AVCR not controlling boost...

tpunx99GSX · 02-22-2008

Hey guys,
I was wondering if any of you have installed an AVCR with an External Wastegate before?
For some reason the AVCR i have isnt controlling boost at all. I have it set at 1bar and 70% duty across the line. but when i boost, it just continues to go higher. Even the avcr shows a peak much higher.
In the manual it states that if you have an internal wg you need to hook up the NO port and the COM port, the NO port goes to the Pressure source, and the COM goes to the WG. But if you have an external WG, then you need to hook the other port to the top of the WG. I didnt do that last part. Do we actually need that or can it be left empty and i should be looking at other problems?
Thanks in advance.
Tom

tpunx99GSX · 02-22-2008

I just looked on tuners, and its showing that that port on top of the WG doesnt need to be used (which i was thinking) it is to hold the wastegate down for faster spoolup, and nothing to do with the opening of the WG.
But why would i be getting high boost when i have it set to low?

TkrPerformance · 02-22-2008

for tial the top port is for elec the bottom is for manuel

**Shane@DBPerformance** · 02-22-2008

What spring is in your wastegate? If it's anywhere near 1bar, then your duty cycle is probably set way too high.

You might also want to hook it up the proper way for an external, using both ports on the wastegate. You can use it just like an actuator or manual boost controller setup, but it won't be able to handle as high of boost. By hooking up to the top port, it makes the wastegate act like it has a stronger spring in it by using boost to hold it shut. A weak spring can be pushed open by the exhaust backpressure, which often limits the amount of boost you can run to around twice the rating of the spring. So, using the top port pushes boost to the top side of the diaphragm and lets you run much higher boost with a weak spring.

Maybe draw a pic of what you have going on, if it isn't just too high of a duty cycle to begin with.

tpunx99GSX · 02-22-2008

Funny you should say that because i have a 1 bar spring.

with 70% duty. Looks like you have found my problem.

Why would i want to use duty to add boost as opposed to just upping the boost per rpm? or do i have to change the starting boost to do that? Maybe i should RTFM.
Thanks again shane.