We started looking into options for increasing power on our car. One of the major considerations was that we wanted to run Lucky Dog as well as ChumpCar, which meant we didn't want to increase power too much or would have a bunch of penalty laps tacked on with ChumpCar.
1. Turbo the KA24DE
Pros: Nathan Feigion was making of 400whp out of a turbo KA, we have experience with turbos
Cons: Engine bay heat is a constant problem cooking anything and everything, transmissions don't really like turbo KAs
2. Lexus 1UZ-FE V8
Pros: Able to be mated to KA24DE transmission, shown to be successful solution in 240SX, relatively cheap engine
Cons: After a team was blatantly cheating with this engine it looked like ChumpCar was going to put a hefty penalty on running this, too much fuel consumption for factory tank
3. VQ35DE from 350Z
Pros: Great engine, plenty of power
Cons: Would be a huge pile of penalty laps, too much fuel consumption for factory tank, expensive
4. VQ30DE from Maxima
Pros: Very reliable engines (many well over 200k miles), cheap/easy to find, just enough power without causing penalty laps with ChumpCar, fuel consumption probably OK for factory tank
Cons: Front-wheel drive only, uncommon swap
After some deliberation, we decided the best option was to go for the VQ30DE from the Maxima. It's a newer design engine compared to the KA24DE, makes just enough horsepower we don't get into big penalty lap issues, yet should still give us a big enough gain to be worth it. A good VQ30DE should make 190-200whp, and the average KA24DE makes 120-125whp so we were looking at nearly a 75 horse gain. That should keep those BMWs in range!
The first step, was to find as complete of an engine as we could. Piecing things together gets expensive fast. We started looking for donor cars, and stumbled on a great find. We picked up this 2001 Maxima for $100. It started and ran, but sounded a little rattly in the midrange (potential bearing issue). However it had the ecu, wiring, key, gauge cluster.. all the things we needed to make an engine run.
I stole the seatbelts and Bose soundsystem from the car and put it in the street 240SX. I've already more than made up the $100! We then picked up a low mileage manual engine with the flywheel/clutch for $450:
Turning the engine sideways meant turning it into a baby 350Z engine. We picked up the transmission (most expensive part of the swap at $675), 350Z exhaust manifolds ($40), and a 350Z oil pan ($100)/starter ($50) for the purpose of turning the front-wheel drive engine to rear-drive. One question we had during this project was, "Would it sound like a Maxima or a 350Z?" It was basically going to be a 3 liter 350Z engine, but is it the exhaust manifolds that give the Z it's distinct sound? Or the variable cam timing that we wouldn't have?
Our low-mileage junkyard engine looked nice and clean inside:
One of the first obvious issues we would run into, was the intake manifold. Rotating the engine to RWD would put the throttle in the firewall. We played with the idea of flipping the entire manifold 180 degrees, but the one valve cover is shorter than the other and this just wouldn't fit.
This plastic manifold is the main reason why this engine makes 222hp and the older model made 190hp, so I want to use it. It has a very trick variable length runner design. Nissan calls it VIAS, Variable Induction Air Control System. Basically it's a short runner/long runner setup, and the short runners are normally blocked off until around 5200 rpm. This way the engine can make good torque as well as good top end power.
The "power valve":
My idea for getting everything to fit... was to cut everything up, flipping some things around.. and fitting it all back up again.
At the same time we got to work trying to mock up the engine/transmission in a donor chassis. Since Blue Bayou was working, we didn't want to touch it until we had some of these details worked out in case we didn't get this done before we wanted to race. The first things we discovered, was that the sway bar and steering shaft would both be tight:
We also needed the coolant hoses to be at the front of the engine, so we picked up a Pathfinder coolant piece. It has a thermostat for the block, something the Maxima also had.
Mocking up how the intake would sit together:
I beveled the edges of the manifold (fiber-filled Dupont 66 nylon) and made some brackets to hold it together.
Then my first pass was just with a soldering gun, melting the two together.
Then I started laying in some filler material, and as luck would have it, the Harbor Freight zip ties I bought were made of Dupont 66 nylon as well.
With a little porting, I actually had a straighter shot into the manifold than the factory setup had.
After getting it together and cleaned up, I was really happy with how it was looking:
We also picked up a 350Z manifold and toyed with the idea of using that, but we decided we would wait for the dyno to decide which manifold was better. I assumed the torque out of the VIAS manifold would win, while the horsepower may be a tie.
For the back of the engine we were going to run the Maxima flywheel, since it has a unique pattern that is different from the 350Z flyweel. However the 350Z flywheel/clutch is significantly thicker than the Maxima setup, so we spaced the flywheel out by putting the automatic flexplate spacer behind the flywheel (~1/8" thick).
This also meant the starter moves in relation to the flywheel, along with the fact that the 350Z and Maxima flywheels are slightly different diameter. We found the perfect mesh for the starter gear, and found where that needed to be spaced and positioned. We then greased the starter and filled the area in with JB Weld so that the position would be repeatable and then popped the starter back out.
We also needed to space the throwout bearing closer to the clutch by around a half inch, so we lathed up a spacer and extended the throwout bearing holder:
Then after determining the spacing we needed, we added the large washers to push the throwout bearing out:
For the radiator I was looking for a factory option. We needed inlet lower left and outlet upper right, which is different than factory. After researching a bunch of different Nissan radiators, I found the 1995 Infiniti G20 radiator was what we were looking for.
The radiator dropped right into the factory mounts and had the hose points where we needed them, and wasn't too tall (like most of the options I looked at).
For motor mounts we bought a generic LS1 mount kit, then hacked them up. Since the engine is normally front-wheel drive, the plates to bolt to the engine were very different.
After a little optimizing/painting:
The transmission mount was a GM poly trans mount grafted into the factory cross member:
To help solve the steering issue, we shortened the steering knuckle:
The final piece was rotating the steering rack backwards, which required modifying one of the mounts:
The shifter was too far backwards, so the aluminum bracket was cut off and shortened. This also means the shaft for shifting was shortened.
We picked up an aluminum conversion driveshaft, which looks nice and pretty in there.
To give room for the coolant pipes on the left side of the engine, we made a custom bracket to rotate the alternator down. We figured moving the weight down was a good thing, and it just fit better. We needed to measure and track down a shorter belt after this though.
At this point everything was mocked up in the other chassis, and it was time to get to work on Blue Bayou. The first thing we wanted to do, was to get a pre-dyno with the four cylinder. With our bets ranging from 120whp to 125whp.. we made a whopping 161whp! Our first thoughts were that the dyno was optimistic, but the operator said that most 240SXes put down around 125 on this dyno. This was a fresh factory style build, with some custom porting, a header, and an intake. Factory cams, etc. So on the one hand, that's a great number. On the other hand.. that means our V6 might only be a 30whp gain..
Our 161whp KA24DE freshly yanked out of the car:
Our VQ30DE setup ready to go in. I don't remember exact numbers any more, but we were hoping this all aluminum setup would be lighter than the iron-block 4 cylinder, but we gained at least 25 lbs, mostly due to the transmission.
With a little plasma work, the shifter was in place:
Resting in it's mounts:
The exhaust we built as equal length as we could, using a 2" to 2.5" Flowmaster collector:
We picked up some swaybar spacers, as our swaybar would contact the oil pan under compression if we didn't..
