G-tech Performance Meter (1-axis)

[alaskax]

Was wondering if anyone having the original single-axis G-tech unit has noticed this happening...



In the 0-60 test, the unit will trigger accurately if MILDLY accelerating (about 12 sec), but under hard acceleration will trigger considerably before 60 mph. If I'm doing about a 8. 5 sec 0-60, will trigger near 55 mph, and tell me 7. 5-8. 0 sec or so. I do not believe that the pitch angle from the rear wheel torque is sufficient over the duration to account for such a difference. I don't know how "off" this becomes when using it to estimate a 1/4 mile run.

 

[alaskax]

Try Again!

Has anybody specifically noticed that their GTech does NOT do what I described mine doing, and rather triggers correctly independent of how hard you accelerate??



Thanks for any input



John

 

[BushWakr - RIP]

I hope to do some more work on the G-Tech myself. I have wondered about the accuracy a bit too... .

The one he had was the G-Tech Performance Meter Pro.

Have you done any "HP" tests with it? If so, how did that work out for you?

Maybe we can compare notes.

Also, I had a young fella set it up for me while I did the driving and it took some fiddling to get it set for the runs. The weight you enter is critical as well, maybe you're having a problem in that area?

Just some thoughts...



bob.

 

[Vaughn MacKenzie]

Speedometer lag

I have noticed most electronic speedometers are slow to respond, and it could be you are hitting 60 before your speedometer indicates 60, and the faster you accelerate the greater the error would be. Although I would think 2-3mph error would be the max.



Just a thought.



Vaughn

 

[ewcmr2]

I haven't used mine much in the truck but in cars I haven't noticed any irregularity's in its performance. If someone wants to make an offer I'd consider selling my G-Tech since I now have a GEEZ data acquisition setup.



Eric

 

[alaskax]

Bob,

When doing hp, 2 issues: I have not found anywhere yet to weigh my truck, so I am assuming 7000 lbs from reading the forums, but I know that is critical. However, it peaks almost exactly where my dyno run peaked, which is right around 280, but that occurs during the shifting when the added momentum of the revved engine (during shift with the auto) "slams" into the torque converter giving a larger brief acceleration spike (thus "horsepower" spike). Again, this is consistent with my dyno results, which was hp vs. mph instead of hp vs. rpm as it should be. It's not quite as easy to control this test as with a manual transmission (or at least I'm not sure about the best way to do it). Also, of course, these results should be lower than dyno since air friction horsepower is not accounted for. Perhaps watching the meter numbers during the 2nd to 3rd gear interval is best, when speed has not yet built up that much??



Vaughn,

My speedo seems to respond well with no delay, and I have the Gtech mounted on my dash so I can see it and speedo at same time. Mild acceleration triggers are always VERY close. Harder accelerations always show 3-5 mph too soon. It doesn't seem to me there is any significant delay in speed indication, but I can't be sure!



I can "compensate" by turning the unit laterally, but don't want to have to do that!



I would love to test the new model and see if the same thing happens.



John