My FP Green won't boost over 18PSI. Please help!
 

I'm running FP Green with Blitz SBC Spec S. And it won't boost over 18psi for 1st to 4th gear. But if I'm running in 5th or 6th gear, it will boost to 23psi then hold.

What is the possible cause?

Please help.

Thanks
Ohm

I'm assuming your wastegate is 18psi?

i bought used in the marketplace.

how can i check whether which psi of WGA i have? But it looks very like stock evo 9 turbo WGA.

Wga spring only limit you to run the minimun psi on the spring. should be the ebc limiting the boost

Ditch that boost controller and get a 3 port

make sure your vacuum lines aren't hook up backwards from the wastegate actuator and inlet. if they are backwards, you will only run wastage pressure. the higher gear could be boost creep. But ditch that thing and get a 3 port. Glimpsed is my preference.

Check lines, then wga. Probably just replace the wga with a turbosmart one and get the gs ebcs

Adjust wastegate actuator to effectively increase wastegate spring pressure. Your current wastegate actuator is adjustable for a reason..... So, adjust it.

Is your FP Green the older version aka the "Old School" Green? Or it the newer revised, 73 HTA Green?

I take it that your car is an Evo IX judging from the 6-spd. tranny. If so, and you have your original IX turbo/MHI WGA assembly then you can compare your original WGA to the WGA that came on your Green to determine whether or not they are identical actuators.

Incidentally, at what RPM are you hitting 23 PSI in 4th gear if you floor the car from 2500?

My car is JDM VIII MR and the turbo is 73 HTA Green.
For now I remove the Blitz SBC and directly connect the vacuum line from turbo to WGA. I'm ordering Grimmspeed 3-port.

I will update more when I got the 3-port.

So, do a WOT run for me starting at 2500 RPM in 4th or 5th w/o the EBC in the mix. This way we will know what your waste gate spring pressure is. I am thinking about 13#.

It went full boost at 0.8 bar to creep to 1.2 bar at around 7000rpm.

Make sure all lines are connected correctly
no leaks on the vac lines.
Check condition on wga rod and preload.
As mentioned prefer to go with 3port grimspeed and turbosmart wga

for now, there's no leak on vac line. The WGA is maximum preloaded, cannot go futhur.

Uhhhh, that's what you think!😎