Removing miata donor parts 4 of 9 body and PPF SEPERATED!



As I mentioned in my last post I now am turning attention to removal of engine and transmission unit. I have decided to do this by separating the body from the power train chassis unit. To explain if you are not familiar with the design of the Miata. The engine mounts, engine and the entire front suspension are mounted to a front sub frame. This front sub frame is bolted to a PPF (Power Plant Frame) which is basically a stamped C shape channel that connects to the transmission at the front and connects to the rear differential which in turn is bolted to the rear sub frame and the entire rear suspension. The body unit is connected to the front sub frame by 10 bolts and to the rear sub frame by 6 bolts. So the plan is to separate the body unit from this chassis unit and lift the body unit high enough and roll the chassis unit forward and set the body unit down on Jack stands. This will allow me unrestricted access to remove the wire harness from the body unit and easy access to all donor parts of the rolling chassis unit.

As a prerequisite please read Chapter 3 pages 3:1 to 3:11 and especially sections 4:1 to 4:81 in the manual to prepare for this procedure. IMPORTANT if you plan to remove the body as a unit as I did in my build do not proceed farther than step 4:81 in the manual.

It is my opinion I would definitely remove the radiator with fans attached and AC condenser if your car is so equipped. You will find this recommendation in the instructions in the manual, but not until instruction 64, that in retrospect the writer would recommend removal of the radiator and fans. In my case as you already know I had no choice do to crash damage. But having completed this process I certainly recommend to do so and may actually recommend to go ahead and take the ½ hour of time to saw the core support out of the way especially if you plan to scrap the body unit. This allows you much easier access to remove some the engine harness connectors which for me were the most time consuming part of this process.

Essentially just follow the instructions in the manual starting on page 4:1 section 4 Removal of engine (with transmission). I will add my comments to number instructions in the manual.

10) This shift boot gator has a formable base, so I place this part in a new pile of parts that I have designated “maybe” in other words not to discard at this time as they may have a possible use in the kit such as this boot gator, this one seems a bit too heavy in weight for my liking. So I now have 4 designated piles. The Required pile, the e-bay to sell pile, the scrap pile and now the “maybe” pile.

17) & 18) at this stage I did not drain fluids, can if you want as you will want to change later.

38) My car used 14 mm socket not 17 as noted.

43) Believe it or not removing these clips on the oil cooler hose on right side of engine for me was rather difficult and took me too much time, this is why I recommend removal of radiator as this allows you better access. Patience required.

47) Be prepared for this step will save you some time. I did not up until this step remove the fuel system pressure as recommended in manual previously. I would wait until now as you can use the fuel pressure to siphon the tank. Get yourself 5 ft of 5/16” I.D fuel line and have on hand enough gas containers to hold all the fuel you have in the tank. Put you fuel container in position and put one end of drain hose in it. Remove the hose clamps as noted in 47. The hose that connects to the front of the fuel rail is the supply line and will be under slight pressure.  Have small plastic (I used an old cool whip container) bowl to collect any spilled fuel. As soon as you pull the rubber hose off the metal (from tank) supply line quickly slip one end of the 5/16 fuel hose on and you will find pressure and ensuing siphon action will drain your tank! My car had more fuel than I thought and I had to vise grip my drain hose so I could make a run to the local Wal-Mart to buy another 5 gal gas can.

61) I deviated a bit here. Using 10 mm socket I removed the bolts that held a metal angle that secures the radiator inlet metal tube to the left front inner fender. I then removed the hose clamps from the water pump inlet casting. I did this to allow better access to the AC and power steering pumps. My notes were a bit vague here, but around this time I also remove the power steering supply and return piping that looked to be in my way. For a car you plan to put back on the road you would not want to do this. But we have no use for the PS rack lines so off they went and out of the way.

70) Not necessary to remove O2 sensor if using the body as a unit but can if you like.

71) I removed exhaust from down pipe back including the catalytic converter. Save the converter.

74) Not necessary to remove slave from transmission. I simple disconnected the slave’s metal supply line at the chassis attach bracket, leaving the coiled line still attached to the slave. But you can release metal line at slave if you like. I removed the slave cap and put some plastic food wrap over the top of reservoir and replaced cap to prevent spills. This worked for the slave but not for the brake lines.

