Boost Gauge Q

Junior Samples

Walk Away
Joined
Aug 3, 2007
After 20 some years of All Chevy I picked up an 87T for 6K

Very Clean with about 14K invested into drivetrain Anyway...

Q is I hooked up boost gauge ...off of vacuum line just off solnoid..should I hook it up before (between Y and turbo) the Y restrictor? close to turbo or what?

Also there are two ports off of solinoid one has the vacuum line and other is left open is this correct?

one more thing...while the dummy bar bottoms out at 15 on spool up the gauge only shows about 10#s (autometer gauge)...I'll trust my gauge i just want to make sure my plumbing is correct



Thanks
Mike
 
Welcome!

You can tap into just about any vacuum line for the boost gauge. I say "just about" because some have one-way check-valves on them. If you "T" one of the lines coming off of the throttle body it might be more convenient. Otherwise, if you want to take it right from the turbo you can T into the line between the turbo and the solenoid.

Yes, the solenoid should have a vacuum line on one port and a foam filter on the other. The foam filter usually falls off a few minutes after having installed it leaving just an empty port.

Disregard whatever the lights in the dash are telling you boost-wise. They're for decorative purposes only. Trust the gauge.

Jim
 
Jim

Thanks

Yeah I'll trust the gauge anyday

I paid 6k for this car, guy had about 14 in motor, trans and rear end work done.

Thing I noticed in all the paperwork was the builder only put 30#injectors in and non adjust fuel reg which pretty much told me that he didnt want the customer to blow up the car...lol

Motor has about 2000 miles on it, lots of goodies, IM learning quick since I am a chevy guy.
 
Actually, I would not recommend plumbing your boost gauge source into the wastegate/solenoid lines as it's not a very true reading as to what is actually going into the motor. The best place to tap into for an aftermarket boost gauge is the line that runs over to the MAP sensor located on the passengers side inner fender. If your car has an analog "needle" style dash, you will have a MAP sensor. Tee into this line and run your new vacuum/plastic nylon line into the car. If your car has a digital dash, you won't have a MAP sensor, but you will have a Hobbs switch. This vacuum line comes off the top of the throttle bodys' vacuum distribution block and is a more accurate reference point to tee into. This reading is the true reading of boost that the motor is actually taking in. You also do not want to tee into the vacuum line that feeds the fuel pressure regulator either. You do not want to create the opportunity for a vacuum leak to occur at the regulator, that is a recipe for disaster.
HTH

Patrick
 
I agree with RUQWKNF...if you tee off before the solenoid you wont have an accurate reading because the purpose of the solenoid is to bleed off boost... MAP sensor line is where I run mine from as well.
 
Thing I noticed in all the paperwork was the builder only put 30#injectors in and non adjust fuel reg which pretty much told me that he didnt want the customer to blow up the car...lol

Actually that was pretty short-sighted of the engine builder. Big injectors and an adjustable regulator would help guarantee he had enough fuel to support more boost.

Jim
 
T-Jim

But on the other hand the guy he built the car for whom I purchased it from had no clue..he took it at face value and assumed thats all she had, but he informed me that he was told to bring it back once broken in for upgrade which he never did.

I really need a scanmaster and fast though, it is idle'n high... no vacuum leaks and now Ive heard some dang powersteering switch could make it idle high as well as IAC etc so I really need to get it plugged in or else I might find myself trippin over dollars to pick up dimes.

Mike
 
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