Even with an EBC, if your tapped post TB the second you release the throttle from boost it would slam your wastegates shut, so the turbos are still producing volume, which is eventually released by the BOV, but since the wastegates close a split second before the BOV releases there is more potential for compressor surge. If pre-TB the pressure in the signal to the wastegates rises when you release the gas, thus making the wastegates open and turbos produce less, leaving less volume for your BOV to vent and less likelihood of surge.

 

So the bottom port should come from PRE-tb but the EBC can still use post-tb.

 

Bottom port?

It should be connected like this
Pre-TB Boost Reference>EBC>Wastegate(s)
Post-TB Boost/Vac Reference>BOV>and any additional accessories such as boost guage, Haltech Map sensor, EBC MAP reference etc

 

Bottom port on my tial refers to the one that is not on the top. Should i call it the side port?

It is the one that is under the spring and uses pressure to open the wastegate.
Top port is the one that uses pressure to close the wastegate.



So for best results when you lift you want the least amount of pressure on the top port and the most on the bottom port.

Least amount of pressure would be in the plenum post tb
Most amount of pressure would be pre tb, in the ic piping, until the BOV equalizes the pressures.

My EBC solenoid valve has 3 inputs. Signal in, signal out and vent to atmos. Signal in is connected post tb, signal out to top port and vent is vented to atmos.

 

don't you run an insane spring pressure though? Most of us are running under 1 bar springs and i think you are running close to 1.5 or 2 bar spring. maybe that's why you need so much more duty cycle. The exhaust pressure on that wasgegate is just so much higher it takes more pressure on top of it to hold it closed.

I could be backwards though. IDK. maybe try running 2 solenoids with a line from each turbo to provide more volume. that could also be the issue like you suggested in the first post.

 

nah i think I was jumping the gun. i did a log and mid 20% duty cycle was still over boosting, so i think its all fine.

 

ah, 45psi instead of 40psi? hahahah

 

corrected my setup today. Summitracing is nice to have so close by! I ordered my fittings late thursday night and they were delivered just after lunch on friday and I only paid for ground shipping.