77) This went easier than I thought. You will need to reach between top of transmission and body to release metal harness clamps. The clamps bend easily. This will allow you to pull the harness toward the passenger side a bit to release the two white connector from the passenger (RT side forUSA) that goes to the neutral switch. I could not get the two black bullet connectors to release. So as the manual suggest I used a 1” open end wrench to unscrew the reverse switch from the transmission. But be careful here. On my car there was some black electrical tape wrapped around the two supply wires about 2 inches from end of switch. You will need to remove this tape, If not the wires will not be able to “twist” when you unscrew the switch and will assuredly break.

79)-81) make sure the supply harness is  free from the PPF and power train.As noted in manual there are severe plastic harness clamps that attach to the vertival face of the PPF from the transmission to the differential.All these plastic clamp need removed. Just leverage them from the PPF. My car had an appox. 1 inch square plastic harness to body support in the location near the right rear wheel area that was removed using a 10 mm socket. This support was not noted in the manual. I also believe I had an additional body ground not noted. So just a heads up as your car may vary so just be careful to make sure the harness is free of the PPF. Remember the harness will stay with the body when it is lifted to separate it from the PPF and sub frames.I used some twine to tie the now loose harness out of harms way.

IMPORTANT!  Stop at step 81 in the manual do not precede with steps 82 to 95 if you intend to remove body as unit as you need to leave the PPF attached to the transmission and sub frames.

AT this point I was no longer following the manual, usually dangerous for me. I looked the over the job, keeping in mind we are going to lift the body off to see what would cause interference to this process.

So I removed all the AC supply and return lines and brackets. I used some twin to tie the main wire harness out of harms way. I removed the speedo cable and put in the donor pile, you will need it if you use the Miata instrument pod.

I released the front and rear brake flex lines at body bracket, because this seemed easier access. I left flex lines attached to calipers, but you could release at calipers.

Next I disconnected the E brake lines from pivot arms. Use 12 mm and 14mm sockets. Loosen cable from bracket, slide cable out of arm and using pliers rotate cable bug 90 degrees and slide out of arm, easy.

At the front I removed the U shaped sway bar brackets from the body.

Sway Bar bracket

You do not need to remove the sway bar from the suspension but you must remove these brackets as these brackets are the only front suspension parts that connect to the body. Note there is a vent hose that connects from the charcoal canister to a static area in the front sub frame on left side of frame, this was not noted in manual. Pull this hose off plastic connector. If this was an airplane this would be a great place for a Pitot tube static port.

Static port vent in from subframe

I finally am satisfied all is clear to lift the body. So now is a good time to decide how I want to lift the body. But first I decided to remove some body parts for the e-bay for sale pile; this also has the benefit of removing some of the weight we need to lift.

So let’s remove the doors. Refer to chapter 11, sec 9 door in the manual. Using a screw driver lever the plastic grommet from the door post and not the door as manual indicated and pull connectors through grommet hole and separate connectors. Use 12 mm socket to remove hinges. If you leave the door shut to support non hinged end, them remove the hinge bolts. Then with on hand supporting the door near post and opening the door with other I was able to remove the door without assistance, but would be easier with a helper. Be careful I almost dropped the first one. But I had a place a cardboard box just in case, I needed it.

Next I removed the trunk lid see chapter 11, sec 6 in the manual. Use a 10 mm socket to remove trunk light harness connector to trunk lid.

Next up tail lights refer to chapter 7, section 30 in manual. 10 mm deep socket required.

Remove the license plate lights and brackets.

Then I removed the rear bumper and fascia and side marker lights as one unit as outlined in chapter 11, section 9.

