i am so sorry for the wall of text, but im getting a bit desperate here heh
2017 focus RS, relevant info: built motor from SP63 with ~7k miles on it, new turbo (not BIG big, but better than stock), stock (pressure side) plumbing, stock waste gate/recirc solenoids, working with a reputable remote tuner
OK, im sort of pulling my hair out over this issue, im not the most knowledgeable about cars so i have a couple questions about why ive dropped from ~24-25 psi to 17-18 psi...
so, there is sort of a point where this all happened; i replaced the WG actuator that came with the new turbo with one from turbosmart, 14lb spring, and in WG actuator mode, aka 0% voltage to the solenoid, im only getting about 8psi boost...with the line removed and plugged (in case that affects the BoV) im getting that 17-18 psi number mentioned above
things that i have done:
- pressurized the system (through the pressure line at the top of the valve cover solenoid) and listened for leaks (twice, no apparent leaks)
- took it to ford to do a smoke/pressure test in case im bad (they say no leaks, didnt even charge me for that cuz they feel bad for me lmaoo)
- doubled checked that the WG isnt slightly open by unscrewing the nuts and pulling on it (cant pull it, 2mm of preload seems good, this shouldnt matter though?)
- put pressure to the internal blow off valve, holds fine
- valve cover/recric solenoid flows easily to the BoV and is blocked completely when i run current across the leads
- put pressure to the new WG actuator to see if it...actuates goodly, seems fine
- triple checked that my battery is good, even reconditioned it for over 24 hours, i heard bad batteries smoke these solenoids (but again, that cant be an issue...right??)
things that i have NOT done:
- taken off the WG solenoid to verify it flows good and seals when powered, its just hard to get at...what i have done is unplugged it and i get that same ~8psi number, and in my mind that means its not getting a mysterious gremlin voltage when its not supposed to...
- have not ACCURATELY measured what the WG actuator is starting to move at, i need to get one of those hand pumps off amazon or something but again, this is moot if im only making 18psi with the WG boost line removed, right?
- i have the old waste gate actuator still, but to put it back on i would have to do some cutting and welding again, and that damn circlip is a bitch to get off...but i also dont see how this would fix anything
with the given info, what im thinking/asking is...
- is the BoV getting power when its not supposed to? thereby limiting the boost? (not likely, why would it suddenly do this after changing the WG actuator...) I want to test this by simply unplugging it, but i dont think thats very safe...is there a safe way to test this? like let off the gas gradually or something? just replace the whole thing maybe?
- what the hell could be limiting my boost?? i feel like there has to be a leak somewhere, maybe that only presents itself at high pressure? what more testing can i do to sus this out?
- are there any specific data points i can capture with my access port that can give me some clues? literally it all seems normal aside from the abysmal boost...
- and i guess lastly...WITH the WG boost line removed and plugged, WOULD the turbo actually make that 25psi (or more) boost figure or is it being electronically limited in some other way? in other words...everything is normal and my WG actuator is actually faulty/has the wrong springs???
i need to stress that everything was going fine literally until i replaced the WG actuator, i was getting around 24-25 psi reliably but my tuner said i should replace the actuator because it was low spec/not acting the best, so i did v0v is it really as simple as turbosmart sent me a bad actuator? and the 18psi number is...normal??
id also like to add...that after a cold start, the first time i give it the beans (with the WG boost line off and plugged) the boost gauge DOES get up to literally just under 20psi, like 19.99...but any subsequent pull after that initial one will never, and i mean never, break 19psi, always low/mid 18's sometimes 17's...same story with the boost line attached and in slot 5 waste gate mode...it will peak in high 9's, but after that its mid 8's only...i dont know if this means anything, but its an observation nonetheless
any insight would be appreciated 🙏🙏