Useing G-Tec

[RB30-ZED]

Thought I would share some G-Tec screen shots and explain them to those that haven't used a G-Tec meter.

The first screen shot is a comparison of horse power between a RB25DET(2500cc DOHC injected turbo) found in the R33 Skyline and the engine in my 240Z which is a hybrid RB30DE(3000cc DOHC injected) naturally aspirated.

The first thing you need to know about G-Tec is that it measures Horse power and torque by measuring G force over time, this gives it a torque figure. It then uses rpm which it picks up from the alternator output noise to work out horse power.

But the horse power shown is the actual power used to accelerate the car, so it will look lower than a dyno print out because you have used H.P. to over come wind and rolling resistance which is a good way to see if Aero mods have worked or not. The only thing to remember is to input the correct weight for the car with driver or the figures will sit high or low.

So if you had the same engine in a small coupe and a large van of the same weight the reading on G-Tec will show a lower output from the van as it lost more to aero losses than the coupe, which would as expected out run the van.

To get a rough idea of rear wheel HP you could multiply the G-Tec output by 20% and the again by 20% for engine HP.

But in reality what it shows on the G-Tec is what you have to use anyway you look at it.

To do a power run on G-Tec you start in first change in to second straight away and put your foot down to the redline, so times shown on the screen shot are of no importance.H.P. comparison RB30DE V RB25DET

The last screen shot is a 1/4 Mile run between the two cars. But if you look closely you can see the Zed was off the throttle before the end as room was running out :cheeky:

1/4 Mile Zed, Lexus SC400 and Skyline

If anyone has a G-Tec Pro Comp we could post files for comparison.

Steven