My sleeper with its mods...
I don't have 100++k budget to play with, I wanted a family car with enough room for the kids & stuff at the back, comfortable for the wife, practical for daily use, and yet packing some decent performance under the hood when required ......or provoked =)
After going thru the options, weighing the pros & cons of the car, having enough performance parts from my decade long collection & spares from a 2nd generation RVR halfcut, I also have a mechanic friend to help me with the mechanical work, a tuner friend to help fine tune the engine, my brother to help me with welding works, an engineering company to design & machine custom made components I needed, I figured we should be able to mod the car to overcome its weakneeses..... PERFECT!!!
Before going into the details, I would like to thank members from
www.airtreker.com for the info & advise that helped me with my project. Sadly, the website most of us Airtrek owners lived by, was shut down last month without any earlier notice.
So, I finally started this "relationship" with a stock 2003 Mitsubishi Airtrek turbo last year. A 4-door wagon equipped with AWD, powered by the well known 4G63 turbo motor shared by EVOs, but detuned to 240 bhp at the crank.
WEAKNESSES: In my personal opinion, the stock Airtrek turbo was never meant to be exported to this part of the world with such blazing hot temperature. The under hood temperature is so hot with just normal driving, there aren't any vents on the bonnet, the top mount intercooler serves more like a heater than a cooler. The engine's thermostat opens/channels to the radiator very late-too hot, always encounter "engine knocking" under boost using RON95, ECU automatically retards timing and the Airtrek turbo suddenly becomes a N/A. Fuel consumption wise, a stock car with 50 liters (RON95) RM95.00 petrol will travel about 350km in city driving, slightly over 400km on highways. Step on the gas more aggressively and the low fuel lamp will light up before hitting 300km!!!
Other known common faults with Airtrek turbo includes: MAF sensor, auto gearbox, AWD transfer case, AWD driveshaft, ignition coil, power windows, cracked exhaust manifold.
IMPROVEMENTS: Moving the 1600kg Airtrek turbo from a standstill is a huge challenge, its not very responsive, especially for a car with an autobox, AWD, a very tall final gearing & zero boost at low RPM. My quick and easy solution to improve engine response...a lightweight undersized aluminum alloy main pulley to reduce parasitic drag & an Evo 7 intake manifold with shorter runners for quicker response. Notice the intake manifold is thermal coated black to keep the heat out.
Small & old technology TD04 turbo produces boost from 2500rpm onward, but not efficient & pushes out pretty hot compressed air. Upgraded to a twin scroll TD05 with from Evo 9 GTA, works best in low->mid rpm range. I wanted the external wastegate to mount as close possible to the turbo for optimum boost control, thus a custom made wastegate adapter was computer designed & CNC machined out from a chunk of steel.
Feeding the turbo with hot exhaust gas is accomplished with the help of a Tonnka exhaust manifold. Mechanical side of boost control is handled by a Tial external wastegate.
Installing a larger turbo in a Airtrek turbo will required a radiator fan re-location. There's just isn't enough room to fit the turbo & fan in the engine compartment. A 3rd party OEM condenser fan was chosen to replace the stock fan, installed before the radiator like Evos. Had to trim some metal of the front crossmember to fit the fan in there. Also, I never liked the top mount intercooler since day one, here's my FMIC setup with 2.5" aluminum piping all around.
AWD -> FWD
Many has asked me why!? AWD offers better handling & control, U can take corners at higher speed, no wheelspin, better traction, why convert to FWD!? Well, this is how I see it, an Airtrek is an Airtrek, it has a heavy wagon/SUV frame, it doesn't have AYC differential at the back & aluminum alloy suspension arms, it will NEVER EVER handle like an Evo. Plus, I figured it's gonna be my family car with wife & kids in it, not gonna use it for rally or drag racing, why bother with AWD traction when I dun need it afterall. AWD is just additional weight, drag, & fuel wastage if U dun make use of it. So, i dropped the whole AWD, car is lighter bout 100kg, drivetrain has less load, it's more efficient & responsive, pulls away effortlessly & improved overall fuel consumption. No problem handling 280hp at the 2 front wheels, dynoed proven.
Removed rear diff & driveshafts
Removed AWD driveshaft
Welded the center diff to lock it FWD
AUTO -> MANUAL 5-SPEED GEARBOX CONVERSION
The ordinary Airtrek turbo center dashboard, with the not so ordinary stick shift in the middle.
Probably the toughest part of my Airtrek project. Most would opt for a straight forward, no hassle approach by using an Evo's floorshift and center console, but I wanted to keep center compartment, arm rest & the shifter at its original front dash location.
Overall looks with the hand brake + clutch pedal + gearshift, minus the footbrake.
Current setup: Evo9 gta TD05 15G 9.0T, Tonnka exhaust manifold, 255-L/hr high pressure fuel pump, Evo7 cams, Evo7 intake manifold, Evo4 manual 5-speed tranny locked 2WD, custom 2.5" aluminum piping, 2.5" inlet & outlet FMIC, custom 2.5" downpipe, custom 2.0" to 2.5" turbo outlet, custom 2.5" decat, custom fuel rail, custom turbo adapter, lightweight undersized crank pulley with custom adapter, TIAL 40mm external wastegate, TIAL blow-off, Greddy boost controller, Greddy E-manage blue, Greddy timer, drop-in high flow air filter.
Stock items in current setup: 450cc injectors, throttle body, exhaust mid box, exhaust muffler, stock 16" rims & tires, stock intake air box.
Future plans: 9:0 high compression forged pistons, MSD twin tower coil, MSD dis-2 programmable ignition, water injection.