So I've begun to research swapping a VQ35DE into my miata.
This is what ive got so far.

parts total without crossmember im looking at $3200-3500 without axles.
thats motor, trans, ecu, dash harness, both clusters, engine harness, trans harness, immobilizer, ignition, chassis computer, chassis harness, diff, driveshaft (will need to be shortened).
ill still need to figure out the other parts to get the speed sensor signal working.
may have to get ABS parts, and have the ECU tuned to the point of matching up to the abs sensors to read my speed signal and output to the dash.
ill need a custom diff mount aside from trans mount and crossmember.
ill also need custom abs axles, and to ensure I dont need to get the abs module and sensors from the 350Z to make this work to have the speed signal or if i can get the ecu reprogrammed to just use something else.

with all abs components, harnesses, motor with all accessories and transmission, and immobilizer/ecu computers, diff and driveshaft im looking at around $3500.
i'd still need a v8 swap crossmember and to modify the mount tabs, diff mount, trans mount, cut and reweld the driveshaft shorter, and get custom axles, and a triple core radiator and CARB EO short ram intake, and vent my hood, and to install everything.
and tie in the exhaust after the cats, and ensure i have all smog components because this is a california car.
then the ref will be a thing to contend with.

Im estimating between $6-10k when im done with this thing.

So.
what did i miss? what did i forget? also, does anyone have any insight on fitment issues with this and such?
anyone who knows dimensions of the motor and headers and transmission and the miatas engine bay and transmission tunnel please throw in your two cents on this.

I know i could probably just get a 350Z or do a v8 swap but thats not the point. i dont like V8s (i respect them theyre just not for me), and i dont like the 350Z car, but i like the 350Z powertrain and drivetrain but i prefer not to use the actual car.
I like my miata. I just want to cram a 350Z power and drive train up its ***.
Anyways, have at it, flame me or whatever, but if you have advice please give it.

 

I think I'm going to try and keep NATS for that ultimate OEM experience and get all the computers and key and immobilizer reprogrammed at a Nissan Dealer to match so I can use them, because from what I can tell, it'll cost about the same to reprogram and buy the equipment needed for that as it will to go without NATS and RF module and 350Z Ignition and Immobilizer and getting the ECU flashed to remove NATS.

 

You forgot to use a measuring tape. That VQ is effing huge. I just pulled one out of a turbo 350z and it is VERY wide. An engine with narrower heads or a smaller overall width would be much better. It is also pretty damn tall from oil pan to intake.

I admire your ambition but packaging might be a serious problem.

Here is what an LSx engine looks like in a Miata for width comparison purposes.









The LSx engines are some of the narrowest 90 degree vee engines made in modern times. They are 26 inches wide and 26 inches tall and 28.75 inches long. The VQ will be 29 inches tall from my research, and somewhat wider lower down than the LSx. You will need room for exhaust manifolds.

 

There are a few threads, I'll try to find and link them, but the engine fits, the people who started have just given up on it after some time.
I'm going to start out with just the bare essentials to get the motor functioning and to get the 350Z clusters to work. Apparently I only need the rear ABS sensors since they are on the inside of the axles on the diff itself, so I will need to make a custom mount for the 350Z diff guaranteed as well as the transmission, I'll also need to modify the PPF to work with this or remove it entirely.

 

I'm going to do a long writeup on the full long term plan for the car, it is not going to be a fast turn and burn project, but rather years in the making. Don't expect much for a long time. This will begin when I have a second car to use as my DD so I can make the Miata into a full project car and completely disassemble it for all of the intensive prep work and paint, resulting in a really clean finished product that also is CA road legal.

 

Good luck. That is quite an undertaking.

 

Updates...updates...updates!

 

I don’t know how to add to the thread but maybe this is it. I I am planning on doing the same swap to my Miata aswell, and I was wondering if you have the blueprints or maybe sizes and such of the motor mounts, transmissions mounts, etc. I have access to people that can build the mounts for me and I have found someone to do the driveshaft aswell in my area but I have nothing to give them for them to get started