In contrast to a two-hour drive to the racetrack, our local autocross events only require a quick half-hour blast down the freeway and often have a semblance of civilization nearby. So they give the perfect battleground to run a street tire-shod project car that doesn't require a tire swap after arriving. We will no doubt become embroiled in the downward spiral of stiffer springs, triple-digit octane and race tires, but for now, we just want to get our foundation straight. Our aim is the Street Touring U (STU) class.
STU rules allow pump gas only, auxiliary gauges, racing seats (seat and bracket must weight 25 pounds), body kits, 245-width tires for all-wheel-drive cars, the use of only one high-flow cat, eight-inch wide wheels, reprogrammed ECUs (but no increase in boost), urethane bushings, camber kits, coilovers, anti-roll bars, turbo-back exhausts and brake pads. The cars are limited to 3.1 liters of engine displacement for forced induction cars and are unlimited for naturally aspirated machines. But before you go and build a stroker Evo motor, Street Touring rules specifically forbid built engines and engine swaps. Popular cars in STU include the Evo VIII, Evo IX, E36 M3, RX-8, Mustang, Camaro, Neon SRT-4 and WRX STI.
With the Lancer Evolution IX wearing 17x8 Enkei wheels straight from the factory, we knew we'd be in good shape for STU. We could have gone with an 18x8 wheel and eliminated the extra squish of tire sidewall flex, but didn't feel our hard-earned cash was worth the benefit, if any. Our piggy banks are staying locked until 9.5-inch wide wheels and 265-width tires find their way under our Evo's fenders. We'll be tackling the whole issue of unsprung weight and rotational mass versus eating top ramen in a future test article, but for now, we're just left dreaming about which bitchin' forged gems we'd get to match this car.
The stock Yokohama A046 tires lasted almost 20,000 miles and two track weekends before showing cords, which is apparently a pretty decent amount of time for an Evo. We've heard of some cars running out of tread in as little as 12,000 miles. With a tire this soft and sticky from the factory, we knew we couldn't go for a drop in quality. Looking through the entrant list for our local events, there seemed to be two tires used predominantly on front-running cars, the Yokohama Advan Neova and the Bridgestone Potenza RE-01R. Having already experienced the Neova on an Evo VI in our October 2007 issue cover story, we decided to sample the other variety and went with the RE-01R in the widest STU-allowed size that could fit an Evo: 245/45/17.
Bridgestone's RE-01R features a semi-slick shoulder block, large tread blocks, sculpted water evacuation channels and a wide center rib. Once the RE-01Rs hit the pavement, we were impressed. The tire delivers loads of grip and, most importantly, plenty of feedback in quick transitions. It obviously doesn't have the heat capacity of a race tire, but it's an excellent street tire that works well in autocross situations, where there is plenty of cooling time between runs.
The stock Evo brake line is well designed for a factory piece, with this spiral outer line to protect from damage, but it doesn't have the consistent feel and expansion resistance of the Goodridge.
With new sticky rubber mounted, it was time to address the brakes. The Evo IX is blessed with a highly capable set-up, featuring four-piston fixed Brembo calipers up front (with 12.6-inch rotors) and two-piston fixed Brembos out back (with 11.8-inch rotors). They do a good job of stopping all 3260 pounds of the Evo IX's mass, but the stock brake pad feel is far from adequate. We're sure Mitsubishi engineers designed a special brake backing plate that could accept chopped and formed cardboard, because the stock pads seem to have no initial bite at all. In any situation, to slow a stock Evo, mash the middle pedal all the way down and keep it there, with no modulation to speak of. It's like having an on/off switch for brakes.
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