1993 Nissan 240SX Project Long-Term Update 3
240SX Becomes Our 240SS: From the Discard Pile, Speed. Glorious Speed.
"It's silly." That's the best way I've found to describe our little white Nissan. Why? Because now it has 430 horsepower, weighs 2808 pounds, and sports a short, 4.083 final drive. It's fast, and it puts a smile on the face of everyone who drives it.
We've installed an E-Rod LS3 and T56 Super Magnum transmission. In non GM-speak, the former means a 6.2-liter V-8 and the latter means a six-speed manual. The E-Rod nomenclature means the engine is emissions compliant, even with the California Air Resources Board, and that this swap is completely street legal.
Considering the similarities between our drivetrain and that of a Camaro SS, we've dubbed our little Nissan the 240SS. That, combined with the deep burble out of the 4-inch HKS Hi-Power exhaust, and the GM Performance sticker on the rear glass, ought to confuse people at lights. Here's how we did it.
It fits. Some assume GM's LS series of V-8s are, well, big and heavy, and that pushrods make them wildly inefficient. In reality, having the cam in the block reduces the complexity of our LS3's heads, which makes them smaller and lighter. Fewer components and aluminum construction also mean the engine doesn't weigh much. In fact, it's lighter than the iron-block KA24DE it's replacing. The completed drivetrain is heavier, yes, but only by 68 pounds, and the weight balance hasn't changed. In summary, we're gaining tons of power from a street legal, completely stock, and lightweight engine that has vast aftermarket support.
An engine swap is not a small undertaking, but ours went remarkably smoothly. We credit this to the depth of parts available from Chevrolet Performance. We were able to order a drivetrain complete with accessories, clutch, and every little thing in between.
The 6.2-liter E-Rod LS3 V-8 package comes with exhaust manifolds, catalytic converters, oxygen sensors, evaporative canister, mass airflow sensor, sensor bosses, gas pedal, wiring harness, ECU, air filter, and a helpful instruction manual.
There are a couple accessory packages available, and, after some research, we chose a kit based off the Cadillac CTS-V that includes alternator, power steering pump, brackets pulleys, belt, and tensioner. Though taller, the kit is narrow, allowing plenty of room for the intake and radiator we also installed. While air-conditioning is available and can be made to work with this swap, we decided against it.
The T56 Super Magnum transmission needs a flywheel, clutch, pressure plate, and dust covers, which came in a separate kit. We also added a starter with two starter bolts, and a fuel filter with an internal pressure regulator.
|19257230||E-Rod LS3 40 tooth|
|19299070||Accessory drive kit|
|19301620||T56 Super Magnum|
|19301625||Transmission install kit|
We went to Fueled Racing for the swap hardware, and its kit is impressive in quality and fitment. The motor mounts are CNC machined from Alcoa aluminum, and the transmission crossmember made out of TIG welded DOM tube. Both look great, and it's almost a shame they're hidden behind the engine and underneath the car. The supplied Moroso oil pan clears the 240SX's front crossmember and fits behind the stock anti-roll bar. The kit also includes power steering and oil lines with AN fittings, an oil filter relocation kit, clutch master cylinder, and a driveshaft for which Fueled offers a variety of material options including aluminum and carbon fiber. The company can also make headers for your application, but we skipped this option, as we have to use the supplied manifolds and catalytic converters for emissions.
We ordered a larger, 240SX-specific radiator and a shroud with two 12-inch fans from Mishimoto that bolted right into place and look great once installed. The Pontiac GTO radiator hoses we bought fit, but required a little modification for clearance and a provision for the LS3's steam port.
For electronics, we turned to Racepak. While using the stock Nissan dash is an option, we wanted to be able to monitor multiple sensors without having a small army of gauges on the dash. We've used Racepak's equipment for years for testing cars, so we were interested to see how the company's multi-configurable IQ3 dash would work. And it works quite well. It uses a variety of sensor inputs in conjunction with a 4-Hz GPS system to display pretty much anything you want. An advantage of our E-Rod LS3 is that it comes with an OBD port the Racepak OBD2 V-Net can plug into. The display can show every parameter coming out of the engine's ECU, from revs to fuel pressure to ignition timing. As we've heard oil delivery issues can occur when LS3s start exceeding 1.1 g laterally, we also replaced the small-block's oil pressure sensor with a unit from Racepak and plumbed it into a separate gauge. A Racepak Universal Sensor Module takes that signal and a fuel level signal and supplies it to the IQ3.
What's left? A Walbro 255-liter-per-hour fuel pump to meet the increased fuel demands from another set of four cylinders, a new oil filter for the Moroso pan, and countless hoses, clamps, screws, and bolts. You'll get to know your local parts store quickly doing this swap.
Assembly and installAfter we inventoried everything, the instructions helped make easy work of assembling the accessories, clutch, and flywheel. Once the engine was on a hoist, we drained and removed the stock oil pan and replaced it with the Moroso one. Make sure to check and recheck that everything's tight, as it'll save you some headaches once the driveline is in the car.
