Hi All,

I’m finishing off my turbo charged 86 N/A; the car runs really well and is quite a wild ride. There is one area that is really confusing me, I have installed a manual boost gauge connected to a port on the hard pipes (before TB) along with a Greddy E-01 that has a vacuum valve connected to the intake manifold. When driving the car it pulls hard and the mechanical gauge displays up to 9 PSI, at the same time the Greddy displays around 5 PSI, can some one help understand the big difference between the two gauges?

Secondly I have the Greddy boost solenoid configured for a single port external wastegate, the wastegate is connected to COM and the boost output form the hard pipe is connected to NC. I read a few posts that say the wastegate is connected to COM and the boost source is connected to NO, with this configuration I only see 4 PSI, this is because COM and NO are open and the waste gate is opened prematurely by the boost out put. Does anyone have a Greddy EBC with a stock wastegate ? How is yours connected?

 

The boost gauge needs to be hooked up after the throttle body. We hook the boost gauge up to the KLR hose in the 951, this hose is attached to the manifold between the 3rd and 4th intake runner.

Moving that hose should get you a better reading of true intake manifold boost pressure.

 

I'm looking at my install manual on my Profec, I have the older one, so it might not help you.

Mine is labeled 'in' and 'out'. The out side goes to the wastegate, so..... If your hose configuration is the same as mine, looking at the top of the solenoid, with the outlet nipples pointing towards you, 'out' should be the right side.

 

What model Profec do you have? I can check it out and see how it compares to mine.

 

Yes, I see on 951s there is plastic hose on a banjo bolt. I don't have the banjo bolt so I use a brass fitting that connects to a TEE, the TEE feeds my boost gauge on one outlet then my FPR, damper, BOV and water injection controller on the other.

Thanks !!

 

I've got the older ProfecB. Back when they were a simple 3 **** device.

Maybe you need to build some sort of vacuum distribution block, to eliminate all the T's. You could even possible drill and tab a new vacuum port into the intake manifold, so that you know you have a good connection for the boost gauge and Profec input.

 

Things are now working great, I created a separate vacuum feed for my EBC and no I see 8 PSI. With regards to the boost solenoid, I followed the external actuator hookup which connects COMM to the wastegate and NO to the boost source, the NC connector vents to the atmosphere.

The Greedy Profec E01 works really well even with the single port wastegate. The E01 can log RPM, AF and boost plus other engine characteristics, you can record then play back how much boost the car made at a specific RPM.

Thanks !!