Your thoughts on portable 1/4 mile, lateral g, machines

[2kanchoo]

I don't really know what you would call them but I've seen a couple advertised, you know they stick on your windshield and can give you 0-60mph, 1/4 mile times, lateral g's etc. Anyone have one or know anything about them? (brands, quality, etc) The nearest track to me is a 2 hour drive away so it would be nice to have something I could practice launches with. (just so long as it was accurate to within say 2 tenths)

 

[nmeofdst82]

Gtech Pro RR

I have had my Gtech Pro RR for quite some time and it is an extremely accurate piece. You can really do a lot with it. Practicing your launches, practice 1/4s, 0-60 times, all very accurate.

http://www.gtechpro.com/

I have the RR version that lets you record the runs you do, then download them via serial cable to your computer and use thier PASS software to see all kinds of great stuff about the run, how you did and how you can improve.

Their is a Drag Race mode and a Road Course function, it has a programmable shift light also.

I actually use mine for that very purpose on a regular basis. I had it in my 04 Procharged GT and now in 08 Saleen S/Cd, man is my 08 faster, haha.

Necessity, nah. Fun and useful to learn without having to get to the strip and to see some really useful good to know stuff, yep.

 

[thump_rrr]

This was my original review of the Passport G timer 2
Since then I have come to discover that it's our track whose MPH is way off at times.

"
I got a deal I couldn't resist a couple of weeks ago. I bought a Passport G Timer 2 for $80.00 including shipping.

I brought it along with me to the track yesterday and these were the results out of the box.

...............Actual.............G Timer
60'...........1.779.............1.77
1/8th.......8.119.............8.10
1/4.........12.679...........12.60
mph......112.177...........109.6


As it has been discussed in the past the MPH is the only thing that looks way out of wack. I have been saying all along that the MPH was off by 1.5 - 2.0 mph. The G Timer shows a 2.5mph difference

Precision can be improved by entering things like vehicle weight, drag coefficient, frontal area ect. "

 

[2kanchoo]

Wow. I'm surprised they are actually that accurate. The Passport G timer 2 was actually the one I was looking at and for only $80 bucks can't really go wrong. How does it hook up? Just the 12v plug or into the diagnostic port? I don't have my 12v plug in the dash anymore just the center console.

 

[srt2stang725]

ummmm how the hell does it work? lol

 

[nmeofdst82]

Accelerometers

I believe that is how you spell it,

Accelerometers are basically gyroscopes. There are several facing different directions. You calibrate the car on a flat left to right and front to back surface. You put in things like weight and such, and you go through a process where it learns your RPMs from a calibration sequence. Once you do this, it knows by your RPMs, the changes put on the accelerometers and internal calculations, HP, TQ, Acceleration, Braking, Lateral Gs, etc.

Its pretty cool.

 

[don_w]

I had a G-Timer that I also tested at the track, and my experience is similar to Peter's. It was good to within a 1/10 or so on ET, but read a little high on the MPH. Part of that can be explained by the fact that the trap speed at the track is actually the average speed over the last 60-feet. It is not the actual speed you are going when the car crosses the finish line.

But, I also noticed that since the unit senses acceleration and decelleration to start/stop it, it is critical that you lift off the gas (or hit the brake) exactly at the 1/4-mile (or 1/8-mile) mark. If you run the car "out the back door" and stay in the throttle for say 1400 feet instead of 1320, it will give you a bad number. The ET will be slower, and the MPH higher. This makes it difficult to use consistently and accurately on the street where there is no obvious 1/4-mi mark.

Just my observations.

 

[freebass55]

I was under the impression these things didn't work. If you guys say they do, I might look into it.

Check Amazon...$70

 

[nmeofdst82]

Accuracy and 1/4 Mile

Not sure about the G-Timer, but the Gtech Pro RR I have lets you do very accurate 1/4s.

You press a button to "Stage", When you launch the run starts and when you hit 1/4 mile exactly, the light will flash and show your run. No braking or worrying about when the 1/4 was done needed. I used it in my 04 Procharged GT for many runs and was always dead on to the track timer.

the RR is around 299 and the SS version is around 199. The RR just lets you download the info to your computer and analyze it in a GUI. If you just need the data and don't need that, the 199 SS version is still a great buy.

I'm going to go look up this G-timer, never heard of it.

 

[don_w]

Not sure about the G-Timer, but the Gtech Pro RR I have lets you do very accurate 1/4s.

You press a button to "Stage", When you launch the run starts and when you hit 1/4 mile exactly, the light will flash and show your run.

That's pretty cool... mine didn't do that.

I'm going to go look up this G-timer, never heard of it.

I'm sure it's a POS... I bought it used for about 50 bucks I think. I only used it at the track a few times. It was helpful finding my 0 - 60 times there.

 

[Charlie Sheen]

I was under the impression these things didn't work. If you guys say they do, I might look into it.

Check Amazon...$70

I have the Gtech also. If you take your time and set it up correctly, and then fine-tune it, they can be pretty accurate. Pretty useful for immediate before/after comparisons for mods.

 

[kenneth]

SCT just came out with their own version of those, Looks pretty intresting.

 

[Hatchman]

I have the Gtech Pro RR. Always within 1/10th of a second, and always read about 2.5 mph fast. Now that Don tells me about the track averaging the speed over the last 60 feet, that makes total sense. The built in shift light and lights up at the end of the 1/4 run is great too. I haven't downloaded it to my computer yet, since you can view all the graphs right there on the unit (time vs G, Time vs rpm, time vs mph, etc) The graphs are a great tool to see where you are granny shifting, spinning, shifting too soon, too late, etc.

 

[Dread53]

I have an older G-tech and it works very well if it's solidly mounted with the supplied mount. I made a custom mount for my Saleen and it was subject to some vibration, which threw everything into chaos. Being a guy that likes to go around corners, it has a cornering light built in that you can program. I set mine up for 0.9 g's and kept it lit all the way around an offramp. You pick a start and end point and the light will blink faster as you get closer to the limit, staying on when you hit it.

With my bogus mount I made three runs at the track. One was almost dead on, one was close and one (high vibration start) was way off.