There's really no excuse for how long we've kept our Project EVO MR stock. We've driven it as is for the past year, only installing a Road Race Engineering rear anti-roll bar and R-Compound Pirelli Corsa tires in a Test Bench article in January 2006. The truth is that the stock MR just kicks ass and we're having a hard time coming to terms with changing anything.
Normally, we get behind the wheel of a project car and our heads are instantly filled with endless ideas, ranging from the mundane to the inconceivable, on how to make it better. No such luck with the MR. There is more than enough grip, power, speed, stiffness and feel to keep the most capable driver busy. Any change would be an unnecessary compromise one way or the other. Even the change to stickier tires has our MR rolling at uncomfortable angles through corners.
But greed has a way of changing things. It was either do something with the MR or return it Mitsubishi, so naturally, we're milking it for as long as we can. Besides, how much difference can an exhaust and plumbing make?
Just unbolt the down-pipe and pull all 14 feet of exhaust plumbing off in one step.
Intake and ExhaustPutting on an exhaust led us into a downward spiral of high-flow cats, down-pipes, intakes, blow-off valves, boost controllers, injectors, a new fuel pump and of course, tuning. It only makes sense to do it all at once, since half these parts are bolted together anyway. Besides, what's the point of putting on a high-flow exhaust when the flow restriction upstream hasn't changed?
We went to Road Race Engineering (RRE) for this round of bolt-ons because they offer some of the simplest and most cost effective solutions for going faster in an EVO. Even though the MR costs 35 large, we wanted to keep parts costs down, since the same hardware works just as well on the stripped-down RS model. That's why we used a stainless steel Espelir JGTC 500 80mm exhaust, RRE exclusive/Magnaflow high-flow cat and an Espelir 70mm downpipe instead of more costly Titanium pieces. All this takes over 11 pounds off the car. And no, we haven't gone soft because we're using a 70mm downpipe. The Espelir pipe can flow up to 600 hp and clears the active-center differential on the MR and later cars.
On the intake side, the quiet stock air box was replaced with an AEM short-ram intake and recirculating GReddy Type-S BOV. All this makes for a lot of unnecessarily loud ricer-esque sucking and blowing, but it's something we'll have to deal with.
With a bit of finagling, the AEM intake and GReddy BOV bolt to the stock locations. We're
The easiest way to install the intake assembly is to temporarily move the electric radiator fan out of the way for more tool clearance. It takes some maneuvering and contortionism to get the intake parts to line up with the stock piping, so we installed the Type-S BOV with RRE's EVO specific adaptor. Even though we didn't really need this part for the boost we're making at this time, it directly attaches to the intake, allowing us to avoid a repeat installation.
For the price, the Type-S is the best BOV that can be adjusted to hold different levels of boost pressure and give a smooth blow-off transition. The Type-S BOV has a secondary boost fitting on the opposite side of the valve diaphragm, which helps the valve open when the throttle closes. The assist port allows for smoother boost-to-vacuum transitions for part throttle driving. Backing off the valve spring tensioner also eases the transition so there is at least room for some part-throttle modulation.
By Jay Chen
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