I g-teched my car twice this morning. It ran 16.0 and 15.9 in 2 different tries. Here is what I have

90 GXL
Gutted cats, stock y pipe and RB mufflers
Cut intake box
Taylor Race ignition wires
Recent tune up

Using the g-tech hp thing, i had 135hp. Not too bad. Car currently has 158K miles on it. Car was dynoed at 127hp when I bought it, 128hp at 93000 miles when I tuned it up. I am going back to the dyno next month after I put my cat in there

 

what about 0-60 according to gtech one time my car ran 6.6 another time 7.0

 

I had a Gtech once tell me I had 17HP.

 

17HP? Any idea why it would do that? I've thought about getting one. Are they usually pretty accurate?
Just wondering. They seem like a pretty handy tool if they can be depended on...

 

From what I hear they work great, I just don't think I know how to properly use it. It's very finickey.

 

They are great at determinig the increase after mods. But they are not so good at determinig the actual performance of a car. Like, lets say you just bought a header; the G-tech will give you a good impression of how much the header did for you, by comparing your old times to new times. As long as you are comparing inaccurate info to inaccurate info your results should be true. Ya know what I'm saying???

 

from what i understand/heard, your exhaust may not be helping you out that much, if at all...
a straight pipe flows better than the gutted cat.

More to the point, how good could those g-tech gadgets be? I think if theyre reasonably accurate, they are a decent buy(at least for your own personal amusement)

 

They are accurate if you have a flat road to drive on. It was accurate at the drag strip. Only the 1/4 time, not the mph read out

I am going to junk the gutted leaking cats and go to Bonez high flow

 

Most of the time the G-tech is right but it also depends on the road you are on. I believe that the G-tech measures your times by looking at how fast the raod is moving or something like that. So if you are going up hill the G-tech is probably off. At least this is what I have learned from my past encounters.

 

Absolutely! If the road is not flat, or if it's rough, it will throw the G-Tech off. Allways make runs on the same stretch of road, both directions, averaging the two for each run.

You seriously need to repeat the timings on the same stretch of road, and under similar weather conditions. The G-Tech is as accurate as your processes are. No, not as accurate as a chassis dyno run, but for what it is if you use it properly, it will be pretty close.

It's easy to get a bad number, you really need to watch what you're doing. For $150 delivered, it's a great tool.

 

A big problem with the Gtech is the car's rear end squat.... rx-7's tend to squat pretty deeply too, it can REALLY exagerate the times....I have found the most accurate timing by "pre-loading" the fron of the G-tech downwards by about 1 or 2 digits on the readout.

Other than that- it's dead on... I also like the "instant G" funtion... it's really going to help me tune my S-AFC (with a/f gauge of course).

Last year I ran with a buddies honda, and when we race, we are almost dead even, and I pull ahead a bit by third gear, but his car is lowered, and doesn't squat much at all. his g-tech time was high 15's, and mine was high 14's!! Every time we tested we ran beside each other, and every time I was only ahead by half a car or so by the end...
That was whan my car was stock though....now it's not even a race!
Ya, so just watch squat.