Did you find the G-tech a useful tool?
yes, very much so. MPH at 1/4 mile after WOT acceleration was telling me whether my ignition and card tune settings were going to the right direction, or wrong. I did my testing outside the city, actually on the countryside, between the fields on those looong straights where is no traffic and where you can see miles ahead. That´s where we tuned, and yes, that´s where we street raced, too
In addition the G-Tech is a very good device to teach you the right way to launch your very own car on normal street asphalt and with street tires. Eventually one of my friends ran 12´s (the fastest of us on the street back then) with that G-Tech and he started to question whether that little device was for real, or bogus. So we took that G-tech to the local 1/4 mile strip and verified it´s ET & MPH against the real clocks. We were astonished how close that little thing got: the ET was 0.1 sec or closer to the real 1/4 mile times at the track, and the G-Tech was showing something like 2 MPH too high. But most important: G-tech was/is really consistent, no matter if the figures are not dead-on, but because they are consistent so this makes the G-Tech a very good tuning tool. And fun, too!
Just my two cents.
