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AFR tuning evo

Introduction to Engine Tuning

Discussion and questions related to the course Introduction to Engine Tuning

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I added lots of mods to my evo 8 (exhaust, turbo anifold, HKS intake, ..).

When tuning using EcuFlash my fuel maps are targetting AFR ratio's.

Does this mean after those mods i actually don't have to tune the Fuel Maps? I mean they are self adjusting then...?

Because they always say you need a tune for mods, but this one seems to be targetting a specific AFR so it doesn't need adjustent in my mind.

Pic of my fuel maps below.

Attached Files

Hello when you log the afr is it matching the afr target with out much +/- trims ? if s then it is correct

Regards Ross

Stock maps are way too rich...

Sorry for the late reply, my internet died.

@Ross: I logged the maps and i have 13.2 AFR when at WOT. Seems a bit lean. That is in evoscan at the AFR-MAP section.

@Georg i noticed the map doesn't come even close to what i actually log, does that mean i need to increase the fuel in the fueling map? Or is there another issue with the car i need to look for?

It has to be richer depending on boost level and duration of high engine load. If that is the stock turbo with stock boost I would be making it 12.5 to 12 in the mid RPM range tapering down to 11.5 by the red line. With higher boost level or long duration of high engine loads i would make it even richer up to 11-10.9 by red line.

@Georg : Thanks a lot mate. I'll be richening it up then. I'll go to around 12.3 (look for a happy middle). Still stock evo 8 turbo with 0.7 - 0.8 bar of boost.

12.3 at WOT by redline? Ain't gonna work- too lean for 4g63...

As the expression goes, 'the engine will tell you what it wants' - going for a specific number isn't the best way to go, tune it for best torque BUT you also need to monitor EGT as some turbochrgers are less tolerant than others, so you may end up a little richer that optimum just to avoid damage to the turbocharger.

However, Georg is VERY experienced with that engine and, if you can't monitor those parameters, I would trust what he says. Also, don't forget the affect ignition timing has on EGTs.