What is the accuracy of a G-tech? I am(at the time) assuming it is analogous to a narrow band o2 sensor.

am I about right on this, or am I missing out on something good?

 

The G-tech is actually very accurate, BUT, it really requires the exact vehicle weight and proper set-up.

A lot of people just guess at their weight and then wonder why its off...

 

This is true. If you had an accurate vehicle weight the HP would be pretty accurate if it was tested on a flat road. Ill test its accurary next time I go to the track.

Sometime though it will give you a really bad reading for some unknown reason, but you can always tell if it is off because its way off.

 

hrm. I wonder if there is a DIY g-tech.

 

The G-Tech isn't an O2 sensor, it's an accelerometer. It's accurate enough to use for tuning and setting up your car, but a dyno and actual 1/4 mi time slip are obviously more accurate. Both of my engine tuners like the G-Tech. Read all about it:
http://www.gtechpro.com/products.html

 

well.. I was talking in terms of accuracy, not function.

 

Oh, I see. Well, the narrow band O2 sensor is very accurate at the stoich point, and it retains a fair amount of accuracy past this point if the temperature remains constant.

In a similar respect, the G-tech is very accurate under certain conditions, and not so much under other conditions. There are some things the user can do to help, such as mounting it level, taking readings both up and down the same strip to average the results, etc.

 

Does the new G-tech work well with turbo/supercharged cars?

I remember reading the older G-techs documentation and it said something about not working well with cars using forced induction. I think it talked about turbo lag messing it up or something. Anyone know if they fixed this?

 

The only problem that they had with the old G-Tech wasn't about forced induction, rather it was to do with cars that accelerated too quickly - and I mean REALLY quickly. The accuracy of the unit fell off in cars that could cover the quarter mile in 7 seconds or less. I don't think that there are too many of those around here!

The key to the G-Tech is 2 fold. 1) as eVil said, if you want to know horsepower, you need the car's exact weight. 2) to get accurate acceleration numbers, it is ABSOLUTELY ESSENTIAL that the unit is level. Not +1 or -2, but LEVEL. If it is mounted properly, then the numbers that you get will be accurate.