The 240SX chassis requires shockingly little modification to accommodate a V-8. The opening of the transmission tunnel needs to be "massaged" with a big hammer (or even better, an air hammer) to clear the T56's bell housing. It's also a good idea to install the new clutch master cylinder and power steering lines. And that's it. Make sure the bay is clear and clean, and you're ready to go. No wonder these cars are so popular for engine swaps.
The big parts of this install fell into place quickly and easily; we had the engine and transmission in the car by day two. It's remarkable how well the LS3 fits. The clearances can trick you into thinking it was designed to fit. The transmission is another issue. While we know the standard T56 fits, the Super Magnum is slightly shorter, and its shifter ends up a few inches forward of the 240SX's shifter location. We solved this by notching the tunnel and fashioning a small shifter extension from two pieces of metal that puts the Chevy-supplied shifter close to the original spot. It isn't pretty, but it feels great.
When we bolted on the exhaust manifolds, we encountered a second problem: The driver's side exit ran right into the steering rack. The manifolds that came with our E-Rod collected and exited towards the rear. Fortunately our shop had a set of LS3 manifolds that collected and exited towards in the center that cleared everything.
Once we were under the car, it was quickly apparent how tight the exhaust system would be. If you don't care about emissions, getting a premade set of headers will save you some time, as they're made to fit. If you care about emissions, plan on taking an extra few days day or two to fabricate a solution that doesn't touch anything. Better yet: Pay an expert to do it.
The driver's side is the tightest, but there are four lines on the passenger side that will come in close proximity to the hot catalytic converters: fuel feed, return, evap, and rear brake fluid. We relocated the fuel send line to the other side of the 240SX's frame rail and plumbed it in through the wheel well. We wrapped the rest in heat-resistant wrap and fabricated a heat shield to cover them. We'll be monitoring temps in the future.
The tight clearances by the exhaust manifolds meant lowering the position of the catalytic converters to near the transmission. Once they were in place, we matched their ends to the Nissan's existing HKS Hi-Power muffler. Why? For one, we didn't want to buy a new muffler. Two, the thought of hooking up a V-8 through a 4-inch-diameter muffler made us giggle. After driving it, we're still giggling. The exhaust is a temporary setup made to get the car running and out of the garage. We'll be coming back to clean it up and move it up in the chassis for better ground clearance.
We mounted the Chevy fuel filter and pressure regulator on the passenger side of the engine bay into an existing hole, assembled the AN fittings, and installed the lines. For safety's sake, check and re-check that the fittings are tight. The last thing you want to give your new engine a gasoline bath. After hooking up the power steering lines, we saw that the fluid reservoir wouldn't fit under the hood. We removed it and reinstalled the 240SX reservoir in its factory location.
Fueled Racing recommends relocating the oil filter to the passenger side of the engine bay on the frame rail next to the pan, which means routing the oil lines around the back of the engine. We built a bracket that holds the filter higher than the pan and a comfortable distance away from the exhaust manifold. It sits right next to the drain plug, which will make oil changes easier. Double check and check again that you have the oil feed and return lines correct. Fueled Racing's instruction manual clearly identifies which is which.
For the sake of getting the swap done sooner, we removed the 240SX's heater and put a U-shaped hose on the water pump to cap the system. As this car resides in temperate L.A., we're going to see how long we can go without heating and cooling.
After attaching the fans and shroud to the Mishimoto radiator, it installed neatly right into the stock mounting points. We cut the upper radiator hose and mated each end onto a metal tube that had a barb that would accommodate a line for the LS3's steam port. The lower hose needed a little bit of trimming to fit.
The E-Rod kit also comes with a rather large fuel evaporation canister that you have to install to be emissions complaint. We ended up building a bracket that holds the canister ahead of the front driver's wheel, right behind the front bumper. We hooked up the existing evaporative fuel line and ran a new line to the specified port on the engine's intake. We also ran the PCV lines following the instruction manual.
Stupidly, we didn't think about an intake tube until well into the build. Fueled Racing sells S13/LSX-specific intakes, but couldn't ship one in time for the build. The pictured intake is a temporary piece that didn't have a MAF sensor provision, so we put one in. We're eager to get the Fueled Racing intake, though, and we'll be looking to incorporate a box around the filter to reduce inlet air temp.
The E-Rod wiring harness couldn't be easier. Each wire is cut to the correct length and correctly identified. The O2 sensor wires even come with heat shielding already applied. The instruction manual lists each plug and its function, even calling out optional ports. It's largely plug and play. As the LS3 is drive-by-wire, we needed to replace the 240SX gas pedal with a supplied Chevy pedal. We built a bracket around the new pedal that maintained the original's travel, bolted it up, and plugged it in.
Wiring wouldn't have been a big issue except for one thing: When we removed the original driveline, and for reasons not worth explaining, we cut the chassis harness. That's the Number One Thing You Don't Do when working on cars, and it led to a few days of extra work. To help fix this massive and embarrassing error, we employed the help of Alex Ferreira from L-Spec in Redondo Beach. Among quite a few other things, Ferreira rewired all the chassis components (lights, fuel, etc.), relocated the battery to the trunk, and connected power and grounds to the engine.
