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Just installed a Profec B into my R34 GTR, and stuck on the last part. T'd the actuators into the new solenoid, blocked one hose off the factory solenoid, and blocked both plenum pressure outlets on the passenger side (found it much easier then digging in under the inlet mani). However, there are no fittings on the comp housings or hot side intercooler piping to get a reliable pressure source for the solenoid. What does everyone usually do? Take the factory source from the plenum, or drill and tap a fitting on the hot side "twin turbo" pipe? Would love to hear some options.

Tried searching but the function on this board is sooo vague at times..

Also taking suggestions on mounting the unit on the underside of the dash, double-sided tape keeps coming loose :D

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I'd stay away from sourcing it from the inlet mani/post throttle body.

Cos in a situation of say half throttle when your on boost, you signal wont read what the turbo is actually putting out.

Under half throttle the turbo will need to spool up more than say 10psi, for 10psi to reach the source...

I'd say find a good spot (reasonably close to the throttle body) and drill and put a hose barb.

And for f**ks sake, make sure its sealed. Some gasket maker should to the trick, better still, get a stainless hosebarb and weld it onto a bit of steel piping, the cross-over pipe to be exact... Don't use the hot side, its not very accurate (hot air = less dense = less pressure)

Happy boosting...

Ok. On an RB26 the inlet mani is pre-throttle bodies, so that would be close to the throttle bodies without being post, as you were suggesting. There is no crossover pipe either like other RB's.

In all my previous turbo cars i have always put a barb on the hot side, because i was always under the impression that it is better to be as close to the comp housing as possible.. I maybe totally wrong, but thanks for the feedback :(

Ok. On an RB26 the inlet mani is pre-throttle bodies, so that would be close to the throttle bodies without being post, as you were suggesting. There is no crossover pipe either like other RB's.

woops didnt see it was a GTR...

yeh doesnt really matter hotside vs. cold side, in the end doesnt make THAT much difference...

Plus taking it from the cold side allows for any tiny leaks in the cooler piping, and youl get that tiny bit more boost out of it.

I've always thought its more accurate cos closer to the TB(s) gives the signal of exactly the pressure that's going into the engine

But yeh, doesnt make a huuuge difference...

As for mounting it, try drilling two little holes in the plastic, then feed a cable tie through and around the controller. Thats if your cool with having 2 little holes in your dash that is...

As for mounting it, try drilling two little holes in the plastic, then feed a cable tie through and around the controller. Thats if your cool with having 2 little holes in your dash that is...

lol, that's actually what i thought about doing! Might use velcro though as R34 dash parts maybe a lil $$$ to replace.

does a profec b have 2 or 3 lines you plumb into engine ? you called it a pressure source . meaning where the pressure supply to open the waste gates comes from . or did you mean the signal line that actually tells the boost controller how much boost is on the intake manifold ? . reading your post i think you did and turbo x trail has the wrong idea about what you wanted

Sorry not sure if i had the right term or not, that's why i tried to describe it.

The Profec has a vacuum source which runs directly to the control unit inside the car. It has another line that runs from the solenoid, which i have t'd both actuators into.

The final line is meant to run from the solenoid to the compressor housing or hot pipe according to the instructions. That is the one which i would like an opinion on.

just use whatever line was going to your actuator before, put the T piece on it and run one line to your solenoid and the other to the profec, done. using the intake manifold for the pressure source is fine, everyone says you cant and it'll never control boost properly but i've never seen it not work perfectly

just use whatever line was going to your actuator before, put the T piece on it and run one line to your solenoid and the other to the profec, done. using the intake manifold for the pressure source is fine, everyone says you cant and it'll never control boost properly but i've never seen it not work perfectly

I heard that i shouldn't take it from the intake mani too, but it makes sense that you can... Perfect, exactly what i wanted to hear! Thanks dude.

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