HA Boost Gauge Hookup

[CzyKats44]

OK my Hobbs switch is inop, the dash lights do illuminate when grounded but that's irrelevant, no biggy. I've read here that set up is inaccurate anyway.
However, is that line tee'd off the back of the intake (that goes to the hobbs) sufficient to hook up to a gauge and be a little more accurate?

Anyone know the best place to route that though the firewall?

Thanks

Greg U.

 

[turbonut85]

Yes. That line is fine...just make sure you zip tie all the connections within that line. Sometimes you can fit the nylon line for a boost gauge through the same grommet the cruise control wiring uses...

 

[CzyKats44]

^ Good info, thanks man.

 

[FJM568]

If my memory is correct and you are still running the stock hot air intake, there is a hex head pipe plug on the front drivers side of the intake. Take that plug out, it's a direct access to the main plenum of the hot air intake, perfect for a vac/boost gauge.

Hope this helps.

 

[CzyKats44]

That little guy down there? (see pic in next reply)

Yup, stock setup, I plan on doing the fuel pump and 86-87 ecm upgrade to run power logger but i will be keeping it in its original configuration.

If nothing else, it gives me options, Thanks FJM

 

[CzyKats44]

Intake pipe plug

 

[BRAD_PADGETT]

If my memory is correct and you are still running the stock hot air intake, there is a hex head pipe plug on the front drivers side of the intake. Take that plug out, it's a direct access to the main plenum of the hot air intake, perfect for a vac/boost gauge.

Hope this helps.

Bad idea here. I tried this and got bad results with my setup. Just tap into the line on the back off the intake manifold. I taped in by the fuel pressure regulator. Brad

 

[CzyKats44]

Seen as how I ran a brand new line out to the inop Hobbs during the top end reseal, I planned on just rerouting from the Tee through the wall. It's already there and not doing much of anything else.

 

[Jerryl]

My $0.02
If I was going to use the front plug, I would run copper line to the firewall . . . Or just into the car and run the plastic hose from there.

I would not tie into the FPR as this is way too important to take the chance of a leak . . . Or adding volume to slow the signal to the FPR.
Tying into this line more than doubles the chance of a leak.

The best way is to run dedicated lines for both FPR and MAP and use silicone hose. If you are not using the boost solenoid to contr boost (most are not), tie into the leg of the "Y" with the line disconnected from the boost solenoid.

Like I said . . . Just my 0.02 worth.

 

[CzyKats44]

Why would one not use the solenoid?

 

[BRAD_PADGETT]

Why would one not use the solenoid?

Hook up the wastegate actuator directly to the turbo.

 

[BRAD_PADGETT]

Hook up the wastegate actuator directly to the turbo.

Hooking up the wastegate actuator to the turbo does work very well. I disconnected my waste gate solenoid and plugged all vacuum lines. It is called tuner style. No BS. Boost is 100% controlled at the actuator rod length. No chance for a screw up which is a blown head gasket. 20 lbs boost is all I run.

 

[CzyKats44]

Solenoid takes press inputs and computer decides when to actuate? Running the line straight to the turbo cuts out the potential for solenoid failure?

 

[CzyKats44]

Solenoid failure causing over pressurization

 

[Jerryl]

The solenoid knows nothing about the boost target and does NOT provide feedback to the ECM. The ECM pulses the solenoid on/off to create a controlled leak in the actuator circuit so the boost pressure changes. The pulse is controlled by the chip based on what target and combo the chip maker was instructed at time of order.

The solenoid has certain limitations to control boost which is why the adjustable WG is still needed. Besides . . . The boost changes with ambient conditions so the tuner needs a way to compensate.

Make sense?

 

[CzyKats44]

A whole lot of sense. Is it inefficient?

 

[Jerryl]

That depends on the setup and target. Lol. On a stock car, it's very effective.

 

[CzyKats44]

Solenoid is binary, relieving press or not. How does the ecm know pressure is near the target? Or does it sense it as throttle/load ect and have previously determined values?

At what point would I want to hook up direct? Is it even necessary in a stock config?

 

[BRAD_PADGETT]

Solenoid takes press inputs and computer decides when to actuate? Running the line straight to the turbo cuts out the potential for solenoid failure?

Yes. I also have never heard of a waste gate solenoid going bad or an ECM mistake. I did it on the advise of my tuner. Really simple . The Caveat is that you are responsible of total boost with the actuator rod. I have left 50 HP on the table in order to be safe buy limiting boost to 20 lbs and running rich. My 2 cents

 

[CzyKats44]

... I have left 50 HP on the table in order to be safe buy limiting boost to 20 lbs and running rich. My 2 cents

Good info. I have no plans on any big power mods, tuning for me at least in the near future will be fine tuning once I can get inside the computer.