I have been thinking about this for a while, and I am going to try this out. The main motivation behind it is the fact that I am keeping my TVIS system and want to get the most out of it, and the oem ecu TVIS operation is far from performance-optimal. Hence, not only controlling its opening point but its opening rate. The reason being, it seems to me best to have it open based on RPM (which many have done), but not only that, to have it open progressively based on RPM.
From studying dyno charts of those that have dyno'd with the TVIS closed and then fully open, and then set their TVIS to open at a certain RPM, there is a bit to be gained, when all those dynos are overlayed. There always is a dip as the TVIS goes from fully closed to fully open rather quickly. This rate of opening is always the same regardless of the gear we are in.
Now what I am curious about, is whether the turbulence from a half-open TVIS will be too disruptive and negate the potential gains. It could be possible that this is the case. However, I am too curious not to try.
What some people have done to control things like throttle bodies on various motors is to use a suitable servo motor (originating from the RC hobby world). I want to control this servo motor using my Arduino (Freeduino actually) microcontroller, and then programming it with whatever parameters I want. Using correct resistors and circuitry, I get the tach signal (probably have to get it down from 12v to 5v (the Arduino needs 5v)... I think its all squarewave... and then write a small program that assigns servo motor positions based on those RPM numbers. So, I can start the motor's movement at 3700 RPM, and finish its movement at 4700 RPM (for example), if it is deemed to be most beneficial in that range. It also does not have to be a linear rate, it can be anything at all.
I am willing to bet that if we were able to dyno in every gear, we would find that one of our gears is closest to having the oem TVIS open at a rate that suits the RPM climb.This is probably first or second gear. The gears that this mod would benefit the most would be 3,4,5, since the TVIS normally opens at the same speed no matter the gear.
In addition, if I figure out that there are other conditions or scenerios in which to make exceptions to the RPM-based rate (such as boost for example), I can write another small program to perform that as well, and run input data from another source such as boost level (signal).
Has anybody done this, or something like it? Any thoughts welcome... Its going to take a bit of homework on my part to figure out the correct electronic parts... I already have the Arduino, and access to a great electro-acoustic lab at school tht is stuffed to the brim with resistors etc... I am studying what others have done to convert correctly from the tach signal to the Arduino so that it all works. Some things are less than 12v in our cars, so it may work to my advantage.
scarecrowX? :angel:
You usually have a way of simplifying over-complicated plans...
One thing I can see right away:
-moisture/heat protection for the servo motor. I can install the Arduino anywhere (like in the trunk for protection).
From studying dyno charts of those that have dyno'd with the TVIS closed and then fully open, and then set their TVIS to open at a certain RPM, there is a bit to be gained, when all those dynos are overlayed. There always is a dip as the TVIS goes from fully closed to fully open rather quickly. This rate of opening is always the same regardless of the gear we are in.
Now what I am curious about, is whether the turbulence from a half-open TVIS will be too disruptive and negate the potential gains. It could be possible that this is the case. However, I am too curious not to try.
What some people have done to control things like throttle bodies on various motors is to use a suitable servo motor (originating from the RC hobby world). I want to control this servo motor using my Arduino (Freeduino actually) microcontroller, and then programming it with whatever parameters I want. Using correct resistors and circuitry, I get the tach signal (probably have to get it down from 12v to 5v (the Arduino needs 5v)... I think its all squarewave... and then write a small program that assigns servo motor positions based on those RPM numbers. So, I can start the motor's movement at 3700 RPM, and finish its movement at 4700 RPM (for example), if it is deemed to be most beneficial in that range. It also does not have to be a linear rate, it can be anything at all.
I am willing to bet that if we were able to dyno in every gear, we would find that one of our gears is closest to having the oem TVIS open at a rate that suits the RPM climb.This is probably first or second gear. The gears that this mod would benefit the most would be 3,4,5, since the TVIS normally opens at the same speed no matter the gear.
In addition, if I figure out that there are other conditions or scenerios in which to make exceptions to the RPM-based rate (such as boost for example), I can write another small program to perform that as well, and run input data from another source such as boost level (signal).
Has anybody done this, or something like it? Any thoughts welcome... Its going to take a bit of homework on my part to figure out the correct electronic parts... I already have the Arduino, and access to a great electro-acoustic lab at school tht is stuffed to the brim with resistors etc... I am studying what others have done to convert correctly from the tach signal to the Arduino so that it all works. Some things are less than 12v in our cars, so it may work to my advantage.
scarecrowX? :angel:
You usually have a way of simplifying over-complicated plans...
One thing I can see right away:
-moisture/heat protection for the servo motor. I can install the Arduino anywhere (like in the trunk for protection).