4G13 and 4G15 Modification From Mild to Extreme
This post is created for those who wish to modify their 4G13 and 4G15 from mild to extreme machine. From what I understand, a lot of car enthusiast wish not to go through all the hassle of transplant an engine and they prefer to play on their factory fitted engine. Some will say that you won't gain any knowledge by just putting in a powerful engine without going through the "step by step" modification experience.
Ok, let's start with the 4G13 engine. It is 1.3 liters engine which is known as economic fuel consumtion engine. 4G15 is 1.5 liters model is the base range model and produced a little more HP compare to 4G13. The 1.5 engine is very much your economy engine with only 90hp on engine. It can be modified easily and with surprising results. If going down to NA (naturally aspirated) path, with some modifications you can easily up the HP approximate 120hp on engine. If going to FI (forced induction) path, the low boost turbo systems will easily produce more HP compare to NA path.
For those older 4G13/4G15 from the Saga, Wira and Satria model, it is a standard 12 valves carburator engine. Normally people will upgrade their engine either to a EFI (electronic fuel injection) or to a performance carburetor, to name one WEBER). However, 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. 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.
So I would like to compile a list of modification that can be done for 4G13 and 4G15. This section is to be used as a guide in your modification - I will be breaking this into sections to provide a well balanced vehicle.
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Mild Modification
The mild modifications are designed for the every day driver, wanting improvements across the board without sacrificing road comfort, fuel economy or driveability.
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. 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 and Cold Air Intake Kits
The factory air box system on these vehicles, is quite restrictive.
1. Fitment of an aftermarket replacement air filter. You can get it from K&N which this will improved air flow and throttle response
2. Fitment of a Cold Air Intake Kit.
The Cold air kit relocates to the front bumper, pulling cold air especially where utilized with a aftermarket front bumper. Any aftermarket open pod filter is fine. The plastic pipe kit we honestly recommend, other than being the cheapest, is one of the best bang for dollar modifications you can do.
3. Exhaust System Upgrade
Since you have done a good job for the intake system, now is the time to do something about the exhaust system.Upgrading the exhaust system is one of the most beneficial modification and gain the most HP compare to others. In short, it worth the money to change the exhaust system. For stock 4G13 and 4G15 exhaust system, the size of the exhaust is about 1.5 inches to 1.6 inches. However, before you start to change the exhaust system, you must make a decision on until which level you plan to mod your car. Mild, medium or extreme modification has totally different exhaust size modification. Why I advised you to make the decision before moding the car because you can save up some money for this modification. To be honest, I wasted a lot of money for my satria's exhaust system. This is because I changed the exhaust for 1.3L engine then change again for MIVEC engine and then change again for my current 4G93T now. So you can imagine how much I had wasted for only the exhaust system. For moding the exhaust system, I suggested few guidelines as following:-
1. Naturally Aspirated - Carb / Stock ECU- 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 1.7" flow oval shaped unit, or complete it with a 1.7" 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.
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, we recommend a 2" diameter replacement exhaust with a new resonator and muffler. No need to go mandrel bent unless you have money to throw away. This setup will handle the majority of modifications we have listed short of turbo systems
3. Naturally Aspirated -Standalone ECU - okay you are an extreme modder. Twin throttle bodies, camshafts the list goes on. We recommend in this case either a 2.2" mandrel bent system
4. Turbo Charged - 2.5" is more than enough for a 4G13 or 4G15 stock bolt on turbo.
4. Suspension Upgrade - Level 1
Basically at this point you are still have a midly modified vehicle and want to just improve the looks slightly and handling. I recommend in this situation the following
1. Replacement of stock springs with some lowering units - either 30mm or 50mm lowered units depending upon how low you want to go.
2. Fitment of a sway bar. Reduces body roll without reducing drive ability.
3. Fitment of a strut brace. Reduces the tendancy 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 safer 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.
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Medium Modification
The medium modifications are designed for those who want more HP from their car.
1. Extractor Upgrade
Original extractors are always not equal. But in reality, any half decent designed unit will be an improvement over the stock manifold on the vehicle. There are two types of designs. One is the 4-1 design which is design to produce power at the high rpm. This setup is suitable for those who always want to rev high. The other design is the 4-2-1 which is design to produce power at the low rpm, better torque response. This setup is suitable for those daily drive machine.
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.
2. Fuel Pressure Upgrades
This is the one thing we believe that these vehicles should always have fitted regardless of how little, or much you modify the vehicle. Quite simply the factory vehicle has been tuned for maximum Economy. This has resulted in a fairly large flat spot off idle when accelerating hard from a standing start of from a cruise mode situation. The reason for this is Mitsubishi has tuned very lean on the accelerator pump settings, resulting in the lack lustre performance on throttle, but excellent fuel economy.
