Big injectors for the EA11R PNP
Our inital PNP tune was built for the OEM Suzuki injectors and manifold pressures above 210 kPa. We went through some rather elaborate steps to make it as appropriate as possible for further expansion. Nonetheless, we have gotten quite a few requests for a tune similar to an Suzuki or Monster Sport N2 ECU; which would be appropriate for larger injectors and manifold pressures above 210 kPa.
What’s necessary for changing injectors
Injectors do not behave linearly. The relationship between the applied pulse width and the mass of fuel delivered is different for every injector. This must either be compensated for, or the nonlinearity ends up being baked into the VE tables. If injectors are changed, then there is a discrepency between the commanded lambda and logged.
There are a few parameters in the engine management system to compensate for these differences. Some of these are better than others. Likewise, some injectors behave better than others. Many tuners do not bother with these changes, as it is time consuming. They allow the nonlinearity to be baked into the VE tables. This is less than ideal, but isn’t the top priority for tuners.
What’s difficult about the EA11R
There are a few things which make the EA11R more difficult than most. The fuel system operates at 2.2 BAR. This lower pressure helps with small pulse widths. Most fuel systems, and therefore most injector response data, operates at 3 BAR or higher. The Microsquirt Module in the EA11R PNP doesn’t have the best compensation system. Some small amount of nonlinearity ends up in the VE tables. Because there are only 3 injectors available for the system, they end up being rather large for the amount of power being produced, and idle pulsewidths end up VERY short. This is where injectors behave the worst.
A bigger problem is that there seems to be a rather large difference from one DOHC F6A to another. More than the difference in history, any individual owner has different intentions, they’ll have put different parts together. I don’t think we’ve gotten two customers who want to use the same model of injectors.
An F6A needs to be particularly healthy to behave above 1.1 BAR of boost for very long. The OEM head gasket becomes a problem. The cooling system becomes a problem. The cooling system problems cause head gasket problems. So turning up the boost first requires quite a lot of preventative maintenance and even replacing the head gasket.
What we’ve provided
We’ve decided that the best course of action would be to pick a set of appropriate injectors and perform the necessary tuning to make them behave with the EA11R fuel system and PNP.After a lot of review, we settled on Deatschwerks 22S-00-0450-4 450 cc injectors. These are current production injectors, available globally, which are plug-and-play for the DOHC F6A. We can include them with a PNP purchase for 360 USD.
This is still not a complete solution, as differences in turbochargers, manifolds, intercoolers, exhuasts, etc. will all change the performance of the overall vehicle, it does provide the next step from our base tune toward more boost. It’s not as polished as our base tune, but it runs, drives, cold-starts, and behaves. All of our tunes will be improved as we receive datalogs back from customers and testers and we’ll be sharing what we learn here.
Current tunes are available in our git respository. More information on interacting with the tunes can be found in our documentation.
contact us if you would like to order a plug-and-play!