Has anybody here ever used one of these as a tuning aid?
The original models (acceleration, hp only) are now available on ebay for $45 brand new.
The newer models that offer downloadable graphic readouts are a lot more $. They claim that these can chart torque curves too by reading engine rpms off the alternator "noise" from the lighter plug power source :roll:
They say that they will work on diesels the same way.
What do you all think :?:
this was discussed on the old board a little...
i've never personally used or even seen one...
but the general consensus was that you want the more expensive one... $45 seems damn cheap though... why not?
the more expensive one lets you do a LOT more though, and you can control it all with a laptop
I have used and own one of the newer more expensive, competition models... and I have played with the older model years ago. IMO, don't waste your time with the older ones, about all they are good for is accurately measuring a 0-60 acceleration time. The "peak" non-SAE corrected, after aero-loss hp and torque numbers aren't very useful.
Supposedly on the competition model they're coming out with upgraded software soon, although it's been a long wait, that can analyze autocross runs and lateral acceleration. That will make it even more useful to me. For now though, it is a great tool for analyzing forward acceleration, and yes it works great with VW Diesels, it reads a good RPM signal from the alternator ripple signal and will plot out hp & tq vs rpm curves. You can see at what rpm range your motor is strong at, where it is weak at, at what RPM does the governor start limiting fuel, etc. Many many things you can do with it. It is fairly repeateable when done back-to-back runs if you start on the exact same spot of road each time so elevation changes are identical, but if you wait a long time weather changes will impact the readings. Really the main value the competition models add is being able to see your hp and tq vs rpm curves. It's a lot cheaper than dyno time and once you buy it you can use it all you want. My suggestion with the g-tech devices is: don't expect to compare absolute numbers and get very meaningful results. The numbers are low as the g-tech measures after aerodynamic losses are factored in, and also they aren't SAE weather corrected so they aren't really repeatable unless you do back to back runs. But, using some common sense, they are VERY useful to see how your power curve might be changed as a result of a modification. And that gives me a lot of value for performance-tuning my motor.
Thanks Guys :!:
That's just what I wanted to know