Aeroking
e.i.
Currently I am running a single external wastegate, and a 12V 3port solenoid valve wired in place of the stock boost solenoid. So I can tune my boost control through the ECM (Code59). I use the Duty Cycle tables to create a MSBC. By setting the DC low at 0mph-20mph, and high DC from 20mph+. This gives me a “launch boost” level.
Problem: Springs for external wastegates can control boost between their rating, and 2x their rating. Therefore a 12psi spring can control boost solid between 12-24psi. Problem being 12psi is too high for me to launch on street tires. So to launch at 5psi, a minimum of a 5psi spring is required, which puts your maximum controlled boost at 10psi.
So, my remedy is to run 2 external wastegates, with 2 different springs. The goal is to be able to launch at 5-7psi and have full boost between 20-26psi. Conincidentally, I have 2 external wastegate ports on my truck, and a spare wastegate :tup:. If I use my boost control solenoid as a diverter switch by DC in the tune, I can divert boost pressure to either of the 2 wastegates, and achieve 2 different boost levels. Looking at the diagram, if I am switched for the high boost wastegate, the low wastegate gets no boost and should not open. However, the exhaust pressure at full boost will be enough to force the low wastegate valve open. So I’ll run a boost line tee’d from the high boost line to the top of the low wastegate to hold the valve shut during high boost.
The final step is to go into my tune, and change my WGDC vs. MPH table. For low boost I will use 0%-1% DC, and for high boost I will use 100% DC. Should I choose to make the system more adjustable, I can use a manual ball/spring controller (by coincidence I have 2 also) plumbed in line with the respective wastegate.
It makes sense on paper, but I can’t test it until the bad weather clears.
Problem: Springs for external wastegates can control boost between their rating, and 2x their rating. Therefore a 12psi spring can control boost solid between 12-24psi. Problem being 12psi is too high for me to launch on street tires. So to launch at 5psi, a minimum of a 5psi spring is required, which puts your maximum controlled boost at 10psi.
So, my remedy is to run 2 external wastegates, with 2 different springs. The goal is to be able to launch at 5-7psi and have full boost between 20-26psi. Conincidentally, I have 2 external wastegate ports on my truck, and a spare wastegate :tup:. If I use my boost control solenoid as a diverter switch by DC in the tune, I can divert boost pressure to either of the 2 wastegates, and achieve 2 different boost levels. Looking at the diagram, if I am switched for the high boost wastegate, the low wastegate gets no boost and should not open. However, the exhaust pressure at full boost will be enough to force the low wastegate valve open. So I’ll run a boost line tee’d from the high boost line to the top of the low wastegate to hold the valve shut during high boost.
The final step is to go into my tune, and change my WGDC vs. MPH table. For low boost I will use 0%-1% DC, and for high boost I will use 100% DC. Should I choose to make the system more adjustable, I can use a manual ball/spring controller (by coincidence I have 2 also) plumbed in line with the respective wastegate.
It makes sense on paper, but I can’t test it until the bad weather clears.
