I am getting some serious surging at any throttle. I am using Profec-b II ebc set for 17-18psi and no matter what it is set to my boost will surge seemingly at random, one pull will be strong at 17psi next one bad. It will drop to about 9psi and almost instantly go back to 17psi. Change the settings a bit for 12 psi seems to be good but still surges by about 2-3psi. The only setting that seems to help is if the waste gates closed until 17 psi or what ever it is set at and as soon as the waste gates open the surging happens. Another thing I noticed is the surging/oscillation is less dramatic if I build boost above 3,500rpm.
I am thinking either the waste gates, boost solenoid, or BOV are bad.
Current mods: 13g turbos, K&N fipk, EMU, Greddy profecB II, Greddy fmic, greddy type s bov, Koyo racing radiator, EGR block off, Supra Pump, DSM 450cc, HKS DLI, AEM UEGO, Pro-M MAFtuner, VAC reduction, Gutted pre cats,Turbo back exhaust w/Tanabe hyper medallion, Denso Supra FP, ACP 1 piece carbon fiber drive shaft, Fidanza aluminum fly wheel, 3 stage clutch,GAB lowering coil overs, Cross drilled rotors, 99 conversion, carbon fiber hood, sparco racing seats. Soon to come: adjustable cam gears, Billet TD05 18g's, Stage 3 heads
adjust the wastegates to open at the same psi
If they are off even the slightest you will get surge because one turbo is tring to over power the other, balance the wastegates and your problem should go away
i see you have 13gs most likley in stock housings i would suspect the wastegate adjuster is set too weak on one of the turbos
TD05 Twin EVO 16gs , Blitz NUR Spec cat back w/ testpipe, M's Fuzzy logic boost controller , Arc-2dr, Pte 680s , Supra pump, Apexi Sitc, Act max street Clutch
My current settings effect 55% gain 15% set gain 1.05 limit 5% warning at 1.3 this gets me around 13-14psi. This seems to be the best I can get it surging about 2psi. Other settings I surge about 7psi.
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