Boost control

[Slowxr6t]

So my car is still having boost control issues. Tuna and I did some on road testing and tuning the other day. Resorted to open loop because he couldn't sort it on closed loop, boost surging all over the show. Open loop he got it sorted or so we thought! It was boosting up fine with no surge at all, I thought ok sorted we'll leave it there. Then today went for a drive, ambient temp about 5 degrees cooler and it's surging bad again! I bypassed boost solenoid with tube straight from compressor outlet to bottom port of external wastegate and it goes to 10psi and holds there so it's not the wastegate setup. Question, if I choose to bypass solenoid permanently due to not being able to get boost control sorted is it ok? I will just run straight off wastegate springs. Does ecu care if solenoid not reading boost? Should I leave it plugged in and just block the lines coming off it? @Captain Yeah Nahand or @JETURBOif you will answer, and anyone else who wants to chime in. Thanks guys.

[Puffwagon]

If you run it on gate it'll be fine. It will be marginally slower to come on boost.

 

The pcm will be doing stuff in the background trying to control it but it doesn't matter. Just make sure your desired boost table is set a few psi higher than the actual boost.

 

At this stage if you can't dial in the factory boost control you may as well chuck a boost tee in there or an aftermarket ebc. I wouldn't be doing that myself but sometimes you're stuck with what you've got.

 

Pm me your tune file and some logs of super cold weather and normal weather and I'll have a look for you. Make sure at least part of the logs has some wot.

 

Aside from that tell your tuna to remove some duty from the cooler part of the wg map. It needs less duty when the air is denser. I reckon this will be the issue.

[k31th]

I agree with everything he said ^^ except this bit:

Quote

If you run it on gate it'll be fine. It will be marginally slower to come on boost.

it'll be wayyyyyyy slower to get to the wastegate determined minimum boost level which is now your full boost level, too... literally the slowest the turbo can get to the relevant pressure. I personally would hate to drive a car that had permanently bypassed the boost control solenoid unless it had a much better aftermarket boost control system in place, just due to the slowness of the building of boost

 

If you just unplug the solenoid (electrically) and use some other form of boost control (which like puff said, is undesirable) then it won't be doing anything and there's boost pressure sensors in both the intercooler piping and the manifold post the throttle body (T-MAP in that case, but same same), so the ECU knows how to handle the boost (as long as it's tuned for it in the first place, e.g. desired boost table etc) either way.