Supercharged holden commodore ecu and other fun topics

[Daniel Collins]

Zak
Basically the engine does not go into boost between the blower and the
throttle body (the boost is between the blower and intake valves) ,
therefore to the ecu it just appears that the engine has a VERY good
volumetric efficiency.AS I said this will only work with a positive
displcement blower.The engine is mapped to what fueling and ignition
requirements are at each load point.
ie at 3200 rpm the blower will make .8bar  boost when the engine is at WOT
this correspond to 100kpa between the blower and the throttle body , if i
close the throttle slightly the map sensor reading drops to 80kpa and the
blower is throttled dropping the boost the engine sees.
I will reiterate this WILL NOT WORK WITH A TURBO OR BLOW THROUGH
SUPERCHARGER.
The other important consideration is that a positive displacment blower will
always make Xbar of boost at Yrpm if at Ztps whereas a turbo is not so
predictable.
I have also used a 2 bar map sensor on turbo cars but this halves the
resolution of the maps and I would advise against doing it - (maybe someone
can patch the code to increase the size of the tables to make this possible
?)

Some calibrations that Ive seen do use a 1 bar map sensor on a 2bar engine
and ignore what happens after 1bar  and just try and run rich /low timing to
allow it to be right at 2bar THIS IS ABSOLUTE CRAP the engine can never
perform properly , may as well put a carby on it and a mecahnical advance
dizzy rather than spending your hard earned dollars on a chip from these
people.

When I am doing something on my own car I will try anything to see if it
gets a positive result , "nessecity is the mother of invention" but you must
always remenber to sit back and look at what you have just done and all the
implications of the changes you have made.

Oh well enough of my rantings , the missus reckons she needs me in the bed
so I had better do as I am told

Daniel Collins


-----Original Message-----
From: Zak - Andrew Wakeling <zakariski at optushome.com.au>


>Hey Daniel,
>
>I'm just a little confused... What do you mean when you said that you
>remapped one of these using the 808? I'm not exactly sure what you mean.
>How did you configure a supercharged car with a 1 bar map sensor? I
>thought it doesn't matter how you treat the internal maps in a
>program... the ECM doesn't know what the hell is going on in the boost
>stages of the car (thus why we use 2 bar map sensors). Did you alter the
>manifold vac so that it had a reduction factor or something? hmm.. I'm
>rather confused.
>
>Isn't this bodgy? I've heard of a company in Oz who were using 1 Bar map
>sensors on supercharging applications... Its was rather funny (or should
>I say ashame???), because they just sorta set VE tables to 100% near
>atmos MAP, and of course as the supercharger started to spin up, it just
>got leaner... and BOOOM.. no more engine!
>
>Also, just to note, turbos aren't really much different from
>superchargers as far as computer applications are concerned... IMHO. I
>find that the positive displacement superchargers just tend to boot in
>very quickly, so many cars need significant mods to acceleration fuel,
>but apart from that... the mapping principal is relatively the same.
>
>Ah well, just my two cents worth. Hope everythings going well for the
>rest of you guys!
>Just for interest sakes, I'll be doing a lot of work on the 808/165
>computers & code!
>
>Cheers,
>Andrew Wakeling
>zakariski at optushome.com.au
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