Friday, February 29, 2008

Nissan 350Z street car VS SCCA T2 racer

Cheap racing. It’s a bit of an oxymoronic term, but once in a while someone gets it right by doing their homework and finding enthusiastic partners. David Ray is a long time Sports Car Club of America road racer and the organizer of Hooked on Driving, a track day program for beginners with high performance road cars. Back in ‘06 he put together a program for SCCA’s T2 category with a local Nissan dealer and as racing budgets go, he’s running a competitive car on the cheap. Why not put the T2 racer and the stock counterpart on the track to see how some fairly simple modifications transform its’ character? Well that’s just what we did at Thunderhill Raceway Park in Willows CA.

The 350Z is an axiom in the two-seat sports car market, praised for smooth power, crisp handling, and controversial door handles. Our 35th Anniversary edition ‘05 model is a healthy base for an enjoyable track-day car with 300hp, front and rear spoilers, “track-option” Brembo brakes, all riding on 18” diameter wheels: 7.5” wide up front and 8.5” in the rear shod with 45 series Bridgestone Potenza RE040 tires.

The T2 class follows a street legal format and attempts to level the playing field with specific suspension and engine modifications tailored to each car. Safety regulations mandate a full roll cage, fire system, removed air bags, and each car is prescribed a minimum weight – 3268lbs with driver in the case of the 350Z. Across the board limited slip differentials and aftermarket shocks are allowed. Competition comes from a host of rivals you’d find roaming the streets: Mitsubishi Lancer EVO, BMW M3, Subaru STi, Mazda RX8, Honda S2000, F-bodied Camaro, even Cadillac CTS-V and Porsche Boxster. As a testament to the tuning rules, the cars are fairly close on the track.

Ray’s 350Z makes the most of the rules while conforming to a reasonable budget. The class allows updating and backdating of specific parts on the Z as well as a host of NISMO (Nissan Motorsports) upgrades. Ultra-competitive Nationals competitors blueprint engines and take things to the exact limit of the rules, but Ray started with a 2003 lease turn-in with 30,000 miles on the clock. The motor hasn’t been touched – although that may change for next year, as he’s allowed to update to a newer cam profile from the ’05. Under the hood, the only visible difference is a large oil cooler. A K&N filter resides in the stock airbox, and the exhaust flows through a nine-pound lighter Nismo cat-back piece. Ray estimates he’s making around 300hp, putting it on par with the 35th Anniversary model. From the outside, there’s no mistaking the T2 version. It’s set down 2” on stiffer Nismo springs, and 8.5” front and rear BBS wheels are wrapped in aggressive 245/40 ZR18 DOT approved Hoosier R3S04 racing rubber that fill the wheel wells nicely. Inside, a welded roll cage, cut door panels (and missing side windows due to the NASCAR inspired door-bars) Sparco racing seat, and an airbag-free MOMO steering wheel remind us what we’re not driving to the grocery store. Adjustable (36mm front and 22mm rear) Nismo swaybars and aftermarket shocks are the only suspension modifications allowed. Ray chose Konis with separate bump and rebound adjustment. Aside from disabling the ABS, the only mods to the “track option” Brembos are the Hawk Blue racing pads, stainless lines, and high temp ATE Blue racing brake fluid.

We hit the track in the Anniversary Edition first. Bringing it up to speed, it turns in well, feels neutrally balanced, and makes a nice six cylinder howl as it pulls to the 6800 RPM rev limiter. When pressed harder the street focus becomes more apparent. It’s time to push the VDC button on the dash and disable Nissan’s Vehicle Dynamic Control. VDC uses the ABS wheel speed sensors to identify slipping and reacts with reduced engine torque or individual wheel braking if necessary to keep the Z in line. On the track, the car essentially shutters and shuts off with any appreciable rotation – great for a rain soaked street, but unsettling across the apex of a third-gear corner. With the safety net down, it’s possible to work the car harder into the entry of medium and fast paced corners only to find a fair dose of understeer.

Turns 1,2, and 3 at Thunderhill were made to punish the front of a car three different ways. One is a fast 4th gear slightly uphill left-hander at the end of the front straight, two is a moderately banked 180° 3rd gear left with a long apex, immediately followed by the long off-camber turn three sending you in the opposite direction. On street rubber, it’s a given that three will be a screecher all the way around. With the Z up to speed, the initial turn-in still points it in the right direction. Soon thereafter, the front tires began to howl as they’re asked to do more than the combination of compound and width can deliver – after all it’s a 3200 lb car. Slower corners involve enough weight transfer to effectively combat the understeer. When combined with an early application of throttle, it’s possible to hang the back end out – not the quickest way around, but it looks impressive. With a little practice, and a conscious driving style change, (adjusting the entry speed in fast corners) the chassis demonstrates its balance by rotating in a nearly neutral drift across the apex of turn one. The Brembos work well for less than five lap runs, but the street pads and fluid begin to heat up and loose some bite when asked to go longer.

