I have a JDM IX and have fitted an EVC boost control. The problem i am having is when i drive the car with the EVC off it boosts above what i presumed was the wastegate pressure, 12psi. It manages to hit 14.7psi and i've seen it reach 17.5psi when it should be maxing out at the 12psi the wastegate is rated to. To my knowledge it is standard and so it is confusing me why the car would be doing this?

Maybe the wastegate is knackered or can anyone suggest a few things i could run through to check all is in accordance?

Many Thanks

 

Do you have the wastegate actuator 'pre-loaded''

 

The 16G turbos on our Evos have a base WG pressure anywhere from 10-12 PSI. That means that with the actuator rod set to the longest length at which the hole in the turnbuckle slides freely off and onto the WG puck´s pivot arm you´ll usually see a reading of about 11 PSI, plus or minus a pound.

However, that doesn´t mean that the turbo fitted to your car as delivered from the factory, is necessarily set to base WG pressure. Usually it´ll be setup with a few PSI of preload, as 9sec9 mentioned.

Usually the factory sets them up with about 3 PSI of preload. They shorten the actuator rod a couple of turns to help spoolup a bit. So, if you add the 3 PSI of preload to the 11 PSI of base WG pressure you end up with about 14.5# more or less.

 

Is it creeping or spiking?

 

His WG is preloaded to 14+ PSI and then it creeps to 17+ PSI(depending on the circumstances). At least, that´s how I read it.

 

If you want to verify that the EVC is not the cause connect a short piece of vacuum line between the turbo nipple and the wastegate actuator and see how much boost it hits then. I'm not familiar with that boost controller so this might be worth a shot. You can also adjust your wastegate actuator by removing the pin and turning the arm. Someone may have already done this to preload the wastegate so the car would hold more boost. My car boosts 12psi when running on spring pressure, maybe they didnt preload mine.

 

thanks for the help, i'll try and detect if the evc is the problem and try and do some logging and post the results back up

 

Good advice! This is a good first test. Be sure to plug the empty ends of your existing boost/vaccuum lines, when you yank them off to do this test.

Did you happen to reuse the factory hoses when you installed your EBC? You should always use new hose as the factory hose assembly has a couple internal restrictor orifices.

 

Hi
in addition to the above : there has been a lot of bad WGA on the IX build after 2007. these bad WGA are showing boost creep over 15 PSI and boost drop fluctuation around 4100-4700 rpm.

On the Euro EVO IX as we don't have a boost pressure sensor we can't log the boost , so an easy way to check the boost is to WOT the car with a friend taking a shot of the AVC-R display with a camera in 'movie' mode.

Anyway I recomend changing the OEM WGA by a reinforced model.
I did it (Forge WGA) and in OFF mode I have 15 psi at redline , peaking at 17 PSI .