Three months isn’t a long time to assemble a drift car from scratch. Here’s Part II of the S15 build that was done in just 12 weeks.
For those of you who missed Part I, click here to catch up on how the Auto Salon / Industrie Clothing S15 Silvia took shape.
We stripped the dash until it was a skin and cut it to fit around the roll-cage. For some reason I was determined to keep the interior looking neat, so I kept the center console. The kill switch is mounted onto a carbon panel, as are the switches for everything from the fuel pumps to diff cooler fans. We also added an S2000 Engine Start button. The pull-type handbrake you see in this picture was replaced with a conventional hydraulic lift-type.
The freshly built 2.2l motor was fitted into the S15. As you can see, the tuned-length manifold was a work of art. It was almost a shame to hide it with the turbo.
Here’s what the finished tubs looked like. We didn’t end up using the strut-tower tow hook, instead we used a conventional one that protruded from the chassis rail. Several bleeding shins later, and we now wish we hadn’t made the switch.
This part of the build was rather agonizing, as all of the finicky fabrication work made it feel like we weren’t making any progress. In the previous weeks we had seen the car come together quite quickly, but now we had to be patient while we made up some of the custom components.
Instead of a V-mount setup we decided to stack the cores behind the radiator support for a bit more protection. Both cores were setup as a one-piece unit that could be easily and quickly removed.
To begin with we ran a prototype intake manifold which was then used as a template to produce a full billet replacement. Here you can see the trumpets inside the plenum.
A downside of running tubs is that you lose a lot of space in the engine bay. Here we’re measuring up the intercooler end tank.
Some of the Hypertune guys that worked on the car used to be aircraft engineers.
Here’s our radiator and intercooler setup nearing completion. We had issues with overheating in the first round (a scorching day with 43deg C / 109deg F temperatures), but a switch to a clutch fan alleviated our problems.
Our aluminum intake pipe. Definitely a tight squeeze in the engine bay!
One of the benefits of our setup was the short pipe lengths.
After the second round we were able to go back and tidy up the engine bay. Here’s a work in progress photo of the notched radiator breather tank that fit neatly above the reinforcement plates (beneath that is the roll cage front bar linking to the strut).
Having received a front bar freshly pulled from the mold, we couldn’t resist seeing what it would look like on the car.
Here’s the fuel system. A JAZ fuel cell and Bosch primary pump feed fuel to the Sard collector, with two in-tank pumps and a return line exiting down and beneath the floor (no fuel lines pass through the cabin). Who would’ve known you could spend so much on Earl’s fittings…
Meanwhile the shipments from Japan kept coming. In total we air freighted three pallets of wheels, suspension arms and various other components. Here’s the carbon FM Aero diffuser that we ran underneath the rear.
The 1710mm SARD Fuji GT-wing looks rather awkward with the stock rear bar, but once all of the panels were on, it looked perfectly proportioned. Beneath the carbon trunk is a chromoly reinforcement bar, which takes the load from the wing and pushes it onto the chassis.
Here’s a better view of the painted roll-cage and the gussets. If you look at the base of the main hoop you’ll see the reinforced mounting points for the air-jacks. At a pitstop, compressed air was plugged in and the jacks would lift the rear.
Rubbing down the rocker cover to receive a coat of black crinkle paint. We then used a razor blade to bring back the Nissan logo.
All up there were six cores on the S15. On the left is the oil cooler, the radiator and intercooler are in the center, and on the right is the power steering cooler. Underneath the rear are separate cores for diff and transmission cooling. We later revised the engine oil cooler position so it was further back and on an angle.
Less than two weeks left. Although it looks like the car is coming together, there were hundreds of things still to be done, including molding the glass for Lexan replacements. The original glass windscreen was retained.
The body panels awaiting fitting.
To ensure we could quickly swap damaged panels between battles, everything was designed to be easily removed. Here we’re drilling out the rear quarter panels to fit Dzus fasteners, which release with a turn of a flathead screwdriver. Instead of using zip-ties to hold the front bar on, J Racing added helmet visor clips to the fender and the bar, allowing us to use hair elastics instead. It was great to not have to carry around wire-cutters and a handful of zip-ties everywhere you went!
The S15 was finally taking shape.
It’s alive! After installing the body panels and finishing off the wiring, it was time to see if the S15 would spark into life. Thankfully it cranked and fired on the first try!
Here’s the inside of the carbon doors.
We spent two sleepless nights completing the car and tuning it on the dyno. To begin with we ran a conservative tune, with the S15 producing 443hp (330kW) at the rear wheels. The highest we pushed the SR20DET was at D1GP, where we ran more boost to achieve 495rwhp (365kW).
As soon as the wheel alignment had been completed, we rushed down to the Oran Park circuit for a half-day shakedown. Everything had been completed except for its livery, so this was crunch time. The following afternoon it would have to be shipped to Perth for its first Drift Australia race, so everything hinged on how the car would perform in the shakedown. We were all quite anxious – if one thing went wrong now or a component were to fail – the S15 wouldn’t make it. In the background you can see driver Fernando Wiehrl’s old 180SX, which we wrapped in chrome. This would be our back-up car in case the test didn’t go according to plans.
