st 204 turbo Options

[lagos]

I didn't know the megasquirt interpolates values, i'm not sure if my ecu does that or not

but i do know that for example if boost references are 5psi apart... and say you had references -5, 0, 5, 10 etc, then optimal timing would be at those points, but 1,2,3,4,6,7,8,9 etc psi levels will have less than optimal timing

i'm betting if i had 50x50 over 20x20 i'd have more overall torque and smoother power, and my highboost where i run out of resolution would be alot more punchy

They all interpolate the values.
The only real benefit to larger maps is that you can add different fuel or timing values in very odd cells, like 10 kpa to slightly smooth out the transition during throttle lifts. Or you can add specific cells for very high boost levels your car will never run.

If you look at your boost gauge, the transition from 0psi to 7psi to 10psi to 15psi happens almost instantly. So you only really need to tune the car for those values, with one extra row for something like 20psi, should you decide to up the boost to a crazy level. If you dial you boost to 13psi, its just going to use the interpolated value between 10 and 15, and since the changes in timing and fuel are linear, that value will be correct.

Personally I think 16x16 for both fuel and timing is perfect. No one is going to dyno tune their car at 1psi, 2psi, 3psi, 4psi, 5psi, 6psi, 7psi + and need some specific settings in each of those to warrant some 50x50 ignition table.

say you had references -5, 0, 5, 10 etc, then optimal timing would be at those points, but 1,2,3,4,6,7,8,9 etc psi levels will have less than optimal timing

Thats actually not true. The transition is linear. No professional tuner takes the time to tune each psi level, because 1) it would take a lot of dyno time and 2) the values they would find would be somewhere in between of the highest and lowest cell they already tuned for.

This post has been edited by lagos: Jul 27, 2013 - 1:06 PM

[delusionz]

my st205/powerfc was tuned with small increments

my dyno tune was from 9am to 4pm with half an hour lunch break to cool down the car

finished off with a 15 minute road tune and i completed the rest

my map is fully in increments of 10kpa from vacuum to 40kpa over atmo (140), then jumps to to increments of 30-40kpa up to a total of 2bar over atmo (300kpa)

its very nice and smooth to drive in the high-res zones, but on highboost im certain i can have more torque as my ignition timing falls by 3-4 degrees per row

IF it is indeed interpolated, then yeah none of this matters