stephens

Has anyone tried one of these, any results?
I picked one up today, will post results after some late night runs.

eclou

I have the original G-Tech. It is very accurate. High trap speeds though for the 1/4.

ntguru

I had a post on here a while back comparing my C32 to my 996TT according to g-tech data..... I like the comp. model because you can download data to your PC. I can't comment on it's accuracy directly since I haven't taken any of my cars to a real drag strip yet but based on car rag's data and others' posted here, it seems to be extremely accurate. 1/4 mile trap speed will always be a bit high because the g-tech's measure (compute, actually) instantaneous velocity at 1320 ft whereas a drag strip averages speed over something like 1270-1320 ft., thus giving a slightly lower trap speed.

stephens

I've posted in the off topic section in the hope of getting more feedback.
I'm particularly interested in finding how accurate they are because the numbers the unit are giving me are better than expected, so I am a little sceptical at the moment.
The new unit is telling me that my modified W211 E55 (pulley kit, intake mods, ECU remapped - pic below) accelerates 0-60mph 4.1sec, 0-100mph 9sec, 0-124mph 13.2sec 1/4 mile 11.9
This was with a full tank of fuel and a passenger in the car.
The unit was calibrated properly and I am getting the same numbers on every run.
Feedback please, I can't get to a drag strip for a month to verify the numbers and I don't want to get premturely excited by potentially dodgy data.

Stephen04E55

Definitely follows from the data I have seen in magazines. Road and Track has the best test #'s for the E55 with 0-60mph in 4.2 sec and 0-100 in 9.4 sec. Their 1/4 mile was approx 12.4. With a passenger on board your 1/4 mile times are .2 or so slower than a solo run. Every 100lb is worth approx .1 in the quarter. Post the climate data for your runs (humidity, baro, temp).

stephens

It was 22 degrees C, I don't have any further data than that.
Another run tonight at 15 degrees without a passenger netted a 8.6sec 0-100 time.
Because I am dubious about the data the unit is providing I decided to do some detective work,seeing if I could correlate any of the data from the g-tech with known vales.
To this end, I matched up the time on the time/g graphs, noting the gear change points, with max speeds in each gear, which is a known value, then correlated the time/speed graph for the speed the car was travelling at the gear change points, according to the G-tech and it matches up!

Stephen04E55

Any new news concerning the ECU upgrades and new crank pulley? Did you supervise the crank pulley install as to the difficulty? It appears that the radiator would have to be removed to access the pulley but I just glanced at it. This pulley is usually pressed into position and retained by a bolt on most cars...but I have never worked on a Merc before. Could you enlighten us on the amount of boost before and after the crank pulley install? All of your data sounds plausible to me with the upgrades you have mentioned. Also, let us know if you used the stock tires with the traction control "on" to perform your g-tech runs. Thanks

stephens

285/30 X 19 rears, ESP on.