stupid cheap app can make it close enough for me to enjoy. I never stated that I am going to get anywhere near a 100% reading, that this app will be accurate per run, or be able to calculate variables due to climate conditions. I am not going to use this app to tune my car. It was something that I wanted to play around with. Would be nice if you weren't so negative on the subject. Yes and what you said a "similar result". You can get a "similar result" out of a stupid phone app. If the app is scripted properly I could see getting relatively close to something like a G-Tech pro. Honestly I really made this post so I can get any variables from someone who has used it before. I've already spent a few hours looking up the mathematics for frontal area. I have most of the parameters I would assume around 97% accurate, which is like I said "good enough". If it turns out to be crap then it's crap. If it works, hey I have something fun to play with.

Back on the topic, PLEASE... I didn't get a chance to play around today since my lifting partner wasn't feelin it. I'll make an attempt tomorrow.

 

I will have to check this out, as I have been looking for something like this for my phone. will be awaiting results to see how this turns out or whether it is worth downloading.

 

I wasn't talking about you. I was talking about the guys questioning dyno readings.

 

I wasn't questioning dyno readings, I get it, doesn't mean I cant laugh at it. I have read "Dyno Testing and Tuning" by Harold Bettes & Bill Hancock, I understand Dynamometers just fine.

When you have your engine calibrated are you more concerned with the HP and TQ it produces or tuning for MBT and correcting A/F?

 

I just did a couple test runs with my buddy after the gym. I was a little worried about getting a ticket.

The software read 289whp and 276 ft-lbs. Which my buddy saved it but for some reason it's not in the logs. I'll do it again and take a screen shot right there when I get the chance. The second run was 293whp and 320ft lbs. The problem I am having is my suspension being so stiff which creates a lot of vibration. I had my buddy hold the phone directly on the dash at a 60 deg angle roughly. The dyno graph looked very similar to mine. If my car had smoother suspension I think it would be much more accurate. Looking at the graph the 289whp\276 is more like 285whp\268ftlbs if you were to smooth it. The one with 320 is because there was a spike when I hit 1 small dip in the road.

I calculated out that fuel in 70 deg is around 6.25lbs per gallon. Which it is colder here so the fuel will be more dense. I estimated 90lbs on a 14 gallon tank. I'm sure with some tweaking I could get this software much closer. I also could not do a 2nd gear pull, for some reason it seemed to be too short of a pull from 17mph to 60mph. I had to run 20mph to 90mph in 3rd gear to get the best reading. If anyone tries this the roads MUST be smooth, the phone must absolutely not move. If the phone shakes at all from not being stationary it will not work. I really wish I could post up the graph but I have no idea wtf happened. Would be nice to show all the stats that it calculated. Either way gives me more time to play with it. I need a mount because I cannot do this with out a passenger atm.

 

I was playing with this a while back, I kind of just lost interest. Here is a link of how I solved your problem.https://www.evolutionm.net/forums/ev...one-mount.html