Mitsubishi Lancer CG-CH 4G94 Modification Guide
Mitsubishi CG / CH Lancer 2004 - 2008 with 4G94 2.0 SOHC 16v engine.
Dummies Guide to Vehicle Modifications!
The Mitsubishi Lancer 2.0 model is the upgraded base range model and came out with the new codes MR & VRX with more body styling. The 2.0 engine is definitely has more torque very responsive to both naturally aspirated and especially turbo modifications. But the engine does suffer from a lack of high rpm power, acceleration and most people find that going from the 1.8 engine to the 2.0 that they are not satisfied with the top end performance of the vehicle. The factory manifold designs both intake and exhaust are extremely restrictive, as is the camshaft profile on this engine. These are the three main area’s where large gains are made. The engine is very turbo friendly and responds extremely well to this.
Not all mods are for power though, there are many area’s of braking and suspension that any stock car can always be improved with – the CG/CH lancer came out with two different brakes packages from the factory, neither being a tremendously good package.. Along with other drive line upgrades, you can have a smooth reliable car, with improved handling, and provide that little bit of sporty power to keep most people satisfied.
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. But that does not mean that people do not want to improve them. This is one of those modifications that can be done at any time.
Our 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, the Rally Spec Unit reduces overall movement by as much as 65% over stock.
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
- Fitment of a K&N Factory Replacement Air Filter for those wanting the Stock look, with improved air flow and throttle response
- This vehicle utilises a MAF – Mass Air Flow Unit which measures air volume and records back to the ECU as the primary referencing source for all ECU management. Universal air filters creates many idling, running rich and other issues with drive ability. Utilising the K&N Specific Ram-pod filter that is oval shaped with an oval shaped adapter. This way we ensure that you do not have any ECU tuning issues.
- Cold Air Induction Kit – we manufacture a polished stainless steel system with that show car quality looks, and price. We manufacture this in various sizes from 2 1/2″ to 3″ diameters depending upon your requirements.
The Cold air kit relocates to the front bumper, pulling cold air especially where utilised with a after-market front bumper, we recommend purchasing a K&N Pre Filter Charger Kits that provides additional filtration and resistance to water
This should produce an approximate gain of around 1 – 2kw with improved throttle response and torque.
3. 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, fitting of exhaust upgrades are only marginally beneficial. The stock system on these vehicles is usually an Asthmatic 2″ system. At this point you must reach your first major decision on where you wish to go with the vehicle – in summary we recommend the following options
- 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 unit, or complete it with a 2 1/4″ press bent exhaust system with new muffler and resonator. Cat converter should remain stock. Any larger on the system would not provide without sufficient more expensive mods, any real gains.
- Naturally Aspirated – Piggy Back ECU / Haltech EMS- you are after mild to some fairly heavy N/A improvements to make the car sportier, with slightly more than average vehicle modifications. This being the case, we recommend 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 short of turbo systems
- Turbo Charged – no more need be said. But don’t go throwing your money away on a 3″ mandrel bent system. A 2 1/2″ 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 1/2″ 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 2 – 5kw at the wheels, with increased rev ability and torque.
4. 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
- Replacement of stock springs with some lowering units – either Lovell 30mm or 50mm lowered units depending upon how low you want to go.
- Fitment of a White Line 18mm rear sway bar. Reduces body roll without reducing drive ability. This is available for both models with and without rear factory sway bar. Factory unit is only a 12mm unit so the upgraded 18mm makes a large difference.
- Fitment of a White Line front 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
- Staying Naturally Aspirated and going a little more extreme
- Looking to turbo charge the vehicle.
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, RPW design a true 4-1 Extractor kit for the 2.0 SOHC cylinder heads.
RPW 4-1 race design kits which bolt up to the factory exhaust system. The factory manifold set-up utilises a solidly welded cat converter into the flex pipe. This means that when purchasing a RPW System for this car, you receive the header, flex pipe and new larger diameter high flowing cat converter. Increased throttle response, torque and horsepower all result from this.
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.
2. 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 4G94 SOHC engine is 54mm. RPW Recommends for the majority of owners to do the following
- Upgrading the stock to our bored out 60mm is very beneficial. Improved throttle response and mid range torque this will require porting the stock manifold to the new larger bore diameter of the throttle body.
