Mitsubishi Lancer CJ 4B11 Mivec

Research and Development Vehicle

Technical Specifications

  1. Mitsubishi 2008 Mitsubishi CJ Lancer
  2. 4B11 2.0 DOHC 16v Mivec (Mitsubishi Innovative Valve Timing and Lift Electronic Control)
  3. Power 113kw, 158 EEC @ 6000 rpm, 191Nm @ 4100 rpm
  4. 5 Speed Manuel Transmission
  5. Four Wheel Disc Brakes

RPW started with the 4B12 Mivec Lancer, but in order to provide the complete range of performance options, we needed the 2.0 model. We were lucky enough to find this vehicle to work our magic on. Over the upcoming months this vehicle will be subjected to many hours of labour, more than a dozen dyno runs and a lot of modifications.

From its stock state – it will be initially have every form of bolt on modifications fitted to it. During the whole event various dyno runs will be done to catalogue the various gains. We anticipate a lot of response and some great results out of this engine. Below our our plans in rough order and as we progress through them – we will update this page with data sheets, photos and dyno print outs etc.

All Dyno tuning will be performed on the Dyna Pack Hub Dyno. The reason being that this eliminates any variations in tyre slippage, heat in tyres etc. This is a mechanical hub connection to the wheels and whilst the numbers may be slightly higher over a normal roller dyno, the gains are 100% confirmed between runs with no variations to worry about other than mild temperature variations which we will be attempting to minimise.

Final point – please note that even though our dyno graphs show the readings as Flywheel Horsepower / Flywheel Torque figures, the calibration option is set to a Factor of 1, which means that hub and flywheel horsepower ratings are identical. Hopefully this will clear up some confusion people have with the results from the dyno print outs.

At this stage we will not be doing any specific suspension / braking upgrades as part of this R&D project, but that may change as time goes on.

Plan of Attack

  1. Get Vehicle to RPW Workshop in Stock Trim, visually inspect vehicle and roll eyes, so much to be done – completed
  2. Download ROM off ECU and prepare OpenECU Definition Files for re-flashing – completed
  3. Run vehicle on dyno to prepare baseline power outputs to compare future modifications to compare comparative results – completed
  4. Remove stock gear shifter assembly – fit RPW Rally Spec unit to vehicle – completed
  5. Install K&N Panel Filter and / Pod filter set-up and compare gains on dyno
  6. Upgrade rear muffler with RPW Bolt on Muffler package and dyno test
  7. Perform exhaust work – fitment of 2 1/2″ system with new expansion chamber resonator including high flow cat converter and dyno test.
  8. Manufacture on vehicle RPW Replacement Extractor packages & Dyno Test
  9. Retune vehicle utilising OpenECU Re-flashing technology
  10. Manufacture and fitment of RPW Stage 1 camshafts
  11. Retune vehicle and see final results

Job 1 – Get Vehicle to RPW Workshop in Stock Trim – 28th October 2009

Vehicle received by RPW and inspected. In completely stock trim  – quite impressed with its starting package.

Driving the vehicle we were impressed with the torque response, throttle response and general willingness to accelerate, especially in comparison to the previous 2.4 CVT Lancer we are also testing.

But we know we can do better. Suspension was very soft, and brakes felt good. Overall very impressive car – impressive because we know how much we can do to it.

Job 2- Re-flash ECU – 28th October 2009

The first thing we did, as part of our plan was to download the ROM off the ECU, and to ensure we could re-flash the vehicle in the future. We have decoded around 50% of the ECU Rom data file, and are now finalising the maps for the variable camshaft technology and drive by wire throttle body control.

This is extremely important as many modifications will invariably end up with a CEL check code, usually by a check routine of throttle load V Desired Torque V Air Flow Volume. With our ability to re-flash, these problems will be easily solved as we change the appropriate maps to give us more flexibility.

