hi,

im thinking about ordering that Gtech device that u plug in your cigarette lighter and it displays your horsepower, 0-60 times, 60-0 times and more.

im wondering how it can measure things like that if it isnt in any way connected to your engine/trans?

If u know how it works, or u have any experience with it or you know a better device then this one, please tell me

thanx

It is only measuring how fast your car is accelerating over time. Imagine a pendulum hanging from the rear view mirror of your car. The faster your car is accelerating, the more the pendulum swings back. Im guessing the Gtech has something like a pendulum within it, and then the computer within it calculates the distance you travel based on your rate of acceleration (which of course is varying over time). I am pretty sure that in order to calculate HP though, you must program the weight of your car into it.

I have read that the g-techs are close in ET (within 2tenths mostly) but the mph is way off because gtech does not calculate mph the way a drag strip does it. Gtech just takes your final speed at the end of the 1/4 mile, whereas at a track, the trap speed is actually an average of speeds over the last XX number of feet of the track. Gtech always reads a faster mph then you are actually trapping at.

I bought one off the internet and when I got it the plastic button on the front was snapped off, so I returned it for another, and it worked well... for about a week. It just mysteriously stopped working. I would recommend just using a dragstrip, these things are too flimsy for what you pay.

yeah a dragstrip , hehe , for what i know there is only one dragstrip here in the netherlands... and its open once a year...

im born in the wrong country

I have one of the GTECH Pros. You do have to put your weight in it. The more accurate the wieght the more accurate the results. Mine has 3 accelerometers, foward/back, side to side, and up down. It also has a temp. sensor which is quite sensative.
You can program your shift rpm and it tells you when to shift with an LED light. It knows your rpms based off of the frequency it picks up through you cigarette lighter.
It also senses traction loss through the accelerometer and engine rpm.
It also gives you horsepower(rear wheel) and torque graphs, which are quite interesting.

I ran mine at the track, I weighed my car before, put it in, and it was only two tenths off. The mph was off, but not much. My hp and tq graphs are a little skewed. There's spikes in them after I shift, but I talked to them, and they said that's because of traction loss. They're probably right. I think its the next best thing if you can't get to a drag strip. Sorry for the long post. ;)

Oh yeah, it does lateral g's if you're a conering or roundy round guy. graemlins/thumbsup.gif

All things considered, the gtech is a nifty device. By measuring accelleration, you can calculate speed an position. Accellerometer technology has greatly improved over the last several years making them cheap and accurate.

The only thing an accellerometer device can't measure is the power loss through wind resistance. But then again, the results will correlate with track times. It's just that your power readings will vary with different wind loads. Great tool for tuning.

-dnult

Hi.

Since you said you lived in Netherlands, maybe checking these things would be a good idea?
http://www.race-technology.com/WebPage/Products/Products.html
For us within EU it is easier with no customs fees, yadda yadda.

Anyway from what I can read about this device vs. G-tech. I believe that it can do a little more. Any comments from folks who might have tried them out?

Regards
Bjorn Aldorsson, SWEDEN.
http://www.qsl.net/sm7sjr/camaro.html

P.S By the way I want to buy some good recordings of DragRacing. Anyone know if I can find DVD's of NHRA, IHRA and Street-type of events? (No illegal streetracing kind of flicks please).

I agree with dnult. Great tuning tool. I've had mine for 3-4 years and it still works fine.

The biggest problem was getting it to stick to the windshield under full throttle.

Make sure you follow the directions to the letter, especially on getting the unit level. It will not be accurate if it is not leveled.

-Chad

I bought one years ago off of Ebay. If I were you, I would check there first--you'll get a better deal.

**Keep in mind!!!** If you don't live near a VERY flat surface, then you better find one. You have to level the gtech to within .01 degrees in order for it to work right.

When I used gtech, I found it to be very inacurate. It displayed every time from a 14.5 to a 17 qt. mi. on the same car. I don't recommend buying one. Nothing beats the ol' drag strip.

I got one from Santa and love it. It's fun to see the "before and after" with mods that you do with your ride. I posted most of the owners manual with the claimed accuracy rates of each function. Try a search if you are interested. And don't forget that the newer version can be linked to your PC and it gives you some nifty looking graphs.

Originally posted by CamaroGuyTLT:

**Keep in mind!!!** If you don't live near a VERY flat surface, then you better find one. You have to level the gtech to within .01 degrees in order for it to work right.
.01 degrees?? Wow, that would be tough tolerance to obtain!

I agree, nothing beats a strip, but sometimes that isn't possible...