Great Wall V240/X240 - with 4G69 SOHC 16v engine.
The Great Wall Motors (Known as GWM) vehicles have become a very popular vehicle in Australia. This is mostly due to there low cost and and some nifty features inside the vehicle. The vehicle is a hybrid manufactured in China, utilising a vehicle specific Mitsubishi 4G69 2.4 litre engine, with Single Overhead Camshaft (SOHC) 16 valve (16v) technology. This is unfortunately an detuned version compared to the same engine found in the Mitsubishi Lancer and Outlander vehicles which had Mivec Technology. This has resulted in may customers complaining about lack of overtaking ability and towing capacity.
This we aim to change.....
The Mitsubishi 4G69 engine is a very robust and strong engine, and responds very well to modifications. The injection system is not Mitsubishi but is all GM / Delphi utilising a MAP sensor based system with a crank driven Motronic style trigger. This system with its emission control restrictions is one reason why the number one complaint of lack of throttle response is so evident. Additionally the vehicle runs in a Semi Sequential / Batch fire style injection mode which is not as thoroughly modernised as most other manufacturers.
The V240 vehicle is a the ute style layout where the X240 model is more of a family orientated four wheel drive model. Both models run identical engines, but have slightly different layouts in the engine bay especially with regards to the locations and shapes of the air box and ECU.
We will not go into suspension or handling modifications, we will leave that to other specialist firms. Instead we will focus purely on the performance aspect of the engine tuning. This is where we excel and hopefully, with this guide, aid future owners with a better idea of what to do to achieve there goals for there vehicle.
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.
Due to the focus on performance, and in some ways limited in range, there is no need to have different sections. The good thing about these four wheel drive vehicles, is that they only require a group of basic modifications to achieve everything the majority of customers would require. Outside of these basic items, you are incurring both very large expenses, as well as turning the vehicle more aware from the effective daily driver / four wheel drive vehicle and more focused on pure four wheel driving performance to the exclusion of daily driving. For those customers, this guide is still of some aid but would mostly require more one on one discussions with there chosen modifier.
1. Air Filters & Cold Air Induction Kits
The factory air box system on these vehicles vary greatly and are quite restrictive in there original design on the V240 model, but on the X240 model are excellent in design. But for the record, we do not under any circumstances recommend replacing the factory air box with a ram pod filter located in the engine bay without some form of heat shield. This is just plain ineffective as it sucks hot air and reduces performance. All modifications should be done with the stock air box where possible.
Step 1A - Fitment of our RPW Designed K&N Cold Air Induction Kit. This replaces the stock air box with a K&N Apollo enclosed filter kit. With its flexible ducting on the end of a enclosed K&N pod filter, by feeding air from the front of the vehicle you get both a ram air effect when moving, and consistent cold air without heat soak issues with an unenclosed pod filter. This system can also be very easily hooked up into a external snorkel system for heavy four wheel drive owners. Gains from these systems are very noticeable with improved throttle response and at least a 2 - 3 hp improvement on peak hp / tq.
Step 1B - Fitment of a K&N Factory Replacement Air Filter with improved air flow and throttle response. This should always be the first thing done. We recommend the K&N because it filters nicely and has good airflow. Foam or cardboard style filters are restrictive despite having better filtering ability and should be replaced as soon as possible.
Step 2 - X240 – The factory air box in basic design is already excellent. It filters well and has a half decent air feed into it. It has one large snorkel set-up coming over the radiator , depending upon the model vehicle which feeds air from either over the top of the radiator or via an opening pulling air from behind the headlight system. The fundamental plan at this point is to try and increase airflow into the air box. This can be done several ways by
· Removing the factory snorkel set-up and replacing it with an external ram system which pulls air from above the roof of the vehicle. If you can have the snorkel system facing into the wind this is particularly effective..
· Removing the factory snorkel set-up and enlarging the hole which feeds into the air box. From here purchase some universal flexible hosing of at least 3” diameter and either re hook up to the original air box inlet (Where mounted over the top of the radiator) or relocate the opening in some way as to feed a greater volume of colder air into the vehicle
· They run a secondary silencer system which is usually pot riveted onto the back or bottom of the air box. What we do on these is remove that plastic chamber off the air box, which then provides a new hole opening of around half the size of the main air feed into the air box. From here you can either get some flexible hosing and mount up to behind the grill somewhere, or our favorite, hook up a small bonnet scoop and hook the air inlet up to the bonnet scoop. Or even an external snorkel set-up. The whole idea is to provide another air feed into the air box. The theory is simple – the more air the air box can get, the more air your engine can ingest and improve performance.
Step 2 V240 – The factory air box in basic design is Terrible. It filters well but has a stepped down pipe size going over the radiator as well as the extended tube going into the air box is further reduced down because of the angle of the air box on the body of the vehicle. It has one large snorkel set-up coming over the radiator , depending upon the model vehicle which feeds air from either over the top of the radiator. The fundamental plan at this point is to try and increase airflow into the air box. This can be done several ways by
· Removing the factory snorkel set-up and replacing it with an external ram system which pulls air from above the roof of the vehicle. If you can have the snorkel system facing into the wind this is particularly effective. We recommend enlarging the intake pipe going into the air box at the same time for increased airflow.
· Removing the factory snorkel set-up and enlarging the hole which feeds into the air box. From here purchase some universal flexible hosing of at least 3” diameter and either re hook up to the original air box inlet (Where mounted over the top of the radiator) or relocate the opening in some way as to feed a greater volume of colder air into the vehicle.
· No matter which system you use above, we recommend cutting away the tube that protrudes into the air box so that it is no longer restricted by the sharp angle of the base of the air box. This can be done by yourself easily in around 1 hours of work.