We now have enough of the factory ROM file to be able to do normal re-flashing of the main fuel maps and ignition maps. Interesting the vehicle uses a factory Knock Sensor for sensing both Octane Level and using two maps, a High and Low Octane map for fuel, ignition and variable camshaft timing.

We will for our purposes, only be modifying the high octane maps, leaving all low octane maps factory for added safety. Since these usually run quite rich and low on ignition timing, these will be safe to leave untouched.

Job 3 – Run Vehicle on Dyno for Baseline Power Run – 28th October 2009

We placed the vehicle on our dyna pack hub dyno unit, and performed several baseline runs.What was very interesting was peak power was produced on this manual model at around 5700 rpm, with the stock throttle body / rpm limiter maxing the RPM at 6400 rpm.

The dyno graph showed a very different result to the 4B12 CVT model, with this 4B11 Manual model producing nearly identical horsepower / torque levels but at a leaner air/fuel ratio. This may explain the tendency of the manual models to be more fuel efficient and easier to accelerate.

Power was very smooth although the torque was definitely something that needed improvement. As can be seen, once the vehicle hit over 3000 rpm, the air fuel ratio’s dropped down into the 12’s.

Power was fairly smooth but as can be seen, there is a little bump. Peak torque was produced at 4250 rpm and tapered off (This can be seen on future graphs). With the ability of this vehicle with its variable camshaft timing and variable throttle body set-ups, this is an area for certain can be radically improved.

Mitsubishi Lancer CJ 4B11 Stock pwrvtq 1DCS493

Job 4 – Upgrade Gear Shifter Assembly.

We sourced separately a new Mitsubishi Gear Shifter Assembly, and like our previous designs for other lancers, we have manufactured our Rally Spec Short Shifter Kit.

We managed to shorten the throw by our typical 60% over factory, on the forwards / backwards movement and by 40% on the sideways movement.

The short shifter kits are now available on exchange for all manual model owners.

Short Shifter Late Plastic Base

Job 5 – Upgrade Cold Air Induction Kits

These vehicles utilise the Mitsubishi new style Hot Wire MAF sensor. These vehicles, as we know run very rich from factory.

There have been a lot of DYI customers fitting CAI (Cold Air Induction) and SRI (Short Ram Intake) kits to there vehicles with mixed results.

As can be seen from our own efforts, this is understandable when you look at the dramatic differences it makes to the Air Fuel Ratio’s of the vehicle.

We first after doing our back to back test on the baseline dyno run, fitted a K&N panel replacement air filter to the vehicle. We did not include a dyno printout, because essentially, we got no increase or decrease in power from the unit. We explain this, by the sheer fact the stock air intake box set-up, is quite restrictive in factory form.

It has a very small opening at the front, with holes drilled into the base around 1/3rd the way back as it sucks air from within the engine bay, and is also heated up by its proximity to the radiator.

The size of the set-up is virtually fixed in the amount of air it can pull at one time. The K&N panel filter, whilst it can flow better is being hampered by the fact that it cannot get any more air being pulled through the factory inlet setup.

The next step was to manufacture a new complete cold air kit for the vehicle. We did this by utilising the K&N Apollo Cold Air kit. We replaced the factory piping, with a new 90 degree silicon elbow which utilises smooth piping. We then cut out of the factory air box the piping that the MAF sensor screws into, giving us an easy 30cm of length of smooth piping.

This was cleaned and buffed, making it a very easy DIY job. This was fitted into the silicon elbow, and we then placed the enclosed K&N air box onto the end of this.

At this point we know have either a SRI system for those wanting that type of system, or can add the additional K&N piping to pull cold air from the front bumper location.

We did both systems, and surprisingly, found that both the SRI and CAI set-up produced the same horsepower levels. Below are the dyno graph printouts.

