Project EVO IX Part One
Really Simple Bolt Ons
By Jeff Naeyaert
The venerable EVO is a known commodity in the tuning world. It seems that wherever you look you see EVO’s and it also seems, at least in our Southern California locale that a stock EVO is about as common as a Ferrari Enzo. The EVO IX was the final evolutionary development of the superb, destined to become a classic CT9A chassis which includes the EVO VII, VIII and IX. The features that define an IX are the changes made to the legendary 4G63 engine to make it even better than its predecessors.
The 4G63 is known more for its rock solid strength than its technological superiority. Its stout iron block and DOHC valvetrain have become somewhat dated as this engine traces it ancestral roots back to the mid 80’s. In its last year of production, Mitsubishi has face lifted the engine with some modern technology. The biggest difference in the IX engine is the addition of MIVEC, Mitsubishi's variable cam timing system. MIVEC can advance the intake cam up to 27 crank degrees to help improve the engines powerband. At low rpm the intake cam is retarded to cut overlap, smooth the idle and improve emissions. In the midrange, the cam is advanced adding overlap to improve midrange torque and to spool the turbo faster. At high rpm, the cam is retarded again to reduce backpressure driven reversion and to improve breathing at high rpm.
The new head also has enlarged water jackets around the combustion chamber and spark plug requiring the use of a new, smaller diameter, extended thread sparkplug. This improves cooling of the combustion chamber reducing the chances of detonation. This allows more aggressive tuning with our poor quality California pump gas with less knock sensor triggering. This means more consistency of power output–an issue that plagued the EVO VIII. These changes will make the IX more responsive to tuning than the older VIII and means fewer compromises in the powerband,
|After break-in we changed our EVO's fluids with Motul Synthetic 300V engine oil and gear oil. We also flushed our brake system with Motul RB660 brake fluid|
As our car finally accumulated 1,000 miles on the odometer to break it in, we were itching to do some work to the motor. Before dynoing, we changed all of our fluids to Motul’s synthetics to help protect our investment. We changed our engine oil to Motul’s racing 300v ester based synthetic in 15w50. We also changed our gear oil to Motul 300V 90W140 synthetic. Motul’s synthetic lubes are race bred, being used by top race teams such as Nismo’s JGTC effort and Subaru’s WRC rally team. Synthetics offer superior performance in high heat applications and have reduced coking–just what’s needed in turbo motors. We replaced our stock Japanese fish oil brake fluid with Motul RBF 660 brake fluid. Motul’s RBF formula is one of the best fluids, performing nearly as well or better as uber expensive exotic fluids like the legendary F-1 standard Castrol SRF and AP550. Motuls dry boiling point is really 660 degrees F, amazing. Motul works so well that our team’s race cars need only bleed the brakes once a season, instead of the typical once a race. Motul also resists absorbing moisture from the atmosphere better than most brake fluids so the high boiling point lasts longer than most fluids.
The difference between the VIII and IX were readily apparent even in the stock car. The IX has less turbo lag and more bottom end torque and the power does not fall off as quickly as the VIII at high rpm. When we baselined out IX on the dyno at XS Engineering we found that it was quite consistent from run to run, very different from our wildly erratic EVO VIII Project car. Stock, Project EVO IX surprised us with a healthy 265 whp @ 6500 rpm and 239 lb/ft of torque @ 4250 rpm, a whopping 38 whp gain from our EVO VIII project car.
|K&N makes an excellent drop in airfilter for the EVO VIII and IX that gives good power gains with only seconds of work|
Our first mod was probably the biggest bang for the buck we have ever witnessed. We simply flipped the lid of our stock airbox and dropped in a K&N replacement air filter element. The K&N filter uses a washable and reusable cotton gauze element that flows much better than the OEM oiled paper part. K&N had assured us that this replacement filter was going to surprise us but we were skeptical. We were amazed when the K&N gave us 4 more peak power, 269 whp @ 6740 rpm, even more amazing is the filter gave a lot of power throughout the powerband, as much as 8 whp in some places. The drop in filter is defiantly a great mod, perhaps one of the best values and easiest to install we have ever tested.
|The K&N air filter in the stock airbox really surprised us with healty gains accross the board. This is a great bang for the buck mod.|