hi I just purchased a 05 evo8 all stock except upper and lower intercooler piping. I am trying to figure out why my boost only hits 14psi and tapers to 11psi. I have searched and found this car should be hitting 20.3 psi and tapering off to around 17. Please help

all the vacuum/boost lines have been replaced and hooked up properly and no boost leaks or exhaust leaks are present, and I unplugged the battery to reset the ecu after replacing the bad lines and fixing the boost leaks.


thanks
andrew

 

Sounds like a boost leak

 

Here is a good place to start:

https://www.evolutionm.net/forums/se...rchid=13710210

 

was this car previously owned?

maybe it had other mods

could be missing the stock boost lines

 

yes it was previously owned and I replaced all the vacuum/boost lines and hooked them up per the diagram on the underside of the hood. the lines going to the bcs were cracked and dry rotted near the ends so they have been replaced. and I reset the ecu.

also there was evidence of other mods like a EGT port drilled in the manifold it has been plugged and a oil pressure sending unit AEM. also there is a after market O2 housing that had loose bolts.... al of these things have been corrected back to stock

also there is a lot of blow off valve "flutter"

 

I also believe there are no "pills"....both are not there (these lines are new and not stock). could this cause a low boost condition?

 

Yes. If you have new lines going into the stock boost control solenoid you'll be limited to wastegate pressure. You'll need either stock lines or a boost controller. My car was the same way when I got it, nonstock lines going into stock bcs.

 

Flutter from bov was due to the fact that the previous owner had the BOV installed backwards

 

yes you were correct!! thanks I Bought new stock boost lines (with the pills in them) now it boosts to 20+ and tapers off to around 17ish...
thanks for your help