G-Tech Accelerometer

I initially bought the G Tech before I started doing mods to my Maxima. The "butt-dyno" just wasn’t going to cut it for me. I, for one, cannot tell the difference between 0-60 times of 7.0 and 6.9 sec. Plus, I know myself enough to realize that after spending money on a mod, chances are it’ll "feel" faster! Hehe At the same time, paying $$ for dyno runs after each mod didn’t seem appealing either. Enter the G Tech accelerometer.

My Impressions:

For less than $150, you can do a lot with this thing. You can measure ¼ mile and 0-60 times. You have the option of turning it sideways to measure g-forces while turning to check out your suspension mods. Since it can do 0-60, it can do 60-0 so you can check out your brake mods. You can even determine horsepower with this device.

But when all is said and done, I basically just use it for the ¼ mile and 0-60 times. To measure lateral g’s while turning means you got to have a skidpad somewhere. If you’re going to compare your numbers to the magazines, you need to mark out a 200 ft circle and see what g’s you can sustain. Heck a Geo-Metro can pull 1.0 g but can it make the turn or is it flying off the road? You have to tell the GTech you want to measure lateral g's. This way, it won't let you cheat. To make a reading count, you have to sustain a g-force for 3 seconds.

To get quantitative results, you can go twisting around (ie freeway on-ramp) to get numbers, but this is very dangerous on public roads. You are, after all, trying to push the car to its limits of traction so lots of spin-out space is required.

As far as getting horsepower numbers from this device is concerned, your results are suspect at best if you don’t know accurately how much your car weighs (with you in it). If you’re trying to measure braking distances, be careful that you don’t lock your brakes and spin-out (assuming no ABS).

For measuring acceleration, though, the gtech gets a standing ovation in my book. Now all you need is a straight, level, empty road. For consistency, try using the same road to do your "official" testing. It’s hard to tell if there is a 1-2 degree gradient. As far as I can tell, the timer stops when I reach 60 and slow. If you keep accelerating, the Gtech realizes this and keeps the timer going until you reach the ¼ mile point.

If there is anything about the Gtech to really complain about, it’s the stupid suction cup that you use to mount it to your front windshield. It used to hold it ok, but as time wore on, it kept coming off more and more frequently to the point that I’d rather not use it. Wheel hops at launch don’t help either. I got to the point where I was going to make a metal bracket that I can use to mount it on the dash…then came the Christmas holidays….

One day, the wifey wants me to put up some décor at home – a Christmas sign in the family room, mounted by a sticky clay - like silly putty, so I wouldn’t have to make holes in the walls using nails. The little light bulb in my head went on – hey! I can use this stuff to mount the Gtech to my windshield! Here's a picture of the GTech and it's new sticky partner...




The GTech also measures your times differently than the drag strip. The clock doesn't start ticking
when the light turns green, but rather as soon as forward motion is sensed. It also tells you your
final speed when you've reached the 1/4 mile. Most tracks average your speed on the last 60 feet.
So it's obvious to expect deviations between the track results and the gtech's.

Finally, we all know that there are tons of variables that affect a car's performance. I think the GTECH instructions say this best:

There are many variables involved in any car performance measurement including air temperature, altitude, oil viscosity, wind, fuel type, driver's timing, humidity and others. Additionally, cars are not like computers. Given the exact same parameters they will not necessarily come up with the exact same results...Considering the amount of variables it's very important to average several different runs, preferably in both directions of the wind.

So when all is said and done, after having it for a year, I can say that I really recommend the GTech for the guys and gals that love to mod their cars. It's a lot of fun. Testing variations aside, you at least have some numbers you can compare before and after a mod.