hook up cheap g meter

[parish8]

i used to use my gtech to help set my shifts. works great. you just look at the g's before and after each shift. it should be close to the same and a nice gradual curve down as the g's fall and the speed goes up. if there are more g's after the shift you are shifting too late. if there are less g's after the shift then you are shifting too soon.

my gtech died after many years of service. looked at buying a new one and they are $300. i decided to go another route.

picked up a cheap acelerometer off of ebay. it came strait from china and was $20 shipped. so far i got it working on the bench. i am going to wire it into the hptuners box. it is a 3 axis g meter, i am going to wire up just 2 axis and i dont know that i will ever use anything but the front/back axis.

that voltage reg was another $1.50 from radio shack. here are some pics so far, i forgot to resize them so they are kinda big >> http://www.neufamily.org/images/gmeter/

tomorrow i am going to wire it up in the car. only question is mounting it. i might just zip tie it to the bottom of the seat, maybe wrap it up in some bubble wrap first? not sure.

check this out, while looking up the instructions on hptuners for wiring in aux inputs i found out hp tuners has 2 programable outputs. i haven't tried it yet but it looks like you can control an output(relay) based on any pid that you are scaning. i might try some cheap 2 stage speed based boost control. it looks like i could run off the wg spring up to a certain mph and then switch over and run off of the manual boost controler. use the relay to control somthing like the purge noid i pulled off the car. hmm. another question for that is will it work without a laptop, just with the hptuners box?

[parish8]

it works pretty good. here is a screen shot from a 1-4th gear run. the yellow is the side to side g's, not telling anything but i left it up there so you can see how not smoothing the signal made things look. i used a 50microF cap on the hptuners input and it smoothed it right out. might reduce that value a little to give it a little quicker responce.

looks to me like the shifts are pretty good. not a big g change after the shifts. the 1-2 shift could be a little later.



here is a gtech screen shot from a stock silverado, you can see the g's after the shifts are way down and extending the shift would help to raise averge g's. you can see how on the black run we ran it to a much higher rpm and it had more g's over that time. of course it pealed out that run and he let off before the end of a 1/4 mile run so the numbers dont show any improvment but you get the idea. more g's over time = faster.