DIY Active Map Clamp, How To make your own Active Map Clamp (Gen 3 3SGTE) Options

[presure2]

so while browzing around for the symtech active map clamp that both dustin and jim use, i came across this diagram on one of the srt-4 message boards,
its a DIY active map clamp.
heres a link to the original post on srt4forum.com
http://www.srtforums.com/forums/f75/how-bu...p-clamp-349656/

the part # in the diagram in the link for the diodes is for 50 of them, since you dont need 50, i modified the diagram with the pt# for 10 diodes.
heres the diagram:



here are a couple links for the parts to build one.
first the potentiometer, PT#271-342


http://www.radioshack.com/product/index.js...oductId=2062307 it costs 2.69$

the diode is 1N914 Radio Shack PT# 276-1122 whic gives you 10 diodes, and costs 1.49$

http://www.radioshack.com/product/index.js...oductId=2062576

according to the radio shack website, the store right down the street has these parts in stock, and they open @ 10am, so imma run down in a bit and grab the parts.
once i build it, ill install it and detail how to use it.


For those of you that dont understand how it works, here's a quick break down.

the map sensor on the 3rd gen 3sgte puts out a 0-5 volt signal that tells the ecu how much pressure is in the manifold.
the higher your boost level, the higher the voltage getswhen you reach max boost. when you reach right about 18psi, the ecu sees the max voltage allowed before boost cut happens, and the car bucks and tells you "STOP IT!" lol
with this device, you can "clamp" the voltage at a level just below boost cut, while allowing the sensor to work as normal below that level.
that way, you can boost above 18psi, and not hit boost cut.

:edit:
went and got the parts, assembled them, and took some pics.
ill install and test it later when Jenn gets home from work.

the pot



the diodes



here it is assembled.
power wire closest to the adjustment screw, 2 diodes wired in series, with the band at the tops (i forgot to take a pic without the heat shrink, so i just stuck a couple of the diodes in the pic for refrence) and the ground last.



once i install and test it, ill report back!

[presure2]

freddy, thats an FCD that locks the voltage at one setpoint, no good for the 3rd gen.
we need somthing active, that allows the sensor to work normally below whatever voltage we set the clamp at.
dan, we need it to be adjustable, to get it as close to the cutoff voltage as possible, so we ensure we're getting full duty out of the injectors.
if we clamp it too low, it'll run lean. BOOM.
jeff, i really wouldnt recommend it. your much better off using a 2 bar map sensor from a 2nd gen 3sgte, with 390-440cc injectors, and using a fuel controller to adjust the afr as needed.

i tried hooking up another way, and it dont work still.
dissapointing.
the unit itself works as it should, it just will not clamp the voltage coming out of the map sensor for some reason.
i wish i was really good with this electrical stuff, im sure i could figure it out if i was, its gotta be somthing simple, maybe the wrong type of diodes or somthing.