First off let me make it clear: I never have believed in these much but I've been using a friends lately a bit because the nearest track is about 2-3 hrs away and I haven't a clue where the nearest dyno is. So I thought I would use this thing for the kicks to see what it would say. Anyway I used it yesterday and averaged out of 5 runs around 14.1 @ 101 There was wind involved so I ran it this evening to see what I could muster. After several crappy launches I got a 13.5 @ 107. Am I using it wrong or why is it giving my such low numbers? I KNOW my car isn't a 13sec car. Any other users have input?

P.S. if you are goin to flame me for using a g-tech please stay out. I know they are for comparison only and do not give real accurate readings. I just want to see what others are getting with their gtechs.

 

well with your mods, on slicks you would probly be able to pull 13's easy, but not likely otherwise. its just the g-tech, ignore it

 

maybe the weight of the car you put in is off, or the g-tech is not calibrated properly...

 

I would have to say it is the calibration of the G-Tec they are very accrurate they are usally within a tength of a second. Recheck your data that is being inputed for your car.

 

What is the right weight to calibrate it with? I put in 3250 but then went up to 3350 because I had some junk in the trunk.

 

Also it was about 25 to 30 degrees out also. Aaron says the difference between 50 and 80 degrees can be 0.4secs would that be the same as the difference between 50 and 25 degrees?

 

that might be the problem. I dont know what you have in your car, but mine with amps and subs and a full tank of gas weighed 3610 with me in it. Also, make sure you are on a level road. Down hill, your 1/4 will be slower, up hill faster

 

accelerometers are just too sensitive to the setup parameters to be very accurate in the hands of the general public for use on regular roads. on perfectly flat roads they can be somewhat accurate but will by nature be optimistic on the trap speed because of how real trap speeds are calculated at the track. instantaneous terminal speed versus distance/time.

the only value they have is judging performance changes for before/after modifications. same car, same road, same setup, etc.

 

Close, but not quite the same. In theory, the difference between 50 and 25 is a little less than 4 tenths. But, launching on a road with a surface temp of 25 degrees will be near impossible. But launching with a surface temp of 50 degrees will be much easier.

But the Gtech will only be as accurate as the parameter you put in. And even if the parameters are correct, they are usually optimistic.

Good point about the trap speed. The 1/4 mile track uses (I believe) the last 60 feet in order to determine speed. They don't use a radar or anything to determine your trap speed. So whatever trap speed you get at the track, you are actually going a little faster than that before the end of the 1/4 mile.

 

i have a gtech and ran 15.0 with a 01 auto that has intake,ypipe and pulley. pretty acurate i guess.

 

an accellerometer doesn't need to know the weight of the car to determine the 1/4 mile times. The weight is to determine the HP and other stuff. I havn't had one since they first came out but they used to be pretty accurate and the first ones didn't even do much so there wasn't anything to enter other than weight. If you car leans bad in the bad when your accelerating then that would make it seem faster. I tried it in a mustang with shot suspension once where the front lifted and the back dropped it thought the car was about .75 seconds faster than it really was

 

I've got tight suspension so that wasn't the deal. I ran it last about 10 days ago and it was around 45 to 50 degrees and got a 14.6. i can't remember the the speed exactly, I'm wanting to say 99 but not for sure. Anyway 14.6 sounded about right on to me considering no track prep and everything.

BTW that was the day I ran a custom turbo prelude! He's running around 8psi with pump fuel. He said his clutch slips too much from a dig so we ran from 20mph. Ran twice and neither one of us could edge the other out by much margin. He was a bit surprised saying "and you're aren't even boosted" Lol! VQ35+6MT = FTW

 

I ran a little test with my G-tech at the drag strip. I made 12 runs with the maxima (slow *** automatic) and found the G-tech consistant. My car was in full street trim and ran 10 passes with less than .2sec diff fast to slow. I threw out the fastest and slowest runs and averaged the other 10 runs. I found the G-tech was aprox .2sec slow ET and 2mph faster Trap than the drag strip. So my 15.9 sec 90 mph G-tech pass was a 15.7 at 88mph on the time slip. I have run the same type of test with my Z32 and found similar results.

 

good to know. I'd probably be running low 14s at a drag strip than. sounds about right to me.