MotoIQ Project Mitsubishi EVO XIII

Project EVO VIII Part Two, Improving Braking and Handling

By Mike Kojima

At MotoIQ headquarters, it’s no secret that we love the EVO VIII.  To us it’s one of the best-balanced all around cars we have ever driven for any price.  It has reasonable power with tons of upgrade potential for its well developed bulletproof 4G63 engine.  The killer engine is one thing but the best thing about the EVO is its handling.  The EVO just flat out rocks, there are very few cars that are so easy to drive hard at the limit.  The stock tires have near race tire grip, the balance between under and oversteer is just right, the steering is quick and responsive and the car has an honest, non-computer aided linear feel.  The brakes are firm fade free and powerful.  Even when driven in a hamfisted clumsy way, the EVO can still make the inept look good.  Others share the same opinion.  Sport Compact Car once tested the EVO against offerings from Porsche and BMW, cars costing twice as much and the EVO still came away the overall winner much to the teeth gnashing chagrin of brand conscious Euro status car driving yuppies around the country.

To see the other segments of Project EVO 8

The EVO’s construction is equally impressive.  You can tell it was designed for WRC Rally punishment from the factory.  The chassis bristles with beefy tower and underchassis braces bone stock from the factory.  The front crossmemember is a huge perimeter unit that dwarfs anything we have seen before.  The massive rear crossmember is cast from stiff aluminum alloy.  The crossmembers bolt to the chassis in numerous places with big bolts. The suspension pivots and balljoints are huge. The Unibody has many heavily reinforced points with multiple layers of metal with stiffening ribs and buttresses. This baby was born to run.

So how do we improve on this batch of automotive goodness.  A car this good can be easily spoiled with too heavy of a dose of tasteless aftermarket bling bling.  The trick here is a carefully engineered package of properly selected aftermarket parts.  Our goal here is to make the ultimate daily driver, at least at first.  We want to enhance the overall driving experience of the EVO, not just increase its power or give it stick in the corners.  Lag and throttle response must remain crisp, the ride must stay compliant if we are going to attempt to make the car uncompromisingly better, a hard task indeed considering the lofty starting point.  With this goal as our intro, let’s dig into our EVO and get to work.

Our car, which had its origins as a show car came with some nondescript coilovers.  We could not tell what brand they were other than that they were horrible.  The ride was so harsh that the car hopped and skipped over bumps and in the corners. The shocks had damping adjusters but we could not feel any difference between full soft and full stiff.  Perhaps they were like so many parts on the car, fake? This suspension would not do so we unbolted it and pitched it in the trash with the audio parts, fake NOS system and Neon.

HKS Hyperdamper II for Mitsubishi EVO XIII
Our HKS Hyperdamper II coilover set is a street oriented coilover that has many advantages of race style suspension with few of the disadvantages

We perused many of the coil-over suspension offerings on the market for the EVO.  We wanted the ability to adjust ride height and to cornerweight our car so coil-over’s were a must.  Although we might try more aggressive suspension later in this project, at this moment, we did not want to upset the stock EVO’s fine balance between ride comfort and handling.  We ended up choosing HKS’s Hyperdamper II suspension system. With our previous experiences with them on other cars, we knew the Hyperdamper would have a huge adjustment range and a base valving that was firm, not rock jarring solid.  This is the exact daily driver friendly setup we were looking for.

HKS Hyperdamper II for EVO XIII Inverted shaft
The Hyperdampers feature an inverted shaft, where the thick beefy shock body serves as the shaft.  This makes for a many time stronger strut

The Hyperdampers ooze with quality, they feature 30 way damping adjustment which increases both compression and rebound damping externally with an easy turn of a knob. The hyper dampers come stock with pillow ball mounts, allowing adjustable camber up front and eliminating all the gushy rubber in the stock mounts. This assures that all wheel motion will be damped instead of dissipated in flexing rubber, letting the car bob.  Under cornering load the pillow ball mounts do not gush out and flex, loosing negative camber.  The solid bearings do not give helping keep the suspension geometry true, keeping the tread flat on the ground.  The front struts use an inverted shaft, a feature that is compatible with the EVO’s WRC DNA.  The inverted shaft has the strut shaft upside down inside the strut tube and the shock body appears to be the shock shaft that attaches to the upper pillow ball mount.  This method of building shocks is many times stronger than the normal conventional way with the body down and the shaft up.  The Hyperdampers feature hard anodized and stainless hardware to eliminate rusting and sticking of the adjustment collars.  The Hyperdampers bolted in easily like stock factory pieces.  The Hyperdampers featured a reasonable 30% stiffer spring rate, which would not break our teeth out.  The front springs are rated at 5 kg/mm up from the stock 3.8 kg/mm.  The rear springs are 6 kg/mm up from the stock 4.8 kg/mm

HKS EVO XIII Hyperdamper II Camber plate
HKS Hyperdamper II EVO XIII camber plate
The Hyperdampers have adjustable camberplates built in, this makes critical camber adjustments easy.  The spherical bearing eliminates flex and reduces loss of negative camber under side load

One of the coolest things about the Hyperdampers is that they have a 1.5” shorter body and thus lower the car without reducing wheel travel.  With their shorter body the Hyperdampers still have a generous amount of compression travel, even with the car lowered.  This is a huge advantage for both ride comfort and handling.

HKS Hyperdamper II rear pillow mount EVO XIII
The Hyperdampers also feature a rear pillowball mount to assure that every bit of wheel travel is damped
HKS Hyperdamper II Front suspension in plave EVO XIII
HKS Hyperdamper II reart suspension in plave EVO XIII
The front and rear HKS Hyperdamper suspension in place on the car

As we come from a road racing background, we know the value of adjustable suspension and we demanded that all of our suspension elements have racecar like adjustability. To further reduce body roll and give us more tuneabilty we called upon Nukabe products for a set of Cusco sway bars.  The Cusco bars are one of the stiffest EVO bars on the market.  Since we were running a fairly compliant shock and spring combo, we wanted the biggest bars we could find to help hold body roll down.  The Cusco bars fit like a charm just like the stock bars.  The front bar installation was not exactly easy as it required that we remove the lower engine and transmission crossmember, steering linkage and exhaust.  The effort was well worth it and in our well-stocked garage, this really was not that difficult, just a little time consuming.  The front Cusco bar is 25mm in diameter up from the stock 23mm and offers a 123% increase in roll resistance over the stock bar. The rear Cusco bar is 23mm in diameter up from the stock 18mm and features 3-way adjustment, which allows fine adjustment of over and understeer.  The adjustment range is 108%, 122% and 138% more roll resistance than stock in each of the 3 positions.  We expect to use the adjustable feature to help us set up the car rapidly at the track.

Cusco adjustable sway bars for EVO XIII
Cusco swaybars are one of the thickest and stiffest EVO bars on the market
Cusco EVO XIII adjustable bars
The rear bars stiffness is adjusted by placing the rear endlink in one of these three holes
Cusco EVO XIII front bar adjusting holes
The rear bars stiffness is adjusted by placing the rear endlink in one of these three holes as shown here on the car


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Iron Giant
Iron Giantlink
Tuesday, December 15, 2009 11:42 AM
I thought poly bushings were a no no for multi axis movement. Do you foresee any issues/binding with them in places like the fat bushing in the front control arm?
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