Hey all, I am looking at getting a zex wet jet system for my 99 tahoe. Only issue im having is that the system requires a vacuum input from the fuel pressure regulator which is located under the intake plenum and dumps directly into the plenum. It requires this line to regulate fuel/nitrous distribution, any ideas on how to go about getting this vacuum input? Drill a fitting into the intake plenum?
Fuel pressure vacuum line for nitrous
- Thread starter russj85
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drakon543
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I think there is an unused vacuum port of the passenger side. Or since your running nitrous im sure you wouldn't mind disconnecting the canister up front and using its vacuum line.
Are you referring to the vacuum line coming out of the purge valve on the passenger side of the plenum?
drakon543
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Yes i try to keep everything connected as its supposed to be but ive seen it capped off without issues. I think there is an unused port over there somewhere tho. You could also t off one of the lines used for a basic similar purpose.
The only thing vacuum wise that I see coming out of the plenum is the purge valve but I don't know that I would get an accurate reading from there
The only thing vacuum wise that I see coming out of the plenum is the purge valve but I don't know that I would get an accurate reading from there
And If I remember correctly the purge valve is one way only.
drakon543
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You would take the purge valve out entirely or put in an adapter to t off before the purge valve. But technically yes i think you could drill and tap a new vacuum port. Id take the plenum off tho to do that.
I've been looking for an adapter but haven't been able to find one. I'm thinking that threading a vacuum port into the plenum would be the better bet. I'm getting ready to tear the top end apart anyways.
drakon543
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If you thread into the plastic plenum step drill and drill slow and you will get a smoother cut. Also even tho its plastic use some cutting oil or regular penetrating oil and tap slowly. Using too much pressure will likely crack the end out when your drilling and a bare tap too fast will get you nasty threads. Im not 100% what type of plastic its made from but being in plastic manufacturing you want to make a clean smooth cut without causing too much friction. Too much and it will push some of the plastic out if the way instead of cutting it and cause issues trying to tap it correctly.
Thanks for the input, I'm a few weeks away from tearing into the motor but I'll let you know how it goes.
Upcoming upgrades:
-Compcams cam 08-411-8
-Compcams locks, retainers, springs, lifters.
-Long tube headers and custom pipe to bypass cat converter.
-mpfi fuel injection upgrade.
-zex wet system with progressive cntrlr @ 100-140 shot approx.
-custom efilive tune to deal with it all.
*eventually a 4l80 swap.
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