- For those wanting more, the RPW Billet 70mm units are now available for those planning on stepping up to higher levels of modifications. Recommended to be used with a RPW Performer series inlet manifold.
- The stock intake manifold on the 4G94 engine is very restrictive running an extremely small plenum chamber design. RPW replaces this with an alternative model which goes back to a larger common plenum chamber, match ported to the 60mm throttle body. This provides noticeable improvement in top end horsepower and low end rpm torque.
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 2- 6kw 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.
3. Engine Tuning
With limited bolt on modifications (Exhaust and intake only) remapping the factory ECU is the preferred method. We are able to remap the facotry fuel and ignition curves to suit these limited range of modifications.
The reason why we say limited modifications only, is due to the factory inbuilt restrictor plate, limiting the size of the intake to a credit card. If you plan on performing more aggressive modifications like camshafts, turbo conversions etc then we recommend instead going straight to an After market EMS system which replaces the factory ECU as well as remove the MAF sensor and tripling the volume of air the vehicle can source.
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 lancer can come in two sizes
- Base Models come with a 254mm single piston on the front with drum brakes on the rear
- VRX Models come with a 276mm single piston on the front with a 260mm rear disc package.
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.
- Next option for those with the baseline model is to convert the front brakes to the same stock 276mm / single piston package for improved performance. Replacing rotors with slotted units / ebc pads is highly recommended.
- For those wanting the final level of brakes, fitment of a RPW 276mm Twin Piston front brake package is the final step. Fitted with larger EBC Green stuff pads, slotted rotors, this will dramatically improve braking. This part is absolutely necessary for anyone wanting to turbo charge there vehicle in order to enable it to be permitted by the Australian Police to be licensed with a turbocharger conversion.
5. Suspension Modifications – Level 2
Okay ready to take the final plunge for power and hit that turbocharger or twin throttle body with computer. 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
- Fitment of KYB Excel-G replacement units for the more budget conscious. Retains improved handling over stock.
- Fitment if Koni Sports Inserts. These are a more precise unit, externally adjustable on the front only, internally adjustable on the rear. For the more sports conscious person these could be the better choice.
Coil over Strut Assemblies
- We recommend the Tien units specifically manufactured for Australian Conditions. To put it quite simply, many Japanese units are set very very hard, so even on there softest unit the car is very harsh, hurts kidney’s and actually has worse handling as it skips all over the road. The hardest setting on the Tien units, are equal to the softest setting on the Japanese normal imported units. We cannot recommend these enough – they are simply fantastic with the ability to set your road height, rebound levels etc.
- These Tien Units are also available to be electronically adjusted on there rebound rates via up to one independent controller per corner, or one controller on all four units as an example. Mostly for extreme racing only.
- Our other choice of coil overs is the K-Sport brand. We have used these on many vehicles now and can only say that we are most impressed with the results. For those wanting semi competition set-ups, these are the best mid range product on the market.
The final items we recommend to improve your suspension is as follows
- Fitment of a RPW Upgraded side engine mount. This polyurethane improved unit, reduces axle tramp and engine movement. Increases traction and reduces the vehicle ability to get that dreaded engine bounce especially on wet roads. Any serious drag racer would feel the benefits of one of these straight away.
- Fitment of upper pillow ball mounts to the strut towers. The stock setup utilises plastic washers etc. These are not the best setup for performance and as such, a proper pillow ball mount setup makes tremendous improvements
- Fitment of a under body K Bar setup. This improves vehicle rigidity and makes the car handle a lot better.
RPW Does not recommend 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 recommend 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.
- 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.
- 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.
- 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 rev easier, faster with less reciprocating weight. No loss of torque but more willingness to rev quicker and harder.
- Auto Transmission Cooler – We cannot preach this enough on Mitsubishi vehicles. If you have an auto, any model, this should be one of the very first things done to the vehicle. 99% of Mitsubishi transmission failures are as a direct result of the oil being overheated by the lack of factory cooling on the transmission oil. Regular changes every 20,000km should be done regardless on these vehicles. Fitting of an after-market transmission cooler, of virtually any design, will improve transmission life and responsiveness by over 100%. The vehicle will shift more consistently, be more reliable and cost a lot less to repair in the future. This is a very easy thing to fit and as you modify the vehicle more, becomes extremely necessary. They are usually mounted in front of the radiator, although RPW has been using the B&M fan cooled units a lot more which have there own thermostatically controlled fan to further improve there reliability.
