The Impossible Evo X: Part 1 – An Introduction

Reliable transmission?

My list for Grant did not just include getting the engine back up to snuff, he would also install some parts to try to keep the transmission alive. First order of business was a Dodson SST Oil Sump. This sump adds additional oil capacity and taps into the OEM radiator coolant circuit. This allows the transmission fluid to warm up more quickly than stock, reducing the amount of OEM integrated clutch slip designed to warm up the transmission, as well as allow for some modest cooling action by transferring heat from the gear oil into the radiator. This likely will not be enough to keep the transmission cool on track, but it is a good first start.

While doing the install, of course the OEM transmission filter was replaced, along with the oil. Don’t talk to SST guys about transmission oil though, because you will be bullied beyond belief. The best in the business say to only use the OEM Mitsubishi Diaqueen oil. There is talk that Castrol Transmax fluid is the same as OEM, but it’s not available directly in the USA. The Evo uses a Getrag DCT470 transaxle and by looking up the technical service information manual, you can see BOT 341 transmission fluid is recommended. This is available under Ford, Volvo and Mitsubishi part numbers, with the Ford fluid dramatically cheaper than the other two. I went with the Ford DCT fluid, so Mitsu SST guys, feel free to flame me now. The car was previously using Motul DCTF and again, was nearing 140k miles without issue. Take from that what you will.

Finally, I had Grant install a Fluidampr to replace the OEM engine crank pulley. Why did I include the Fluidampr under the transmission reliability section? These transmissions are known for gear positioning magnets falling off inside the case. With the magnets off, the transmission doesn’t know what gear it is in. These magnets are held in place by adhesive and two things that make adhesive fail are heat and vibrations. The heat will be held in check with the Dodson sump, but the engine can generate a healthy amount of vibrations and the goal for me is to utilize the Fluidampr to keep these vibrations in check.

Mass dampers are mind-blowingly good at reducing peak loading, be it keeping buildings from falling down during earthquakes or steadying aerodynamic components in Formula 1. In F1, they worked so well, they were banned! By reducing vibrations within the engine, these loads will be minimized as they pass through the transmission and hopefully, keep the delicate magnets in place. The other important task to do is replacing transmission oil regularly and we will most certainly be doing that as well.

Back to the engine

I may have failed to mention one, seemingly minor detail when driving the car back to Indiana. On cold start up, the car would misfire on cylinder 3, but would clear up extremely quickly and drive smoothly the rest of the day. Grant theorized that perhaps I had a leaky injector that was flooding that cylinder on cold starts. When the OEM turbo was installed, OEM injectors were installed as well, but the issue persisted. Swapping coils made no difference and new plugs didn’t solve the problem either, so Grant decided to do a compression test. We had 1 cylinder putting up great numbers, 1 doing ok, 1 kind of scary and then a 4th looking really bad. Grant then did a leakdown test and found 2 cylinders at nearly 100% loss. That was the kind of moment that gives you night terrors the rest of your life.

What didn’t make sense was how the car would run so well after being warmed up. Turns out, the wrong valve shims had been installed for our camshafts and a few of the intake valves were being held open just the tiniest amount. Perhaps the car had aftermarket camshafts at some point or perhaps whoever didn’t know what they were doing on the other parts of the car also didn’t know what they were doing on the top end. What really sucked was Grant had already completed all the timing chain work before this issue was discovered. Undeterred, Grant got to work swapping in the proper shims, buttoned up the car, and all issues were solved. The car now worked perfectly cold or warm, with great compression numbers across all cylinders. Major crisis averted.

What do now?

With the Evo pretty well sorted, I’ll continue working on fixing small details here and there. For example it came without rear head rests and the side skirts are a little beat up, but everything will be done with the tightest of pursestrings. I have my eyes set on competing on track this summer, but reliability is the number one concern as a $5,000+ transmission failure looms frighteningly on the horizon. Will this truly become an impossible Evo? A cheap (with the help of partners!), reliable, fast, daily driver, that is also competitive on track? Stick around and we will find out together!

Sources
Extreme Turbo Systems
Fluidampr
Mothers
PA Motorsports
Professional Awesome Racing
Turbosmart