Why does my full bolt on , fp green on e85 onlyboost to 28psi. Its a OS green stock wastegate car made 443hp 420tq at 28psi. How come i cant boost to lets say 32psi im tryn to get near 500. Ecu controled boost

 

Either bad wastegate or your blowoffvalve is leaking under the pressure and you could possibly have a boost leak.

 

Is the car doing anything strange at Idle?

 

What size wastegate? Seems like it's not setup correctly.

 

He's on stock wastegate. Wondering if that could be the reason?

 

Seems like it's not preloaded enough.

 

BOV will actually start to leak at 26psi. Do a boost leak test to 35psi and make sure the BOV isnt opening up. It will also tell you if there are other issues. What intercooler is on the car?

 

OP: Are you on the stock plastic diverter valve(DV), a metal IX DV, or an aftermarket blowoff valve?

 

Repeat post

 

It is best to check wastegate spring pressure first. You know how to do this, right? You will need to get a couple feet of 4mm rubber vacuum hose. Have some zipties or little 1/4" hose clamps handy. A couple golf "t"'s to plug open hose ends while testing too.

Remove the factory vacuum/boost hose end attached to the compressor discharge tube(j-pipe) nipple. Also remove the hose end attached to the nipple on the WGA. Plug off both open hose ends with golf t's.

Now connect a length of the new rubber hose that you bought directly from the nipple on the WGA to the nipple on the j-pipe. With the car setup in this manner take it for a WOT run in 3rd or 4th gear. See what peak boost reading you get with the car setup this way.

Depending on the reading, we should pretty much be able to tell if you are running base pressure or if the gate is preloaded and to what pressure.

Note: this is assuming no boost leaks and the DV/BOV not coloring the picture.

 

I am thinking that you are probably better of purchasing a heavy duty WGA for running boost levels up over 26-27#. I would suggest one of the two FP actuators. Since you want to run over 28#, then maybe the 25# unit would be best suited to your needs. I have run the FP 18# actuator at boost levels up to 27# and it works well.

 

I have the metal 9 crushed, custom intercooler n piping, and stock 9 turbo wastgate. I never played wit the preload and im pretty sure i have leaks. Thanks guys

 

At idle the rpms will climb but not oast 1500 and someimes drop low to where the car bogs

 

You probably should switch from your stock IX WGA to a FP 25# unit. Why?

I found the following explanation online at www.max-boost.co.uk:


"Under low boost(idle, etc.) the exh/inlet pressure ratio is just over 1:1. At 1 bar of boost it has increased to 2.5:1, and from then onwards it increases disproportionately.

Very roughly and for a stock(ish) turbo and a catless exhaust, backpressure is about 2.5 times the boost pressure. So, if we are running 1 bar boost, we've got 2.5 bar pushing at the wastegate(against the actuator spring). Then we calculate the area of the flapper(valve) that the gases "see". Say it's 1 inch square. We get:

(2.5)x14.7=35.8 PSI.

So, even at 14.7 PSI of boost pressure, the exhaust gas forces pushing the flapper open is 35.8 pounds. SIMPLE! At your boost level of 28#(essentially 2 bar), the seat pressure forcing the flapper valve open is actually way over 70# because the exh/inlet pressure ratio is significantly higher than 2.5:1.

So, that's why actuators that can hold high boost pressures need to have much stronger springs."

 

I made a dumb post(again?)