Using MBC on low-psi actuator vs. stronger actuator
#1
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Using MBC on low-psi actuator vs. stronger actuator
My current setup is to have two boost settings - low and high, using an EBC solenoid running off a switch in the cockpit as a switch between vacuum inputs to the actuator - low boost runs an unimpeded vac line which allows wastegate to run at its own setting (7 psi or so for the Greddy actuator), high boost has an in-line MBC which raises the boost to 11psi or so. I like this because I can run a lower-power setting that stresses everything less for non-competitive events.
So far, that's seemed to work pretty well. I do get a bit of boost drop near redline, but it hasn't been drastic..
I think I jacked up my existing wastegate actuator during motor re-installation, so I'm looking into replacement actuators. Wondering if there is a drawback to getting a low-psi actuator so that I can maintain my low-boost setup and just use MBC for the high boost vs. getting an actuator intended to hold slightly higher boost?
I like the 6 psi actuator from ATPTurbo: Wastegate Actuator 6 PSI : atpturbo.com I would fab a bracket and modify the rod to be adjustable and proper length. Just wondering if I'm leaving something on the table by going with this vs. a 10 psi actuator for example..
Thanks
-Ryan
So far, that's seemed to work pretty well. I do get a bit of boost drop near redline, but it hasn't been drastic..
I think I jacked up my existing wastegate actuator during motor re-installation, so I'm looking into replacement actuators. Wondering if there is a drawback to getting a low-psi actuator so that I can maintain my low-boost setup and just use MBC for the high boost vs. getting an actuator intended to hold slightly higher boost?
I like the 6 psi actuator from ATPTurbo: Wastegate Actuator 6 PSI : atpturbo.com I would fab a bracket and modify the rod to be adjustable and proper length. Just wondering if I'm leaving something on the table by going with this vs. a 10 psi actuator for example..
Thanks
-Ryan
#3
I've been thinking about this exact setup lately. I have an HKS 12 psi wastegate actuator that I picked up last time I was in Hiroshima, and I also have the same 6psi actuator linked above. The HKS is on the car at the moment because of the higher boost pressure, but looks pretty ratty.
Ryan, if you wind up doing this be sure to post how you feel about it, I'll be doing the same.
Ryan, if you wind up doing this be sure to post how you feel about it, I'll be doing the same.
#5
On single port actuators, once you start getting to twice the pressure the exhaust manifold pressure can be enough to force the wastegate flapper open even if you completely disconnected the vac line from the IWGA. This is a huge problem with EFRs on on cars that flow serious air because the wastegate flapper is HUGE. If you want to run an IWG on a roadrace/auto-x car where you care about more than full throttle but want to run ALLOFIT, low psi spring, 2 port actuator, 4 port boost controller. With that setup you can pretty much run unlimited boost even with like a 7psi acutator using the boost to hold the wastegate closed.
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