Mitsubishi Lancer with 4G69 2.4 SOHC 16v Mivec Engine.

Dummies Guide to Vehicle Modifications!

The Mitsubishi Lancer Mivec 2.4 model is a fantastic package to be provided to the world market. With the Mitsubishi 4G69 SOHC 16v engine, producing 115kw of power, it revved hard and handled well with a very well designed factory suspension set-up. With disc brakes all round, a solid 5 speed Manuel transmission, it was the first real Mitsubishi hot sports hatch out there with good looks.

Like any factory set-up, the vehicle responded very well to upgrades especially in the exhaust department. With the larger motor, torque was freely available, and enabled this small light car to have the characteristics of a larger engine vehicle, with the handling of a smaller lighter vehicle.

This vehicle also incorporated all new electronics with fly by wire throttle body control, a new hot wire air flow meter sensor, ABS and EBD (Electronic Brake Distribution) as standard to all models. The only major let down of this vehicle, was the under gearing of the gearbox, making the car rev very high compared to other engines, poor fuel economy due to this under gearing and very difficult to modify due to the very complex electronics which virtually make any check engine light situation lock the throttle body via the integrated throttle body control.

RPW Has spend approx 7 months developing products on this vehicle, which has brought us valuable information and experience on knowing what we can do and how to do it. For more information on this check out our Customer Cars Section – the R&D Projects.

This section is to be used as a guide in your modification – we will be breaking this into sections to provide a well balanced vehicle. Additionally the modification package will be set-up so that as you increase the power of the vehicle, your alternative items like brakes etc are matched to your new power level. This guide has also been done in an order which provides successive gains from the modifications power wise. Jumping say to number 20 first, may result in a LOSS of power until you have done other items to match its effect.

RPW does not take any responsibility for people performing these modifications on there car without professional involvement. Check with your local government regulations before modifying your car as these items may not be legal in your country.

Group 1 Modifications

The group 1 modifications are designed for the every day driver, wanting improvements across the board without sacrificing road comfort, fuel economy or drive ability.

These are also the baseline modifications for the more extensive Group 2 modifications.  Standard horsepower for the vehicle is 65kw on average at the flywheel.

1. Quick Shifters

The Mitsubishi gear shifter system is one of the better ones on the market. This is one of those modifications that can be done at any time. The RPW Modified units suit most people who want something to reduce the long throw and give a more precise feel to where the gears are located. For those performing any level of competition work, or just want something a little more extreme, this unit reduces overall movement by as much as 50% over stock and provides a much better feeling of control over where your gears are and enabling faster gear changes.

RPW also designed for this model vehicle, our now new Rally Spec Shifter, which is for competition / road use for those wanting an extreme kit. Be warned, once you have one you will never want a standard shifter again.

2. Air Filters & Cold Air Induction Kits

The factory air box system on these vehicles, is quite restrictive. There are several ways to free them up – we recommend two main options

  1. Fitment of a K&N Factory Replacement Air Filter for those wanting the Stock look, with improved air flow and throttle response
  2. These vehicles utilise a new form of sensor, being a hot wire unit. This means any universal Ram-pod can be placed on the vehicle and is very effective. This can be done simply by removing the sensor, and cutting the plastic pipe from the air box, and then manufacturing a bracket and fitting a ram-pod filter onto the end of the new short tube. Very effective for a short ram intake system.
  3. Fitment of a RPW Cold Air Induction Kit. A pre manufactured 3″ diameter kit kit which relocates the K&N Ram-pod filter into the front guard. Highly recommended.

The Cold air kit relocates to the front bumper, pulling cold air especially where utilised with a after market front bumper. Of course a K&N large pod filter is used. RPW designed a new kit which utilises the K&N Apollo enclosed air box set-up which we highly recommend. Legal in all states of Australia.

This should produce an approximate gain of around 1 – 2kw with improved throttle response and torque.

3. Fuel Pressure Upgrade

The Mivec Lancer runs a new style non return system, meaning fuel flow is regulated at the fuel pump end. There are several ways to improve the efficiency of this system though as this does mean that flat spots are common on acceleration, especially when you start modifying the vehicle for better performance.

  1. RPW manufactures a new CNC bored out fuel rail, which increases the fuel capacity within the fuel rail. This enables upon acceleration, a greater volume of fuel to become available before leaning out. This also reduces the tendency to pulse the fuel and create disturbances in the fuel flow, providing a smoother transition to power. This is a new RPW product. This is for those looking to go multiple throttle bodies / forced induction later. The unit has a blanked off fitting fitted to the end of the fuel rail to allow for future fuel pressure regulator fitment with upgraded fuel systems.

This will not produce any HP Gain, but will provide an approx 10ft/pd torque improvement at low rpm off idle.

