Need to pressure test my intake

[Satisaii]

I think that I have a leak on an intercooled hotside. Instead of just guessing about where it may be, I would like to test it. My budget is not allowing me to pay for this service, so I need a way to do it on my own.

Here is my plan:

Cut a circular piece of wood to block off intake at throttle body.
Place fitting in supercharger to hook up an air compressor.
Regulate air to ~15 psi.
Listen for leaks.

It would be nice to add smoke, but I don't think setting the car on fire is a good idea. Well, it MAY have been a good idea a few $$$ ago, but not now. Hindsight is 20-20.

Drawbacks that I see:
Air blows past valves and rings and I can't really pressurize the intake tract.

Any opinions or ideas on how to do this?

[FormerDatsun510Man]

For a test like this, you could just use duct tape with a hose clamp around it to seal off the end. I think you are likely loosing air at the silicon connectors and hose clamps though. I would try blocking it off at the TB (where the flex hose normally connects) and at the end of the outlet pipe of the intercooler (the pipe going to the intake manifold) first. If that holds the pressure, then you can move over to just the intake manifold and retest. True, you would possibly also hear air leaking past the rings if your rings are leaky, but you still hopefully will have a good enough seal with them :), that you hear air that would be leaking out of the manifold.

One other question, are you sure the manifold pressure is low? I am aware that on some of the DTBs from BRP, the fitting that was used caused the pressure (and vacuum) to read low at that point. The safest place to get manifold vacuum/boost readings is from the stock test port located just aft of the DTB on the stock intake manifold. That is also a good place to hook up the signal line for the PC Pro. Another good port is the factory port located at the very back of the intake manifold that I believe runs to the cruise control (in stock form).

This brings me to one other point. A good way to know if you are seeing an accurate boost reading is to check the vacuum reading at that port at idle. You should see somewhere in the 17-20" range. If you see 15" or less at idle (850-900rpm), then you have a vacuum leak or that port is reading off.

Bill

[Satisaii]

I have pretty much the same set-up that you had. Not much stock left in it. I went over and checked all of my intercooler connections today, but really should test it.

[Satisaii]

I do have a leak around one of the silicone couplers. My pipe OD is 2.125" and the coupler ID is 2.25". It gets up to 10 psi and starts to leak.

If I am going to take this car to the track tomorrow, I need a source for these things in Los Angeles. Anyone know of one?