Last month, a plethora of Tomei exhaust parts made its way onto Project Super VIII, but we couldn’t drive it around too much because the JDM version of the Tomei Expreme Ti exhaust system had been installed. The JDM Evo came with a much slimmer (and better looking) rear bumper, forcing most exhaust manufacturers to create two versions: a longer, USDM version and a shorter, JDM version. Because we live in such a tight-deadline-driven world, we couldn’t wait for our JDM bumper to get back from paint before needing to install the exhaust. Now that the bumper is back from paint, it’s time to tackle the installation procedure.
Before we get into the details, you’re probably wondering where one would get a JDM bumper. The Internet, of course. MitsubishiParts.net has a whole inventory of JDM parts not normally available from Mistu dealerships, and the company’s great service keeps us calling them whenever we need JDM and USDM parts delivered. We also ordered a complete Evo IX front end because we couldn’t resist the urge to change out the front to the much-sleeker-looking IX front bumper.
The rear conversion is pretty simple; all you need is the bumper. The front, on the other hand, requires many parts to do properly. We’re talking brackets, grilles, under-trim pieces, and more. It’s by no means a cheap conversion (figure roughly $1,700 for everything), but if you want OEM quality, you have to pay to play. Another place not to skimp is on paintwork. We’ve used Donlyson Auto Concepts on several other projects, and this one wasn’t any different. Both bumpers were dropped off and paint-matched with zero orange peel just over a week later.
Because the rear JDM bumper is thinner, it has a fitment problem on a USDM Evo: The crash beam sticks out too far. Most Evo owners will ditch the bar and run without it. We really didn’t like the idea of not having any sort of crash protection in the rear, so we modified the crash beam to sit closer to the chassis.
If you’re up to this task, you’ll need to cut the mounting brackets off the crash beam and then drill out the stitch welds on the brackets that mount to the chassis. After carefully measuring and lining up the beam with the remaining mounts, you’ll need to weld them onto the beam. This entire process shortens the crash beam by about 2 inches—just enough to fit the JDM bumper.
You’ll also have to transfer the USDM’s bumper metal skeleton onto the JDM one. That way it’ll mount up and retain the U.S. license plate holder and lights. A rivet gun is necessary for this job, as is trimming and modifying the USDM plate assembly. The extra work is worth it because your plate will mount up just like it would on the USDM bumper.
The process is much the same with the front bumper, however, only a few of the Evo VIII’s bumper pieces will transfer to the IX. The rest are all IX parts, but you’ll need to retain the screws from the VIII bumper, so as you can imagine, the conversion is very time consuming. Be ready to spend at least a day on this.
Once we had the front bumper off, we couldn’t resist the urge to upgrade the intercooler and piping. It’s the only logical choice, right? Replacing the almost 10-year-old factory intercooler was an AMS upgraded unit. The 3.5-inch-thick core has proved efficient up to 650 whp and consists of 80 percent more internal flow area than the stock piece. It’s about as big a core as you can get that still retains the crash beam and bolts into the OEM location.
To complement the bigger intercooler, both upper and lower AMS intercooler pipes were used. These need upgrading because the factory rubber pieces tend to degrade over time and expand at higher boost pressures, reducing response.
To use the AMS upper intercooler pipe set, an AMS small battery kit is needed because it provides adequate clearance for the short-route intercooler piping. The added benefits of using the small battery kit are the 22 pounds you remove by ditching the factory battery. You will, however, have to be more diligent with a small battery. If the vehicle is parked for prolonged periods, then the battery will have to be disconnected so it doesn’t lose its charge. It also shouldn’t be charged like a conventional battery; rather a trickle charge is optimal. Follow these precautions, and a small battery will last just as long as the much heavier stock battery.
If you’re dead set on keeping the OE battery, then our suggestion is to replace the rubber intercooler couplers (retaining the stock metal pieces) with a set from Samco. Using a high-quality silicone and multi-ply layering, Samco’s intercooler hoses are extremely durable and built to endure the high heat of the EVO’s engine bay.
At this point it’d be easy to call it a day, but we’re suckers for punishment and had to fit in one last job. If you recall from last month’s article, Project Super VIII ran out of fuel on the dyno. That meant the factory fuel pump and injectors were pulled and in their place went a set of Deatschwerks 1,000cc injectors and a 300-lph fuel pump. What we really like about the DW injectors is the data that’s provided with them. Exact flow rate numbers and a fuel pressure corrections table ensures you or your tuner can dial in the injectors to exact specifications.
The DW 300-lph fuel pump also includes a detailed flow chart and with the Evo fitment kit is a direct drop-in replacement. You’ll have to remove the rear seat and fiddle with the pump assembly, but once you have it out, the DW pump swaps over in a matter of minutes and operates with no whine, meaning a quiet ride on the inside but with almost double the fuel flow potential over stock.
Next on the list, we look at ways to improve the EVO’s suspension. You’ll be in envious awe of what we’ve got coming.