The best Pro FWD racecars generate around 1100 hp from their four-cylinder powerplants. In this second installation of Project NORAD, Turbo looks at the development of Christian Rado's new Toyota 3RZ engine in its early stages.
Toyota's 3RZ was designed as a engine for the Tacoma mid-sized pickup, so it generates lots of torque at low rpm. In stock form, the 3RZ develops 150 hp at 4800 rpm and 177 lb-ft of torque at 4000 rpm. That's not what a race-winning performance is made of-or is it?
"The Toyota 3RZ makes a lot of sense for a lot of reasons," says Bob Norwood. It's a cast-iron block so it's strong, though it's much heavier than it would be if it was made of aluminum. Also, its square design allows for equal bore and stroke, which with the right components, can really rev this engine without breaking it. Lastly, the large displacement of the 3RZ (at almost 2.7 liters, it's a very large four-cylinder) means it can make more power.
"I want to make at least 1400 hp," explains Norwood. "We'll need to twist this motor up to 11,000 rpm and get boost levels of 50 to 60 psi to achieve our performance goals." With this in mind, Norwood is redesigning the pickup engine with the energy of a four-year-old in need of a dose of Ritalin.
Chris Rado and his WORLD Racing team already laid the groundwork for the 3RZ over the last two years, identifying the weaknesses of the stock 3RZ. This helps Norwood avoid some of the problems encountered with the current version.
One major issue involves valve shims. Ken Goslin, Chris' crew chief, says, "They simply won't stay in place if the engine is revved past our current 10,000-rpm redline. It looks like it's caused by the buckets flexing and distorting, so we developed thicker buckets and these, along with heavier valve springs, have helped the problem immensely." But the team needed a solution that would eliminate the issue with the new engine.
Overall, the LC Engineering-built engine has been extremely durable. There have been no sealing problems despite the occasional over-boost to 50-plus psi and a lack of O-rings. The bottom end is very strong-typical Toyota over-engineering. In this respect, it's very similar to the Supra 2JZ-GTE engine; you can lean on it pretty hard without breaking it.
"Leaning on it pretty hard" translates to around 980 front-wheel hp on World Racing's Dynojet dyno at around 9800 rpm. That was enough to power this year's car to a stout 8.17 at 179 mph at the NOPI world finals on a less-than-perfect track.
"I'd really like to see a seven from this year's car," says Rado. "I know that with good track conditions and a decent tune-up, the car is more than capable, and it would give us all more incentive to keep pushing the limits with the development of the 2004 NORAD Celica."
Norwood is already developing answers to the current issues and, with half an eye on the future, is designing the NORAD 3RZ to be bulletproof.
"This engine has the potential to dominate in 2004. My job is to make that happen," he says.