2.0L 4B11 NA Tuning/Adjustments - MIVEC

Hello I am Eric, I've got a 2017 2.0 FWD Manual Lancer ES,

I've been doing some experiments myself on MIVEC with NA inspired by Evo/Ralliart MAPS, I'm no professional in anyway just an enthusiast learning to Tune my own vehicle with my Tuners help, but understandably MIVEC Tuning on NA engine is quite different to those with Forced Induction.. I'd like to share my Adjustments on a 4B11 NA MIVEC and would like some feedback/tips to improving this in any way. Its rare to find any public Information as to how Dual MIVEC can be fine tuned.

MODS and SPECS:

2.0L 4B11 Lancer NA - 4B12 OEM Exhaust Header - RESONATOR Delete + Greddy Muffler on stock CATS - EGR Delete - K&N Cone Filter with 2.5" PIPING to TB - 500CC injectors (10% scaled = 450cc in ECU FLASH)

Weight - 2980lb (including tools etc.) | Driver - 186lb

Car was able to make an average of 160WHP@6140rpm& 211Nm@4320rpm @16°C 99KPA Bar.Pressure from EVOSCAN to Virtual Dyno from ROAD TUNING. Correction factor 1.0 (Unknown result from any DYNO) on Pump fuel aka REGULAR 87 OCT.

I have not touched anything with THROTTLE MAPS as I'm very unfamiliar with how any of it works.

MAF Downscaled 15% on ECUFLASH as oem intake is 3" and new intake is 2.5"

My AFR WOT @2500rpm12.6:1 - 12.0:1@5500rpm & @6000rpm 11.9:1 - 11.8:1 @7000rpm (stock only goes to 6500rpm & was rich everywhere for NA -> 10.6:1 close to redline )

Ign. Adv. from 2500rpm 15° to 22° 6500rpm and 7000rpm is retarded to 20°

The Photos are my MIVEC Maps and feel free to use for those interested but atleast credit me if you show it off (atleast for base map if you're fine tuning to your desired adjustments.)

Eric,

The process usually involves testing combinations of ignition timing and cam phasing, as well as lambda target to a lesser extent.

Ignition timing gets involved because altering cam phasing can alter peak cylinder pressure as well as the shape of the trace, cylinder temperature, and require more or less ignition advance to achieve best torque.

On pump gas it's often more about how much ignition advance you can use at each cam phasing combination without causing knock.

How you sweep the cams during testing is really up to you, but out of habit I usually set ignition advance safe enough to test cam phasing without knock first.

Then I sweep intake cam in 5 degree increments without touching exhaust cam settings, to see what 5-10 degree range of intake cam timing made best torque at each 500 RPM of the rev range, at full throttle.

Then sweep exhaust cam timing every 500 RPM at full throttle while using intake timing in the middle of the intake cam range that seemed to work best.

Then once you have a ballpark intake and exhaust combination across the rev range, start testing different combinations of cam phasing in the +/-5 degrees or so from that range.

Tweaking lambda target, ignition timing can also help find a cam phasing combo that didn't at first seem optimal, but actually works better.

In one areas leaner AFR, more timing, less aggressive cam phasing might work better than a combo of more aggressive cam phasing that required less timing advance and richer AFR.

All the way I monitor other items to stay within limits important to the application whether that's emissions, catalyst temperature, etc.

This takes a good bit of time, but this is still the short version.

It only relates to full load operation, and without testing all combinations of cam phasing, ignition, lambda, throttle, engine speed you may not find the best combinations. On applications where additional time is being invested, perhaps multiple days of dyno time on cam phasing, then you can arrive at a more optimized calibration not only at full load, but also in other load areas. There have been times where the "short version" took 4 hours and then on day 2 I found something that added another 2% power via a more in depth investigation, so it really depends how much dyno time, and your time, the project can support.

On a street vehicle, leaving light and mid loads stock helps avoid unwanted emissions increases or drivability quirks.

Hey MIKE!,

Thank you very much for the info on how to get the best of a PUMP FUEL VVT/MIVEC NA without causing Knock, unfortunately I don't have open access to any DYNO that are open so it'll be a lot of ROAD TUNING at MIDNIGHT for me. I do remember watching some of the tuning guides with VVT on I believe ya'll 350z where Increasing EXHAUST CAM degrees decreases power at a certain point after finding the best TRQ with Intake Advance.

I will probably do more experiments as I left my MIVEC Adjustments to this aggressive setup without testing lower Values in WOT.. I've only ROAD DYNO LOGGED the current setup flashed. (Labeled "162whp" corection - Vehicle Weight 2980lb+Driver186lb - Tires 25.33 - 3RD GEAR 1.33 Final - 3.94). As of my basic knowledge its best to tune in OPEN LOOP (uses more fuel?) then enable CLOSED LOOP (ECU ADJUSTS according to the table and Temp ETC?) when done especially for everyday driving as its my fun daily. I've also provided a screenshot of my SPARK-FUEL-MIVEC Maps Tuned as well as the STOCK Values to compare so it's more understandable than just me yapping.

(FYI my I have my Injector Scaling set to 412cc compared to the rated flow rate according to A-Premiums FJ972 "500cc/min" on stock BATTERY LATENCY since I can't figure out how to adjust this)

I really do appreciate the HELP and guidance this would be so much easier with a DYNO for me for sure. I'm still learning more of the basics especially on this NA 4B11 MIVEC. I hope to hear more lovely Teachings!

Doing the best you can with the tools you have available to you is a theme of tuning whether you have a dyno or not, so well done trying your best. Even when I have a dyno and a bunch of extra sensors, there are always more that could give me an even fuller picture of how to optimize things.

That said, the changes in torque output from cam adjustment on this engine can be on the order of 1-2 HP per 5 degree shift, which won't show up on acceleration testing and can be caused by all sorts of other factors since it's such a small change. Finding best torque without a great dyno seems challenging and honestly I'm not sure it's possible.

It's unlikely you'd see a significant shift in airflow via MAF or MAP unless perhaps you get very far from optimal.

You can end up lean after a cam phasing change by sending fuel out the exhaust unburnt due to excessive overlap, so that's an example where your observation of wideband during open loop could lead you away from proper values rather than towards them.

In terms of fuel, your targets seem reasonable.

For ignition advance, if you're road tuning on pump gas, then tuning ignition timing to just below where knock occurs is typical practice. Using a dyno is more ideal because you can see where adding advance stops helping much, without running the engine into knock. For those of us tuning similar vehicles repeatedly, what you learn on the dyno can be applied to road tuning, but in your case finding the knock threshold then taking a few degrees ignition advance back out will still likely allow you to make performance improvements over stock.

finding the knock threshold and then backing timing off a little. Some engines allow achieving MBT on pump gas, but most I've tuned encounter knock first, so that