1. Fitment of the Fuel Pressure Regulator kit eliminates this flat spot, whilst only marginally reducing your fuel economy. Without going into huge detail, trust us when we say, flat spots are eliminated, your car will actually accelerate properly without hesitating and your fear of being run over at stop signs will diminish rapidly. This is an easy bolt on kit and can usually be done in around 1 hour maximum.
2. There are company manufacturing 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 tendancy to pulse the fuel and create disturbances in the fuel flow, providing a smoother transition to power.
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 4G15 SOHC engine is 46mm. I Recomends for the majority of owners to do the following
1. For all 1.5 SOHC owners, upgrading the stock to 51mm or a 55mm is very beneficial. However on the SOHC models, anything with the stock manifold and cylinder head over 55mm is really just not effective
2. For all 1.6 SOHC owners, upgrading to 55mm is extremely beneficial.
3. For 1.6 SOHC owners with upcoming computer mods (Piggy back ECU) then a 60mm is also very beneficial if you are remaning Naturally Aspirated and don't plan on going to a twin system. If you are going to a turbo, then stay with the 55mm.
Whilst this work is being done, I recomend fitting at the same time a Thermo Block Kit. Consider this an extension of the cold air intake 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 tempatures by 25% overall resulting in improved combustion, fuel economy and throttle response.
This package adds 3-5hp, but does improve throttle response and low rpm driveability. The thermoblock kit reduces heat soak and this allows the engine to maintain maximun ignition timing with max throttle response.
4. Drive Line Upgrades
There are three main driveline upgrades which can be done, which go a long way towards improving the reliability of the engine as well as driveability.
1. Lightweight Crankpulley - 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 coverplate 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 strengthens by an additional 25%. This provides slightly increased pedal effort and more tendancy to be shudder on take off's but will handle the higher torque characteristics of a turbo.
3. Lightweight Flywheel - this has two benefits being increased strength over stock units and also make the semi ceramic clutch units more driveable 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. However, do not skim the flywheel to much because this will cause loss of torque.
5. Suspension Modifications - Level 2
Is time to have some upgrade for your suspension again. Since mild mod is only changing to a lowered spring, it is advisable to change the shock absorber as well for a medium modification.
1. Fitment of KYB Excel-G replacement units for the more budget conscious. Retains improved handling over stock.
2. Fitment of KYB AGX units. These are externally adjustable and are perfect for the all round street / strip / circuit car. You can set them soft when your on the road, hard when your driving hard. Adjustment takes less than 1 minute
3. Fitment if Koni Sports Inserts. These are similar to the KYB AGX units, but are serviceable and provide that little bit more control. They 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.
6. Brake Upgrades
Since the performance of the car is higher now, so it is better for us to have a good braking system. The stock brakes on the front is a 235mm single piston caliper package with drum rear brakes. There are few ways to improve the braking system.
1. For those already satisfied with the current HP gain, minor improving on front brake is fine by just changing the front brake pad to a performance brake pad and changing the rubber hose to those stainless steel brake hose. I personally recommend Pro-RS because it is cheap and reliable.
2. Next, you can replace the rear drum to rear disc. For Wira and Satria owner who wish to maintain PCD 100, you can always opt for Wira 1.6 rear disc brake, Putra, Satria GTi or Mirage Cyborg rear disc brake. While owners who wish to change to PCD 114.3, you can try to change to Lancer or Lancer Evolution brake system.
3. For those wanting the final level of brakes, fitment of a 276mm Twin Piston front brake and brake master cylinder upgrade is the final step.
Ok, let's start with the 4G13 engine. It is 1.3 liters engine which is known as economic fuel consumtion engine. 4G15 is 1.5 liters model is the base range model and produced a little more HP compare to 4G13. The 1.5 engine is very much your economy engine with only 90hp on engine. It can be modified easily and with surprising results. If going down to NA (naturally aspirated) path, with some modifications you can easily up the HP approximate 120hp on engine. If going to FI (forced induction) path, the low boost turbo systems will easily produce more HP compare to NA path.
For those older 4G13/4G15 from the Saga, Wira and Satria model, it is a standard 12 valves carburator engine. Normally people will upgrade their engine either to a EFI (electronic fuel injection) or to a performance carburetor, to name one WEBER). However, 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. 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.
So I would like to compile a list of modification that can be done for 4G13 and 4G15. This section is to be used as a guide in your modification - I will be breaking this into sections to provide a well balanced vehicle.
--------------------------------------------------------------------------------------------------------------------
Mild Modification
The mild modifications are designed for the every day driver, wanting improvements across the board without sacrificing road comfort, fuel economy or driveability.