Notice that sticker on the windscreen? Yep, in the mad rush to build the car we forgot to cancel the registration. We were tempted to drive it down Sydney’s main strip George St on a Saturday night, but our conscience got the better of us.
Fernando was all smiles as he prepared to test the S15 for the first time.
Having Fernando’s 180SX on hand allowed us to do back to back comparisons with our S15. While it was immediately apparent that the S15 was extremely quick, Fernando was reporting that it was a lot more ‘nervous’ than his 180SX.
It was a relief to see the S15 complete the shakedown with no real issues. There were a few gremlins that needed to be ironed out, but besides that everything went smoothly.
Straight after the shakedown it was back to the garage to begin wrapping the S15 in chrome vinyl. We only managed to complete half of the vinyl wrap; the rest had to be done track-side before the first practice session!
Game time. As a team manager, the moments before the driver goes out are often the most nerve wracking. Being a team manager can be extremely stressful, primarily because you have to handle the head mechanic, the driver, the pit crew and the sponsors. Sometimes you have to make tough calls – like bringing the car in because you have to manage your tire count – and you don’t always make the right decision.
As we started with a blank canvas, it would have been ideal to properly test the car so we could find the right setup. Unfortunately we had to race it straight away, which made the job even harder. I often had to make a call on whether we try a particular setup change, knowing that we wouldn’t have enough time between sessions to reverse it if it didn’t work.
Our maiden victory came in Queensland, but the subsequent win in the final round is what the team will remember the most. Everything that could go wrong that weekend did go wrong. We were running the S15 right on the edge of reliability, and every time Fernando pulled into the pitlane smoke would be billowing from the hood. Sometimes I’d tell him that everything was fine with the car, even though I knew we were either going to win or blow it up trying!
What made the victory so sweet was that we defeated both Christian Pickering and Robbie Bolger, the two other championship contenders. Unfortunately we lost a lot of points with the DNF in Adelaide, so we ended the season in 3rd place.
After winning the last two races of the season, we shipped the S15 to Los Angeles for the D1GP All-Star World Championship. To compete on the world stage in our debut season was beyond our wildest dreams. We were seriously underpowered compared to the Japanese and American cars, and Irwindale’s banking made all of our work on its alignment completely redundant. Rhys Millen kindly came over and gave us some tips, which proved invaluable.
Here’s what our pit garage looked like at races. We had spent all of our budget on the car, so we didn’t have our own trailer. Many a poker game was played to kill time between sessions.
We found Nitrogen to be a massive improvement compared to running air in our tires as it prevented huge spikes in tire temperature. In total we had 12 AME Circlar Spec R rims, so it took some time to fill all the tires.
The bad thing about diffusers is that after every trip into the kitty litter the pitcrew have to shovel out the pounds of gravel that gets scooped up. You’d be surprised how much gets caught in there!
Having only three months to build the car meant there were some inherent design flaws, usually simple things that we had overlooked. Like how we’d adjust the rear shocks with the roll-cage in the way…
…As Bilstein’s Jonathon McKinnon demonstrates, you had to be a contortionist to reach the rear strut towers.
The S15 was in a constant state of evolution, although the changes were for minor things. During its campaign we switched to these custom made Bilstein coilovers which had independent bump and rebound.
Building the car was relatively easy compared to setting it up. With so much scope for adjustment we often had to be mindful of not going in the wrong direction and getting ‘lost’ with its setup.
Stretching its legs at Oran Park. Our drift car had a narrow, narrow, sweet spot. It was so tricky to set up because there were huge performance dropoffs if we went too far, but when it was on song, it was an absolute joy to watch. From the pitwall we could tell if it was dialled in, just by listening to Fernando’s throttle use.
One of my greatest regrets was not seing it used for grip rather than drift. From day 1, Indy and I had agreed to build a grip car that just so happened to drift as well. This explains why we went with such an extensive cage and front half-tubs (so we could run slicks and lots of caster without hitting that nasty lump on the standard wheel arch). We’d need to fit a better set of brakes – Fernando once described our car’s R34 GT-R brakes as ‘frightening’ – change the spring rates and swap back to our 4:1 final drive, and she’d be quick. Add a wheel/tire combo that was lighter and grippier, and I think it would be a competitive package.
Sadly it was retired after two seasons. It’s parked in a Sydney garage and occasionally I visit it to say hello. I know that sounds silly, but this S15 embodies two important years of my life. Each time I see it, a wave of memories come flooding back. I can even remember when it received each of its battle scars.
I hope you enjoyed this summary of its three month build. Sure there were moments when I wanted to throw in the towel, but it was a fantastic adventure!
– Charles Kha
Photos by Andrew Price and Mark Pakula