IcemanG17

I was looking at the in-car performance measuring device called a G-tech. Apparently they make two models ranging from $199 to $299. Both look very interesting, but I wonder how what you need to do in order to hook them up to a 928? Also are they accurate? It sounds like you plug it in to the cigarette lighter and thats about it?

Mark

Brian - I have one and have played with it a few times. Yes - it just plugs into the cig lighter - that is the ONLY connection...there is a setup procedure where it 'learns' your car's electrical system, and will actually show RPM's, too. It has 3 'accelerometers' that measure the g-forces in all directions and computes the 'answers' on the display. You can set a warning light for lateral g's - so it lights up just before you start to have that big butt facing forward!
It seems to be pretty accurate.

IcemanG17

Mark
They sound really interesting....luckily for me Xmas is coming soon!

GoRideSno

Ice,
The g-tech is supposed to be very accurate in measuring acceleration. You have to make sure you are on a flat straight road when using. To get an accurate measure from the HP feature you would need to weigh the car with you in it.
I got one of the low end models off e-bay brand new for $39.00. I believe they are commonly sold at that price on e-bay by the company that makes them or a company associated with them.
HTH,
Andy K

Richard S

Anyone try out the Passport G-timer? I think Grassroots Motorsports Magazine did a comparison with G-tech and Passport vs. real timers at a drag strip. Passport appeared to be more accurate than G-tech. Any experience with the computer download program features? What is downloaded and displayed on a computer?

Thanks, Rich

Z

The newer G-Techs are supposed to be more accurate than the older original models, because of the newer ones having three accelerometers and improved internal software. The newer models also don't require being mounted in a level position like the older ones for those same reasons. I don't know about the actual accuracy, but they are consistent, which was what I was mainly interested in. The following shows a comparison of four runs done in my '88 S4 A/T.

Tony

Your getting those 0-60s in your S4!

edit: Ok, just noticed, why does it show yo going 4-5mph at the "0" sec line?

Gtech Pro?

mspiegle

correct me if i'm wrong, the gtech pro and competition are the same thing... right?

928Quest

I ordered the $299 model two days ago. Many years ago I had a Turbo 300ZX that had a built in G meter. It was rather crude and coarse but still useful for adjusting things. This 'G' meter made it real apparent that my Butt-O-Meter was not reliable.

Recently after adding an RMB, my first mod to my otherwise completely stock 91s4, I found myself wanting that G meter again. After all an RMB makes a sound that is worth at least 50hp..right? Anyway, all I care is that it is reasonably repeatable, the graph from Z above, and others I have seen, seem to bear this out. I also think it would be interesting to share graphs like Z made to get a better idea of what mods are worth what.

I should have some graphs to show in a few days.

Z

The charts show the acceleration beginning before the "0" because of the rollout. The rollout is the distance that the car actually moves before breaking the staging beam and starting the clock at a drag strip. Typically a 12" rollout value is used, but the actual rollout can be greater than that if you've got small diameter front wheels, like on a dragster. Most magazines publish performance results using a 12" rollout when they do their testing.[/QUOTE]

Mine is the Competition model. The Pro did not have the ability to download the runs to the computer software as pictured above.

No, they're different. The Pro was the orginal model. The Competition was the newer model with more features and is supposed to be more accurate. With the latest firmware update, the competition is identical to the new RR model except for the color. The various models are shown at G-Tech models

The data files are pretty small. The software allows comparing up to four different files to be overlaid for easy comparison. There are data files that people have posted for different cars on the G-Tech forum at http://www.gtechproforums.com/forums

928Quest

I just downloaded the PASS software from G-TECH and spent some time looking at the files on the G-TECH forum, very cool.

Z can you post or email your GTP file?

Z

When you click on one of the threads under the "various vehicles" section on that G-Tech forum, the default view is to show only the posts from the last 30 days. If you chose the option at the bottom to show all threads from the begining, you'll get a lot more threads with data files to download.

The data files can't be posted here like they can be on G-Tech's board, but I sent you an e-mail.

The main reason I got my G-Tech was to see the results of any modifications or changes, but comparisons to other cars that the data files and software allow can be interesting as well. Here's a comparison of two of my runs that were posted above to one from a 2000 Pontiac Formula with the LS-1 engine, and one from a 1999 Mustang Cobra. All four of the runs are using the same default 12" rollout value. The Formula is supposed to have a 3200rpm stall torque converter, aftermarket airbox lid, exhaust dump, and underdrive pulleys. The Cobra's mods are an x-pipe, exhaust cutouts, underdrive pulleys, cold air intake, and a K&N filter. The black line is the Formula, the red line the Cobra, and the green and blue lines are my two. Mine are only 0-60 runs, so end early where the other two continue off the chart.

The speed vs time screen shows that the Formula and I have very close numbers for as far as I go, with the Cobra not doing as well. The distance vs time screen shows that the Formula and I are about dead even, with me being slightly ahead on one of my runs, and the Cobra being left behind.

IcemanG17

Andy
You have the ebay $39 special, does it have 0-60, 0-1/4 mile times? I looked on the website and it looks like the old "pro" model only did lateral acceleration?

GoRideSno

The Pro does 0-60, 1/4th, HP, 60-0 and lateral acceleration.
HTH,
Andy K

GoRideSno

BTW there are atleast 10 new g-tech pros on e-bay for $39.95 now

Here's one.
HTH,
Andy K