Ok before I get started yes I have done my research and yes I've been trouble shooting for a week now and finally am posting here.
2003 Evo 8. Prior to issue mods (turbo back, megan O2 housing, injen piping, FMIC, Perrin MBC @ 24psi)

Last July I got my car tuned made 315 and has been running amazing. I recently decided I wanted to step up my game a bit. On came Ported Mani, Ported 8.5 Turbo, Kelford 264/260s, Ported IM, and 65MM TB.. And I have precision 880's but am going to have the shop install them prior to tuning so i can drive there.
It is a 2 hour hike down there so I have been driving around town and to work a few times to make sure everything seems ok before I drive that far and realize somethings wrong.

I know I shouldnt go WOT without a tune but I wanted to make sure I am hitting boost levels and everything seems alright.. Well thats where the problem is. I have been set on 24 psi and never had an issue until now. I am basically hitting 15 psi and it tapers down after that. However a few time I have made it to 24 psi.
I have done boost leak tests and the TB seals were leaking so I just replaced them and am having the same results. I have pretty bad leaks around all 4 injectors but the seals will be getting replaced when the injectors are. Even with them I am able to hit 25 psi during the test, and it takes a while to leak it all out.

Where do I go from here? Could the cams have something to do with it?

 

When you installed the new turbo did you readjust the wastegate spring tension, or not? For running a 24# peak you should raise spring pressureup to at least 18#. Are you on the stock actuator?

I don't know if I can help you. But, for sure I can make you more confused. LOL

 

..no i did not adjust it. It is a stock wastegate, is there some adjusting that needs done?

 

If you are controlling boost via MBC, you can ascertain your turbo's current WG spring pressure by simply rotating your MBC's adjustment knob out counterclockwise all the way to full-soft (-). That is, you will be backing the knob out, counterclockwise to its lowest attainable boost setting.

Just to be excruciatingly clear....whereas to increase boost you would rotate the adjustment knob inward clockwise, I want you to rotate it back out counterclockwise to the lowest possible position. Comprende?

With the MBC set thusly to full soft, take the car for a WOT run in 3rd, or 4th gear. Note the peak boost level achieved on your boost gauge. Report back with the boost reading.
.

 

http://store.forcedperformance.net/m...Info_wastegate

 

Ok, now im real confused. I just completly unhooked my perrin mbc and took it for a drive. I boosted 25ishluxary psi through 3rda and 4ththe and it felt good. Now what?

 

Don't unhook it just turn it all the way down then go see was the boost gauge reads after a pull.

 

Do what ak47po advises above. Reconnect MBC. Turn MBC down all the way counter clockwise to the lowest possible boost setting, as I outlined in my post above. Do a WOT pull in 3rd. Tell us what boost reading is with the MBC set at its absolute lowest setting.

This will give us actual spring pressure which includes preload. It is a starting point. We will use it as a reference for further troubleshooting. Please.

 

We don't know what preload the turbo you installed was adjusted to when you installed it. Obviously it has a different level of preload than the turbo you replaced. That is the nexus of your low boost situation, I think.

The method of turning the MBC all the way to its minimum setting will tell us the actual preload level, without the need of resetting to "zero preoad" as outlined by FP in their how-to vid, as provided by fireman.

We need to establish spring pressure level which I am guessing will be in the 9-12# range. Then from that point once established we will proceed to add spring pressure by dialing it in via the adjustable WGA.

 

Ok, its acting very similiar to when i bypassed the mbc, boost raises to 14-15 psi for maybe a second or 2 and then continues to climb to 20+

 

So, what is the desired target boost level? It's 24-25# right?

 

#1 Dude do not go full throttle at 24-25psi un tuned when you just recently added a crap load of stuff including cams.
#2 if your wastegate is unhooked and your only hitting 25psi then you have a boost leak or you BOV is screwed up. your factory Bypass valve will only allow about 25 before it starts leaking so more then likely everything is fine and your vacume lines going to your turbo then to your MBC and then back into your turbo has a slight hole in it. change the vacume lines check your J pipe connection and intercooler piping.

 

also might I add do a boost leak test it will essentially tell you everything that is wrong

 

hes on a MBC no matter what his target says in his "boost" maps on his Rom its not going to matter. There is no "target" when manual boost controllers are concerned its pretty much just set and go. also hes using a factory ported turbo with the same wastegate so the preload on the spring would make sense except he unhooked the boost controller and it hit the max psi his blow off valve will allow before it starts to leak (which is a good thing because you sure as hell could have blown your motor) I have seen stock 9.8 housing turbos with aftermarket o2 housings hit 35psi with a stock spring (spiking)

 

By "target boost" I merely meant peak boost level. I didn't realize that the term was only applicable to ECU controlled boost and EBC's. My bad. I just wanted to make sure how much boost he wanted to run.