4. Exhaust System Upgrade

Okay you have done the easy mods, now time to do something about the exhaust. Contrary to what many people believe, without any form of induction work or fuel work, fitment of exhaust upgrades are only marginally beneficial. The stock system on these vehicles is usually an unusually good 2 1/4″ system with some sharp bends to a restrictive rear muffler. At this point you must reach your first major decision on where you wish to go with the vehicle – in summary  the following options

  1. Naturally Aspirated – Stock Computer – You are only after mild improvements to make the car sportier, but don’t intend to do any real serious mods. This being the case stick with replacement of the stock exhaust with either a rear muffler upgrade only 2 1/4″ oval shaped muffler.
  2. Naturally Aspirated – Piggy Back ECU – you are after mild to medium improvements to make the car sportier, with slightly more than average vehicle modifications. This being the case,  a 2 1/2″ diameter replacement exhaust with a new resonator and muffler. No need to go mandrel bent unless you have money to throw away. This set-up will handle the majority of modifications we have listed including turbo systems up to around 12 psi.
  3. Turbo Charged – high boost – no more need be said. But don’t go throwing your money away on a 3″ mandrel bent system. A 2 3/4″ press bent system, high flow cat converter are more than you will ever need. Keeps the car quiet, no droning and has a great sound. Mandrel bent on the 2 3/4″ system could be done but honestly, you don’t need it.

RPW Systems done in house, are guaranteed to not drone, have a great sound and provide much improved throttle response and in some cases, improved fuel economy.

These can produce small gains with the basic systems of around 3 – 6kw at the wheels, with increased rev-ability and torque.

5. Suspension Upgrade – Level 1

Suspension Package? Level 1? What is this. Basically at this point you are still have a mildly modified vehicle and want to just improve the looks slightly and handling. We recommend in this situation the following

  1. Replacement of stock springs with some lowering units – Lovell 30mm lowered units which make the car look great and remain legal.
  2. Fitment of a White Line strut brace. Reduces the tendency of the vehicle to float on the road and makes it less sensitive to changes in road camber, resulting in less need to constantly adjust the steering wheel to keep the car driving straight.

This package will proved a well balanced vehicle, capable of handling corners at higher speeds, will feel safter at higher speeds especially above 100km/hr. The steering will feel more precise and you will have overall more confidence in pushing the vehicle harder.

Group 2 Modifications

Okay the basics are done and you have a plan. The following mods require you to decide, which of the following ways you are going which will be

  1. Staying Naturally Aspirated and going a little more extreme
  2. Looking to turbo-charge the vehicle and have some significant torque / horsepower.

1. Extractor Upgrade

Not all extractors are equal. But in reality, any half decent designed unit will be an improvement over the stock manifold on the vehicle, although we are one of the few firms that manufactures a true 4-1 Extractor kit for the 2.4 SOHC Mivec cylinder heads which are not the same as any other unit. Additionally, the cat converter on these vehicles is a solidly welded section of the website. Australian vehicles run two cat converters, one in the exhaust manifold and another in the flex pipe. USA models run a single cat converter as part of the flex pipe.

RPW provides our own 4-1 race design kits which bolts up to the factory exhaust system flange, but comes supplied with a 2 1/2″ high flow cat converter as part of the package. Increased throttle response, torque and horsepower all result from this. RPW was the first to design a superior system for these cars, and our systems are found on more modified vehicles than any other brand. RPW has manafactured two designs for the majority of customers

  1. Automatic Model Vehicle and midly modified Manuel’s – RPW has a 41mm Diameter Header pipe for improved torque, hp and overall performance. This diameter pipe provides the best balanced gains available.
  2. Manuel Model Vehicles heavily modified – RPW has a 44mm Diameter Header pipe for more aggressive results at the mid to higher rpm range. Slight loss of torque when compared to the 41mm units at lower rpms, but still improved over the stock header design. Add some cams and other work, and this design just keeps on breathing.

Both units come with a pre manufactured 2 1/2″ diameter flex pipe and cat converter. Designed for Australian and USA model vehicles, this has all appropriate O2 sensor fittings to avoid any check engine light issues.

If your plan is to go turbo, then save your money and jump ahead several more levels. This is not for you. For everyone else, this will complete the balance of your exhaust system modifications.

This package adds around 5kw at the flywheel with increased torque and improved upper acceleration and rpm range.

3. Single Throttle Body Upgrade / Thermo Block Kit

Time to look at improving throttle response again. Now if you are wanting to go a little more extreme, to a twin system then you need to wait a little longer. For everyone else, time to start looking at improving throttle response, even if you are going turbo.

The stock throttle body on the 4G69 SOHC engine is 55mm. Due to being a fly by wire unit, there is no real way to machine the internal bore of the stock unit.

