vacuum modulator vs no vacuum modulator
#21
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porting a MAF reports less load to the pcm which causes you to run a little leaner AND makes the pcm think "less load...dont need so much line pressure"...that aint good. The stock pcm calibration is not what I want interpreting my mods for line pressure. Vacuum mod does this...foot to the floor...full line pressure..it dont care if you even have a maf. Take my car..half throttle and I can have 2-3psi of boost....I dont want the pcm to think "half load so half line pressure".....the vacuum mod see boost or no vacuum and applies full line pressure.
#22
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The vacuum modulator can also increase the main line pressure in manual 3 from about 170-190 psi., to about 220-235 psi at WOT. This is a "big " advantage when addressing the 3-4 clutch life expectancy. It also makes a dramatic difference in 4-3 or 3-2 downshifts, it happens instantly, instead of the the usual 1.25 - 2.0 seconds delay. The vacuum modulator is using "real world" readings, instead of "pcm calculated load" quoted earlier. I am sure that one day the PCM will be able to do what we want in all circumstances, but that time is still a ways off, from what I can see. Till then, I will use the vacuum modulator in all of my High Performance units.
#24
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Originally Posted by sleeperstyle
is vaccum modulation a good or bad idea in an otherwise stock 4l60e w/ a shift kit?
#25
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Originally Posted by Dmoney
I installed mine and love it. Did a little tweeks in the tuning and my tranny is like a new monster. No more 2-3 shift problems.
Dmoney,
I just bought a vacuum modulator kit for my 4L60E. The installation was more than I expected looking at the instructions. Did you actually have to drill your valve body?? What kit did you use? Can you give me an overview of what you had to do in order to install?
#26
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Originally Posted by real82it
Dmoney,
I just bought a vacuum modulator kit for my 4L60E. The installation was more than I expected looking at the instructions. Did you actually have to drill your valve body?? What kit did you use? Can you give me an overview of what you had to do in order to install?
I just bought a vacuum modulator kit for my 4L60E. The installation was more than I expected looking at the instructions. Did you actually have to drill your valve body?? What kit did you use? Can you give me an overview of what you had to do in order to install?
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