minimum mapsize for mapped ignition

[SirYun]

well the subject header says it mostly.

how many sites does one need?

i looked at a megajolt liteJr (fordEDIS with a DIY box) wich has a 10x10 map which seems a bit small compared to DTA, Emerald, Omex etc..

quite cheap to make though

it is to be used on a road going vehicle and it is said that the drivability with bigger cams improves a bit...any thoughts on that?

if not, i can just fit a 123ignition which has a bunch of curves switchablewhich will probably provide a 90% solution and that will take about ten minutes to install.

[SteveNZ]

Well distributers have 2 or 3 points :!:

10 load points is probably enough.
10 RPM points is a bit limited if thats 1 per 1000rpm. Most systems have at least a point every 500rpm.

It really depends on your engine and how much tuneability you need.

Have you seen the Link item?
http://www.linkecu.com/products/engine- ... nitionlink

[Julian]

Most modern aftermarket mapping systems that I've looked at have load points that are adjustable rather than fixed points.
Typically you would see between 10 and 20 load points that by default are at 500rpm intervals but you have the ability to redistribute the load points along the rpm scale to best suit your engine. Typically this means a few low down to provide very accurate idle mapping and then a grouping around your most sensitive region of the map or problem areas where the interpolation algorithms cannot cope.

The OEM systems have become exceptionally complex as flash memory has decreased in price. The systems used on the Fiat Fire engine do not bother with complex interpolation algorithms and instead used fixed breakpoints at 2.5rpm intervals (that is 3000 load points for the stereotypical car). Not surprisingly the programming software tends to be much more complex as the hard work is performed prior to loading rather than leaving the ECU to calculate values on demand.

The latest aftermarket systems have edged in the same direction. To give an example the DTA E48 uses 20x14 load maps, the latest ECU from DTA uses maps four times that size (I can't give you the exact size since I haven't got my hands on one yet but this is what the boffins at DTA have told me). The replacement for the P8 Pro is reputed to use twice as much again but is pure prototype at the moment and getting any solid info on the unit from DTA is not surprisingly like getting blood from a stone.