The K&N Panel filters can vary between models but on average are around the $110.00 bracket. ARB and other large Four wheel drive after market manufacturers produce a range of external snorkel set-ups for the GWM range of vehicles. Manufacturing of a secondary improved system with a second air feed other than time, can be done with materials for less than $100.00.
2. Exhaust System Upgrades
The Great Wall vehicles have a extremely restrictive system from the start. They generally run a 2" mandrel bent system (In effective diameter). We say effective, meaning that in some points it can be slightly smaller, in other area's slightly larger. In fact the internal diameter of the flange coming out of the factory headers is only 1 5/8". The double cat converter set-up is naturally restrictive to retain good emissions. 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 - a complete 2 1/4" mandrel bent system, with the addition of a high flowing cat converter upgrade. The cat converter should be a metallic high flowing unit. The stock system is just so restricted at so many points, doing only one small part has no real benefits.
- Naturally Aspirated - for maximum performance a complete 2 1/2" mandrel bent system is our recommended size, with the addition of a high flowing cat converter upgrade. The cat converter should be a metallic high flowing unit. The stock system is just so restricted at so many points, doing only one small part has no real benefits.
- Forced Induction - no more need be said. A 3" mandrel bent system with cat converter will be required. Keep the car quiet, no droning and has a great sound. Going larger than 3" for any vehicle producing less than 600hp at the flywheel will not produce any further improvements other than to make more noise.
These can produce small gains with the basic systems of around 5 - 10kw at the wheels, with increased torque. Approx prices around $1000 for a mandrel bent custom system with single cat converter.
3. Extractor Upgrade
The stock system on these vehicles utilises a semi header 4-1 design, which bolts directly onto a primary cat converter. Due to the massive 1 5/8" internal diameter outlet on the headers, the motor just does not breath anywhere close to what the vehicle needs.
RPW has arranged a direct replacement 4-1 system to replace the factory system. The factory design is already a 4-1 set-up, but has very small diameter pipes and a very small outlet. As well they are known for cracking over time. The longer length than factory has a dramatic effect on low to mid range torque as well as effectively allow the vehicle to breath properly without any further restriction. Our Race Design Headers have an effective 2 1/2" outlet with larger diameter pipes for maximum flow and performance.
If you plan on Forced Induction for your vehicle (And why not) then header upgrade is absolutely mandatory and here designs with larger pipe diameters are most important.
The key to getting good exhaust results on the GWM vehicles is to do the complete exhaust, not just the header.
This package adds around 5 - 10kw at the flywheel with increased torque and improved upper acceleration and rpm range. Approx value around $750.00 fitted.
4. Throttle Body Upgrade
Time to look at improving throttle response again, looking at improving throttle response, even if you are going Supercharger later.
The stock throttle body on the 4G69 SOHC 16v is approximately 55mm. The usual practice is to machine out the internal diameter and fit a larger 60 - 65mm butterfly. This improves the airflow into the intake manifold, and requires the intake manifold to be machined to suit the now larger diameter of the throttle body.
These changes have significant effects on both airflow and throttle response. Going larger also provides more air for the motor to ingest. This will work nicely with exhaust modifications. Improved airflow results in better fuel economy, and better acceleration, mostly by no longer needing to open the throttle as heavily as normal.
This package adds 2- 5kw at the flywheel, but does improve throttle response and low rpm drive ability. Average price fitted is around $500.00 for the throttle body.
5. Computer Modifications
- Re flashing the factory ECU was worked on and will be available very soon and is our preferred tuning option. Unfortunately despite our best efforts we were unable to get a working system going and gave up on this package. We will attempt to continue with this in the future at some point but we have no estimation on when this may ever become available.
- RPW has completed the fitment of the Haltech Platinum Sprint and Sport Series ECU's into the vehicles with great success. This enables full advanced tuning to be performed on the vehicle with no issues with check engine lights or drivability. The only side effect is that this requires wiring to be modified on the vehicle with the extra wiring harness which can create possible warranty issues.
- (A) The Haltech Sprint 500 system is the most economical option for those remaining naturally aspirated, with its ability to control the fuel and ignition curves only (and a number of external items)
- (B) The Haltech Sports 1000 system is the best system with its ability to completely replace the stock ecu. This will control all factory features, as well as enable advanced tuning for future forced induction applications. The pricing for this is higher but not significantly.
The factory tune is unique (To our eyes) that it holds closed loop fuel control at 100% throttle all the way to 3500 rpm on some models. This is why these vehicles suffer so badly from bad acceleration. We have also found the factory ignition maps are very retarded and not smooth.
The replacement systems can provide around a 10 - 15kw gain at the flywheel, with improved much driveability and torque. Average price is around $1750.00 for a Sprint 500 package or $2500 for the Sports 1000 system
6. Camshaft Upgrade
Replacement camshafts are available with improved profiles over stock. From naturally aspirated to forced induction profiles (For maximum Power / Torque) these can have dramatic improvements. Our planned stage 1 profiles will still work with the stock ECU (To some degree), but ultimatly any camshaft upgrade should be done in conjunction with some ECU Tuning.
Average price for the camshaft package , is around $750 - $800.00 plus fitting and tuning.
7. Turbocharger / Supercharger 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, depending upon your throttle control, increased fuel economy, higher insurance and lots of money.
RPW will be developing a Garret Ball Bearing system for these vehicles to be used with a small Front Mounted Intercooler system or Water to Air Intercooler system. We are also looking at the possibility of an Eaton Style Roots positive displacement supercharger.
Good idle, smooth power and massive throttle response is all to be gained, but all emission control features are retained (Excluding EGR). Externally there is no visible changes other than when you lift the bonnet.
Average price of a Turbocharger kit fitted, is around $7500 - $8000.00 depending upon boost level and options used.
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.