Just saw this advertised on SpeedVision
http://www.gtechpro.com/prod.html

It claims to not need any install, kinda like a window-mounted radar detector. Looks kinda suspicious to me.

Zoinks

 

They work great.

 

Actually they work fairly well. Maybe some kind soul can post a link to previous discussions about the G-Tech and other products which perform the same function. Or you could try a search, I'm just not sure if it was here or H-A.net where I saw it.

 

Maybe this will prove of interest...It's from some old posts of mine in this board.

Here's a comparison of two performance testing boxes, the Gtech and the Vericom.
http://www.gnttype.org/techarea/misc/perfcom.html

Some other boxes to consider include the Road Dyno which is kind of tricky but gives actual torque and HP curves and corrects for weather conditions, aero drag, etc:
http://www.charm.net/~mchaney/homedyno/dynokit.htm

And the AC22 which is a bit more $$ than the Gtech but much more flexible - it can do speed to speed tests:
http://www.race-technology.com/WebPage/Pro...celerometer.htm


And the Geez which is autocross oriented but can do dyno stuff too.
http://extremegeez.com/


And various other boxes or gizmos such as memory tachs, dataloggers, aftermarket ECUs and so forth.

One very powerful feature of the programmable units is speed to speed testing. This can allow in-gear tests from one RPM to another. The least time = the most area under the curve. For example I often test 2nd gear times from 30 to 50 or 60 mph. The driver simply holds their foot to the floor. Zero skill or talent is needed and if you start on the same piece of road, even if it is less than perfectly flat, then you get comparative results which repeat down to 1 or 2 hundredths of a second if nothing changed. Tests such as 0-60 or 1/4 mile require skill and many repeated runs to get consistent reliable results. So you can quickly compare air filters, oil, chips, exhausts etc easily with in-gear testing. One huge benefit over an engine or chassis dyno is that EVERYTHING is tested. Including air flow (which varies with vehicle speed), wheel rotating inertia, etc, etc. I found 2-3 extra HP by moving my CAI entry point about 2 inches. A chassis dyno is nearly blind to such changes. Much better for turbo cars too since intercoolers need actual airflow to work properly.

BTW my near stock but with cheap bolt-on / custom mods early 4 cylinder M3 does 0-60 in around 6.2 seconds after lots of tuning with in-gear tests. I think I'll be able to get into the fives with some more mods such as ditching the stock restrictive Bosch flap-box air flow meter and replacincg my very heavy 16 inch wheels and tires - 44 pounds apiece. For such a test the driver launches at about 2500 RPM which gives you an idea about the difference in torque curves between the two vehicles. Tremendous wheelspin if you launch at 3000 RPM. And that car has a no-low-end torque reputation!!

The S2K is likely to benefit from in-gear testing (compared to from 0 and with gear shifts) more than other cars since the driver skill and random variations are removed in such a test. Easier to get useful, credible information.

Stan

 

Thanks for all the great info

 

I have a Gtech. It is very accurate. I tested it out at the dragstrip, it is about 20% of the time right on and the rest of the time within + or - 0.1.

However gtech tends to be less accurate with cars that have soft suspensions, since when the front of the car lifts off at take-off the gtech, since it uses Gs to measure performance, thinks the car is accellerating while it is not.

So on a car like our stook it is great, i would highly reccomend it.