Instead RPW has sourced a replacement throttle body with the choice of either a 60mm or 65mm internal diameter for maximum air flow. The stock intake manifold will need to be removed, machined and then fitted up with a modified gasket. No ECU tweaks needed, simply fit up and start driving. Massive improvements in throttle response and low rpm torque due to the greater air flow the vehicle can now ingest. These are supplied on an outright basis Ie no exchange and are a brand new fly by wire throttle body with full electronics. (Requires retuning via a piggy back ecu to be used effectively)

Whilst this work is being done, we recommend fitting at the same time a RPW Thermo Block Kit. Consider this an extension of the cold air induction kit be reducing heat soak into the intake manifold from the engine and the throttle body which have hot water running through them. This drops the average intake temperatures by 25% overall resulting in improved combustion, fuel economy and throttle response.

This package adds 5- 7kw at the flywheel, but does improve throttle response and low rpm drive ability. The thermo block kit reduces heat soak and this allows the engine to maintain maximum ignition timing with max throttle response.

4. Brake Upgrades – to suit all future modifications

Before doing any further power or suspension modifications, brakes now need to be seriously looked at. The stock brakes on the front of the Mivec Lancer is a 276mm single piston calliper package with a 260mm rear disc brake. This is a very good design for the majority of average drivers, but like anything, it will not handle consistent spirited driving.

  1. For those wanting something marginally better, and are not planning on doing ANY MORE Horsepower mods, then minor upgrading of front brakes only. Retaining stock callipers, fitment of some EBC Green Stuff brake pads and slotted Rotors is very beneficial. Improved braking by around 25% with better feel and dramatically less brake fade.
  2. For those wanting the final level of brakes, fitment of a RPW 276mm Twin Piston front brake package and brake master cylinder upgrade is the final step. Garaunteed no brake fade and this large rotor will fit very nicely inside of any 15″ or larger rim this is highly recommended for any turbocharger conversions or competition use.
  3. Larger packages are available with an upcoming 294mm twin piston calliper package for the front and Brembo packages, but that is for the very serious only.

5. Suspension Modifications – Level 2

Okay ready to take the final plunge for power and hit that turbocharger. Wrong. Lets take a look at your suspension again. Factory shock absorbers will increase your braking distance, especially if they have been running inside lowered springs for 10 – 20,000km. They are marginal at best when new. Time to go for more extreme options

Shock Absorber Options – three choices here with standard type strut assemblies

  1. KYB replacement units are now available for fitment for improved handling and road comfort.
  2. Coil over strut kits are also now available from brand names like Tien, Ksport etc. Full road comfort, height and rebound settings means it can be individually tailored for any vehicle with great improvements in handling

RPW Does not recomend replacing the balance of the vehicle rubber mounts with Polyurethane ones for any street going vehicle unless being used for competition use. This results in a very very harsh vehicle on the road with much increased road noise and vibration. We feel the packages we have recomended provide that best balance of street vehicle and performance without sacrificing drive ability.

6. Drive Line Upgrades

There are three main drive line upgrades which can be done, which go a long way towards improving the reliability of the engine as well as drive ability.

  1. RPW Billet Lightweight Front Under Drive Pulley – this unit reduces both the moving mass of the front harmonic balancer, as well as being physically smaller by around 25% diameter over the stock unit. Helps to make the car rev faster, spins up faster and higher. The reduction in drive ratio’s means that the power steering and alternator are turning less at higher speeds further reducing engine load. This is just small enough to reduce load without reducing the effectiveness of the operation of the alternator and power steering units. Highly recommended and very easily fitted.
  2. Clutch Kit – At some point your clutch will need upgrading. Two options available – for naturally aspirated drivers a standard cover plate with a semi ceramic five pucker clutch disc package. This will increase clutch efficiency by 50% without any extra pedal effort required. For turbocharged vehicles, this is upgraded to a Heavy Duty unit with the cover plate strengthened by an additional 25%. This provides slightly increased pedal effort and more tendency to be shuddery on take off’s but will handle the higher torque characteristics of a turbo.
  3. Lightweight Billet Flywheel – this has two benefits being increased strength over stock units and also make the semi ceramic clutch units more drive able by not allowing them to shudder as much. Second benefit is that they are lighter and enable the engine to reve easier, faster with less reciprocating weight. No loss of torque but more willingness to rev quicker and harder.
  4.  Quaife ATB units are available for both Manuel model vehicles. Improves traction, reduces torque steer and ultimately produces the best improvement in acceleration for any modified vehicle.

Group 3 Modifications

Now we are down to the serious modifiers. You are usually plan on going turbo or serious Naturally Aspirated Throttle body packages. Comfort and drive ability is usually second to engine performance and speed is your goal.

