Boost Gauge Connection

[z11375ss]

I can't understand how we as an SHO community have not figured out conclusively where to put the line hookup on the engine for the boost gauge to function in vacuum and boost conditions and read correctly. Anyone have any answers?

I've tried the small line on top of the motor toward the front. Got a very weak signal. I then tapped into the 3/8ths line running along the cowl. Got nothing but vacuum readings off that. I have thrown up my hands. Other than drilling a port into the intake (which I really don't want to do as it could lead to bigger problems) I have not seen a definitive answer to this conundrum. Anybody got anything?

 

[z11375ss]

Ok f***ers. I have found the solution! I have no clue as to why the examples on the internet show very complicated brass type fittings made from cobbled together hardware store items.

Using a T-shaped plastic vacuum connector and just cutting the line to work is just fine. Cost? .05 cents? So the T connector should be 3/8ths to 3/8ths with a third line coming off it with a 1/32nd line. Hook the gauge to the small one and run the two other ends into the brake booster line that runs along the cowl.

I have found that using this method seems to interfere with the operation of the power brake booster. As in when the motor is making boost, the brakes act as if they are manual and that freaked me out as when all of a sudden you have lesser brakes. You would think this condition would occur with or without the boost gauge installed. The problem goes away when you move the vacuum line to the intake. Think about this though. You are racing the car and need your brakes, RIGHT NOW! They are ineffective. Panic ensues.

There is a hose ('1/32nd') on the top of the intake that goes from the intake to the intake providing a constant source of vacuum or boost depending what the turbos are doing. This line is right in front of the MAP. I used that instead of the brake booster as I want my brakes to be great all the time. This was way less hard than it should have been and I hope this sheds light on something I couldn't find an answer to on the INTERNET!

One more thing. I saw a vid where a guy had put a boost gauge on his truck. He said the gauge worked but only showed the difference up to a zero boost/zero vacuum state (0). I suggest if you find this to be the case on your car to take it out and run the damn thing. My gauge would only show vacuum in the garage even when under boosted condition. As in, power braking the car to get it into boost mode.

I took it for a ride because I had faith in my work and lo and behold, the gauge read well above zero vacuum. Like 12 lbs of boost. I couldn't replicate this in my garage or on the street in front of my house. Take it for a rip and see if it works before giving up.

Good luck to all.