1. Quick Shifters
2. Air Filters and Cold Air Intake Kits
1. Fitment of an aftermarket replacement air filter. You can get it from K&N which this will improved air flow and throttle response
2. Fitment of a Cold Air Intake Kit.
The Cold air kit relocates to the front bumper, pulling cold air especially where utilized with a aftermarket front bumper. Any aftermarket open pod filter is fine. The plastic pipe kit we honestly recommend, other than being the cheapest, is one of the best bang for dollar modifications you can do.
3. Exhaust System Upgrade
1. Naturally Aspirated - Carb / Stock ECU- 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 1.7" flow oval shaped unit, or complete it with a 1.7" 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.
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, we recommend a 2" diameter replacement exhaust with a new resonator and muffler. No need to go mandrel bent unless you have money to throw away. This setup will handle the majority of modifications we have listed short of turbo systems
3. Naturally Aspirated -Standalone ECU - okay you are an extreme modder. Twin throttle bodies, camshafts the list goes on. We recommend in this case either a 2.2" mandrel bent system
4. Turbo Charged - 2.5" is more than enough for a 4G13 or 4G15 stock bolt on turbo.
4. Suspension Upgrade - Level 1
Basically at this point you are still have a midly modified vehicle and want to just improve the looks slightly and handling. I recommend in this situation the following
1. Replacement of stock springs with some lowering units - either 30mm or 50mm lowered units depending upon how low you want to go.
2. Fitment of a sway bar. Reduces body roll without reducing drive ability.
3. Fitment of a strut brace. Reduces the tendancy 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 safer 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.
--------------------------------------------------------------------------------------------------------------------
Medium Modification
The medium modifications are designed for those who want more HP from their car.
1. Extractor Upgrade
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.
2. Fuel Pressure Upgrades
1. Fitment of the Fuel Pressure Regulator kit eliminates this flat spot, whilst only marginally reducing your fuel economy. Without going into huge detail, trust us when we say, flat spots are eliminated, your car will actually accelerate properly without hesitating and your fear of being run over at stop signs will diminish rapidly. This is an easy bolt on kit and can usually be done in around 1 hour maximum.
2. There are company manufacturing 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 tendancy to pulse the fuel and create disturbances in the fuel flow, providing a smoother transition to power.
3. Single Throttle Body Upgrade / Thermo Block Kit
The stock throttle body on the 4G15 SOHC engine is 46mm. I Recomends for the majority of owners to do the following
1. For all 1.5 SOHC owners, upgrading the stock to 51mm or a 55mm is very beneficial. However on the SOHC models, anything with the stock manifold and cylinder head over 55mm is really just not effective
2. For all 1.6 SOHC owners, upgrading to 55mm is extremely beneficial.
3. For 1.6 SOHC owners with upcoming computer mods (Piggy back ECU) then a 60mm is also very beneficial if you are remaning Naturally Aspirated and don't plan on going to a twin system. If you are going to a turbo, then stay with the 55mm.
Whilst this work is being done, I recomend fitting at the same time a Thermo Block Kit. Consider this an extension of the cold air intake 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 tempatures by 25% overall resulting in improved combustion, fuel economy and throttle response.
This package adds 3-5hp, but does improve throttle response and low rpm driveability. The thermoblock kit reduces heat soak and this allows the engine to maintain maximun ignition timing with max throttle response.
4. Drive Line Upgrades
1. Lightweight Crankpulley - 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 coverplate 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 strengthens by an additional 25%. This provides slightly increased pedal effort and more tendancy to be shudder on take off's but will handle the higher torque characteristics of a turbo.
3. Lightweight Flywheel - this has two benefits being increased strength over stock units and also make the semi ceramic clutch units more driveable 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. However, do not skim the flywheel to much because this will cause loss of torque.
5. Suspension Modifications - Level 2
1. Fitment of KYB Excel-G replacement units for the more budget conscious. Retains improved handling over stock.
2. Fitment of KYB AGX units. These are externally adjustable and are perfect for the all round street / strip / circuit car. You can set them soft when your on the road, hard when your driving hard. Adjustment takes less than 1 minute
3. Fitment if Koni Sports Inserts. These are similar to the KYB AGX units, but are serviceable and provide that little bit more control. They 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.
6. Brake Upgrades
1. For those already satisfied with the current HP gain, minor improving on front brake is fine by just changing the front brake pad to a performance brake pad and changing the rubber hose to those stainless steel brake hose. I personally recommend Pro-RS because it is cheap and reliable.
2. Next, you can replace the rear drum to rear disc. For Wira and Satria owner who wish to maintain PCD 100, you can always opt for Wira 1.6 rear disc brake, Putra, Satria GTi or Mirage Cyborg rear disc brake. While owners who wish to change to PCD 114.3, you can try to change to Lancer or Lancer Evolution brake system.
3. For those wanting the final level of brakes, fitment of a 276mm Twin Piston front brake and brake master cylinder upgrade is the final step.