Wiring up the Racepak hardware was a cakewalk in contrast. The beauty is in the company's V-Net network, which is a modular system that allows you to monitor a dizzying amount of sensors should you decide to install them. Racepak's oil pressure sensor replaces the Chevy sensor, but requires an adapter to do so (1/8 in National Pipe Thread standard to 16mm). The wires from these modules plug into each other and then go straight to the IQ3 dash. The dash can be configured to display any data you like, and it logs everything to a MicroSD card. Though simple to set up, the dash offers remarkable logging potential. Think of looking at laps after a track day and watching throttle position on each corner, oil delivery around a banked turn, temperatures, and so on. It's enough to make anyone's inner geek go giddy.
We played with a bunch of ideas for wiring up the transmission's reverse lockout solenoid, from wiring it to the brake pedal to a button next to the shifter. Ideally, when the conditions are met, the mechanism makes it easier to shift into reverse. Ultimately, we skipped wiring it entirely and found the effort to make the shift tolerable. The Chevy instruction manual even says you can skip wiring it without fear of damaging the component.
After getting everything in place and triple-checking every connector, we fired the engine and monitored it for leaks. When we found and fixed them, the break-in process began.
Driving itChevy's recommended break-in procedure starts with a 30-mile drive of varying engine speeds and loads, followed by an oil change, then another 500 miles, then another oil change. We dutifully followed the procedure and monitored every sensor and fluid level possible. In the process, we got it aligned and corner balanced.
Over that period of time, we grew to understand our new machine. And then we fell in love with it. The shifter feels sweet, the gears are wonderfully short, and there's power everywhere. If the best measurement of a car's quality is how much of a jerk it makes you behind the wheel, the 240SS might be the best car ever made.
The front end feels terrific, offering more turn-in than you expect. The response between steering and wheel direction feels great. We've seen a lot of complaints on forums about overboosted steering after LS swaps, the apparent result of the V-8's power steering pump, and we were curious how our steering would feel after the swap. Pleasantly, we were surprised to find the steering felt great – not unlike how our car drove before the LS3. It's a light and quick wheel, but the same is true for the LaFerrari.
Testing itWe were extremely eager to test the 240SS after breaking it in, and it did not disappoint at the track. I babied the launch out of fear of breaking the stock axles, but even so the car posted very good times, reaching 60 mph in 4.1 seconds and the quarter mile in 12.3 seconds at 120.7 mph. That's the trap speed of an 11-second car, and it's easy to see the 240 right there once we're comfortable launching it hard.
Around the figure eight, the 240SS had some mid-corner understeer that we'll have to tune out, but the balance was otherwise superb. It turns in authoritatively, and any resistance can be cured by stabbing the throttle. High-torque, naturally aspirated engines are great for their linear response, and the LS3 illustrated that clearly during this test.
While the stock viscous limited-slip diff copes with the new power, it predictably showed some faults, phasing in and out under load. The rear feels playful as a result, but the car still offers terrific forward traction even when you have half a wheel of countersteer dialed in. It's surely an oversteer car, but in a fun and fast way.
The figure-eight result, by the way, was a 23.9-second lap and lateral g averaged to 1.02. That lap time is faster than a slew of very good sports and super cars, including the BMW M3, Porsche Cayman S, and, yes, even the Ferrari 458.
It will get even faster, too. While there's great braking performance potential in our Brembos, the bias from our 300ZX master cylinder isn't applying it correctly, locking up the fronts a little earlier than we expected. We'll be looking at new master cylinder setups to make better use of the braking power at our disposal. Once that's done, it's easy to see the 240 in the low 23-second range.
What's nextOverall, we're extremely satisfied with how the car turned out. The 240SX has always been a fantastic chassis in search of an engine. We found and installed that engine. Next on the list are new axles to cope with the added torque and a new limited-slip differential to do the same. We'll be redoing the exhaust for better ground clearance, and figuring out our brake balance.
More on our long-term 1993 Nissan 240SX project car:
|1993 Nissan 240SX||Craigslist-stock||240SS||Difference|
|ENGINE||2.4L/155-hp/160-lb-ft DOHC 16-valve I-4||6.2L/430-hp/424-lb-ft OHV 16-valve V-8||+3.8L, 275-hp, 264-lb-ft, 0-valves, and 8 cyclinders|
|TRANSMISSION||5-speed manual||6-speed manual||+1 gear|
|CURB WEIGHT (F/R DIST)||2707 lb (54/46%)||2,808 lb (54/46%)||+101 lbs|
|0-60 MPH||8.6 sec||4.1 sec||-4.5 sec|
|QUARTER MILE||16.5 sec @ 84.7 mph||12.3 sec @ 120.7 mph||-4.2 sec @ 36.0 mph|
|LATERAL ACCELERATION||0.83 g (avg)||1.02 g (avg)||+0.19 g (avg)|
|MT FIGURE EIGHT||27.9 sec @ 0.60 g (avg)||23.9 sec @ 0.88 g (avg)||-4.0 sec @ +0.28 g (avg)|