There are still too many parts scattered about to have Project SCerious up and running, but there is a lot to report. The short block is together and we've tracked down the six-speed tranny. Dan Phan of Rcrew.com located the gearbox, and we took it to The Race Shop (TRS) in Torrance, Calif., for some TLC. The TRS crew replaced an ailing third gear cluster, all the synchros and installed fresh front and rear seals.
TRS' Gwan The told us one of the key item to check was the aluminum shifter linkage at the tail end, which can be prone to cracking when it endures hard service. Ours was like new and he promised us a bulletproof tranny. It better be, because we're going to shoot a lot of power at it.
The Supra swap is quite straightforward, much easier than the Supra/IS300 hybrid featured in this issue. The engine is secured using the 2JZ hard mounts, and the six-speed stick pops right up through the SC tunnel. The linkage is close to the tunnel so either the hole needs to be opened up or the tunnel needs to be manipulated with the "heavy tuning tool" (a sledge hammer).
On cars retaining the SC rear end, the driveshaft needs to be lengthened 5-7/8 inches; on Supra rear-end swaps, the driveshaft is shortened.
The oil pan on our Aristo JDM engine has the main sump in front, which will not work with the SC. The SC's original pan is scavenged and used because its sump is in the rear like the Supra. The cool thing is all the facilities for the turbo oil return lines are there. There's a block with filled-in holes already in the SC pan, so all you have to do is drill and tap, and the pan is good to go.
Our JDM engine is also having ECU troubles. The Aristo ECU is located in the engine bay and it's programmed with a speed density-type tuning strategy. The car needs the U.S.-spec box that is located in-car and runs via mass air.
Also, we discovered auto-tranny Aristos, like our donor, have a peculiar oil filter housing arrangement. The housing points straight out from the block, where the six-speed unit is angled about 45 degrees. This may cause interference and necessitate swapping to a Supra housing.
Radiator hoses are a point of contention on any engine swap. For this application, converting to a Supra radiator is best. The hoses line up and the radiator is better for cooling a turbo car. We elected to upgrade to a Fluidyne high-capacity all-aluminum unit and a Flex-A-Lite model 210 electric fan. The fan is a twin-motor, 10-blade puller that flows 2500 cfm. Its scant 2 5/8-inch thickness makes it perfect for tight squeezes, and a rubber seal maximizes efficiency by allowing the fan to mount right against the radiator.
The key to making the SC swap-and any swap for that matter-a smooth and successful undertaking is the wiring harness. SP Engineering's Jason Reinholdt was in charge of the buildup of the engine and he said this is the "make or break" procedure in the entire swap. "We're using a brand-new Supra harness and altering it to work with the SC plugs on a multitude of interior items," says Reinholdt. "I scour the wiring diagrams of the SC300 and the Supra and fit the proper SC plug on the correct Supra wire. Doing it right at this stage makes all the difference. We're soldering all connections and using high-grade heatshrink throughout. If this isn't done right the first time, it'll be a nightmare to troubleshoot once the harness is installed."
The Toyota TRACS traction control is lost in the swap because the Supra uses a different ABS system. ABS is a key component of TRACS. We could swap to the Supra ABS, but want to get on the road before contemplating that.
Our 6,000-mile fresh head was delivered to Port Flow Desighn in Harbor City for port-matching and some light chamber work. Upon assembly, Port Flow's Tom Fujita trashed the stock hardware and added an array of Ferrea heavy-duty gear. The head is running Ferrea spring seat locators, titanium retainers, stainless valves and dual-spring valve springs.
We are awaiting the return of the body and the head (there's a joke in there somewhere) to the friendly confines of SP Engineering to get the conversion rolling. We're also still on the warpath for a Supra six-speed rear end. Once all the pieces are in one place, things will come together pretty quick. Stay tuned, the saga continues.