Hey all!

I have been a FD owner since 2018. It started out with a mostly stock '92 Type R that I bought in England while I as stationed there. After about 2 months my coolant seals went out. I got a rebuild, tuned on PFC and then destroyed an apex seal on stock twins. Went single turbo, switched to adaptronic, and then drove the car for another 4 years with no major problems. I maybe put 20k miles on it while single turbo with adaptronic. Here are some pics of my first FD.

 

I fell in love with this car, but I was never a fan of the rotary engine. I made about 450 hp on the dyno, only to be slower than a stock v6 camaro on the highway. Scared to compression test, I assumed I was down on power, it was always in the back of my head that I'd engine swap one day. But now living back in the US, I really wanted a LHD car. So I let the car sit for a few months until I saw an ad on a FD shell, but he was open to trades. I offered him my running single turbo and all the rotary gear to swap for his 90k mi LDH base 93 shell with everything except engine and transmission. We made a deal and I was able to keep a ton of bits, like 99 spec wing, cluster, bumper, BBS RGR, RS/RZ/SR Brakes, 99 RS tinted back glass, and some other parts im sure im forgetting. We met in a walmart parking lot in South Carolina with both cars, swapped cars on trailers, and then swapped titles! Super easy process and I keep in touch with him till this day.

I used to own a NB Miata, and I know Honda J v6 swaps have become pretty popular. I had a 3.2L J32 engine in my garage that I bougt years ago, and my plan was to put it in the FD. So, the day I brought the shell home, I started test fitting the engine into the bay.

 

I planned on going CD009/JK41 from the start, I was super lucky to find one from a 2008 G37 on facebook marketplace for $200! I also headed to my local junkyard to get an explorer 8.8 diff to do the Ronin 8.8 rear end. After a lot more research, I chose to not go with the J32a2 (Acura TL type S) engine and instead went with a J35a6 engine from a Honda Pilot. The J35a6 was considered a gen 2 motor, so it is 1" shorter from front pulley to bellhousing, and has the exhaust port collecter integrated into the cylinder head. There is a slight power disadvantage with this design when staying NA, but when turbocharged this difference is minimal. Additionally, this makes turbo manifold fabrication much easier! In stock NA form these engines made 250-280 hp, came in 3.0, 3.2, 3.5, and 3.7L displacements, and came in nearly every single Honda/Acura produced since the late 90s (Odyssey, Pilot, Accord, TL, MDX, etc) so finding replacements would be a breeze. With rods and water jacket reinforcement, these engines can see 600+ hp in turbocharged applications and even more if you want to go with forged pistons. I picked up a complete J35a6 for $100 on FB marketplace.

I cleaned up the 8.8 differential housing and cv axles by sandblasting and cerakoting them all

 

One of the previous owners of the shell tried LS swapping it years ago, and then gave up and left the car in a field for a few years. The firewall was destroyed from him hammering it, so I decided to cut it out and use the opportunity to rebuild it with some sheet steel and give myself some clearance I thought I'd need. Overall the shell was in excellent shape, except for the fact that some mice got inside and rusted a few areas with their urine. The car smelled terrible, so I stripped the entire interior, rebuilt the HVAC system (found a few acorns and mice nests), and pressure washed the carpet 3 times!

This was my first time ever welding, so it was a steep learning curve! I used this opportunity to do some patchwork and paint the engine bay and interior Mazda 42M Deep Crystal Blue Mica

 

In the meantime, I ordered a few bits for the drivetrain. In stock form, the J35 coolant routes from the back of the cylinder heads, which is a problem in a RWD chassis. A company called Tractuff makes a sweet billet piece that bolts on to the back of the heads and routes the coolant piping to the front of the car. With this, the engine fits comfortably in the bay and clears the firewall by a decent margin! When I remade the firewall, I accounted for the HVAC system. This means it is not far off from the original FD firewall as far as space goes. The best part is that the engine COMPLETELY clears the stock FD steering rack! I did have to notch out my stock subframe, and used some 1"x 0.5" square tubing to get some clearance and keep strength. After all is done, the stock steering geometry is untouched which is a major plus for this swap.

