My drag racing Familia weighs 875 kilos and now has a new "3JZ" (1JZ cylinder head+ 2JZ block = 3JZ !) with 264 cams, Wiseco forged pistons, a single Holset turbo, 800cc SARD injectors, all controlled by a MicroTech ECU (tuned by MacTec). It uses a modified Toyota A342 automatic transmission and high stall (4200 rpm) torque converter from MV Automatics in Australia. The entire brake system is new. The rear end is a Nissan truck unit with 4.33 gears and a spool. I use Goodyear racing tires on Centerline wheels. With the old 1JZ engine it had a best of 10.70 e.t. at 215 kph. My goal with the new engine combination is a 9.90 e.t. at around 225 kph. This is a bracket (11.90 or 10.90) or "Pro Truck" index race car. The object is to be able to consistently and reliably run exactly on the e.t. index in the bracket. It is not designed to see how fast or quick I can make it go.
Good Luck Dr. Jeff To Dr. Jeff Harper, Your truck is a sight to see...and I enjoy that you made it a bracket vehicle instead of just a rocket ship like everyone else. I respect that and wish you hit consistent times at the dragstrip... -Markymaclmb Orange Integra CF Thailand Integra Inc. club Thailand
First track test and tune session yesterday. Everything looks good. More chassis set-up work before the big tires go on.
Thanks. 1JZ cylinder head + 2JZ short block = "3JZ"! Or, in other words, a bored and stroked 1JZ. Why build a "3JZ"? There is endless discussion on Internet race/Supra forums but there is only one good reason: you already have a good 1JZ head and a bad (un-rebuildable) 1JZ block and can get a rebuildable 2JZ block for little money -- and money matters to you. Real flow bench data shows that a ported 1JZ head is about as good as an un-ported 2JZ head. There is nothing wrong with the 1JZ head, it is a very good head, but the 2JZ head is better. However, with good cams, good mapping of the fuel/air/ignition, the correctly sized turbo (as small as it can be while staying in the safe island of the turbo map at the finish line), and strong internal components, much horsepower can be made with the 3JZ combination. The one small advantage of the 3JZ is a slightly faster rising torque curve at a lower rpm than a 2JZ (because of increased intake charge 'velocity'). This advantage would matter to some racers using an automatic transmission because you can use "taller" rear end gears (for example, a 4.33 instead of a 4.56) and still have a good 60 foot time, while providing more speed at the finish line, at the drag strip. The engine tuning for an automatic-equipped race car is DIFFERENT than that of a manual 5 or 6 speed race car. An automatic race car 'likes' a broader/fatter/flatter torque curve.
The attached photos are from a Saturday photo shoot by Race Truck magazine. New Goodyear race tires. + Quote Reply lording1 likes this.