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[quote author=LaraW link=topic=119098.msg2503775#msg2503775 date=1217428366]
Whaaaaaaaaat. I wonder how accurate that could possibly be?
[/quote]

+1. If it plugged into the OBD II I'd maybe give it the benefit of the doubt (and my $13), but just using the accelerometer? Half the time mine can't even tell what orientation the screen should be in
 

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Sweet, I'll try this out on my 3G. I'll wait till they jailbreak the app :quiet:
 

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[quote author=budgy link=topic=119098.msg2504023#msg2504023 date=1217434524]
probably wouldnt be much less accurate than a G-Tech because it basically works the same way.
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Depends, how sensitive and accurate is the accelerometer in the Iphone and how sensitive are the two accelerometers in the G-Tech? Just because they both have accelerometers don't mean the level of accuracy is even remotely the same. That being said, the latest versions of the G-Tech at least seem to be resonably accurate on acceleration numbers, still not super accurate on dyno (even WHP measurements)...probably in part because most people don't enter terribly accurate vehicle weights and drag becomes a sufficient enough factor getting up around 60+mph to scew things somewhat.

Personally I'd be interested in it if 1) I had an Iphone and 2) It was maybe a 2.99 download. $12.99 for something that I am going to go out on a limb and guess is probably not terribly close isn't something I'd be willing to pay more then a small curiousity fee for.
-Matt
 

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[quote author=azazel1024 link=topic=119098.msg2504257#msg2504257 date=1217439266]
[quote author=budgy link=topic=119098.msg2504023#msg2504023 date=1217434524]
probably wouldnt be much less accurate than a G-Tech because it basically works the same way.
[/quote]

Depends, how sensitive and accurate is the accelerometer in the Iphone and how sensitive are the two accelerometers in the G-Tech? Just because they both have accelerometers don't mean the level of accuracy is even remotely the same. That being said, the latest versions of the G-Tech at least seem to be resonably accurate on acceleration numbers, still not super accurate on dyno (even WHP measurements)...probably in part because most people don't enter terribly accurate vehicle weights and drag becomes a sufficient enough factor getting up around 60+mph to scew things somewhat.

Personally I'd be interested in it if 1) I had an Iphone and 2) It was maybe a 2.99 download. $12.99 for something that I am going to go out on a limb and guess is probably not terribly close isn't something I'd be willing to pay more then a small curiousity fee for.
-Matt
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Acceleration times will always be pretty easy to get. Figuring out WHP based on weight and acceleration alone is never going to be very accurate, but it does give you an educated guess so to speak. Good for those just wanting a "baseline" and to know if their mods have done anything measurable in real world conditions.
 

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tested by autoblog for accuracy:

http://www.autoblog.com/2008/08/01/dynolicious-vs-v-box-and-dynojet/

"Give us an iPhone application that relates to cars and we're all over it. Apparently, so is the crew at Motive. They took out an Audi S5, mounted a Racelogic V-Box onto the windshield and brought along a Dynolicious-equipped iPhone to see how it stacked up.

The V-Box uses both GPS and yaw sensor data to serve up 0-60 times, 1/4-mile trap speeds and lateral Gs, whereas the iPhone only makes use of yaw information to deliver the same numbers... along with estimated horsepower figures. While Motive wanted to find out how the Dynolicious would do with 0-60 times, we were interested in how close it would come to wheel horsepower given both an estimated weight and drivetrain loss. That meant hitting up the Dynojet at Modacar and strapping our own Project Track Slut onto the rollers.

For $12.99, the Dynolicious software seemed too good to be true, but we were willing to reserve judgment until testing proved otherwise. While we've played with a few Racelogic boxes before, and found the data acquisition and customization capabilities to be beyond reproach, the cost of an entry-level model – around $499 – may be a bit prohibitive for your average enthusiast.

Motive turned off the one-foot rollout setting on both units – interested in only 0-60 times and not quarter-mile runs -- and performed ten seperate sprints to 60. You can check out Motive's screen shots of the results here (http://www.motivemag.com/pub/news/Tested_0-60_MPH_Times_Dynolicious_iPhone_Application_Versus_VBox.shtml), but the results showed the Dynolicious software was anywhere between 0.24 to 0.65 seconds behind the V-Box, which kept very consistent times throughout the test.



With our 1992 BMW 318is mounted onto a Dynojet on a 90-degree day, it put down a respectable, if not particularly powerful, 122 hp to the rear wheels. The graph above shows the last two runs (red and green) were within one horsepower of one another, while the first run (in blue), was done with the A/C on... whoops.

After unstrapping the Slut, we double-checked our tire pressures (38 psi all around for daily driving), inputted our estimated weight (2,900 pounds, with 1/4 tank of fuel and a monkey in the driver's seat), estimated drivetrain loss (17 percent) and set off to make a few passes. We ran to 60 six separate times, with semi-consistent launches (although we weren't clutch dropping for the quickest time) and recorded output figures ranging from 125 to 141 hp. Excluding the outliers, our average "Peak Horsepower" rating was 129 hp. Dynolicious' website says that its software provides both wheel horsepower and engine horsepower figures, but the only information displayed (see right) is the "Peak Horsepower" calculation. If that's supposed to be power to the wheels, its close, but far from exact.

Is it worth it? For $12.99 there are worse things you can spend on your ride (see: LED windshield washer nozzles), but we're not ready to give up our dreams of V-Box ownership yet. And with detailed horsepower and torque curves (not to mention AFR), a traditional dyno is still the best means of getting accurate figures at the wheels. Neither are cheap, but price and precision are rarely mutually exclusive.

 

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Discussion Starter #17
Exactly is not perfect but hey 12 dollars for an application that would give you a very accurate reading, or spent 500 on a "professional" Racelogic thing that lets face it is too much for what it does. And if it does the same thing as the iphone application I will try this one.

Now I just need to find an iphone......................
 

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It's only $12 ya buncha cheap asses.

I tried it out on the cars are work and the m5/6's always said about 430 whp.

I'd say its pretty accurate, as accurate as you're going to get for 12$. The important thing is the changes in your times after modding and being consistent.
 
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