Turbo limit or BCS limit - Install restrictor?

[awdonly]

Not sure how they calibrate them. When testing on the engine stand they seemed to be fully open at about 14PSI

[Jimvr4]

Do you have a MV8500 pressure tester? I would hook it up to the Tee and check what pressure causes both WG to crack open.

[awdonly]

I do and did. Cracks at 12psi gauge (9 PSI raw). This altitude offset thing sucks

[awdonly]

I think with actual exhaust pressure in the system the pressure on the wastegates makes them open earlier than when testing static

[KeithMac]

As awd only says, when the car is running and under load the exhaust flow puts pressure on the flappers basically reducing the relative spring stiffness in the actuator.

[awdonly]

My testing of MAC and Tactrix vs 3 port FPS delayed due to family/work issues. In the meantime, I found this link to similar Evo research - http://www.evolutionm.net/forums/ecu...ting-data.html

[awdonly]

Tested MAC and Tactrix and both were indistinguishable from the 3 port stock FPS pressed into duty as a boost controller. Next test - Hallman MBC. In theory the 100% duty cycle on the EBCs should be mirrored by maxed out MBC, but others have reported an ability to get to higher boost levels With the MBC so I'm very curious.

[murphys_law]

Tested MAC and Tactrix and both were indistinguishable from the 3 port stock FPS pressed into duty as a boost controller. Next test - Hallman MBC. In theory the 100% duty cycle on the EBCs should be mirrored by maxed out MBC, but others have reported an ability to get to higher boost levels With the MBC so I'm very curious.

My mbc is ~21-22psi maxed.


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[KeithMac]

You need to work out if your turbos are capable of producing boost at higher levels (with good octane fuel).

Secondly you need stiffer wastegate actuators.

Thirdly you then can start tesing different solenoids/ mbcs, if the springs are being forced open no solenoid/ mbc will address that.

[awdonly]

I suspect I'm at the limit of the turbos and not limited by wastegate springs/actuators. At 100% duty cycle I'm peaking at 21PSI on a 90 degree day and at 25 PSI or more on a 70 degree day. The springs shouldn't be impacted by temp.