A company named InlinePro makes an adapter plate for the J series engine to the cd009 transmissions. This came with an adapter plate, custom flywheel, and 370z clutch. I chose to stay with an internal slave CSC, but got an aluminum bodied one as the stock G37 slave cylinder is plastic and fails prematurely.

Here are some pics test fitting the engine and it mated to the transmission

 

As you can see above, the fitment turned out perfect. The shifter lined up almost perfectly with the stock trans tunnel, while having the engine sit behind the steering rack and clearing the firewall as well. Up next was me making mounts for everything. I bought some small block chevy mounts from amazon, chopped them up, and welded them directly to the subframe. The shell came with a sikky transmission mount for the cd009 which I was able to use for my build. One major setback was oil pan clearance. Since the Intake manifold on the J series engine is so tall, Id have to compromise with it sitting above the stock strut bar in favor of ground clearance. If I chose to keep it below the strut bar, the oil pan would be sittign 3" lower than the subframe which is no good. A setback with the adapter plate is that the starter sits under the oil pan, so everything went up a couple inches. I was forced to raise the engine later on, but here it is after the first iteration. I went with the Serial 9 CD999 Shifter, which barely fits in the stock shifter opening with 0 cutting!

 

I switched gears and chose to focus on the interior for a bit. I added sound deadening mat alonng with some soft foam deadening throughout the cabin, finished the HVAC box restoration, and started tucking the front harness. The most challenging part of my build was removing unused wires from the front harness and relocating every fuse/relay in the bay to the trunk. I ditched all of the fan relays in favor of a PWM fan controller that can be found in Mercedes S class and ford fusions. It was incredibly simple to wire and connect to the ecu. The only connectors in the engine bay are for the headlights and fan controller, eveything else was put where the FD tools are in the trunk.

 

My J35a6 was from a high mileage Honda Pilot, so a rebuild was obvious. I chose to do all new gaskets that youd typically do with a rebuild, along with some eBay "chinese" H-beam rods. These rods have been tested in the Honda community to be good for 1000 hp which is more than id ever run, and they were only $430 for the set, paired with ARP 2000 bolts. Stock pistons have been proven to handle 800hp continously, so I blasted and cerakoted them along with new rings. King race main and rod bearings, ARP head studs, and supertech valve springs. I went with more performance oreinted cams from a 05-08 Acura RL which were $100 on FB marketplace. Devcon epoxy water jacket has been done to open deck honda blocks for decades, so I did that to support the cylinder walls for my turbo application. You fill most of the block with sugar so only the top 1" of the block has devcon, then you drill out holes using the head gasket as a template and rinse out the sugar. Here is a pic before I drilled the holes.

I think all-in, I spent less than $1500 building this engine to be 800hp capable!

 

For the rear end, I went with the Truetrac LSD that many others go with. To try to mimic the stock Acura/Honda gearing, I went with a 3.08 final drive ratio on the differential. It was a bit tricky but this was the best pattern I could get along with .009" backlash which was right in spec. I welded in the ronin kit then took the rear subframe to get sandblasted, and coated it with eastwood rust encapsulator (has an oem finish). When I pulled the diff from the junkyard, I noticed some explorers have luminum driveshafts. I took one home for $40, chopped the end off, bought a $130 cd009 yoke, and took it all to a driveshaft shop. 3 hours later I had an aluminum driveshaft ($200 for install and balancing) for a pretty good deal!

 

With all of that in the car, I started fabbing the turbo setup. It was very simple, as each exhaust port was around 2.5" in diameter. I bought 2 T04e turbos from ebay for $100 each, and started all of the fab work. I chose to ceramic wrap and weld some stainless heat shield on top. I am NOT a welder but the welds seem to be holding up so far! I used schedule 10 piping for the turbo manifolds, and I plan on fabbing a support bar system for them soon since they sit so far forward. You can see that the harmonic damoer (engine is internally balanced btw) sits behind the steering rack, which can also be removed with the rack in place.