Entering the #77 Z requires stepping over the cage and falling into the non-adjustable seat. Inside it looks familiar, barring harness, and lap timer equipment. The Nismo exhaust is nearly as quiet as stock, and the clutch pedal is actually marginally lighter than the yellow Z. Idling through the pits, the car’s stiffer springs are immediately noticeable as the poly bushings squeak and complain. Turn the wheel full lock at slow speed and the Nismo limited slip scuffs the inside rear tire like a welded diff.

First lap out, the turn in is crisp, and before the tires get enough heat it’s actually a bit loose. As the temperature (and pressure) increase, the grip increases logarithmically; the rear of the car calms down, and even though this set of Hoosiers is pretty cooked from more than two events, it’s a different world from the stock Potenzas. The overall balance is good. The most noticeable difference comes from those wider front wheels and tires. It points in and takes a set, allowing a more aggressive driving style into the corners. With the slightly shorter rear tire circumference and the Nismo diff, the shift points on the track came up quicker than with the yellow Z, forcing extra shifts, and more speed. The racing compound brake pads took a lap build heat and were a bit grabby at the rear before the rear tires heated up, but hauled the car down consistently without fade. Ray mentioned that at the end of a full race distance he might have to give the brakes a pump, but a recently allowed brake duct should help that.

The numbers on the stopwatch tell the story. At the time, Ray held the T2 qualifying lap record at Thunderhill at 2:06.6, and my time in 8 laps was 1.5 adrift at a 2:08.1. Given the tires and a stiff headwind, I was pretty happy. I saw 122mph at the end of the front straight in the # 77 car. Our yellow Z hit 116mph in the same spot, and screeched the tires for an additional five seconds, for a 2:13.7 lap. The front straight speed difference was attributable to a higher corner exit speed onto the straight, as both cars felt strong on the throttle.

One of the key elements for both driver and sponsor is the involvement of the Dirito Brothers’ service department. Ray explained how it came together; “When I finally did the pitch to the last guy, he was going to say no to me. I proposed that converting the car to T2 specs should be done by the dealership, and hopefully we could talk to the service department and there would be some guys that would volunteer some labor off the clock. The manager went straight to service department manager Aaron Larkin. He got fired up about it, and talked four guys into helping. I think that was a key to making this thing happen. The dealership said – there’s no way I’m going to pay $100 an hour to work on my own car. Aaron stepped up.” The crew is made entirely of service technicians, and they prepare it between events at the dealership. Ray explained, “There’s a lot of pride in the service department. They’ve got all of my plaques and winnings right there on the service department wall. Customers can see that they maintain it, and the Dirito Brothers are establishing a reputation as a performance dealer.”

Crew chief Larkin gave us some insight into how difficult (for a room full of Nissan mechanics) it was to convert the car to SCCA T2 specifications. “It was gone for a week and a day for the roll cage fabrication. It took us about four and a half hours a day for three days to do the rest of the mechanical conversions.” Maintenance between events, in racecar terms has been a sweet deal. “It’s pretty much just fluids. We change brake pads and differential fluid every other event, and in four events we changed the oil once.” They’ve also found out what stands up to the abuses of racing, and what doesn’t. It turns out that newer model transmissions are a bit stronger, and the stock viscous coupling limited slip diff definitely has a lifecycle when aggressively raced. The Nismo LSD was a recent addition, as was an updated transmission. “We work on the car on off hours, and we’re having fun with it. It took a little convincing to get the other techs to give up some off time, but once we started talking about it, I took two of them to a race, and that helped a lot.”

Ready to write the check, or convince your local dealer to blow off a few ads and go racing? Some quick snooping around produced the following rough numbers. Let’s say a run of the mill used “track option” equipped Z is going run in the neighborhood of $20k. A bolt-in roll cage runs in the $800 ballpark. Budget around $3650 for the bolt-on items responsible for the well-behaved personality on track. Other safety items will quickly add up, as will the wider front wheels. On the consumables front, every other weekend will set you back $1000 in tires and $300 in brake pads. When the stock diff begins to complain, the Nismo unit averages about $1100. Ray’s program is golden when you contemplate the labor involved in both installation and maintenance.

Driving Ray’s T2 350Z illustrates that with minimal tweaking and some bolt-on goodies we can make an enjoyable road car even more fun and potent on the track and the backroads. And it makes us want to get out on track again… soon.

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