These next levels are also the most expensive ones, but be warned, if you have not done any of the Group 1 or 2 Modifications yet, you are WASTING YOUR TIME AND MONEY. Finish them first.

1. Computer Modifications

Okay two choices. EMS or Piggy Back. Pro’s and Con’s.  But We like to think of it this way.

  1. If you are still budget conscious (And your at Group 3?), then stick with the piggy back if you are remaining naturally aspirated. Don’t go more than the 60mm throttle body package and no larger than a stage 2 camshaft. You will be fine.
  2. Then EMS is the way to go. Much more advanced tuning, with options like shift lights, in built boost controllers, many many more mapping points, much finer tuning especially if you are boosting the vehicle or doing very large cam work etc this is the ONLY choice.

Haltech Interceptor system – provide a great unit for baseline tuning. The Haltech we recommend for people who have gone all the through the Group 1 & 2 level modifications, but don’t plan on going any further. This can be used in a turbo package setup, but we do not recommend this due to complications with the factory ecu in closed loop fuel mode. . The Haltech Interceptor will control additional items like shift lights, duel mapping and nitrous control to name a few. Very powerful system and due to the unique nature of the Mivec Engine set-up, one of the only systems which will be compatible with these vehicles and allow both fuel and ignition adjustment.

Haltech EMS systems are what RPW specialises in. We make our own plug and play ECU packages which means we can have your car running in around 15 minutes with a Haltech EMS system on there. We use the Haltech Elite series which has full control over everything including the drive by wire throttle body. With the inbuilt boost controllers, and hosts of other functions, these are way ahead of trying do piece together a piggy back with separate boost controllers, shift lights, guages etc.

Note that RPW does not recommend plug in pre programmed computer chips. These are not tuned in real time on a dyno to suit your individual car. As you modify your vehicle you move further away from the standard average formulae of your engine output. This requires significant tuning and can only be done in real time, not on a computer 3000miles away from your car.

The interceptor units usually provide around a 5kw gain at the flywheel, with improved drive ability and torque. The full EMS units provide a little more at this point, but really show there benefit later with more extensive modifications.

2. Intake Manifold Upgrade Conversion

If you are remaining Naturally Aspirated you have several options.

  1. You can go for a single throttle body RPW Performer Intake Manifold with Internal Ram Tubes. Massive throttle response, Haltech piggy back system great looks without extreme levels of tuning requried. Significant torque improvements and can be utilised up to a single 65mm throttle body

The single manifold upgrades in n/a form can take the car with tuning up as high as around 130 kw at the flywheel producing much stronger mid range acceleration, single units much broader torque from a lower rpm range.

3. Turbocharger Conversion Package

What more can we say other than your a horsepower and boost Junkie. Welcome to the rest of the world. This combines extreme levels of torque and power, with neck snapping acceleration. It comes at a cost though, increased fuel economy, higher insurance and lots of money. But lets get something clear first.

  1. Anyone believing they can effectively fit a turbo kit on there car safely, properly and legally for under $5000.00 AUD$ is just plain dreaming.
  2. These engines in stock form will not handle above 1 PSI boost without after market computer management despite what people believe. Larger injectors, moving the distributor to retard timing all these tricks – none work. Don’t skimp.
  3. 5th Injector systems are something that came and died in the 80’s. Quite simply this does not distribute fuel properly to all cylinders and has a delay factor from when it actually provides the fuel to the cylinders inducing lagginess, rich and lean area’s etc.
  4. Due to the nature of this vehicle with its fly by wire throttle body control, significant work needs to be done in order to ensure that the vehicle will continue to run properly without throwing an error code and locking the throttle body. This is not a vehicle which can just have any turbocharger kit thrown onto it. RPW Spent 6 months alone devloping a working turbocharger package so that the vehicle drives exactly like a stock vehicle, utilising the majority of stock ECU componentry.

Do the job properly and although it may cost more, it will last longer, provide trouble free maintenance and be everything you want it to be.

  1. For boost levels up to 12 psi can be done saftley on the stock head gasket dependant upon tuning and intercooler efficiency.
  2. For boost levels up to 16 psi requires an upgraded decompression head gasket which RPW manafactures.
  3. Do not boost above 18psi on the stock piston / conrod setup otherwise you will learn what a banana conrod looks like.

The 4G69 SOHC engine at around 10 psi is good for around 220kw at the flywheel. With forged components you can go up to as high as 300kw reasonably at around 18psi boost.

Averrage price of a turbo kit fitted, installed with a FMIC and Haltech ECU System is around $9,5000

Did you like our guide? Something did not make sense. Please let us know and we will try to update this with more relevant information etc. We hope this helps you plan your vehicle modifications in a more informed manner.