Hey guys,
I've done some searching on here and generally on google and can't seem to find anything super definitive as there's a couple of factors, so i'm hoping someone on here might have some solid ideas;
Issue:
I'm running a Profec B Spec II EBC, and a Tial MV-S external wastegate on my 6Boost mani and GTX2876r. I recently had the car remapped (Nistune @ Horsham Developments) and after that the wastegate started opening itself way too early, even with the EBC set to 1.4 bar. I took the external WG off and changed the springs inside, as I read the exhaust pressure can open it early if you're using a weak spring with an EBC. Turns out the spring inside was a 0.3 bar spring, so I changed it out (which cured the initial problem) for the combo Tial recommends to make 1.2 bar and would set the boost controller to do the rest. With the EBC turned on it would spike massively (2 bar or so) - absolutely shat myself so I turned it off and ran it without so as to not damage anything, and just running off of the wastegate spring pressure it would hit about 1.5+ bar, even though there's just a 1.2 bar spring combo inside.
I then changed the spring combo again to make 0.9 bar. It did drop the boost without the EBC but it still does the same thing with the boost controller turned on - spiked to about 1.7 bar for a split second, so I switched it off again and ran it off of the wastegate spring pressure; with a 0.9 combo annoyingly it'll sit at around 1 bar for a while, so it is opening, but then creep up to about 1.3+ bar quite strongly as the revs get higher? The wastegate is a few years old I think, but seemed ok inside when I had it apart.
I'm a bit lost - EBC is plumbed in correctly, no issue with pipework and lines etc. Could the solenoid be faulty on the Profec? And even if that is the case, does anyone have any ideas why it might be overboosting with lower rated springs inside the wastegate?
Like I said, I've done a search around and couldn't find anything concrete, so if anyone has any ideas, even if you think it's simple, throw it out there so I can check it out!
Spec if it helps:
- SR20DET, Nistune
- GTX2876R, 6Boost Mani, Tial MV-S 38mm, External pipe
- Greddy Profec B Spec II
- Tomei Poncams
- 1000cc Injectors
- Fujitsubo Legalis R Exhaust
Cheers