30psi said:
Well that was an easy mistake to make. I haven't seen inches of mercury for some time. Easy to mix up with Kpa. Anyway I'm not here to compare different engines, but there are some incorrect facts about the ECU.
I clearly stated what pressure I was talking about, (millimetres of Mercury) you should check before you criticise. I use this value as most Nissans with boost sensors use this as their scale.
Firstly the ECU does not even think about air temps. Its not some sort of artificial intelligence advice. It purely runs off pre programmed data.
Its known indirectly by the fact that the MAF measures Moles of air passing through it. Some MAF sensors also include an airtemp sensor. Its a fact that directly or indirectly the ECU has to know the density of the air and the Figaro bases this all on the fact it does not have an intercooler, if you then add one, under some conditions you will get a much denser air charge for which there will not be enough fuel.
The water temp is a static adjustment, ie 20% enrichment over the whole range when at a particular temp and so on. It is actually set to have 0% adjustment at normal operating temps.
Water temp just so happens to be one of the largest correction factors on ECCS too, it also adjusts ignition timing.
There will be spare capacity in the ECU for fueling and its probably at a bar of boost. Naturally this doesn't mean the boost can just be wacked up, but to certain degrees it will compensate.
This is true, but there is a right way to do this and a wrong way. If it is checked after an increase with the right kind of gear then all may be well. But its not something I am going to recommend to someone.
Pre ignition is caused by the hot air temps, which the ECU doesn't know, and its best to have an intercooler.
Hot air temps is a contributory factor. Its not the cause. Its not pre-ignition either. The cause is cylinder temps and pressures above that which the fuel is stable. Det often happens AFTER the spark has been initiated, the flame front causes an increase in pressure that is too much for the fuel to remain stable and then the remaining un-burnt fuel in front of the flame front explodes, before the flame has propergated to it. This is why retarding the ignition will reduce this, as it lowers the combustion pressures to a point where the fuel is stable, getting cooler air in will also definitely help.
Not all the ECCS systems have a fuel cut. Only systems like the S13 and upwards have this.
I can guarantee you that the fig does, as does the March ST. I have several ST ecus from the basic road to rally ones, and a pile of daughter boards from other various Nissan ecus.
You don't have to spend £1000 to get an increase of power. There are ways to introduce more fuel. The system could be run on larger injectors and quite likely could be mapped.
Right and the flexibility of mapping a standard ecu and then testing it and making alterations is not as straightforward as a piggyback nor as flexible, plus without ICE (in circuit emulation) cannot really achieve this in a real time basis.
I have an S12 which I've increased the power from 135bhp to 237bhp. This is from a few mods on a poor engine design along with a boost increase. Now this was at the maximum the injectors could supply. That is possible due to the available fuelling capacity.
The March ST is similar, stock injectors allow upto 160bhp but then they are at 100% and you will get no where near this on a stock ecu due to various reasons.
So in summary... A remap isn't essential for a boost increase. Its ideal for optimum results, but not everyone has the money to do this.
At no point did i say it was essential, but at any point turning up the boost and hoping for the best is the WRONG way to do things and as such is something I would never recommend.
We are lucky to have such a flexible ECU system that compensates for the extra boost
Very true, but really they just see it as extra airflow, since they don't have
