Haltech Elite 1500 base fuel for a Boost + ITB

Hello all,

I'm a first timer setting up a base fuel map for a boosted 4AGE 20v with ITBs. What is the best practice for axles values on the base fuel map?

I was looking at setting up a 4D map with RPM(32 values), TPS(32 values), and MAP(8 values). The 4D being Map as we only get 8 values. Would this be overkill or am I overthinking it an just should use RPM and MAP?

Thank you all in advance.

Personally I approach it like this:

Loadsource = TPS, calibrate fuel table as precisely as possible below 120 kpa.

32 sites for TPS is excessive. Use fine grained sites below 10% TPS. 0, 1, 2, 3, 5, 7, 10. Then, 12, 15, 18, 20, 25, 30, 35, 40, 50, 60, 70, 80, 100. That is plenty resolution. More will only make you more work without yielding better control.

This in itself should suffice to have a nicely running engine off boost.

In a turbo application, I'd view the transition area, off boost up to ~120 kpa, not 100 kpa.

Observe where MAP pressure corrections are needed and apply them conservatively, likely in the transition area by the use of a 4D correction map.

You may likely find that Lambda in that area is inconsistent when comparing part throttle acceleration to part throttle deceleration (going rich). This behaviour can be optimized. It originates largely from the fuel film being drawn in this higher vacuum situation.

From memory, Elite already has provision functionality for transient mixture optimization, but I do not remember in detail.

Your map source ideally comes from a vacuum accumulator where pressure pulses are collected from all intake runners and dampened.

Pressures >120 kpa, depending on the fuelling model, the ECU already accomodates for the needed additional fuel if modelled mode (Volumetric Efficiency Mode) is the choice.

If traditional, create another correction table for the boost part, pressure >120 kpa. In therory, the added amount of fuel needed is linear. Add 80% fuel in the 200 kpa row and linearze down to the 120 kpa row where 0% is the correction.

Subsequently I'd enable wideband closed loop control with -5 and +10% control range. Gain perhaps below 8% -ish to prevent over/undershooting the target.

Make use of the long term trim table.

There is more than one way to skin a cat but I trust that this approach will give you a good starting point.

D

Thank you Dominique, This was very helpful!