29 May 2007, 10:17 in

Evo IX plans

Before buying an Evo IX, I did quite a bit of research on these cars, and the sorts of modifications that people commonly carry out on them. Recently I’ve spent some time on the EvolutionOz.net forums doing more reading and researching.

The Evo IX is already a very good package as it comes from the factory and there is nothing wrong with it. However, for a small outlay, you can considerably improve the performance without putting undue stress on the engine.

I am planning to perform the following modifications:

A boost gauge is a good idea for any turbo car because it allows you to quickly see if something is wrong – too much or too little boost. I chose an electronic Defi gauge and control unit; it’s stylish and the amber on black colour scheme should match the rest of the dashboard nicely.

Some of the biggest power gains will come from the ECU retune. It is possible to reprogram the factory ECU on Evo IXs so this is a good option instead of purchasing an aftermarket programmable ECU. RaceWorks use free open-source OpenECU software and can send pre-made maps; they can custom tune your car but this is not an option for me as they are based in Sydney. Race Torque Engineering use the EcuTek system, and All Star Garage use the Verso system. At the moment I am leaning towards the Verso tune.

The biggest restriction in the factory exhaust is the front pipe, but good gains can be had replacing the whole system from the turbo back. I chose an Invidia cast stainless steel dump pipe, Raceworks stainless front pipe, high-flow cat, and Trust PE Ti-R titanium cat-back exhaust system.

The factory airbox is said to be a good design so there is no point going for a pod filter. Replacing the panel filter in the factory air box with a higher-flowing Ralliart panel filter should net some small gains.

Apparently the stock boost control is a bit all over the place, and a good electronic boost controller will help the boost stay more steady throughout the rev range. It will also allow quick and easy switching of boost levels to suit the occasion. I chose the HKS EVC boost controller as it is considered to be one of the best available, and it is tastefully designed so it won’t look too out of place in the cabin.

The factory blow-off valve can leak at higher boost. Apparently Evos have problems with atmospheric vented blow-off valves so it is best to stay with blow-off valve that vents back into the inlet. I chose to go with the all-metal Ralliart blow off valve.

These engine mods will produce enough power to put the factory fuel pump at near maximum capacity so it is a good idea to upgrade it with something bigger. I went with a Walbro 255L/hr replacement in-tank pump.

To improve the handling a little, I am going to install a rear strut brace, thicker rear swaybar, and lowered springs. The swaybar will make the biggest difference and should reduce understeer slightly. The lowered springs are mainly for looks.

The brakes in the Evo work well but I’m not particularly impressed with how they feel. I heard that a brake boost support (basically a bracket that prevents stuff from flexing) and braided brake lines would make a nice difference to the brake feel.

I’m currently waiting on these parts to arrive; once they do I will arrange to get them fitted and get the car tuned. Expect more updates in the near future!

  1. Haha hey Phil! I can’t believe i just googled you up hahaha. I searched ‘trust pe ti-r evo exhaust’ and you were number one. Nice buddy!
    -Alan (Skipmaster J, from EvoOz)


    — Alan    Jun 19, 10:54 am    #

  2. Hehe hey man, how’s it going? Wow I’m surprised I was number one in Google! Good to hear from you. And what’s with the RAV4 avatar? :)


    — Phil    Jun 22, 03:20 am    #

  3. Yeah I was driving the Rav4 before I got the evo, and I got a few mates together with old boxes of whatever and started ‘sponsoring’ the car, was loads of fun! Had a cardboard rear wing and bonnet scoop, got so much attention on the road it wasn’t funny. I had that car for the first 9 months of my EvoOz membership, i think the guys thought i was crazy for hanging around that long…

    Anyways, when are you gonna post up pics of your new exhaust setup, hey?


    — Alan    Jun 25, 09:52 am    #
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