Well now back to how to lift the body. I have never done this before so I am not sure how much lift I will need, so I guestimate is in order. I decide I will leave the damper struts attached to the lower suspension arms, so I will need to lift the body unit high enough for the rear dampers to clear the under body as I roll the chassis forward. I roughly estimate 24 inches of lift should do it. I have a standard ceiling height. I have at least 32 inches from top of windshield frame to ceiling clearance and the body is currently sitting on 20 inch jack stands. So I should have plenty of room after the car is sitting on its tires, this is good news for any builders working in shops without high ceilings. I have a crane style engine lift and I also own a 1 ton harbor freight chain hoist. My original plan was to use two chain hoist one front and one rear as I would not have to concern myself with balancing the body during the lift, but I decided to be brave and cheap and use the single chain hoist with the $25.00 Harbor freight 2 ton load leveler I bought previously for engine removals. Caution must be used here. Again I am estimating I will be lifting a body unit weight just shy of 1000 pounds or so. So you will need to be use good judgment in how you attach the chain hoist to your ceiling supports. Consult a professional if needed. In my case, my ceiling joist are 16inches on center and 6 inches in depth. I constructed two beams using four 2×4 x 8 ft. I screwed two 2×4 by eights togetherto make each of the support beams. I place each support beam across 6 of my ceiling joist within 2 feet of the bearing wall supports. If my joist were 2 ft on center I would have used 2×6 min material for the support beams. I could have used say a single 2 x 8 x 10 at the center line but I did not want to apply the vertical loads where they would create max bending moment on the ceiling joist, this is why I used the two separate beams located within 2 feet of the end walls. I then nailed together two 2x6x10 to make a crane beam with and additional 2 x 4 x 8 cap plate centered over the 2×6 x 10 beam. The chain hoist will contact the 2 x 4 cap plate  portion of the 2 x 6 x 10 support beam  the 2×4  will act to distribute the point load across the 2×6 beam. See picture of my set up.

Hoist set up

Please excuse this rather long description of the chain hoist support, but proper design consideration is a must otherwise serious injury or damage may result, further as a disclaimer I make no recommendation or fitness or suitability for use or guarantee of safety for anyone who copies my support set up. Please be careful.

I attached the chain hoist to my crane beam with chain with a load rating of 2000 lbs.



But where to attach the load leveler? I made a guess and dropped a plum bob and locate the hoist line 2” to rear of windshield. If you are following along locate the hoist line 7 ½” to rear of windshield, this will get you closer to the balance point. I used the chain supplied with the 1 ton load leveler and attached using the bolts used to locate the center console. I had some concern here the spot welds in this bracket would hold, so as a safety net I attached 1000 lb capacity tie down strap to the front load level chains and to the door hole bolts, I used larger fender style washers to prevent slip off.

Front load attach points

I bought a 5ft length of min 1000 lb working load chain and used it instead of the shorter chain provide with the load lever and attached this chain using the shoulder belt bolts with large washers. You want the chains connected to the load level to be inclined greater than 35 degrees from the horizontal.

use shoulder belt attach points at rear

I am now almost ready to lift the body but I still have to remove the bolts connecting the front and rear suspension frames to the body and the bolts connecting the shock towers to the body.

So using a 14 mm socket loosen but do not completely remove all 4 shock tower mounting nuts,  there are two nuts for each shock . Do not remove the larger central nut covered by a dust cap, or the shock unit will separate under considerable pressure. If I remember you may need to remove the left side trunk trim panel the hides the fuel supply filler tube first to get access to the rear left side shock nuts.

Now time to remove the large diameter bolts that mount the sub frames to the body. You can refer to the manual page 8:12 for illustration. Remember our car is still supported by jack stands located on the body unit and not the power frame unit. So essentially the engine and PPF is hanging from the body unit.

I made a purchase of a ½” Harbor Freight (OK there is one near my location) 700 ft lb torque air Impact gun (called the Earth quake, about $100.00 to assist in removing the body frame bolts. Use 6 point impact sockets. I should mention using the recommended 90 PSI pressure this tool worked great and made  easy work of removing the body bolts.

At the front each end brake loose only but do not remove the 2 bolts using 19mm impact socket located near each front shock tower. Then break loose but do not remove 1 bolt using 17 mm Impact and 2 bolts using 14 mm impact socket at each front corner of the front sub frame. In total there are 10 bolts that hold the front sub suspension frame to the body. WARNING. Do not remove bolts, only break loose. Remember our engine and PPF is hanging from the body unit. If you remove these bolts at this time the engine and front subframe will fall on you and you will die! After front bolts are broke loose I turn my attention to the rear suspension frame.  Refer to the manual page 8:25 for an illustration .You can review in the manual chapter 5 rear subframe removal on page 5:15. Most of these steps we have already completed. Do NOT remove any bolts that connect to the PPF Unit! Using the impact or suitable breaker bar and 6 point 19 mm impact socket brake loose only( remember, the remove and you will die part) the 3 bolts each side  that are located in the area of the shock towers. They are easy to find.

