I've been having problems with regulating my boost for a while. Finally was able to confirm that my wastegate was defective (running a Tial 44mm). I bought another 44mm and installed it with a 9lb spring and ran straight on wastegate and it boosted properly to 10lbs, being that there is a 1psi creep. I have a blitz sbc-id boost controller, we plugged the line up and set it to 13lbs. and it would not regulate it to that, would boost to 16+ and had to let off. All lines were triple checked to make sure everything was set up properly. Have no clue why its not holding boost. We turned the boost controller off and did another run and it would still spike. Pulled the line off and it would boost to 10 only on wastegate. So it has to be something wrong with the conroller. I bought the unit used (as i should not have done with a boost controller) but the only thing i can think of now is that the solenoids are bad in the brain (black box). If i replace the solenoids, do you think this might be the cause? I don't want to buy it and it ends up still broken. thanks for any help.

 

Sounds like the Wastegate is just too small...

What size turbine housing are you running? what turbine trim?

 

How far are the lines from the WG to the solenoid box? Should be as short as possible, and not more than 3 feet in lenght.

Also, what do you have the Blitz set to, manual or automatic? Did you set the Blitz to an external WG? I found that using automaitc on an external wastegate doesn't work well... at all! It was set to 16 psi and it took a bit to learn in auto mode, spiking a few psi. Then driving it home it spiked to 23 psi / fuel cut.

Luckily the engine is okay, and I started using the manual mode and worked my way up from 10 psi. I have it set to 13 psi in manual mode and it holds rock solid.

 

Solenoid box is tucked underneath the UIM, so the line is a little over 3 feet.
You are absolutely correct on this one, it was not set on external wastegate. My mechanic did that and also set it to manual mode and we did a few pulls. Played with it from there and it holds solid at 15psi.

Bobybeach - the wastegate is the right size as it came in a kit that I bought from A-spec...it's the GT3574, .84 housing.


Just out of curiosity, after we did a couple of pulls to get the right boost setting, we came back and lifted the hood. I noticed oil residue that must have misted from my Greddy RS BOV onto my cold pipe. Kinda freaked me out because I thought I blew a oil seal on the turbo, but realized the compressor inlet is completely dry. Only possibility I could think of that happening was that I had a crap ebay turbo on there before A-spec's kit, and that ebay turbo blew a oil seal on idle and that must have been the left over residue from the intercooler spitting out when I did the couple of hard pulls. Might that be the case? Other than that fact, I don't know why oil is spitting out.

Thanks for the help/input guys.

 

yes, unless you pressure cleaned your IC...you have loads of oil still in there.

 

Ahhh i see, nope never pressure cleaned IC...anyway to get rid of that oil sitting in there?

 

take it to a radiator shop...they should be able to clean it.