Question about kpa and boost: Why goto lets say 240kpa

TTC · Post by **TTC** » Sun Sep 03, 2006 5:35 pm

I'm looking at various maps, and for instance why go as high as 240kpa if your only running 10psi of boost? Everything over 100kpa is positive manifold pressure so why not just run your talbes to 170 kpa? 100 kpa +70 kpa is 210 which is all the manifold pressure im going to use. Now for saftey incase u over boost lets say goto 200 kpa which gives me maps till 15psi if i spike or over boost. If im only running 10psi doesnt that mean ill never see activity in those 240kpa load sites? I havent done any data logging so maybe im just thinking to much.

chicksdigwagons · Post by **chicksdigwagons** » Sun Sep 03, 2006 5:57 pm

No, you're absolutely right. If you're only running 10psi and never intend on running more than that, building a map out to 21psi is not only silly but you lose resolution in the cells you DO use. I like to give myself some headway on a turbo motor and richen up the very last and non-used cells as something of an overboost safety net (especially on a car without a stock turbo). But in reality, once you get into high boost your VE doesn't change a whole lot and you can get away without that as it will continue to ramp the fuel appropriately. Lots of people have successfully run over 21psi on the stock 250kpa MAP sensor thanks to this feature of MS.

TTC · Post by **TTC** » Sun Sep 03, 2006 6:02 pm

Another question, how do u know which intervals to set kpa and rpm at?

chicksdigwagons · Post by **chicksdigwagons** » Fri Sep 15, 2006 4:07 pm

You don't

What you want to do is give yourself more resolutions in the areas in which you need them. Start with pretty evened out cells and as you get more comfortable and more dialed in you may find you want a little more control in your peak torque range or at idle/off idle, etc.