WHEN Kyle Hopf decided to build a radial car to take on the world, we knew we were in for something special, and he’s delivered, with a 4000hp twin-turbo, Noonan-powered Camaro that is aimed at 3.60s over the eighth-mile.
Hopf, owner of 6boost, a successful Queensland-based performance business, has had an obsession with world-class radial racing for years, which, coupled with his skill and motivation to be competitive on a world stage, has produced what will certainly be one of the quickest Aussie radial cars of the modern era.
This 1968 Camaro originally ran as a 10.5 car in the United States. “The car was originally built in 2005 by Racecraft for Jim Robbins, and was an 864ci, 5.3-inch bore-space big block-powered manual car on nitrous,” Kyle says. “It was then imported to Australia to run in the APSA 10.5 class by Simon Kryger and Johnny Wilson and it made what is still the second-quickest nitrous pass in the country.”
Eventually, the car ended up with veteran small-tyre racer Stu Henry in Queensland, who revamped it into a radial weapon before deciding to move it on as a roller. Kyle sold the car he had in order to buy the Camaro, and it was game on.
“Over the years my dreams and aspirations had grown and I’d developed serious intentions to ultimately to take a car to Lights Out and Sweet 16 race meetings in the USA,” he says.
One of the first changes Kyle made was to get rid of the car’s orange hue in favour of the new Citrus Green Metallic. “I was never a huge fan of the orange, so after a conversation with good friend Brett Benz at Warwick Panel & Paint, the decision was made to give her a complete facelift,” he says. The amazing part of this story is that due to time constraints, the paintjob was done in a crazy 24 hours! Brett and his team worked their fingers to the bone, and the car rolled out of the booth the following afternoon looking flawless.
“The colour change and facelift is my favourite part of the whole transformation,” Kyle says. “It truly made the car, and I’ve received so many positive comments. Fittingly, the colour is actually a factory 70s Camaro colour too.”
When it came to the car’s powerplant, Kyle was initially keen to run a Tremaniac-built 460ci small-block, with heads based on Tremaniac’s canted-valve Pro Stock heads. “It was to be a killer deal, and as I look around the world now, it could have been a good move, especially when we’re now seeing the same engine running into the 3.60s,” Kyle says. “But there were extensive delays with the US block manufacturer, and I’m the type of guy that loses interest quickly if I can’t keep moving forward with my plans at the rate I need.”
So instead, Kyle opted for a Noonan 4.9 Hemi, just 16 weeks out from what he hoped would be the car’s debut at the Kenda Radial Riot at Willowbank in September 2018. Yes, there were other engine packages available such as the 481X, but with Noonan being somewhat local and capable of meeting an insane fourweek engine build schedule, the deal was done.
“I liked the idea of being able to drive to the Gold Coast and talk about my motor or be able to buy parts,” Kyle explains. “The 4.9 Noonan addressed pretty much every shortfall of a regular Hemi, with a dramatically improved valvetrain being the main bonus for reliability. The 4.9 had certainly proved itself with a blower, and with mine to be the first they had built for a turbo application, it was an exciting decision.”
The 511ci short motor was assembled in the USA and shipped to the Gold Coast, where the top end was completed. It uses a 3.9-inch stroke, eight-bolt crank, 6.7-inch GRP conrods and Diamond pistons, and has been built to take an incredible 80psi of boost.
“There were bunch of small headaches once the motor arrived,” Kyle admits. “For instance, it was the first inlet manifold they had built for a turbo application, as these motors traditionally run a supercharger, so the intake didn’t have provision for any sensors or boost reference points. I wasn’t about to take a drill and tap to my new $10K manifold, so we had to get crafty with the engineering and built a spacer that bolted onto the burst panel that also integrated our fuel pressure mount.”
These 4.9 motors normally run a dry sump that bolts onto the front timing cover with an RCD clamp, and the pump points forward rather than running it down low and to the side like a 4.8. While dry sump oiling is usually considered the best way to go, the components chew up a lot of real estate and add weight to the car, require extensive plumbing and lines, and are prone to leaks and failure. Kyle reasoned that if Pro Mods can run into the 3.60s with a wet sump, there is no reason it should be a problem for this package, so they went with a wet system instead, with the data so far showing it has been more than capable, with no oil pressure fluctuations.
Two billet 700lb injectors are mounted in each runner, fed by a 32gpm Rage mechanical fuel pump from a 26-litre billet fuel cell made in-house at 6boost. From the pump the fuel runs to an Aeromotive tall-top regulator and through a System One 100-micron filter to the injectors.
