Can't get over 15 psi boost with external wastegate

[Flyin Brian]

Ok, I have a 3.5" DP with an external 46 mm wastegate and the Turbonetics variable boost control regulator P/N 10402-25 for 0 to 25 psi.
I have it plumbed up just like the Turbonetics instructions show. Boost connection on compressor housing going to a "T". "T" going to inlet of regulator and to the boost port on the wastegate. Outlet of regulator going to vacuum port on wastegate. With the regulator at full turndown I get about 13 psi boost. I am finally getting my tuneup together and am turning up the boost. 4 turns of the controller knob gets me to around 15 psi boost. More turns all the way to full on gets me no additional boost. I have had the wastegate apart one time before and it has a single large spring in it which I assume is the 13 psi one. What do I need to do to get my boost up past 15 psi? I am looking to get up to 20 psi hopefully. I would like to get a real boost controller someday but that is not in the budget right now. I am looking for an inexpensive easy fix here. Thanks.

 

[dpasadena]

Sounds like you have a faulty regulator. I have installed quite a few of these on cars and I also use one on my car and they work pretty darn good. It seems like the regulator is not putting pressure to the top of the gate. I would test it to make sure air actually passes through it. I have one laying around that I know works if you need one

 

[Flyin Brian]

Sounds like you have a faulty regulator. I have installed quite a few of these on cars and I also use one on my car and they work pretty darn good. It seems like the regulator is not putting pressure to the top of the gate. I would test it to make sure air actually passes through it. I have one laying around that I know works if you need one

Thanks.
I figured my lines running to the Turbonetics controller were too long and too small. I re-plumbed it last night and moved the controller from inside the car to the fender near the air filter. I got rid of all the smaller line I had and it now has 1/4" id line everywhere to and from the controller. I thought this would fix the problem as I tried blowing through the old long small lines and it was difficult. Figured I was not getting enough air to the top of the gate. New setup is way easy to blow through. However I drove it today and it acted about the same except at 6 turns of the controller it caused the boost to spike up to 19 psi briefly but it then settled back to around 15 psi. I tried blowing through the regulator and it acts like you think it would. No flow at full closed and gets progressively easier as you turn it up. I had the gate apart and it moves freely etc. Maybe I should try pulling both lines and seeing if I get 26 psi which would be the expected 2x the 13 psi spring which I think I have in there. Anyone running the RJC/Grainger style valve with an external gate?