[All] [Generic] Tips for setting up open loop boost control

[Wingers]

This is probably one for the tuners out there but I’m trying to set up my Link G3 ECU to give sensible manifold pressures at all times. The difficulty I’m having is due to the varying engine load because when the engine is more loaded, I need to set a higher duty cycle to maintain the correct MAP level. For instance, in high gears and/or going up hill the duty cycle may need to be several % lower than the same condition in a lower gear and/or going downhill. I have set different duty cycles for each gear but how have others dealt with the varying engine load due to road gradients etc.
At the moment I find that I often hit the boost limiter at 1.7bar when going uphill but may only reach 1.3bar if going downhill. I think I need another input, or some way to run closed loop but I don’t think that’s possible with my ECU.
Has anyone found any tricks that might help?

Thanks,

Wingers

[Andy F]

Surley you have set your boost on the flat to say 1.8 bar
then when your going up hill it will only reach 1.8 bar then
the waste gate will open!
It should only reach to what you have set it

[Jim Galbally]

open loop should be simple. you set it up under FULL LOAD (ie up a big hill, motorway, or braking whilst accelerating)

you wont hit that boost in lower gears or when youre not under load, thats more of a mechanical limitaiton, just live with it.

or use a closed loop system be it either a seperate boost controller or see if your ECU supports this feature

[Wingers]

it is simple in that respect but I find that it can be a long way from what I consider "full boost".
At times I'm only hitting 1.3bar, other times its 1.7bar.

I haven't got around to fine tuning the boost map yet so maybe I'll get it more consistant that that once it's done properly, but i wanted to run through the process now so i'm more familiar with it when i come to do the final map.

I understand that this is the limitation of open-loop control but I just wondered if there are any tricks that people have emplyed to work around that and get a better response.

It seems that there may not be, and unfortunately I don't think my ecu has any closed loop control

Wingers

[RyanRs]

I have the linkplus G3 and i have been told by a couple of people that the boost control on these is not very good at all. i don't know exactly Why but when i asked Ryan.g about using the Link to control boost he advised me not to use it and to use a good independent boost controller instead.

[Wingers]

I’m beginning to see why…
I have the LEM so it’s one down from the LinkPlus. Not sure if that makes any difference when it comes to boost control specifically or not.

I'll give it a proper shot first but might look to do something similar myself...

Wingers

[RobCrezz]

I have heard the same of the Power FC boost control. Might just be worth getting a basic EBC like the Profec B Spec II.

[dai21t]

Ryan mapped my car with a link plus G3, I've never had any issues whatsoever with boost control. Ryan didn't say anything to me about problems with them. He did my brothers car the same day, he's running a powerfc and Ryan did advise him not to use that to control boost as they're not very good.

[RyanRs]

i dont want to speak for him, but that could have been because of a couple of things. Ie, you have the hardware , you've paid for it and even tho its not the best option , it does the job -and his job is to make it work as good as it can -not criticize it!

The reason i got into the conversation about the Link boost control on mine was because i had a boost fluctuation. We thought it was either a faulty actuator or my old blitz EBC playing up. He advised that i get a good 'newer' EBC such as a profec-b and also to test the actuator. I said 'i might get the link to control the boost' and he replied along the lines of 'no, dont use the link,it works but it doesn't do a very good job, A standalone EBC would be much better'. -im sure he mentioned the PFC being the same. Turns out my issue was the BOV spring setting being too loose!!

Im thinking the prob is due to difficult calibration / lack of parameters and poss a crap solenoid?? cannot remember, it was a long time ago!

dai21t - It may hold good boost and function correctly, but do you know if your getting maximum gain control over your wastegate? you may find that you could hit your maximum boost a lot faster using a Profec-b or DSBC and therefore making your car accelerate a lot faster!!

[Jim Galbally]

ah wait i see what youre doing now i got confused.

i'd agree with the other posters, from what ive seen of most cheap aftermarket ECUs their boost control is pretty junk and are just staic PWM outputs ona single line "map"

[Wingers]

I probably won't have time to do any more until after i've been mapping next week so other than a few data logs on the way to work I think I'll leave it for now.

All in all I don't think there's much more i can do with the Link but I'll have another go with the new boost level.

Wingers