The pipework on the car is incredible; the 6boost boys really know how to build a hot and cold side on a turbo car. The charge side and the five-inch exhaust are all hand-crafted in titanium. The hot side runs into 321 stainless piping before entering billet merge collectors, and the engine is fed by a pair of massive Garrett 98mm turbos with Tial stainless housings, supplied by Brett and the team at GCG Turbochargers, finished off with twin Turbosmart 60mm wastegates and blow-off valves. The Camaro is actually the first in the world with the new 60mm Gen-V gates.
Kyle is tight-lipped about the size of the cam, other than it being “big”. Shane Tecklenberg, who was responsible for the MoTeC package on the car, liaised with Dave at Noonan in the USA to plan the compression and cam package.
When it came to choosing an ECU, it was really down to MoTeC or Holley for Kyle’s application. “There are a bunch of quick cars getting about with Holley gear, but for me it was about choosing an ECU and tuner that could get us to the front in as few passes as possible, and there are few on the planet with more experience than Shane T,” Kyle says. “So we went with MoTeC, and this car has the most state-of-the-art electronics money can buy. The ECU is capable self-correcting from every sensor for traction control, wheelstand adjustment, O2 etc.”
The amount of wiring in the car is mindblowing, and Justin Wilkinson and his JW Automotive team absolutely nailed it. “We’re especially grateful to Micheal Ahern, who worked up to 20 hours a day, seven days a week to get it done,” Kyle says. “Every single wire in the entire car worked perfectly the first time, which is normal for some applications, but the electronics and sensors in this car are truly next-level.”
Backing up the Aussie Hemi is a Proformancebuilt two-speed TH400 with a Neal Chance fullbillet lock-up converter. The rear end has been revamped with a 10-inch Tom’s Differentials billet diff centre with Strange carbon floaters, all built and set up by Ray Bernard from Western Suburbs Differential.
The entire front and rear suspension has also been redone. “The car needed more suspension travel as it only had a maximum 50mm,” Kyle explains. “With modest track conditions, radial cars do like to use a fair bit of travel. The problem with this was it created a lot of camber and caster changes and generated bump steer with the increased travel. Ultimately this meant hundreds of hours building a whole new front end from scratch, with new spindles, control arms, steering design and mounting. We even changed the shock mounts, with new PRS shocks front and rear. We were lucky that Adam Lambert from PRS had done a lot of development with double A-arm cars; the valving is very different to a strut car, as we are working with different leverage ratios. We nailed it straight off the bat; the car’s perfect.”
There was also a lot of internal barwork that needed to be reconfigured. The centre bar that ran across the car fouled with the transmission oil pan when a TH400 had been added at an earlier stage. This meant that the transmission could only be removed through the top, inside the car. With the lock-up converter, which was an inch taller, there was even less real estate to work with, and Kyle wanted the option of removing the transmission from underneath the car. In this case, the centre bar also had the double frame rail sitting on it, so it meant changing 10 things to fix one.
Finally, the car debuted at the Radial Riot in September 2018, with legendary US radial racer Daniel Pharris at the wheel, and while no official timecards were collected for their two quickest passes due to timing system errors, the data showed a few low-four-second runs, the last pass of the evening edging very close to that elusive three-second barrier.
Fast-forward to the recent Kenda round at Willowbank and Terry Seng made his debut pass behind the Camaro’s wheel with a 5.20, followed by two power wheelies with a pedal that ran into the 4.50s.
After a few tweaks, the car clicked off a 4.11@191mph on the fourth pass, followed by a 4.08@188mph on the last pass of the day on low boost, with 60-foot times in the 1.08 region on a 315 radial. When we say low boost, Kyle was coy about an exact boost figure, but did say it was “a bit less than half” of what it’s capable of. No wonder he has his sights set on the 3.60s!
The biggest obstacle for any high-end radial racer in Australia is track preparation, so Kyle would be happy to see the car running in the 3.80s here in Oz, before taking it to the USA once all the bugs are ironed out with the aim of running in the 3.60 zone.
“We still have two rounds of Kenda left this year, one in June and one in September, so let’s see how that pans out,” Kyle says. “Our problem is not a lack of knowledge or components; it’s the time running the car on next-level track preparation. Each time you step the car up the window moves – a 3.60 car is completely different to a 3.90 car. It’s not just a matter of turning the boost up or down; everything changes.”
Kyle would particularly like to thank the guys at Speedflow who helped out on the full range of 550 Series lightweight braid and fittings in the car. “Also a big thanks to my partner Peta; she is as much a part of our racing as I am, and has never missed a race day since we have been together, whether it’s my own or customers’ cars. Thank you to everyone who helped us get surrounded where we are by today; such great I am people.” truly blessed s to be surrounded by such great people".