Boost by gear suggestion

[aidandj]

Currently boost by gear sets the max boost in a certain gear. Does it take control away from the boost target table? Or just not let it go any higher?

It would be cool to have boost by gear be percentage based. So we can still have TPS based control and table switching. So when traction is low we can switch to low boost, but still have the option of boost by gear.

This came from me thinking about how to have wet boost targets and dry boost targets. But either way 1st is useless at max boost. So I need boost by gear and also boost switching. So if I set 1st to 70%, 2nd to 85% and 3rd and up to 100% then I will always have those different boost levels per gear but I can switch tables at will.

Any interest?

[nathaninwa]

You can do this by using the blend curve in the drop down, then select gear on the graph. You'll set min and max and determine the percentages Inbetween for the other gears

[aidandj]

Cool thanks.

Ignore my suggestion.

Just looked at this. How will it give me a switch between low boost and high boost mode. Won't this just blend between the 2 tables?

[elaw]

If I understand your request correctly, it's not supported.

It sounds like you need combined switching and blending. In "wet mode" you'd blend between boost tables 1 and 2 by gear (with the table axes being TPS and RPM so those are included too), and in "dry mode" you'd blend between tables 3 and 4 that have higher boost targets.

It's definitely an interesting idea... especially for those of us who live in areas where it snows. But it's something that would have to be added by the developers.

Of course it's also a classic example of a "slippery slope": as soon as you add blending + switching, someone else will want blending + blending, then someone else will want blending + blending + switching...

[aidandj]

Thats the general idea, but it could be implemented much simpler.

My initial suggestion was to change the boost by gear parameters to percentage of boost. So if target boost in table 1 is 190kpa. And 1st gear is 75% then my first gear target is 142.5kpa.

Then when I tableswitch my rain target table is 165kpa, and my first gear target is 123.75kpa.

[elaw]

Ah, I get it!

That does seem like it could be pretty easy to implement.

[nathaninwa]

Sorry I missed the double blending. How about an off switch to run wastage line the. On for boost by gear

[aidandj]

Sorry I missed the double blending. How about an off switch to run wastage line the. On for boost by gear

That is what I am currently running. But wastegate spools slower and doesn't hold boost nearly as well.

[juansh2385]

I suggested this before but either I haven't explained my self correctly or it is not as easy to implement because the answer from the developers is to use the blend tables and I have not been able to get the expected result just with the blending tool.

Juan

[sturgeo]

What are peoples workarounds for this?
I too had planned for 2 separate boost target tables, one for road & one for track, whilst also implementing gear based targets to limit boost in 1st & 2nd.

Would it be feasible to do the following:

Boost Table Switching - Gear Based (so now 1 table for 1st & 2nd, and 1 for 3rd+ instead of one for road and one for track)
Boost vs Speed/Gear - Off

And then enable overboost protection on an input pin, this will act as the road boost limit so when i'm on the track simply turn the switch off/on?

Also for a "wet" mode killing the 12V to the boost solenoid so simply running off the actuator wouldn't cause any issues would it? Not sure how closed loop would react to that

[aidandj]

This is my current solution

https://www.youtube.com/watch?v=TtwR2RTSP4w

6 position rotary switch turned into a rotary potentiometer.

ADC input. Boost blend curve based on that input.

Table 2 at wastegate, table 1 at full boost. Blend between the 2.

[sturgeo]

I did consider a rotary switch on an ADC input as I'm going to use them for launch rpm and TC % slip, but have you lost the gear based limits?

[aidandj]

Yes. I believe I lost gear based limits. I have not tried though.

[sturgeo]

I've been digging deeper into this and think i've got a solution that'll work for me.

I wanted the lower gear limits purely for drag racing, as we're using launch control i'm going to have a play with the "Boost Timed From Launch" & "Specific Launch Target" settings.

May i ask why you set the first boost target below wastegate?

[aidandj]

I've been digging deeper into this and think i've got a solution that'll work for me.

I wanted the lower gear limits purely for drag racing, as we're using launch control i'm going to have a play with the "Boost Timed From Launch" & "Specific Launch Target" settings.

May i ask why you set the first boost target below wastegate?

For ease of math when tuning the curve. If table 1 is 100 and table 2 is 200 then 50% is 150kpa, 60% is 160kpa. Etc.