Group 3 Modifications
Now we are down to the serious modifiers. You are usually plan on going turbo or serious Naturally Aspirated Twin 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
At this point whilst there are choices of remapping the factory ECU or piggy back ECU’s, we recommend going straight to an after market ECU. This is because the factory MAF Sensor has a restrictor plate built into it which cannot be removed. This restrictor plate reduces the air intake to the size of a credit card, which nullifies doing any further upgrades as no additional air can be sucked into the engine.
A plug and play after market programmable computer eliminates the need for the MAF sensor and allows full programming and much more advanced tuning, with options like shift lights, in built boost controllers, many many more mapping points, much finer tuning. If your going Turbo, twin or quad throttle bodies, then this is your ONLY choice.
This will have gains of between 2 – 10kw depending upon the modifications done to date. Gains in throttle response and upper rpm ranges will be very noticeable.
2. Intake Manifold Upgrade / Twin Throttle Body Conversion
If you are remaining Naturally Aspirated you have several options.
- First 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 required. Significant torque improvements and can be utilised up to a single 65mm throttle body
- Upgrade utilising stock manifold, modified with fitment of a second throttle body – twin throttle body conversion. Either twin 50mm, twin 55mm throttle bodies work very nicely for a progressive throttle response and great top end rush of power. This system is fantastic and highly recommended if insurance premiums are a worry. Requires a Haltech full EMS to run this effectively as larger injectors are required.
- The third option is a combination of a RPW Performer Intake Manifold and twin throttle body. Massive plenum chamber, improved air flow, progressive throttle response, this is nearly equivalent to a qaud throttle body kit without the side effects and all of the benefits. Massive air flow and the ability to tune with a piggy back or EMS system. Not turbo compatible of course.
- Qaud Throttle Bodies – extreme yes and very effective.
The twin / single manifold upgrades in n/a form can take the car with tuning up as high as around 110 – 115 kw at the flywheel. Twin units produce much stronger mid range acceleration, single units much broader torque from a lower rpm range.
3. Camshaft Upgrade
The stock camshafts is very very ordinary on these engines. There are several great improvements available
- Stage 1 profile works extremely well. Great torque and improved upper RPM range. To get the best out of this camshaft, we highly recommend the intake manifold be replaced from stock to a minimum of the improved plenum chamber design with a 59mm throttle body.
- Stage 2 camshafts are quite aggressive. These require a valve springs and vernier camshaft gear. Very effective but rough idle. Not recommended for auto model vehicles. With a twin TB set-up, after market ECU and exhaust 2 1/2″ this is an awesome combination.
The camshaft upgrades in n/a form can take the car with tuning up as high as around 115 – 125 kw at the flywheel. Average price fitted is around $1000.00 without valve springs, or $1500.00 with valve springs and camshaft vernier gear.
4. 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.
- 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.
- These engines in stock form will not handle above 1 PSI boost without after market computer management despite what people believe. 25 : 1 rising rate fuel pressure regulators, larger injectors, piggy back ECU’s like Apexi, Greddy etc all these tricks – none work. Don’t skimp.
- 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 still does not provide ignition timing adjustment
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.
- For boost levels up to 10 psi can be done safety on the stock head gasket dependent upon tuning and inter cooler efficiency.
- For boost levels up to 14 psi requires an upgraded decompression head gasket which RPW manufactures.
- Do not boost above 14 psi on the stock piston / conrod set-up otherwise you will learn what a banana conrod looks like.
The 4G94 SOHC engine at around 13 psi is good for around 200kw at the flywheel at the extreme. With forged components you can go up to as high as 250kw reasonably at around 20 psi boost as a good starting point.
Our final advice – if 200kw is not enough for you – the finish reading this page, and instead either look for another car or look to do a engine swap to a larger Mitsubishi engine.
Average price of a turbo kit fitted, installed with a FMIC and Haltech ECU System is around $8500 – $9000.00
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.