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Which model?
In person? Or posts/article from the internet?
Yeh lets stick with some factual info here before it becomes like all the other threads!
I've used things like Gtech's many times over the years and while never 100% accurate, they're usually good enough to give a decent indication of where things are at.
I finally got my Gtech RR today (one of the GPS ones) and had a quick chance this arvo to do some runs.
The road was in pretty good nick, dead flat and dead straight. Ambient temp was 24deg. 1 pax, 1/2 tank of fuel.
Roof racks and 2 x bike carriers fitted to the roof. Car has 1700km on it. Stage 1 Tune only. 5dr DSG.
Run 1
0-100 4.87s
Run 2
0-100 5.02s
Run 3
0-100 5.07s
What was also interesting was the 200m (1/8 mile) time of 8.58s (run 2 i think...) which is almost exactly the same as wooduck's drag strip time of 8.592!
I'll download the data and have a closer look...
On the accuracy of such things... My old RaceTech AP22 (accelerometer only) proved to be within 0.2s to my 400m time and under 0.1s once calibrated for vehicle pitch. I can only hope that technology (and the inclusion of GPS) has improved this accuracy from 10 years ago!
Also, while I was reading about, AdamD stated that there was a "significant issue with the accuracy" with the GTech due to its 10Hz GPS engine, the RaceLogic PerformanceBox also has a 10Hz engine... a VBOX (depending on version) can be even slower!
GTech Fanatic 10Hz
PerformanceBox 10Hz
VBOX Mini 10Hz
VBOX Micro 10Hz
VBOX II Series 5/10/20Hz
VBOX 3i 100Hz 100Hz
RaceTech AX22 5Hz
What version of the VBOX has been used in the above testing?
Anyway, it seems RaceLogic are the only people who have properly compared a VBOX 3 with the Gtech (non-GPS) and determined it was accurate. There are some others who have compared a VBOX Mini and come to the same conclusion. (see next post...) As well as Car & Driver who have compared it to the strip! The info is out there guys!
2011 Golf R - 5dr, DSG, Candy White, Black 19's, Recaro's, Sunroof, Bluetooth, MDI, APR Stage 1Pics Here
2008 Lotus Elise - Solar Yellow, LTC, 2bular SS Exhaust
2007 Ford Falcon BF2 XR6 Ute - Black
The 3 images of the VBOX Mini and the screen shot are from the US. an explanation below.
The graph is from Car & Driver, the final table fro RaceLogic (the document I'm sure you've all read).
"This morning I had a chance to test my car with both my Gtech Pro RR and a Racelogic Performance Box (GPS based) at the same time. Amazingly, I reeled off three straight runs at 12.9 on both the Gtech and Vbox. The mph on the Gtech has been known to be somewhat conservative compared to the Vbox, so you can see that is the case here. So at least you know my terminal speeds that I have reported previously aren't optimistic. Also I had a chance to instrument a 335i with the Procede V1.47. It is a E92 335i steptronic coupe. On his car the Gtech was almost 1mph too conservative, but the ETs were right on. My quickest times and mph were a tiny bit faster/quicker than the Procede 335i, but so close, there is no real world difference. In fact, we ran 3 roll ons with pretty much identical results. There couldn't be 2 cars that were matched any closer than his Procede 335i E92 vs my JB2 335i E90. He can chime in if he wants. My car consistantly ran 110mph+ in the 1/4 mile,. His car ran from 109-110.5mph. We probably did a total of about ten 1/4 mile runs. FYI..with results from both test instruments, you can probably bet the results are pretty accurate."
You had an improved quarter mile time.. not cause of a change in temp, or freak situation.
You changed your engine moiunts to get a 13.6 in your GTI that is a STG 1, because last time you went they were snapped and didnt realise/hadnt changed them.
When they were snapped you ran a 13.9 or something?
So you got a 0.3 improvement - from the fixed engine mounts.
Is that right, or is your car not stg 1/something I missed.
Anyway, it seems RaceLogic are the only people who have properly compared a VBOX 3 with the Gtech (non-GPS) and determined it was accurate. There are some others who have compared a VBOX Mini and come to the same conclusion. (see next post...) As well as Car & Driver who have compared it to the strip! The info is out there guys!
Great work, and thanks for the useful info Beena!
I have a new Gtech as well (the SS; same unit as the RR minus the extra logging module). Based on the results I've seen, and on its specs, I wouldn't question its accuracy at all once the clock is rolling. I suspect the biggest margin for error is in the initial detection of launch and the starting of the timer. Once the clock is running, it should be very close to spot on.
You had an improved quarter mile time.. not cause of a change in temp, or freak situation.
You changed your engine moiunts to get a 13.6 in your GTI that is a STG 1, because last time you went they were snapped and didnt realise/hadnt changed them.
When they were snapped you ran a 13.9 or something?
So you got a 0.3 improvement - from the fixed engine mounts.
Is that right, or is your car not stg 1/something I missed.
I get it now.. sport on.. with the broken mount i was running 14.2-4.. simply couldn't get off the line...
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