The primary turbo is the same setup or perhaps even identical to the single turbo on the 2.7 and seems to suffer from the same sticking actuator malady. The secondary turbo is not variable so has no actuator.
 
The initial 2500 RPM cut-in of the secondary turbo was supposedly altered to start opening at much lower revs as part of the solution to the oil build-up problem. I considered that I felt the change from 2500 rpm to around 1800 rpm after my secondary turbo was replaced along with the s/w update. However I still find the management of the secondary cut-in rather rough because if the gbox is manually up-shifted with part throttle at around 2500 rpm, the engine's performance drops off significantly for quite a while until revs get back up towards 2500 rpm in the higher gear. This suggests that either the secondary turbo is being virtually closed-off when the revs drop or the primary turbo is backed-off way too far with the slightly reduced torque that is requested by the gbox ecu prior to the up-shift, but either way the dual turbo management is not particularly refined, not on my vehicle anyway. Part throttle up-shifting at 2200 rpm is quite smooth, as is at around 3000 rpm.
				
			 
			
		 
			
				
			
				
			
			
				MY21.5 L405 D350 Vogue SE with 19s.  Produce LLAMS for LR/RR, Jeep GC/Dodge Ram
VK2HFG and APRS W1 digi, RTK base station using LoRa
			
			
		 
	
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