Gain/Response Boost Controller settings for Single Turbo FD ?

[AndyGen3]

Guys got one of these Gizzmo IBC boost controllers and was wondering did any1 have suggestions for the Gain etc ? Even what to start it off with to test and change etc ?

Cheers
Andy

[rx7boy]

You should be able to find out what gain to use by Googleing your wastegate spring pressure and the boost controller name.

I know that on a standard FD that the gain is set to 5 on a blitz sbc boost controller.

I think im correct in saying gain is set in accordance to your wastegate spring rate and response is the level of boost on top of what it takes to open your wastegate.

So with standard FD wastegate opens at 0.7 bar 13 psi so repsonse is a percentage increase on that.

please correct if im wrong

HTH

[AndyGen3]

What if you dont know what spring is in it  ?

[rx7boy]

then that would suck lol !! normally there only a few options with certain wastegates,. what one you got, is it internal or external

[AndyGen3]

External HKS 60mm... When i didnt have the boost controller it would only boost to .6 so id imagine thats what its set for... Cheers...

[rx7boy]

got this from their website IBC

# Boost Setting / Duty Cycle: You don\'t directly set the boost level to the PSI you wish to see... the Duty Cycle is what controls the maximum boost and this is in percent. i.e. 60% Duty Cycle will produce a lot more boost than will 15%. This percent is a measure of the time the wastegate remains open. So, reducing this percent reduces the time the WG is open. You then test the engine running and see what sort of boost each particular setting creates. Typically, for initial settings on any engine, we recommend beginning at 10% and then increase from there as you test drive the car. In your case, the EVO can take a bit more boost than most cars and you could probably start safely at 30-30% on the duty cycle. After testing things, you may be able to run as high as 40-60% but please do a little testing before just jumping to those high numbers.

# Gain: The gain controls how quickly the boost comes on, i.e. how fast the wastegate is allowed to reach full open. Generally, we recommend also starting with this on 10% and test things out. You do not want the Wastegate to just slam open immediately or you\'ll get an overboost situation as it hits the peak faster than the wastgate can react and begin throttling down to control the max boost. But obviously the slower it opens, the more turbo lag you\'ll see so you have to just find the balance that best works to bring the boost on without over shooting. Ideally this would be set as high as possible, but if too high you can have problems overshooting and create an unstable boost situation. So you\'ll just have to work out how much gain you can manage without overshooting.

[bumpstart]

gain and amplitude are , in PID/ PLC talks is respectively the response rate
( samples per second )
- and the scale of movement in each change step

yes,, in this application they relate to the physical dynamics of the controller out in the field
-- in this case a PCV ( pressure control valve ) used for boost control

gain and amplitude tuning is science to itself,,
 so with out giving you a very big headache,,,
 lets just say you may wish to read up on something called open loop tuning 1/4 decay ratio theory

and the hint in all that,, when starting with unknowns in the field
-- start your gain and amplitude LOW,, as while this may prove slower to react
it will however avoid an overshoot control hunt ,,
----thats what whacking in large numbers will certainly bring

( i am industrial systems process PLC/ DCS qualified )

[bumpstart]

to clarify that a little better,,
 note the information is not your brand specific,,
- but intended to help all people using a PLC needing gain tuning

on analog controllers,, with two dials
----they are usually expressed as gain frequency,, and gain amplitude

-- in your digital EBC,, they are expressed with the manufacturers interpretation
" duty cycle " is the proportion,, or directly the gain amplitude
-- how much change it can add

and "gain" is more directly the sampling gain frequency,,
basically--  how many times a second the controller has a chance to add some proportion and re sample the current PV
( process variable,, ie the boost right now )


if you err large,, it will overshoot,,
-- and hardly ever hold set point with a radical hunt that will see the wastegate pulsing in out rapidly

if you err small,, it will hit set point given a few overshoots , but may get there at less than optimum speed

-- if you get them bang on,,,, you will get 1/4 decay pattern on the PV vs SP
-- it will overshoot then undershoot  three times and then on the 4th swing SP=PV and it will not hunt off
this is almost impercievable to the user ,, but can be plotted
-- and results in you getting set boost and holding it

NB
-- some good closed loop systems will fuzzy logic themselves
and only use your setting as an initial start point before learning your systems dynamics

my tip to all, ,, in absence of supporting data for your install
-- start with the numbers LOW,, creep up on it !!!

[DR SCHNITZEL]

what about a profec b with soft and sharp as the only setting parameter, does that use fuzzy logic too?