Subaru Powered Datsun 240Z

This is a reboot of a build thread that I started a year ago where I had planned to swap the sub-frame of a Miata into my Z.. I bought a Miata, my first, drove it around for a year and then sold it. Needless to say that build never even got started. I do still think its a good idea though.

Then earlier on this year, I picked up a wrecked WRX with the intention of using it to swap the turbo engine into my daily driver, a Subaru Legacy GT Wagon. However, while stripping the engine and wire harness from the WRX I started having thoughts of using the WRX sub-frame in the Z.

The idea of the WRX as a drive train platform in a Z car is as crazy as it sound. Yeah That alien guy might think it would be possible...

The main problem is the width of the engine. I will not fit in the Z at all without cutting. Since I dont want to cut the Z body without knowing for sure, my plan is to cut up weld back the WRX until I have a suitable rolling platform to fit under the Z.

I need to shorten the wheel base and move the engine back quite a bit. The WRX chassis will be converted to RWD and have a front-mid engine layout.

Getting it gutted!

The engine ran good. no bad noises and the turbo was still making boost but dang! that is one dirty boxer.

I removed 100% of the wire harness without braking or cutting a single wire! I'm so proud of myself!

Well guys and gals, the game is a foot! I will be going nuts with the SawzAll this weekend and be posting more Suabru WRX destruction!

I for one fully support this venture, WRX swap all the things!

Did you use a ruler before you grabbed the sawzall?

IIRC, that boxer is 33" wide (not counting space each side to remove the plugs). I'm afraid the first thing you might need to chop out is both frame rails, followed by both A-arms.

Yes. Lots of measuring. The Z frame rails will have to go for sure.

Ok...watching.

I'm in. I may not have much to contribute to the technical knowledge here, but I'll be following along to see how this one turns out.

Oh yeah. Here is the Z. This photo is ten years old. I should probably take a more current picture.

I love my wrx and love my Datsun but never thought to combine them

Im curious. Not a fan of the boxer motor but Im a fan of crazy fab work.

Have you figured out where you are cutting a piece of the Subaru out so that you can match the wheelbases?

When you say "Convert to RWD", I thought the WRX already had a rear differential? Other than not installing the front driveshafts what will this entail?

Moving the engine back is also going to be interesting to watch. The boxer pretty much straddles the front crossmember and will need to go back a long ways in order to find a new home behind the crossmember and steering gear. This will also get rid of any existing routing for the very convoluted boxer exhaust system.

Struggling to see where the set-back engine is going to find a new home in here.

I will admit that a part of me is struggling with this new direction because my FRS has a boxer engine and after 5 years of driving it I still think it is a ridiculous engine design; nice chassis, weird ass engine.

NOHOME wrote: Moving the engine back is also going to be interesting to watch. The boxer pretty much straddles the front crossmember and will need to go back a long ways in order to find a new home behind the crossmember and steering gear. This will also get rid of any existing routing for the very convoluted boxer exhaust system.

Yeah, in a Subie, the boxer actually sits ENTIRELY in front of the axle centerline. The bellhousing matchline is about 3" in front of the axle centerline.

So, the setback is 2 full engine lengths to be mid-engine.

While you are probably right that the exhaust will be routed through the radio, on the plus side there will be plenty of space up front for a pair of basketball sized twin turbos!

NOHOME wrote: When you say "Convert to RWD", I thought the WRX already had a rear differential? Other than not installing the front driveshafts what will this entail?

you also have to weld/lock the center diff so that you get full power to the rear

While I'm a fan of silly projects that most people would tell you not to try... This one seems like a waste of a perfectly good datsun... I mean, I helped bring a non running challenge car to the challenge that was loaded on the trailer by hand, (we literally picked it up and put it on the trailer, not rolled it on) so I can't say anything.

Watching closely to see how this one goes. And in all honesty wish you the best of luck with this. It will be epic if you pull it off.

It will be epic if you pull it off.

