# A question about the spark table (MSnS-e on stock 1.8 8v)



## TheTimob (Sep 13, 2003)

I've been told a few times that I run a very aggressive spark map.

My car is a 1.8L JH 8v with a 4k transmission (.75 5th gear) The car has 280,000 on it.

My ECU is Megasquirt I with MSnS-e 029y4 on a V3.0 PCB with no relay board.

Here is my current spark map:









Now, I know changing the spark timing will affect the air/fuel ratio, but I have not played with it too much. Are my ranges (like the kpa side) even right?

The question: *Any insight into tuning the spark map for economy?* I I have a great section of highway I can road-tune on, and sporadic access to a dyno.

My goal is economy. I want to get the best MPG I can out of this engine. power is a low priority.


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## Prof315 (Jan 5, 2009)

Well for starters you should rescale the load(kpa) side of your table. 100 kpa is WOT but you stop at 59 kpa. Also why the rpm bins at 6100 6200 and 6300? Especially since they all have the same values in them. Go to www.msruns.com and look in the VW section at some msqs other folks are running.


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## -RalleyTuned- (Nov 17, 2008)

yes start with the kpa fix and re-scale your ignition map to suit. Do you have any form of knock detection? If you are not pinging then you are probably ok, however a trip to the dyno would eliminate any doubt :beer: from the looks of your map the spark is being reduced at about 60kpa (which is barely half throttle) so MS would then be reducing the timing down at WOT. So realistically your WOT timing may even be fairly low. I'd be interested to see how it runs with a correct timing table. Is your VE table setup the same?

I generally use big steps in the upper rpm, especially for the spark map since most engines tend to like the same timing through the upper rpm wot range anyways. More adjustment near idle and int he cruise/light load areas will benefit you so that you can dial in a stellar idle and cruise


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## ValveCoverGasket (Mar 20, 2002)

consider taking some examples from some of the other spark maps posted in here, and rescale your load axis... as the other guys have mentioned. otherwise the map is probably on the aggressive side - i doubt youre making any more power running over 30deg at full load than you would be down around the high 20s or so
id also take some resolution out of your rpm axis in the higher values, and bring it lower to help with tuning drivability and idle stuff :beer:


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