[tadukuttan]

Originally Posted by quicksilver

Let us know how it goes and I might have reason to look for a 3G iPhone

Originally Posted by srijit

Good job tadukuttan. Please do post a review

The night is still young.

But, the saving of preferences is crashing this app on my phone, hopefully they will fix that soon. Emailed support, but don't really expect to hear from them any time soon. The timing part seems to be working, so will test and let you guys know how it goes.

And there is another one called g-tac for 5$, if this does not work, I should try that. And pretty soon, there should be even more, maybe even free.

[srijit]

That is true. But the website that reviewed this app gave it a "fair to good" rating.
I am also interested in where the iPhone is placed in the car? Do you have to place the iPhone in the dock or flat down? Any idea about that? How do you get the iPhone in the same place time after time?

Also as someone asked before, how much does getting one's car dynoed cost?

[tadukuttan]

Just got back from testing. Here goes the screen shots.


Stock, well almost.


Petes at work.


And now, with a little bit of extra boost.

Basically, the data it is showing very accurately reflects the amount of mods we switch on, and yeah, whatever is there in the cars can be switched on and off.

All pictures from driving done by me, and on 3 different Elantras, the readings match up with the mods turned on for each and every drive.

if anybody at Autocar is reading this, would you guys please compare this software with a vbox and post the results?

And that goes to anybody with a GTech also. Would love to see comparative results for same driver/car in a GTech also.

[Rehaan]

Originally Posted by Shan2nu

These things can never be accurate since they don't consider drive, gearing, aerodynamic/rolling resistance, traction etc when calculating power through acceleration.

Well for some readings (acceleration, speed etc) they can be pretty accurate. However, for others using more variables (HP etc) they may not be as good.

Originally Posted by akshay1234

seems like a cheaper alternative to the gtech which also uses an accelerometer but i dont think this will be too accurate.

Well, if we take a look at the Gtech Pro SS for example :
- It has a 3-axis accelerometer
- Has a pretty lame black and white LCD
- It uses the lighter 12v socket to calculate RPM based on the ripple in the current generated by the alternator.

Everything else is software based.


The iPhone :
- Has a 3-axis accelerometer
- A high res touchscreen
- NO way to directly measure car RPMs

Everything else is software based.


So as you can see, the only physical difference between the Gtech and the iPhone is the direct RPM detection!!
In terms of software, its possible that Gtech has a few tricks they currently use for better accuracy, since they have been in the game for a long time.

I'm sure if the iPhone software was designed smartly it could also detect RPM using a combination of - detected speed, manually entered gear ratios, accelerometers (jerks when shifting gears), and even audio (frequency/amplitude) input available from the microphone.

In the case of the Gtech, you are paying for the hardware (screen + accelerometer + everything).
In the case of the Dynolicious, you already have an iPhone so all you are paying for is the software. Hence the low price.

I havent seen the software, but i'd imagine that for best results you are expected to keep the phone perfectly horizontal or vertical. (Though its possible that a 3-axis could correct for this?)

Here are the specs and datasheet of the accelerometer that is in the iPhone if anyone is interested : SparkFun Electronics

Well, thats my understanding of it. Feel free to correct me if im wrong.

cya
R

[Rehaan]

Cool stuff Taddukuttan!

Originally Posted by tadukuttan

...if anybody at Autocar is reading this, would you guys please compare this software with a vbox and post the results?

...or Mad Monkey.

Originally Posted by tadukuttan

..And that goes to anybody with a GTech also. Would love to see comparative results for same driver/car in a GTech also.

That would be interesting, to see the differences between two devices built on the same technology.

Since you've used the software, any comment on this >

Originally Posted by Rehaan

...i'd imagine that for best results you are expected to keep the phone perfectly horizontal or vertical (Though its possible that a 3-axis could correct for this?)....

cya
R

[srijit]

Thanks for the review tadukuttan
I also read a comment at TUAW that the software showed 25bhp less than a dyno, but also that it was consistent. So theoretically, you can take a base reading and see if your car improves on adding mods

[mclaren1885]

Can I get an invite for such testings in the future . Let me see if I can manage to get hold of a gtech. Then we should be able to do a comparo between the iphone and gtech.

[tadukuttan]

Mounting instructions, as shown in the application-

[Shan2nu]

Well for some readings (acceleration, speed etc) they can be pretty accurate. However, for others using more variables (HP etc) they may not be as good.

Yeah, i was talking about the "dyno" part. This basically uses the perfomance of a car to calculate power but performance is never consistant even when you compare 2 cars with the same power and weight.

So it' possible that even though both cars show identical bhp figures on a real dyno, they may perform differently during acceleration, causing the i-phone to calculate wrong bhp figures.

Shan2nu

[tadukuttan]

Originally Posted by Shan2nu

So it' possible that even though both cars show identical bhp figures on a real dyno, they may perform differently during acceleration, causing the i-phone to calculate wrong bhp figures.

Shan2nu

The weight of the car/transmission losses etc are given as input to the software. The accuracy of your input will determine the accuracy of the bhp figures etc?

And I was not really bothered about the bhp figures, really. What mattered where the timings on road, and what difference the incremental mods make on a car.

So buy an iPhone, and no tuner/pretender will ever bull**** you again?

[mclaren1885]

Shan, I don't think anyone is going to take the bhp claims from such devices too seriously. As tadu mentioned its just to check if a certain mod is working on your car or not. Its just for reference purposes.

[srishiva]

For the bhp figures, it atleast gives a widely accepted figure which could be considered a average of all the cars.
For not so well engineered car, it might give a bhp figure which could be less than the spec. But since the reviewers are saying its fairly accurate, should be a o.k thing.
Repeating the tests on many cars could tell us how much is the deviation.

[Shan2nu]

Shan, I don't think anyone is going to take the bhp claims from such devices too seriously. As tadu mentioned its just to check if a certain mod is working on your car or not. Its just for reference purposes.

I mentioned this since the topic was on "dyno" testing a car using this device.

Acc and G force wise it'l will be way more accurate than the dyno figures it will provide.

Shan2nu

[tadukuttan]

Originally Posted by mclaren1885

Shan, I don't think anyone is going to take the bhp claims from such devices too seriously. As tadu mentioned its just to check if a certain mod is working on your car or not. Its just for reference purposes.

What you dragged Satya into doing is working wonders for his car. That car is out of the world. That 15 timing can be improved on by better driving alone. I made two mistakes even when I got that time.

And we were looking for you yesterday. You were not reachable?

And the cops were out in full force, even on the completely deserted NICE corridor, we could not spend enough time to really understand all the nuances. How about you find a GTech, and we do this again some time later?

[mclaren1885]

Originally Posted by tadukuttan

What you dragged Satya into doing is working wonders for his car. That car is out of the world. That 15 timing can be improved on by better driving alone. I made two mistakes even when I got that time.

And we were looking for you yesterday. You were not reachable?

And the cops were out in full force, even on the completely deserted NICE corridor, we could not spend enough time to really understand all the nuances. How about you find a GTech, and we do this again some time later?

I am still not completely satisfied by the state of tune of his engine in stock form. We need to work on that as well. Or test it on Rajiv's car for best results.

Ya. Having lots of issues with my cell. About time I pick up an i-phone too .

Sure, I'll look around for a gtech. Maybe we can do it this Saturday.