At this time before I change our support base I thought a good time to take some engine to firewall clearance measurements. The cam position sensor is close to the firewall. Actually the Mazda firewall is recessed in the center to allow clearance. The distance from sensor to recessed fire wall is 1 -1/2 inch. Likewise the distance from the coil back to firewall recess is 1 -1/2 inch. The area of closest interference is the EGR pipe, which is only ½” at closest location to fire wall. The firewall offset by the way is 1 ½ inch.

I also wanted to measure the angles of the motor, transmission, driveshaft and rear differential. I was going to reference this angle to the door sills. But using my digital level the door sills were actually 0.00 absolute level, could not do that if I tried too.

Rocker absolute level, Pure luck!

The level positioned on the valve cover is 2.10 degrees sloping to rear, hi in front.

I recorded a 2.10 at the engine oil pan. I measured the bottom of the transmission at where it connects to the PPF also at 2.10. The driveshaft at 2.80 and the rear diff at the flange that connects to the PPF at 1.95.

Diferential mounting angle

I wanted to make this info for record to use as reference for fitment of power train into the VortX for comparison to the factory driveshaft angles.

Now we need to move our support base. Install all for wheels and tire and snug wheel lugs, no need to torque. At this time I jacked up one end of the car at a time, removed the 6 ton support stands and replaced them with car ramps. I position the front ramps facing forward (like you would drive off) and at rear the ramps as you drive on them. Now all 4 wheels and most importantly the engine and subframes are support by the tires on the ramps. We do not have brakes, so make certain the car can not roll front or rear. Nice thing about ramps position as I have they prevent this movement.

I have a concern about what is going to happen when the shock towers are unbolted and when the body is lifted I believe the suspension will collapse onto itself and the chassis will possible drag on the ground. Certainly making it difficult to roll the chassis out from under the body after is lift. So to prevent this possibility I went to the lumber store and bought a 2 x 3x 8 utility stud. I then cut (4) 7-3/4” pieces or wood support struts from this stud. At rear I placed one end of 7-3/4” piece near outer lower wishbone. I used duct tape to position this material so the top end will contact the upper part of the subframe upon collapse. I repeat at other rear side. See pic.

Positioning rear wood support strut

At the front I place one end of wood strut up against sway bar mount on lower wishbone and again using duct tape positioned the wood so the upper end will contact the front subframe. See pic.

I am going to give some instruction slightly different to what I did. For reference at this time I completely removed all 8 shock tower bolts. I am going to suggest now to leave the front tower nuts several turns on. Now that the car is on safely on the ramps you can go ahead and remove completely remove the subframe to body bolts. Note at the front when the last bolt is removed the body made a rather startling pop and jumped up. This certainly got my attention and I did not expect. But what happens is the front spring preload is such that as the last nut is removed the spring quite abruptly forces the body away from the subframe. So this is my suggestion as to leave the upper tower nuts a few turns on as this should limit this explosive action. But no harm was done, and when removing the other side bolts I was expecting this to happen it was not a big deal. But it does shake the body a bit and you want the car securely supported and make sure it can not roll. I actually do not know what would happen if after all front body bolts are removed and then you follow my suggestion and remove the front shock tower bolts from above since I did not do this. Some of the preload will have already been released. But I would use caution removing these bolts if you try this method.

At the rear use 19 mm socket to  remove the rear subframe to body  bolts. Thespring  preload at the rear is not an issue to be concserned with. Now we are almost ready to remove the body. We just now have to get the tires back on the ground. Carefully jack the car up, place the jack on the center of front subframes, lift and remove ramps and lower to tire. At rear I placed jack using a wood spacer on the rear part of the PPF near the diff to lift car, remove ramps and lower to tires.

use level to verify balance point

load leveler in position

It is now the moment of truth and time to lift the body off the frame.  I position a level on the transmission tunnel of the body to assist in maintaining a level lift. See pic. One more quick look around to make sure the harness, brake clutch lines,  are all disconnected and free  from PPF, engine and any part of the dive unit. I recommend an assistant for this part, this was the first time I used an assistant. For me I asked my neighbor Drew who is retired and a car enthusiast and currently restoring a “doodle bug”. I had Drew assist by operating the chain hoist while I would observe the lift making sure all is clear and the body lifts free, at the engine compartment you want to make sure the body clears the cam sensor. On my car the throttle position sensor and the throttle body linkage required some tending to. We lifted the body in 3 inch increments, and then I would do an all clear check, repeated this several times. I did have to adjust the load leveler; I would not attempt a single point lift without using a load leveler. After we found the balance sweet spot we hoisted the body until the door sills were 34 inches above the ground this allowed at least an inch clearance.

