newbee needs help with megashift

A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
Post Reply
RICH454MC
Posts: 9
Joined: Tue May 08, 2012 9:50 am

newbee needs help with megashift

Post by RICH454MC »

Hi there. I just built my first megashift and am planning on using it with a 4l80e. I have some questions that I cannot locate the answers for and was hoping someone can help.

- Do I need the range sensor on the side of the transmission or does the mshift input only from the pressure manifold?
- I am planning on using a map sensor for load calculations. Do I need to calibrate the sensor and if so how do I do it?


I think I am forgetting a question but will post it when I remember. thanks in advance.
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: newbee needs help with megashift

Post by Bernard Fife »

Rich,

You need three digital signals that will indicate the current manual gear lever position. Generally this is taken from the pressure switch manifold (PSM), but you can use anything that works for you. (http://www.msgpio.com/manuals/mshift/4L80E/4L80e.html)

If you are going standalone, and are using a MAP sensor for load, then you calibrate the MAP sensor using this procedure: http://www.msgpio.com/manuals/mshift/V22tune.html#gn

For example, if your MAP sensor has 0.0 kPa and 0.00 Volts, and 255.0 kPa at 5.00 Volts, but the maximum pressure you expect is 150 kPa (~ 7psi boost) then you have 0% = 0V and 100% = 5*150/255 = 2.94 V. Then you would enter 0% = 0 V and 100% = 2.94 V in the calculator in the link above, and it will give you that slope and intercept values to enter into TunerStudio. In this case they would be 'Load at 0 Volts' = 0 and 'Multiplier' = 34.01.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Post Reply