Open loop or closed loop Boost

[bugsy]

Hi guys

I have been running my territory open loop for boost control.

Just wondering what are the pros and cons of OL verses CL?

Thanks in advance

[timwds]

Closed loop uses the open loop values as a starting point and then adjusts them if it hasn't reached its target (under or over).
You won't get consistent boost pressure running in open loop due to changes in air temperature, air density and many other factors.

I don't see any reason to run open loop other than temporarily for diagnostics and configuring the initial values for closed loop.

[45T-XR]

Most of the tunes I've seen for workshops are tuned in open loop then just have a boost cut thresh.
I was tuning mine like that when I first started playing around. It does give you a good understanding of how much things can change with not only the the factors Timwds mentioned, but different loads etc. On the street/Track and so on.
Becuase I pay for dyno time though, I went with the eboost as it saves me a heap of time tuning on the dyno. It also allows to me to play around on the fly as I change tyres. Road surface, racing etc. But it still essentially is tuning in open loop. You set a % duty cycle to set your desired boost, then you have a gate pressure setting and an overboost threshold. The downside is because it only has once dc point on the basic setup, you cant increase the duty cycle to maintain a flat boost curve if you are leaning on a turbo. that is why my car at the moment makes a nice 25psi down low then falls to 20psi. Im working on the RPM correction that is has but involves extra wiring. Im just waiting for Eric to add a couple tables for me then I can use my spark adaptor and rpm correction that will help keep the boost curve flat and bring me some more mph hopefully. But if you have the time to tune the stock EBC then definately do it mate, it works mint