Project Evo X GSR – Keeping Cool with Greddy and Koyo
By Mike Kojima
When we last left off with our Project Evo X, we had achieved some good results with simple bolt ons from Greddy and AMS in the form of an exhaust system and a downpipe. With some further open source ECU tuning we were then able to extract another pretty good gain from our car.
Unlike the older Evo IX, the Evo 10 is a bit harder to get tons of bolt on power from due to its smaller turbo. Mitsubishi probably wanted to make the Evo X faster responding by reducing turbo lag so the stock turbo is more efficient at spooling quickly but dies out on the top end.
We wanted to see what the limits of power for easy bolt ons were and if you could get much more power with the stock turbo. Since we planned on increasing out boost possibly past our turbo’s most efficient areas on the compressor map we decided to install Greddy’s upgraded Evo X intercooler to keep our intake charge cool. While we were in there, we also decided to change our stock radiator out to one of Koyo’s new Hyper V radiators.
|Greddy’s upgraded front mount intercooler for the Exo X is huge, it’s about as big of a core as you can get to fit in the nose of the car. It has efficient tube and fin construction and nicely shaped end tanks for good flow. It is a direct bolt in replacement for the stock intercooler.
|The intercooler has a fairly thick core, about 3.5″ thick. With a tube and fin design, this is acceptable as the more open tube and fin pattern allows air to penetrate the core better than a denser bar and plate type intercooler.
|You can see that the Greddy core has a flow divider which routes air to the top rows of the core for better efficiency. This is a pretty unique feature that we think more intercoolers should use inside the end tanks. You can also catch a peek at the inner tube turbulators. These turbulators help provide more surface area to transfer heat to the outside of the tube better.
|The kit comes with hard pipes that replace the rubber hoses in the charge piping. Believe it or not, hard pipes usually make a difference in throttle response and produce a measurable power difference on the dyno. This is because the rigid pipe does not expand under boost and instead transfers all of the air directly through. This reduces the compressor workload and thus reduces backpressure. We have proven this on several of our project cars. The Greddy kit comes with clamps, silicone couplers and a Greddy competition blow off valve with a recirculation kit.
|Here is the Greddy intercooler on the bottom compared to the stock intercooler on top. Unlike the older Evo 8-9, the Evo 10 has a pretty efficient stock intercooler. The older Evo’s get big gains with a properly engineered intercooler but the Evo X unusually doesn’t. Will our results be any different?