Ok,
One by one....
St3V3_C,
OK - here is one - what happens when things go wrong with boost? I know some have got overboost protection in the chip, but is that always there?
Depends what application it is, but we will choose Marelli.
The 3bar can have a boost limit up to and including 28.5psi thats still reliable. If you want to run more boost than around 26.5 held, then the boost limit must be removed completely.
The alternative is to fit an alternative method of boost limiter, such as a pressure cutoff switch or a blowoff valve.
St3V3_C,
Same question re ACT's I guess?
ACT's are mapped within most Ecu's and as such nothing can really go wrong with them that the ecu cannot deal with TBH.
M Brian,
ERST - what stops you from 'livemapping' the ignition on these for example?
Bosch KE's Spark control map is part of a Motorola "processor" and not stored on an "Eprom" as per other designs. Processors cannot be emulated live by conventional emulation methods.
M Brian,
OFAC and OFAB would these be different to map with the different map sensors, and to if the map sensor is limited to 1 bar positive - how would you get around this for running say 18-20psi?
The map sensor doesnt really "limit" anything. If you look at this fuel map:
The left hand column is map sensor output voltage, so obviously, should we change the sensor, the column meaning will change, yet fuelling remain the same.
EG:
Top line is 4.9volts. That on the std OFAB sensor is 1bar positive or 2bar absolute. If we change to a 3bar, that line now equates to 2bar positive or 3bar absolute.
Result = very lean everywhere.
This effect obviously happens to every map that is pressure related.
As for the upper limit of the sensor, once we hit the 4.9volt line, we can run all the boost we like, we will never get anymore fuel, hence when your tuner says: "set it to 28" you dont set it to 34 and presume it will be ok. lol
M Brian,
and also t2 to t3 conversions on the frst - would the fueling be totally out for the same boost pressure on these, given that the gains would primarily be down to exhaust housing and pressure efficiencies on the inlet? would there be lots of factors in the map and tables to alter for this simple and common mechanical change?
Generally fuel and spark will both be wrong, with the onus on the fuel. The charnges required arent immense, but they are enough to melt the engine if not dealt with