This ^^^

Some diagrams to consider while thinking about that engine setback:

In reply to badfrogg:

If you'd like to consider a project redirect, I'll trade you a Justy for your 240.

I'm kidding- the Subaru R5 takeoff was what I was going to do years ago when I came across a WRX rollover.

Carry on!

I've done the trans conversion before. It is not hard. See the Wreck Racing Subie-powered Insight. I think it's the only part of that car that hasn't broken yet

The process is the same for FWD or RWD. Just cut and weld the center diff and throw it back in, remove the axles you don't want to power.

Write-up with pics

In reply to maschinenbau:

ok... What about the rest of that job... The plate to close up the back of the trans, and the bearing plate/holder thing to keep everything lined up. Or at least that's my understanding on the process.

Whoa now. Slow it down a bit

Yes the center diff is to be locked. Either weld or buy the delete thingy. Then I will remove the front diff and ring. The engine will go way back in the WRX chassis. The WRX fire wall will be completely removed. The intake and exhaust manifold will be reversed. They just bolt on backwards. Will take advantage of all the room left up front.

Yes a lot of fab work, but... the WRX was a wreck and the Z has a half rotted floor so its going to be OK

Spinout007 wrote: In reply to maschinenbau: ok... What about the rest of that job... The plate to close up the back of the trans, and the bearing plate/holder thing to keep everything lined up. Or at least that's my understanding on the process.

Once the center is locked, both the front output and rear output turn together. I will delete the front and just use the rear output only. I will just plug the holes where the front axles were so the gear oil doesn't fall out.

Oh an I will be cutting the floor just in front of the rear sub-frame to shorten the wheel base of the WRX.

I like your idea of getting the WRX into a roller with he engine setback done before you drop the bottom out of the Z.

Another measurement worth taking and comparing is the distance from the center of the two seats. You might find that the WRX seats, when bolted in the stock position, put you behind the Datsun's A pillar. It is not always trivial to move the seats inboard from there.

Yep that's pretty much it. For FWD you replace the tailshaft with a flat plate of the same bolt pattern, and remove the rear output shaft. The rear output shaft of the trans is parallel to and meshes with the center diff shaft. So for FWD you just remove the rear output shaft. The center diff shaft keeps its bearing, no modification necessary.

For RWD, it's even easier like badfrogg said. You just pull out the front axles and plug the holes.

NOHOME wrote: I like your idea of getting the WRX into a roller with he engine setback done before you drop the bottom out of the Z.

Yes. Me too. It is a way for me to get to a solid proof of concept before I touch the Z.

NOHOME wrote: Another measurement worth taking and comparing is the distance from the center of the two seats. You might find that the WRX seats, when bolted in the stock position, put you behind the Datsun's A pillar. It is not always trivial to move the seats inboard from there.

With the amout of setback for the engine, I will be practically sitting in the back seat position relative to the WRX chassis. Yes, seat fixtures will be custom. I will have to get racing seats most likely as OEM WRX seats are too tall for the Z. Plus the interior of the WRX smells like a Hobo Brothel. So that will be CL'ed to some poor soul. I will be honest in the ad though. "WRX seats for sale. Was 10 owner car and recently a homeless shelter!"

In reply to maschinenbau:

One complication to each:

For FWD, you do actually need something to hold the center diff in. We found this out when we were driving the car, then suddenly none of the gears did anything. Pulled the cover off, and the diff had fallen out. There's now a big aluminum stick that just rides on the tail plate (not suitable for the longevity you expect from a street car, but fine for a challenge car).

For RWD, you still have to do something about the center diff, because it'll just spin and incinerate the viscous LSD if you don't lock it.

I have a 240Z and I've put STI motors where they don't belong before but combining the two is not something I think I'd be willing to attempt in the way of hackery that would need to happen to the Z for everything to fit. Not because I'm a purist but because it would be so much work. Honestly, an STI swap in the rear of a 308 with a locking collar and blockoff plate fit pretty easily.

Good luck though. With the strut towers and frame rail modifications, just make sure it's safe.