Fokker

Maybe you're misunderstanding what I mean by fine. There's two compartments in "secret" compartment and the forward one which is very small is where I leave the GPS unit. My GPS unit is not going to be able to tell the difference of a few inches. I have a tire gauge and rag that I keep in that compartment as well and the GPS unit can't be moving more than fractions of an inch.

Having gone over the data logs from my time at Streets of Willow with it rattling around in my cup holder, the fractional differences in GPS coordinates that were logged when the car was passing through the same point on different laps is so small as to be insignificant and not necessarily attributable to any motion of the GPS receiver.

I don't think there is any driving need to tape the unit down or secure it in a more permanent manner.

matthugie

It's not the unit moving around that I'm talking about. My point is that GPS is most accurate when it has an unobstructed view of the sky. When you say that the GPS resolution isn't that fine I'm assuming you aren't getting the most accurate readings since, when properly mounted outside of the car, the unit can clearly show differences of a few feet on a given run. Given the slight obstruction that the lid of the secret compartment provides that may be enough to decrease the accuracy of your data.

SlowTeg

I haven't heard of SoloStorm but I use racechrono pro for Android with a qstarz 818xt, bluetooth module, and a gopro for video footage. Apparently racechrono pro can record video so you don't need a gopro but I haven't tried it.

I leave my Galaxy s4 in the center console w/ the door closed. I have my qstarz mounted on the passenger top side of the windshield. I used double sided sticky tape w/ velcro to attach it and put a piece of duct tape over it.

Edit: I guess solostorm is more auto-x specific? I'm not sure how racechrono works for autoxs.

FormulaRedline

This is unlikely. At the electromagnetic frequency GPS uses, most plastics are transparent. It would have to be really thick to attenuate the signal to something unreadable.

Fokker

You can use Harry's for Autox too, I wouldn't be surprised if you can do the same with Racechrono. Solostorm allows you to easily compare different runs onsite between runs as well as other features specific to autox I think aren't necessarily available in other programs.

DavidNJ

Wow! I thought this was going to be simple. Instead:

There are at least three products. Harry's, an iPhone/iPad app now also on android and RaceChrono on android. Note that these are $20, SoloStorm is $200.

• There are lots of different devices that can attach: different BT 10+Hz GPS receivers, VBOX Sport, RaceDAC, RaceCapture/Pro
• That there are power management issues with the android device...this application, with its high sampling rate and use of accelerometers is power intensive.
• That, as I suspected, a bigger screen is helpful.
• Mounting can affect the accelerometer readings.

Not clear which way to head. A couple of these boxes have significant data acquisition and suspension transducers would be interesting. However, none appear to have the integration of Performance Trends DataMite which feeds suspension transducer data into their Suspension Analyzer suspension modeling software.

This is going to need some thought...and maybe a thread or two. Possibly some of the track racers may have some insights. After all, this stuff is expensive for a B/Street where all the modifications cost less than $2000. Some track racers have more than that invested in their rear wing.

Sidebar: How do you make a small fortune in auto racing? Answer: Start with a large one.

IntegraR0064

For autocross, solostorm is far superior to the other ones. If you're on a budget the others will do in a pinch but solostorm is definitely much more tailored to autocross.

There is a guy who races an MX-5 in STR in NJ who has the race/capture pro with solostorm, could check out his setup at some point. http://www.autosportlabs.com/sponsor...-joe-ottofaro/

King Tut

Oh lord. That is my favorite saying in racing.

User 121020

^ This. Solostorm takes much of the hassle out of data acquisition, video capture and data review. Well worth the $200, in my opinion.

clarkster009

Do you have a roll bar?

I got the RAM X Mount and roll bar attachment. Seems very solid. I put my Galaxy S6 in the X grip and shake it around and it stayed put. Let's put it this way, if your car is shaking worse to make the phone come loose your problems are a lot worse.

I plan on using the phone with the Android Race Chrono Pro app that takes video. The stabilization seems good enough on this phone to handle video, but I still need to test it. But it would be $55 shipped for the mount and 20 or 30 for the app...if it works it's cheaper than buying a Go Pro, and I think I can get data overlay like lap times easily (I hope).