I recently had an avcr and afcII installed on the evo and I noticed that the boost seems to be oscillating....rougly between 1.35 kg/cm2 and 1.2 kg/cm2. I have read that adjusting the feedback speed can solve this problem but I have no idea what to do with the settings. The feedback speed settings are currently at 3 for all gears. So do I increase them or decrease them or what??? As an aside the avcr/afcII combo netted me 45 peak whp on the dyno and a maximum hp gain of ~60 at redline! Thanks in advance for any responses.

 

Ok, really basic question here. When you say oscillating, do you mean

a) it's at different boost levels at similar RPM points or

b) as you're running through the gears, it goes from a higher level to a lower?

If "b", it's supposed to do that.

 

no not b...haha i'm not that stupid. what i mean is as the rpms are climbing it will bounce up and down. it is trying to achieve 1.4kg/cm2 the whole way. what i have noticed is in gears 1 through 3 it does really good. In forth it bounces around between 1.2 and 1.3 until about 5000 rpms when it suddenly goes to 1.4 and holds steady. In 5th it seems to bounce around more. Is it possible that because the controller is so new it is still trying to learn the duty cycles for the individual gears? I was also wondering if anyone has any suggestions on what the start duty should be. the start duty is currently set at +5 for first, 0 for second and third, -4 for forth, and -8 for 5th.

 

What's your feedback speed set at? When I first installed my AVC-R in my 240, the F/B speed was at all 9's...and the boost went UP and DOWN and UP damn bad. Try setting them at 1 each, and see if that fixes it!

 

cool i will try that. thanks! oh by the way they are all at 3 right now. what is the downside of lowering this number? slower response?

 

No, frankly, I don't know know why they have F/B speed, unless it's so you can induce a boost spike?!??? Who knows, just set them all at 1 and see what it does