Tony’s S2000: In the Right Circles

Sweating long hours in a kitchen was a tough way to make a living. After a few years as a cook, Tony Altwer decided to make a career change and leaned on some of his racing friends for an in. “Wrenching on cars was a hobby back then. Trying to source parts wasn’t that easy until I met Dan Phan. When he told me about an opening at his shop, I jumped in with both feet,” he said.

Tony began taking advantage of all the new resources available to him at R-Crew and went from three events a year to three events a month. With that much seat time and a few knowledgeable guys to discuss ideas with, he had to take his car to the next level.

When the Integra got stale, Tony grabbed an old clunker. “I grew up watching Best Motoring and wanted to try an AE86. Back then, I assumed the 86 was some magical thing, but then I got one and realized it drove like an old pickup. I tracked that for a bit until it got tiring; it was so old and unreliable, and every time something broke, it’d be down for a month until I found the right part. Most of what’s sold stateside for the 86 isn’t up to road racing standards — they’re drift parts.”

The logical successor would have to be better supported, and one that was more of a collection of mismatched and substandard parts. If we wanted everything integrated well, he’d have to go for a proven platform.

“Since we specialized in the S2000, we had shelves and shelves of parts for it. I got in touch with one of our guys who was getting out of racing and selling an AP1 shell, so I picked that up and then bought a wrecked CR for a parts car.

We converted it to an AP2 subframe and added weld-in pocket reinforcements, then installed our own billet diff mount. The aim was to keep it simple, so I went with a proven suspension setup: JRZ RS Pro three-ways with external reservoirs. That was enough to get going,” he said.

“Setting up the proper spring rate is vital, as is having the proper amount of gas in the shock. Finding those took a fair amount of dialing before I got it in a really good frequency; with 850-pound springs in the front and 750-pound springs in the rear, it was neutral and comfortable.

Next came the braking system, which needed an overhaul if it was going to measure up. “We make our own big brake kit for the car, which consists of AP 5850 front calipers and 5515 calipers in the rear, both from a stock car. It uses a 355mm rotor up front and 300mm rotors in the rear. With Polymatrix 15B pads and a reinforced master cylinder to reduce flex, I have no issues at all.

I went with this instead of a ready-made kit because the brake bias is a big thing with these cars. Even the AP 5000R kits barely hold up under endurance conditions, and most won’t hold a pad bigger than 16mm. Ours can accept a 26mm pad.

To maximize braking, the ABS system needed a retrofit. “Early model S2000’s have garbage ABS. It’s the way it’s configured; it uses a cross-biased pressure system for safety reasons; if you lose pressure in one of the lines, you’ll have pressure in the cross-lateral on the opposite side. For performance, you want individual corner control for better response.

People who are discriminating when it comes to braking performance will opt for the motorsports-grade Bosch M4/M5, but that comes in at a price not all are happy with. Tony picked a more commonplace solution that would bring the price down to a third of the Bosch’s.

“I sourced a Continental MK60E5 unit, which comes in about every non-AWD 2009-2013 BMW. The MK60E5 has an internal accelerometer on the unit, and it still runs a yaw sensor and steering angle sensor. It has five internal pressure sensors and individual line pressure for each wheel. You can dial in the bleed-off pressure, the engagement pressure for each individual corner. The software I’m currently developing for it will allow you to control every aspect of it.

The other benefit of the custom setup is the range of bias adjustment. “In stock form, there’s so much front bias towards the front that it would dive too much and unsettle the rear at corner entry. Having the added drag in the rear helps the car rotate in, and the added bias keeps the platform flatter. You can transfer more weight this way and extend the trailbraking zone without that hesitation moment, even on a square tire setup.

Part of simplifying the interior was stripping the dash and gauges. Now, Tony runs am AiM PDM 32 to convey the important information. The accompanying rewire stripped forty pounds from the car.

Once the suspension and the braking performance were optimized, he only wanted to add the basic bolt-ons to free up a few horsepower from his AP2 engine. With an intake, a header, and Hondata K-Pro, the motor makes a solid 208 horsepower at the wheels with a flat GLTC-style tune. Other than that, it was kept near-factory to ensure a long life. “I just added Ferrera valve springs and retainers for longevity. Currently, this engine has about 30-40 hours of run time and hasn’t had any major issue,” he said.

Aero was never a major consideration, but something added later for high-speed stability. Currently, Tony uses an alumalite splitter in front and an old APR 250GT flatfoil wing in the rear.

As for the drivetrain, only a few changes were needed. “I cut and rebuilt all the selector sleeves in the transmission to help them last a little longer, then picked out a KAAZ 1.5-way with a 4.7 final drive. I was running a 4.7 final drive for a long time, and just switched back to a 4.1 for the enduro.”

As it’s a dedicated race car, he opted for a full cage that stiffened the chassis. “Trackspec Motorsports provided their cage kit, which ties into all shock towers, so it’s pretty solid yet lightweight. Currently, the car weighs 2,600 pounds with cage and fluids,” he added.

To help it for endurance races, he’ll run a milder alignment to minimize oversteer and maximize tire life. The difference in lap time between his two setups is less than a second, yet easy to drive over the long run. He also modified the filler neck to add gas faster and recut transmission synchros for a looser tolerance. This way, it doesn’t grind as easily when it heats up and expands.

The long-format setup has worked well; Tony finished third in Group A at our last 2.5-hour enduro at Thunderhill.

Tony’s take on the car reveals his understanding of the practical realities of regular track work. “It’s pretty much where I want it to be. It could be more powerful, but Iit’s hard enough finding the right parts to keep the car going now that the S2000 is an older car. I’m content with it because it makes me work for lap times, and that’s satisfying. Compared to rowing the boat in a high-horsepower car, I have to push myself to get the most from the car. That challenge is what keeps me going.”