You notice I also have some rope attached to the front and rear of the body. I tied these ropes off as a safety precaution to prevent to body from tilting. I simply pulled in the front sway bar and easily moved the chassis forward and clear of body. I position by jack stands in position at the same 20 inch height as before and lowered the body till lift cables are slack.Mission completed. It is nice when a plan works according to plan.

At the end of my last post I asked the question if this method of power train removal would either be a good one or a dumb one.

Having completed this, It was a GOOD idea. I would certainly do this again. I do not think it takes any more time this way. There were several steps in chapter 4 from 82 to 95 you do not have to do. It only takes about a ½ hour or so to loosen the body bolts. Now I am in a position where I have unrestricted access to remove the rest of the harness from the body unit and the same goes for the separated power frame unit. I should also make say I had a good donor car to work with. It has very little rust and came apart easily. As a help hint I typically would spray the next days bolts to remove at the end of the day. This may have help make this car disassemble easily. From start to this divorce of body and power unit I have about 27 hours invested so far. I am not counting my time to take e-bay pictures, or time to build the crane support and certainly the time to write this blog.

Easy access to donor parts

I will make one final comment. I forgot to measure the height of the Miata door sill before the lift; I would guess this around 10 inches. So if you have a simple engine crane with a 1000 pound lift capacity and have a lift range a little over 24 inches this should work fine. If the crane could be positioned so the legs could be roll from the rear between the Miata’s rear tires, this would be the easiest way to go, especially if you only plan on doing this procedure once.

Next is to finish removal the main wire harness from the body unit. I should be making post more often.

Removing miata donor parts 3 of 9, Sawed out the core support

I decided now is a good time to shift focus to the exterior. What I want to do is salvage the wiring harness from the crash damaged area. The portion of the wiring harness that feeds the front combination lights (turn signal & running lights), headlights, side marker lights, horn, headlamp motors, air bag module and cooling fans are rather engulfed in mangled metal on the passenger side. A big hammer and pry bars were the tools of choice and after about 3 hours time I was able to extract the harness from this crushed area.  I was lucky and did not have to cut any of the harness and except for some minor chaffing to harness near the right side marker I was able to save the harness and keep it intact and undamaged. Next step and prerequisite to engine and transmission removal is to remove the radiator and AC condenser core. For this step please consult your Miata enthusiast work shop manual. But in my case standard procedure will not work per the book as the radiator and condenser as well as the core support are rather a single unit, pushed into each other due to the accident damage.  One reason I needed to remove the harness first was I realized that I would need to saw out the core support as this would be the only way I will be able to remove the radiator and I wanted the harness out of the way of my planned saw cuts. I used an inexpensive $35.00 Harbor freight electric Body shop saw to cut through the core support. Notice I marked out in black marker(see pic)

Core support marked for surgery

my planned cuts to remove the core support. I used about 5 blades to complete the job and feel I rather abused the tool but it got the job done and worked great. And now I have easy access to the radiator removal and an idea.

cut out support allows easy access to remove rad and AC condensor

Now would be a good time for some commentary regarding crash damage and donor car selection. One should consider the where and extends of damage and how this may add time or complicate the disassembly. In my case the crash damage added approximately 5 additional hours, but  from this point on I will no longer need any additional time dealing with twisted metal. My salvage donor car was advertised by Co-Part as start and drives. Which means it starts with the key and will engage gear and move. The car was able to drive itself onto the trailer and that is about it. I am suggesting more caution should be used to purchase cars with front end collision damage, after all,the engine is the most expensive and valuable component we will be purchasing. My donor car seems to be in good condition prior to the accident and so far so good but do feel a bit lucky the engine was not damaged in the crash.