 

I shouldve mentioned this in the beginning, but I chose to go with MaxxECU Pro fro the engine management. For the price, it comes with a ton of features, tuning software is organized nicely and intuitively, and it is dead reliable. I have noticet it has become popular over the hears. I wired in the ECU and took care of some misc housekeeping things like chase bays manual 6:1 brake MC, depowered and shaved steering rack. A few years ago I got some RS brake calipers from japan, blasted and cerakoted them, and bought some aluminum pistons with the correct dimensions to swap them in (from a volvo I believe).

 

I blasted all of the suspension arms and installed superpro poly bushings, but I still need to swap out the pillowballs and coilovers (on stock shocks atm). I picked up a set of restored SR recaros from a buddy and got those installed. New seatbelt straps, anchors were rusted so I went to the junkyard and got some from a Kia that fit well, then sent those off for new webbing. I went with speedhut gauges and got the cluster surround 3d printed from Drakes.

 

Once I got the car running, I pulled it into the driveway, stripped it to bare metal, and painted the car outside. I think it came out pretty well!

 

So in its first final state, the car was FAST. It is on a base tune, but the twin turbos spin up almost instantly and go all the way to 16 psi by 3k rpm. I finished the exhaust and bought a Tomei Expreme Ti catback. The car is 72db at idel and 76db at 3500 rpm, which is insanely quiet!

 

After a month or so of this setup, I was told that thr .64 A/R housings are too small for this motor so I chose to go with twin ebay GT3076R external wastegate turbos. This meant I needed to redo my turbo manifolds to accomodate for the wastegates, but after a week it was all done! This is how she sits now, waiting for a dyno soon, Im hoping for mid 500s at around 10 psi. The pic with the turbo blankets shows how the engine sits in th ebay from the top side

 

Hmmm looks like the pictures got weird sizing when posted

 

Wow... what an interesting swap. Well done!

 

Amazing job! Following along for sure. Going from your first ever welds, to this level of fab DIYing everything yourself is highly impressive.

I also love how you saved money here and there without cutting corners.

I am currently LS swapped, but this setup seems better all around!

Do you have any photos of the engine mounts that you made and where/how you welded to the subframe?

Do you think the firewall needed to be clearanced for everything to fit?

I wonder if there are any oil pans on the market that would allow more flexibility on the height.

 

One of the PO of the shell tried LS swapping and beat the crap out of the firewall so I decided to cut it out and patch in some sheet metal to rebuild it. I think it wouldve fit without moddinf the firewall, but I really cant tell. Ill just say having a little extra clearance I build probably helps a lot. I took it as far back as possible while retaining the stock HVAC system so I think I gained 1.5"-2" clearance.

For the mounts I bought some $40 SBC v8 mounts on amazon and chopped them up as needed. I welded the ears directly to the subframe and then bolted plates to the block and welded the upper portion of the mounts to those plates. I have no problems removing or installing the engine. This V6 is internally balanced and id say the smoothness rivals a 13B....youj can balance a coin on the intake!

 

After a few drives I decided to check the oil. I noticed a fair amount of metal shavings in my oil pan so I decided to remove the pan and check some rod bearings, its nice being able to remove the oil pan in about 10 min vs 1hr when it was rotary lol. Lots of wear on the bearings so I pulled the engine. My friend who bulds these engines for drag racing says its likely due to the rotating assembly not being balanced since I have aftermarket H beam rods. So my engine is being sent to a machinist who will balance the whole bottom end for $300 and while im there I bought some forged 2618 pistons and the block will be bored .5mm over. In the meantime, I bought a second engine for $250 on FB marketplace and threw it in my car so I can at least drive it while the serious engine is being built. This bone stock 180k mi engine handles 5psi like nothing!

 

Ok dude this thing is sick. Nice work.

 

Would you mind taking a photo of the starter configuration? Does it place the starter basically behind the oil pan? Any clearance issues (starter to ground)?

Was it a tight fit running the downpipes back? Or was there plenty of room for that?