I have a question for everyone. I have a 1996 nissan auto. which is supposed to do 15.7 in 1/4. I tested it on a G tech and all I could get with a cone filter and performance exhaust was 16.3 but the thing I found wierd was that I hit 92 MPH I thought that was a high speed for just 16.3. someone tell me I'm wrong or the machine is

 

You're wrong or the machine is

Seriously, though...I've always been skeptical of accelerometers' accuracy at determining distance travelled. If it's measurement of 1/4 mile is actually more than 1/4 mile, then you'll see results like that. (read: that time is for 3/8 mile, so 16.3/92 would sound right for that run)

 

The G-tech may be off by a bit but it should be consistant, so it should be OK for seeing what benifit you get from mods.

The Gtech trap speed is what you are traveling at the end of the 1/4 mile. At a track your speed is averaged over the last 50 feet (I think), so the G teck speed will be higher.

Perhaps the Gtech is right and you need to improve your launch. Or your car may have an engine problem or just be a little tired?

 

the most accuracy the goverment will allow the public is 50 feet, for satelight devices, gps and such. Although im not sure if they did but i heard they were gona cut it down to like 11 feet for boating. kinda weird to think how acurate gov can be...

 

This has nothing to do with GPS. It uses accelerometers to determine how fast you are going over time.

(IIRC, we can get 30' resolution via satellites alone, but greater precision can be had with repeater beacons in heavily navigated waterways)

 

As long as you center it properly it should be fairly accurate on the 1/4 mile time. From personal use, I noticed that the MPH speeds are sometimes high. Be sure to use a road that is fairly flat with no bumps or dips.

 

G-Tech has nothing to do with GPS, but just to feed your paranoia (heheh)... Civilian GPS can be degraded / disabled however the gov't likes. The key to GPS is how accurate the satellite's clocks are (very, they're atomic). But THEY can make the satellites not tell your receiver exactly the right time, so after all the calculations, you end up a little bit off. Of course, THEY get the time as exact as possible, and have matching atomic clocks on the ground, so it's very easy for them to get 3m (or better) GPS resolution.

Oh, and did you know that commercial satellite imagery now has a resolution of 0.6m? Imagine what the gov't satellites can actually get... Now put your tinfoil hat on and go to bed. Sleep tight! heheheh...
GMT

 

16.3 isnt that bad for just a cone, remmeber factors like temp and weight, weight i have heard is rather important with those things as well as holding it level with the front of the car and calibrating it to your rpms.

i gteched at 15.3 with ypipe intake and 50degrees at night

they are deffinatly fun to mess around with and great for comparing cars running on the same stretch of road

 

learn something new everyday