OK I am in the middle of reinstalling my avcr after a bunch of custom work and in the instructions one line needs to go to surge tank (UImanifold), it says for another line to go to a nipple on an IC pipe. Now I just put this line to the manifold too since I thought the pressure would be the same and I didn't happen to have a nipple on a pipe. After thinking about how the blow off valve is attached to an IC pipe and that the vac hose from it goes to the UIM I began to think that maybe the pressure is different or at least it takes a split second longer for the pressure to get to the UIM as apposed to the IC pipes. Anyone have any thoughts on this? Thanks

 

If it wants you to put a vac line to the Manifold and the IC, it probably has a way of measuring pressure drop, or to prevent ur turbo from overspooling in case of a massive leak *blow an IC coupler, the turbo would be pushing 20+ psi and your UIM would see 0psi* But since i dont own a AVCR, im just throwin out an idea


-Zach

 

I was thinking the same thing...the only thing is that the directions for the avcr seem to be a little worthless...they ask you to T into the vac line between the surge tank and the fuel pressure regulator. they are very specific that they want you to do that. That would be the same as plugging in to any spot on the UIM so I now don't really think I need to follow the directions exactly. Do you know how the blow off valve works? Why does it need a source from the uim when it is already on the IC pipe? Some guys even put it on the greddy elbow then the vac line to the uim...that is hardly any distance and I don't think there could be much of a drop in that space.

 

About that massive leak theory...say the coupler from the turbo to the IC pipes is where the leak is, then the pressure at both the ic nipple and the uim would be 0. I am hoping that the author of the directions couldn't think of another spot that would definitely measure manifold pressure (on every car) so he went with the IC nipple. I dunno

 

one line goes from a pressure source after the TB, ie boost gauge nipple, to the pressure sensor. This is the input for the unit.

Then one line goes from the primary compressor housing nipple (or if you are single, a pressure source close to the turbo) to the [NO] port on the solenoid valve. Then one from the [COM] port on the solenoid valve to the wastegate/actuator. This is what controls the boost (output)

 

Yeah I'm single...I guess i need to weld a nipple then huh

 

You could reference the solenoid from a souce after the TB, but you want to keep the hoses short to have fasrter reasponse. Plus the nipples off the UIM are fairly small, opposed to a larger nipple off of the IC piping or compressor housing.

 

http://www.rx7turboturbo.com/robrobi..._r_install.htm

he just used manifold taps. I think the sensor must go to manifold, and the NO port is the control pressure source. at part throttle, you can have zero in manifold and 6 psi before the TB, so their recomended set-up would help avoid any overshoot with rapid wot from part load.