[Turk1969]

Hello,

I am planning on doing an engine swap on my Peugeot 106 1.1. I bought this car with the intent to do a motor swap, as I have a spare 1.4 with mods, and I want a standalone ECU for that.

What I want is:
-wasted spark
-batch injection
-IAC stepper control

I am torn between the UA4C and NO2C. NO2C would be enough for what I want, but I am concerned about the barometric correction. My favorite roads have an elevation of ~900 m from my place to the top of the mountain. Is this change enough to upset the tune?

I have experience with wiring and ignition tuning, but this will be my first full EFI build.

[jonbill]

If you use the MAP sensor for load index, it 'automatically' takes into account the variation in pressure.
i.e. 90 kpa MAP at sea level with 70% throttle and 90kpa MAP at the top of the mountain with 100% throttle are the same load on the engine and take the same tune values.
[well, actually if you search, there are a number of threads on this with varied opinions, based around how significant pressure in the exhaust is, but it's very small differences and it'll be a long time before your tune is good enough to join the argument, and your car will be running well and you'll only join the argument for fun....]
if you're using TPS as load index, it's a different kettle of fish

[PSIG]

Speeduino takes a reading at startup, which can cover most of the difference in fueling due to barometric pressure, for most applications. As the differences in effects are based more on hardware rather than just pressure, the effects are different for every application, so you may or may not require it. However, this only applies to modes using MAP, such as SD. Other fueling schemes that do not incorporate MAP or barometric pressure do not compensate, such as AN.

Unless you have that concern or will build a second sensor into it (all Speeduino boards I have seen can accept a Baro sensor signal), just try it with the MAP startup reading. If you find it would be useful, add it later. If you have no Baro sensor, you can do as I did for years, and key off/on while driving the mountains to update the Baro reading to regain better fueling with density altitude change. It's a pain, and the engine will run worse until you do, but at least you are not stuck running worse.