Well, first let me thank everyone on the forum for your help. It is way cool to have a resource like this.

I bought a boost/vacuum test gauge and hooked it up to find a big surprise. The car is quite stock, but was running 13 psi on the primary with a stock intercooler. In my thinking, this is a ragged edge and it made me quite nervous. I suspect there is an aftermarket exhaust contributing to this, so I resolved to do the right thing and get 'er done.

I pulled the boost and pre-spool hoses off the engine to check them for leaks and cracks. Nasty and covered with oil, my thinking was that they may be partially plugged causing an increase in boost. I replaced the hoses with silicon tubes, but was absent minded enough to miss the point about the pills in the line. I read up on it before hand, but didn't understand the whole in-line pill thing.

Plain hoses fixed my overboost problem. car was now limited to 7 psi with a terrible lag in the middle. Back to the robinette sight.

Well, fortunately the garbage went out before I took the hoses off the car, so they were still laying on the floor of the garage. I looked down the hoses and viola! a major revelation.. I tried to clean these up and blow them out with the air. Now, one of my pills is laying out in the front yard somewhere. It came screaming out of the hose at Mach 2 with a pop. After overcoming that sinking -what the hell am I going to do now feeling, I got the kids looking for my pill. The proverbial needle in the haystack. .......Quite a fruitless excersize.....mazda parts for the worms.......

So, I resoved to install valves and tune accordingly, having no other obvious choice than machining my own pill set. Pretty easy swap, except I am having problems finding hose clamps small enough for that size hose. Once installed, I went to testing starting with almost open valves. First run: 8 lbs boost and big lag.

You can't really adjust one and then the other because the pre-spool increase, pulls from the exhaust, decreasing the boost .....well a little it seems. I got the boost dialed into about 9 lbs and then worked the pre-spool. Both valves are mostly closed in the end, but I guessed this would be the case. I dinked around with them a lot before I installed them. The valves I have didn't close off real tightly until the very last bit, so I figured they would be almost closed. When I got the boost cranked to about 10 psi, there was a spike of a few lbs, maybe as high as twelve. Made me nervous, so I backed it off. From lag to spike was maybe a 1/4 turn at best on the pre-spool controller, with the valve almost closed.

I have gotten it to the place where I can hardly feel the transition in the ride, but it does show on the gauge. The car feels smooth now with strong power. I am calling it a pretty flat 9.5 psi, with maybe a 1 psi dip. I can't be any more accurate than that because driving and watching the gauge is not so safe. I have about two to three feet of vacuum tube on each control. I am pretty sure this has a dampening effect to the response. The short stock tubes seem to have less restriction for higher boost, so comparing the two before installation is just going to get you close. When I blew into them side by side on the bench, the resistance seemed the same, but the long tubes were maybe 2 psi less in boost on the car.

As for the mod, I would say it is a must. I will redo this with better valves like one of the other posts I have seen. The total cost was $16 for now and it prevented overboosted (a potentially costly mistake). The car runs better than it did with the stock tubes.

 

I suggest that you replace the pre-spool valve with an OEM Mazda hose (with the factory pill). It can be nearly impossible to get the transition and boost levels to operate properly with two needle valve controllers. Yes, that is the voice of (bad) experience you are hearing .

Keep the controller for the wastegate. It works nicely without the other valve hooked up.

I believe that you are correct in your assumption that the extra length of the pre spool hose is responsible for your difficulties.

Adam