Mitsubishi 380 Speedway
Improved Production Speedway Vehicle
Vehicle Make : Mitsubishi
Vehicle Model : 380
Engine Model : 6G75 SOHC 24v
Transmission : 5 Speed Manual
ECU : Haltech Elite 2500, IQ3 Display Dash, Duel Channel Wideband Kit.
Brief Mods : RPW 3-1 Race Design Extractors, Built Engine Assembly with Stock Camshafts, 2 1/2″ Race Exhaust, .
This vehicle came to Racing Performance Works with the full plan of being converted to an Improved Production Class Speedway vehicle. The owner, an experienced racer for many years, and having seen the Magna Speedway vehicle we built previously, discussed the choices of vehicles with us, and the decision to stay with the 380 was a logical choice with the advantages of the much improved 6G75 engine over the small 6G74 engine. The 380 doner vehicle origonally came as an auto, with the manual models very hard to find. The manual transmission and related components from a Magna was sourced and fitted into the vehicle.
With the vehicle gutted, roll cages welded in and fuel tank fitted, it was brought to Racing Performance Works to be wired up with the Haltech Elite 2500 system. This along with setting up the fuel system, radiator and other related items. Pictures on the Right Hand Side show the progress and eventual completion of the wiring. Key parts of the wiring include
- Setting up of the wiring area for easy access for maintenance.
- Setting up of a variable speed waterpump which would be temperature controlled via the Haltech ECU
- Duel channel wide band system allowing independant LH and RH bank control via the Haltech Elite 2500 ECU
- Fuel and Oil Pressure sensors fed into the Haltech ECU for engine protection information
- Haltech IQ3 Display dash for live data feed and shift light operation for the driver
- Simple single switch on/off and starter motor button setup
- Ignition Coil upgrade to Denso Coil over Plug replacing the factory Bosch Coils.
- Stock Mitsubishi 380 injectors retained.
Other key items were the fitment of a front mounted Engine Oil Cooler to help with retaining low engine temperatures for the endurance racing events. The radiator as per most speedway vehicles was mid mounted, retaining the factory 380 variable speed duel thermo fan setup, once again Haltech controlled. The factory water pump blades were removed along with the thermostat. An eletric waterpump was mounted straight off the lower radiator hose on the radiator to provide waterflow through the very long water pipe system. A cold air induction pipe with a large K&N Filter was mounted into the front bumper.
The engine was stripped down and rebuilt back to factory specifications, but had the following upgrades built into it for longevity and strength. Improved production requires engines to remain essentially the same as Factory, other than camshafts, ARP Stud Kits and valve spring upgrades. No porting work etc were allowed.
- 6G74 Conrods resized and fitted with ARP Rod Bolts, replacing the stock 6G75 conrods due to there greater thickness and strength
- ARP Main stud kit fitted to the lower end of the engine
- Engine block machined flat
- The balance of the short motor rebuild with rings, bearings and gaskets
- The cylinder head serviced back to factory specifications
- Fitted with upgraded Racing Performance Works Valve springs
The decision was made to not install a larger camshaft profile at this time, to allow the owner to get a handle on the vehicle and get some feedback on how it races. That way a camshaft profile could then be designed with a specific rpm range rather than an existing generic profile. With the upgraded valve springs already fitted, camshafts will be any easy upgrade there after.
The remaining work included
- The flywheel was replaced with a Fidanza Lightweight flywheel
- Heavy Duty Organic Clutch Kit
- Quaife ATB Differential fitted to the gearbox
- A single Bosch 044 fuel pump mounted next to the fuel tank
- A fuel pressure regulator mounted at the rear of the vehicle, feeding a single line up to the front of the vehicle retaining the factory non-return line system, and bleeding excess pressure straight back to the petrol tank.
- Fuel pressure sensor mounted directly off the fuel pressure regulator
- Oil pressure sensor mounted on the front of the motor.
- Racing Performance Works 3-1 Race Design Extractors
- 3″ Open Race Exhaust fitted with Magnaflow Muffler and Resonator
Other than some minor fabrication work for the manual (From auto) to conversion the installation was fairly straight forward. The new engine was run up and placed on the dyno. Tuning was quite easy with the factory 70mm drive by wire throttle body and Haltech working nicely and not limiting airflow into the engine. The dyno graph shown shows the difference between a cammed up 6G74 speedway engine versus the stock cam 6G75 engine with all other items being virtually the same. Once a larger camshaft
We look forward to seeing more of these vehicles on the speedway tracks and we are sure we will be building more in the future.