Now what’s next.  I will be reading chapter 3 on the how to remove engine and transmission as a unit in the Miata MX-5 enthusiast manual, which for now on  I will just say “the manual” when referring to this book, but I am currently not planning to follow the manual to the letter but will use as a guide as to what needs to be disconnected. I am considering leaving the engine and transmission bolted to the Power Plant Frame(PPF), and unbolt the front and rear sub-frames from the body and then lift the body off the car and then roll the engine still attached to front sub frame suspension unit with  transmission and rear sub frame differential suspension unit. In other words a Miata body less roller. Others have done this before. The manual discusses this option but decided they could not see any benefit as compared to the procedure they outline in the manual, but the manual is not considering additional harvest of parts, or starting with a salvaged car and the eventual scrapping of the body. But by doing so I will have even easier access to remove the harness from the body shell and complete unobstructed access to the brakes and power train components we need. I had ruled this out as my shop ceiling is standard height and did not want to find out I could not lift the car high enough to clear the engine and transmission. But what has now inspired me to give this method a try is by sawing out the core support for removal of the radiator I can now see how I no longer have to lift the car body over the core support but actually can roll the “engine chassis unit ” through where the support was.See first pic. That and this car is a rather rust free example and I am counting on the sub frame bolts to cooperate. If not I can always follow the manual and remove the engine and transmission in the standard format. Stay tuned to see if this is good idea or a dumb one.


Removing miata donor parts 2 of 9 Stripping the firewall

Seperate core from mixing unit


Continuing where we left off. The plan is to strip the fire wall to gain full access to the wiring harness in front of the firewall. To do so we need to remove the heater control mixing box that contains the heater core, the AC condensing unit and then the blower fan box. We start with by unclamping the heater core vent clamps, then using a 10 mm socket remove 2 upper nuts and 1 bottom. Pull the box forward. You will need to angle to allow access to remove the plastic side cover located by the core’s supply and return lines, remove the 2 Phillips screws and pull off cover. Now angle, see pic above, the core housing and pull and wiggle to facilitate separation from the core element and put mixing box in the discard pile. Next up we remove the condenser unit. Open hood and at rear firewall we need to disconnect the AC supply and return lines from unit. I should note if your system is charged to appropriately remove the refrigerant. I disconnect the  top line first using a 17mm wrench on the inner but and ¾ on outer and moved out of the way to get access at lower line and using 1” inner and 1 1/8” wrench for outer this line was quickly disconnect. Now from inside the car use 10 mm socket remove condenser housing retaining nuts .Unsnap and remove duct clamp. Pull housing forward and remove the condensation drain hose,

remove moving the condensor unit

Disconnecting refrigerant lines at firewall

see pic, remove unit from car and put in the pile. Finally we remove the blower fan.  Use a 10 mm socket remove 1 upper top bolt and 1 nut located lower right and another nut located lower rear left

removing 10 mm nuts and connectors

. Make sure wiring harness is unplugged (and tagged for future reference) and pull forward and put in the pile. Now we have excellent accessibility to the wiring harness at the fire wall. It is obvious it continues under the carpeting. So I will now remove the carpeting. First I removed the lower drivers and passenger foot well plastic scuff panel by just prying off. Then I removed the plastic and metal door sills, 4 screws each.

remove foot well trim

removing seat should bolts for

I then removed the seat lap belt retainer harness using 17 mm socket for passenger side and oddly enough a 16 mm for the drivers side. Remove the shoulder belt retaining bolts next.

use 10 mm socket to remove clutch rest

Now using a 10 mm socket remove the 2 bolts that secure the clutch rest. Now we are all clear to remove the carpeting. The carpeting is typically held in position by ½”dia. plastic headed one way push on speed nuts. If you want to save the carpet you should remove these by prying off under the head of fastener, see pic,

the correct way to remove trim clips

otherwise you will tear carpeting, I do not plan to reuse the carpeting and must admit to pulling and yanking as my primary method of removal. Start by removing the carpeting by the rear window that covers the fuel tank.

removing carpet over fuel tank

Then I remove the carpeting that is behind the seats. Then after making sure all wires are fed thru the floor carpeting you can simply grab it from the rear and pull back and up and lift to  remove and put in the pile. As you have already observed you have exposed the location of the Power Control Module that hides behind the passenger seat carpeting and  it’s  associative harness. see pic.

