in kpro you can select what you want it to be, are you sure the wastegate lines are hooked up correctly?

i had a problem a while back where it would boost too much, then boost cut would kick in, the problem was it was letting off boost when it was supposed to because the vaccuum lines going to the wastegate had slipped off

if the vaccuum lines are hooked up in reverse or not hooked up at all, the situation i described above would happen

 

In order to establish you lowest boost setting just negate the boost solinoide and run boost reference (never vacume) to the bottom of the waste gate, this will yeild your turbokits lowest possible boost scenerio. I beleive when the mac solinoides are not energized port 2 and 3 are open. You can use this internal gate methode on a external gate and still get around double your spring rated pressure depending on the systems back pressure. so if ur cool wil 16 to 20 psi max then this is the simpilest manner of plumbing.

 

which mac solenoid do you have, the one w three vaccuum ports, 1 on each side and one in the middle?

 

Yes

 

The top and bottom ports on the wg should have a vacuum line connected

 

never vacuum. you only want boost reference ( before the throttle plate after the compressor outlet)

 

Try it with just the wastegate spring. If it overboosts, then you know its not a problem with the solenoid. Are you SURE you have an 8 psi spring? Take your wastegate apart and check the color of the spring and if its the smaller size or bigger size. Some color springs (eg. Green) come in 2 sizes; 7 psi and 13 psi. Yours could be over what you are shooting for. Just narrow down the possible problems and go for there. I had this problem at the dyno. It turned out to be a bad map sensor.

Good Luck

 

i may be old school with profec BII and HKS EBC's, but on those you would T the turbo compressor and TOP of the wg, then run the other line from the other EBC port to the side of the gate. the side is what opens the gate, the top adds additional pressure to the spring to hold at different psi's. ive never used a mac sol, so i dont know for sure, but it sounds like its hooked up backwards to me.

give it a try.

also, if you run only a line from the compressor to the side of the gate, it will 99.9% open at your 8psi. if it doesnt, the diaphragm may be ripped and not holding pressure to pop the valve open and release the spool.

i bet you have the lines mixed up though. LMK

 

You guys are going to laugh at this. Apparently there's a port at the top and one right below it. Then there's two more below that. I just hooked the pressure source to one of the two lowest one and now holding 8.7 psi. This car pulls hard! I can't imagine what it would feel like at 13-14 psi on the 5857 precision turbo!!!

 

It should feel like 4xxwhp.