An interesting little ap popped up on the iTunes ap store for your iPhone or iPod touch: Dynolicious

It uses the built in accelerometer to do performance measurements, like 0-60 or Quarter mile times and skid pan gs. It'll even estimate your effective horsepower, though it thinks Tristan only has 50HP, so I'm not convinced of that. Its fun, but I also found out 2nd is just short of 60mph, so I haven't got a 0-60 time yet. The 0.95g on the freeway on ramp is interesting though.

 

ouch $12.99

 

Trying to get it to calibrate but it's taking a long time. No information on how long calibration should take.

 

It took very little time for me. In fact it took too little time, I'm still reading the prompts and it thinks I've done that. You stand it on end, it beeps, you lay it on its side, it beeps, you stand it on its head, it beeps, etc.

 

It starts on end like you said, then beeps, then I turn it on it's side and it just sits there, no beeping.

 

Compared to real world dyno costs of...???

 

Yeah, how an $12,99 be ouch? I spent $300 on my GTech and now my iPhone does the same thing...geez!!

This is the bargain of the century

 

It is a fun tool. Worth it for 13 bucks. Like DrPhilGandini said, it does the same thing as the gtech devices.

 

I'm really interested in this software. I'm sure one it is calibrated it is at least close to the accuracy of a G-Tech.

$13 is a steal.

 

Anyone understand what the "rollout" options for speed tests and distance tests are?

I've left them at default settings, but it would be nice to know what they mean.

I've seen the drivetrain losses argued in dyno threads, but does anyone have a suggested percentage of loss from an R53 MCS? (manual transmission) I'm using 15%

 

I bought this and my friend has a G-Tech. We'll be doing a comparison soon. I'm looking forward to the results

 

subscribing!

 

I have a GTech, so will do some comparisons.
The roll out is the distance the car moves before the device starts to read--sort of like how far you are away from the line at the dragstrip.
I used 11% for manual R53 which I think is pretty generally accepted figure.
Let the fun begin...

 

http://www.dynolicious.com/index.html

Performance Measurements

• 0-60 MPH
• Other Speed Tests (0-10 MPH through 0-100 MPH in 10MPH increments)
• Quarter Mile Elapsed Time
• Quarter Mile Trap Speed
• Elapsed Time and Trap Speed for standard intervals (60', 330', 1/8 Mi, 1000')
• Lateral G's (current and peak)
• Braking G's (current and peak)
• Wheel Horsepower
• Estimated Engine Horsepower

Results Presentation

• Realtime Speedometer and Graphs
• Realtime graphical skidpad display
• View results for latest test run or any saved run
• View averages based on vehicle, date, or modification
• Compare results between vehicles, dates, or before-and-after modifications

Configuration

• Rollout 0" to 24" (separate settings for 0-60 and Quarter Mile tests)
• Stores vehicle weight and drivetrain efficiency in your vehicle's profile
• Calibration routine gets the maximum accuracy possible with the built-in accelerometers

Accuracy

• 0-60 MPH: +/- 0.08 sec*
• Quarter Mile: +/- 0.10 sec*, +/- 1.5 MPH*

*Results based on preliminary testing. A detailed accuracy analysis using professional timing equipment at a regulation dragstrip will be posted soon.

 

11% ??

just doing a google search for "cooper S drivetrain" loss brought up posts from folks putting the cars on an actual Dyno machine.

I noticed 17% - 21% was the norm. So I put 19% on my config.

where did you get 11% ?

google said the norm for any car is 15% - 23%

 

The only way to know the exact drivetrain losses on a particular vehicle would be to measure horsepower at the wheels, then rip the engine out of the car and measure power at the crank/flywheel. Obviously, these numbers would mean very little unless the Dynos used were calibrated to one another and atmospheric conditions were indentical, or correctly accounted for.

That being said, none of the drivetrain loss numbers you see on dyno sheets are measured, they are assumed by the dyno operator and used to derive power at your crank from the measured power at the wheel.

I've read that FWD cars with manual transmissions can have very low drivetrain losses... but the claimed numbers on this site and others are all over the place.

I used 15% in the setup of Dynolicious.

I put my car on scales today. 2653 lbs with a 1/4 tank of fuel
06 MCS, sunroof and leather. I'd guess this is a pretty standard curb weight. Don't forget to add your own cheeseburger induced lbs...

All I can say about the accuracy of the app, is that the speedometer matches that of my GPS almost exactly when doing a run from a stop.

Even though the math behind all this is fairly simple, it's a very impressive application.

 

 

I actually purchased this app. Wasn't expecting much, but I figured why not give it a shot. Well, I must say it is fun to play around with and compare my results with the screen shots. The road was short, so I didn't even get to open it up. I used the same drivetrain loss used in the sample screen shots (which happens to be a 2003 Mini Cooper) shown on their website. http://www.dynolicious.com/index-2.html

My Settings:
Drive Train Loss = 25% (MCSa)
Vehicle Weight = 3505

I've only done one run so far, but I plan on doing more this weekend. If nothing else, it's fun to play around with. Here are some screen shots of my only run.

 

It's pretty obvious that for this to be as accurate as possible, it will need to be secured in the car a bit better than setting it in the cup holder as I've been doing. While seeing what sort of lateral G's I can pull, the thing keeps shuffling around. I'll be using a hunk of clay to keep it still next time, but would prefer a more elegant solution.

Does anyone have any experience with the various suction cup mounted iphone cradles available?

 

3500 pounds? Were you using the Gross weight or the curb weight? The gross weight is the MAX you can safely put in the car. The curb weight is what it actually weighs (+ the weight of the people in the car). I think the curb weight for Minis is closer to 2600-2800 lbs. That might change your performance numbers a bit as the program gets the figures by comparing the G forces generated VS. the weight of the car (if I'm wrong about that, someone please correct me )

 

I opened the driver side door and read the sticker. GVW, which I believe means Gross Vehicle Weight. The iphone was placed in the cup holder and held in place firmly by the rubber side holders. Having a CVT also gives smoother shifts so there's no jerking around while shifting. I'll change the weight to 2800 and compare results. I'll post updated results this weekend.

 

Phones are getting so advanced now, but my phone is a classic antique. I can't part with it.

 

Does it have Snake???

 

GVW is the maximum weight of the car plus driver/passengers/luggage. The weight you should be putting into the program is the actual weight of the car when you do the test (usually curb weight plus driver).

I have the iPhone program and a G-Tech Pro RR, so I'll also do a comparison between the two at my next autocross event (August 23rd).

 

Thanks ScottRiqui. I'll adjust and run it again.