We tested three variations of air induction kits being

(1) Utilising the Apollo kit as a SRI system sucking from the larger air inlet, pulling air from the rear of the engine bay

(2)  Adapting the pipe work from the K&N Apollo kit onto the factory air inlet tubing for a cold air feed

(3) Utilising the full setup of the K&N Apollo Kit and sucking form the inside guard of the vehicle for a complete cold air feed

The results were interesting, especially when you do a comparison against the same tests done on the 4B12 Mivec engine.

We also took the opportunity, utilising EvoScan data logging technology, to record the average air intake temperature from each test.

Test 1

The first test resulted in a loss of horsepower and torque over factory with the short ram intake system.

The average air intake temperature was 40 degrees Celsius.

Looking at the dyno graphs it shows that the air/fuel ratio went richer overall which is more than likely the main reason why the vehicle lost power/tq.

With tuning there may be possible gains over a stock air box set-up but the high intake temperatures would never be an optimal situation.

Test 2

The second test resulted in virtually an identical horsepower / torque result which is not surprising considering we have really just replicated the factory air box set-up.

The average air intake temperature with this system was 36 degrees, which we can take as the factory average as well.

We put part of this down to the factory system utilising heat off the radiator to provide a minimum / constant air temperature.

Test 3

The third system, was with the full Apollo kit with the piping sucking air from inside the front guard.

The average air intake temperature dropped down to 30 degrees, even going as low as 28 degrees.

The vehicle produced a slight gain in power / torque.

Once again, the air fuel ratio’s richened up over the factory levels indicating that great power gains are obviously available.

What is interesting, is that in comparison to the overly rich tune on the 4B12 engines, which leaned out with the fitment of the very same cold air induction kits, the 4B11 motor richened up instead.

We believe this is due to the difference in the engine capacity with the larger engine pulling a greater volume of air with the less restrictive air intake system compared to the smaller 2.0 motor.

Job 6 – Rear Muffler Upgrade

The next step is the fitment of a RPW rear muffler upgrade. Below is a picture of the rear muffler.

The system will be made available as either a single outlet rear tip like factory, or a twin tip set-up for those with modified rear bumper’s. We are doing an independent test on the rear muffler, although we realise that the majority of owners would end up doing complete systems. We at least wanted to show how effective the rear muffler upgrade is as part of a step by step approach for future customers.

We test fitted a rear muffler system onto the vehicle, and found that on the dyno it only resulted in a 2 – 3hp gain. Shaking our head, we then removed the rear muffler completely, and found another 1hp gain. Upon further investigation, and measuring, it was quite simply found the stock middle pipe system is so restrictive, being slightly smaller than 2″ internal diameter, that the rear muffler stock or after market, did not make any significant change other than sound.

With one customer, we removed the rear muffler, fitted a tiny hot dog style muffler and it sounded fantastic. We did not bother printing dyno sheets due to the minimal gains the rear muffler systems made.

On the road a muffler change had mild improvements in response and sound, but ultimately, replacing the axle back rear muffler system is a part process towards getting a full improved exhaust system. By itself it is not going to make any major changes.

Below are photos of the two muffler styles we are offering with our eventual full exhaust systems.

Job 7 & 8 – Rear Exhaust Upgrade

The next step is the fitment of a complete rear exhaust system (retaining stock exhaust manifold). Here it can get a little confusing, as we have done two different tests on two different vehicles.

We will break this into two parts as otherwise the results could be confusing.

Take note of the Dyno Sheet Run ID data to see what we mean about the different model vehicles.

Part 1 – Regular Test vehicle with hand made system (Stock Exhaust Manifold)

The first vehicle was on our normal test vehicle, with full CAI air intake kit. We hand made our 2 1/2″ system with a lukey ultra flow muffler, resonator and Magnaflow High Flow Cat converter.

The vehicle was then dyno tested with those changes only and the overall results were recorded.

The two dyno sheets show the changes compared of the vehicle with modifications prior to the rear exhaust system fitted.

As can be seen there was a solid gain across the board with a net gain of around 7hp across the board and the torque improving from 4250 rpm slightly as well as the motor was able to breath.

