Over several posts that I have run across I noticed alot of S2K owners turning to Gtech to measure their 1/4 times, Horsepower, etc. I have been eyeing this product for some time but I wonder if any of you have tested with the G-tech and a real track or dyno and found the results comparable?

 

From what I have seen on the web, from friends, and with my own experiementation, the GTECH is pretty accurate, provided you are. What I mean is that assuiming you set it up right (physically, and the weight data), it's pretty accurate. Beyond that, it's *very* repeatable, and good for testing mods- assuming you have a 1/4 mile stretch of straight road and no cops!!!

 

At the very worst it's good at measuring mods relatively. If you ran a 14.1 stock then a 13.1 modified, then you can at least say it's 1 second faster. I personally think it's very accurate, from my tests, and that a 14.1 is a 14.1 and a 13.1 is a 13.1.

 

Thanks for the feedback guys.

 

No dont get the Gtech, it'll get you in Sh!tloads of trouble. Dropping the clutch at high RPMS and things like that are so bad on our cars and the Gtechpro measures everything exept lateral G's that way. I have one and its fun but it's alot of trouble for our non-draggin cars

 

The accuracy depends on both the car's supension and where you drive the car. I've tried it on several different cars and lots of different roads. Most important the road has to be flat. I spent a long time riding in a 5.0 mustang trying all sorts of different roads and noticed that even roads that appear fairly flat to the eye consistently give different results depending on which direction we were going on the road. Even a *very* slight downhill anywhere along the stretch of road would give noticeably better results.

The other big factor seems to be the car itself. The softer the suspension is the worse the results are. The issue here is body roll. I tried my beast ('89 mercury sable auto ) for kicks and noticed that the times and traps were too high and it accumulated so much error even on 0-60 runs that if I tried to do a 60-0 the G-tech thought my car was still moving after I had stopped. Another example was a '86 CRX that is just slightly slower than my car was getting 0-60 time nearly 3 seconds slower since the suspension was much stiffer. Side by side the 2 cars are seperated by a couple car lengths to 60. This implies that as a car gets more powerful it will lean more and therefore the g-tech will get more and more optimistic as a car gets more powerful.

If you don't believe that roll makes that much difference, let me just give a couple peak lateral G numbers we got:

mercury sable: 1.01
s2000: .96

Seriously. How'd that happen? I cheated. I got the sable a little sideways going in to a corner then it caught *hard* and the car leaned way over as it entered the corner, giving a really high *peak* number. In real driving the s2000 could sustain close to that number while the sable struggled to hold less than .8

So given all of this I'd say that the g-tech is good if you remember a few things:

It isn't great for comparing different cars since the supension can affect the times.

Either find a road that is completely flat or else always run on the same stretch of road.

Don't trust the numbers as real performance numbers, but rather as a baseline to practice against or test mods against.

Major power adders are probably going to to give bigger increases on the g-tech than on a drag strip (I'm guessing about this, but it makes sense that you'd get more weight transfer with a more powerful car.)

 

I can vouch for that! Nonetheless, it is a very nice gadget for measuring improvements (or lack thereof) of performance mods. Good luck.

 

[QUOTE]Originally posted by rolotomasu
[B]

 

The GTech is cheap, but sometimes it's better to pay a bit more IMO.

Something like the race technology AP-22 for about $100 more gets you MUCH more capability. It's programmable. You can save runs to memory and upload to your PC. You can calibrate it to your car. For example, you can allow for suspension squat. You can easily compare mods using speed to speed tests in one gear. That way you avoid the skill requiring, variable, and hard on the drivetrain standing starts while getting repeatable results. Draggers can do 60 foot times to test technque without doing the whole 1/4 mile. Lotsa fun but you need to be careful and methodical with whatever method you use.

There are also rumours of a ne g-tech model coming soon. Not sure if its a replacement or what. Supposedly early next year.

Stan

 

I have used it and I like it - what more can I say. Except that the many (50+) high rev clutch drops I performed during the week I had the g-tech had no noticeable negative impact on my vehicle.