This is still all done on the factory rich tune so further gains are definitely available.

When you compare it against the stock vehicle, there can be seen considerable torque and power gains, although still with the very wonky power curve from the variable camshaft timing.

So the full exhaust results were quite pleasing.

Part 2 – Alternative Test vehicle with RPW 61.5mm Exhaust System

Once we received our new exhaust including the first prototype of our 4-1 street design headers, we immediately looked for another test car to try it on. Unfortunately our normal vehicle was no longer available so we had to source another vehicle. With this vehicle, the owner wanted to retain the stock air intake system, the only modification done to the vehicle was the fitment of a K&N panel filter. In hind sight, we should have removed the system for the purpose of accurate testing and fitted on of our K&N kits, but unfortunately this was not done. But in many other ways, this is a good indication of showing both how restrictive the stock air intake system is, and shows the gains you can get on the vehicles with that limitation.

The vehicle was then placed on the dyno before modifying the exhaust, and a baseline run performed. Interestingly, this vehicle in stock form with the K&N panel filter performed worse than the original test vehicle with stock Mitsubishi paper filter. The vehicle was considerably down on torque, by at least 12 ft/pd and was down by around 5hp at peak, although with the many peaks and dives on the dyno graph it can be difficult to show a good comparison. Not to be deterred, we then fitted the full RPW 61.5mm exhaust system. Note that the origonal test vehicle utilised a 63.5mm system which was slightly larger so this was a great opportunity to test sizing as well.

We then dyno tested the vehicle after, but was quite disappointed with the results. The vehicle gain horsepower and torque, but was still not able to match the torque and horsepower of our original test vehicle, even with these modifications. From this we came to the following conclusions

  1. This particular vehicle with the stock intake system is just too restrictive and cannot simply get enough air into the engine to make worthwhile gains from exhaust modifications. We recommend that for those using the stock system, that they definitely get the Ralliart Air Intake with the larger scoop to maximise airflow into the air cleaner box.
  2. This vehicle was lower on horsepower / torque compared to our baseline on our test vehicle.
  3. The smaller 61.50mm diameter piping, whilst not able to be utilised to its full benefits, is probably slightly small for the vehicle.
  4. Interestingly, the majority of all other after market systems of both rear mufflers and headers, we have since looked into, are all running on average 58mm piping. Just over 2″ but not quite 2.25″. This explains many things as to why there have been no serious power gains from both there headers and rear muffler systems.

So there is a silver lining in every cloud, this testing allowed us to identify several key weaknesses in the vehicle, and confirmed to us that these vehicles definitely prefer the larger bore systems. 63.50mm diameter piping is definitely the preferred size for these vehicles. We could have hidden this result, but we feel that these R&D guides are here to show the failures as well as the success. Below is the dyno printout of this test vehicle which despite all the negativity about it, the customer loves as it definitely drives better on the road, has much better sounding exhaust and has a lot more potential for horsepower with some further key modifications.

Job9 – Retune Factory ECU – Stage 1 Flash Tune

Whilst we had our 2nd Test car on the dyno, we took the opportunity to test our Stage 1 flash tune on it. Nice freebie for the customer. The results were impressive, with an average of 5hp gain at the wheels, improved torque across the board, and more importantly we started to smooth out the horrible dips and dives in the power curve. As can be seen in the 2500 – 4000rpm range there was significant gains and flattening of the power curve. The AFR ratio’s were leaned out slightly to a more acceptable level to improve the fuel economy.

Obviously if this same flash tune had been applied to our primary test vehicle, the gains would be much larger. We will expand this as we develop more advanced tunes. This stage 1 tune is only really a Tweak, with several degrees more timing, mild changes to the intake variable camshaft timing only and the fuel curve. This has since been made available to many customers with great results and the feedback has been excellent. as can be clearly seen the increased rpm range has been provided with the flash tune which we know everyone loves.

Mitsubishi Lancer CJ 4B11 Exhaust Tune 1CWX523