PCM and harness along right side

Now this PCM and harness is a keeper we will need for the VortX. So this segment went very quickly taking only about 2 hours to remove all the parts that are in this pile, see pic,

pile of parts for discard or e-bay

none of which are needed for the VortX but many can be listed on e-bay.And a pic of our naked and exposed wireharness at firewall.

stripped firewall and exposed harness

What’s next? Note sure. Need to study a bit. What I absolutely recommend and I consider mandatory is purchasing the  Enthusiast’s Workshop manual for the Mazda MX-5 Miata 1.8L There is also an addition for the 1.6L. I purchased mine at Amazon. The author is Rod Grainger and Pete Shoemark published by Veloce Publishing. For the 1.8L the ISBN # is 978-1-845840-90-7   The UPC# is  6-36847-04090-1.  I will later get the numbers for the 1.6L manual. I will post this info on Reference page when I get a chance. That went pretty easy, So far I have a total of 9 hours in donor.


Removing miata donor parts 1 of 9 or where do I start?

We start by removing the dashboard




Getting started . My first thought is where do I start?

Most build blogs I reviewed do not chronicle the disassembly process in much detail, and why should they as this part of the build is not much fun and is a matter of necessity. But on these pages I hope to post for record the disassembly process I used. I am sure  at the end of this parts harvest I will be more qualified to make recommendation of what or how I would do differently.

At this stage of the build I am still planning of using the factory wiring harness and have decided to start this build by removal of the dash and necessary interior assemblies to allow full access for easier  removal of the harness.

I started by removing the interior dash panel. Refer to this dash removal file.DashRmv_89_93 This is an excellent tutorial with quality photos prepared by Anthony Meeks for Miata owners for a step by step “how to” for dashboard  removal for 1990 to 1993 Miata. My donor Miata is a 1994. I found the procedure to be very similar. On the 1994 there no need to remove the air vent closest to the side widows. There are less screws to remove at glove box. The wiring harness connection will vary somewhat too. But in general just follow the instruction and you will succeed.

The instruction indicate to be very careful when removing the instrument panel cover. This is an understatement. I did break a clip or two during the “wiggling” back and forth process and I did not think I was using much force. The good news is I believe if you plan on using the donor instrument cluster you may need to “trim” the cover to suit the vortX dash shape and the clips are in the area that will need to be trimmed. But at this point of the build I am not sure and recommend extra caution  during this step. Also some notes when you come across the orange/blue connectors, these connector were a bit challenging to get apart.

Blue and orange connectors

you will need to remove the orange one first then the blue one see pic, To do this you need to press hard on the orange clip release  while at same time pulling back. I found where room permits to use a very small screw drive and using like a tongue depressor press down on the flat tap and pull. The blue will release easily after orange is out of the way.

lower column protective boot

Removal of the top half of the lower steering column U joint protective cover see pic is not covered in the dash removal instruction but is easy enough. You will need a 10 mm socket to remove 3 nuts that hold the column in place. You may need to cut or depress some of the firewall sound deadening insulation to get the socket on , but the good news in comes free after the 3 nuts are removed. I retained this part as it may be useful to serve it’s protection duty in the VortX.

Also I labeled all my connectors as I took them apart.. The system I used was to use self stick labels I bought at Wal-mart. They are about 1/2” by 2”. I would wrap an identification letter/numbered tag around the wires of the male connector and an exact same number tag around the female side of the connector. I also used a permanent marker and noted same numbers directly to the connecter halves. I also used a note book and kept record of every Letter/number of every connector I pulled apart. I would also make a note as to the location of the connecter and if I could determine what the connector is used for in a note book. An example of a note would be D19= steering column, igniton switch gear.

The D would symbolize the general area is the dash, steering column give more precise location and ignition switch gear indicates where the connecter was used.

Often I did not have the third level of location. As D18= Dash, near column, main harness connector. This would mean general area of Dash and was a harness connector. It did not terminate at a device but was junction connection.

You can devise any system you want to use. But I think it to be a good idea to use a system that defines the area. For me D= Dash area, E= engine compartment, T= Trunk, PC= power control module, etc This way when harness is removed you can lay it out with reference to the to the general components of the car.

parts removed time 7 hours


Anyway after following all the steps in the dash removal instructions and 7 hours of time  I had the pile of parts removed in this photo.

But we only need the parts in this photo which include the

lower steering column UJ split plastic protection cover.

Steering column with all factory switch gear.

Split plastic switch gear cover and screws. Includes removable 2”x 4” cover.

Solid state instrument panel.

Instrument panel cover

Steering wheel

Gear shift knob.

All hardware for above.

Not pictured but retained for possible use.

Gear shift lever leather boot.

Hazard/pop up light switch.

Center console light.


This ended day one work.  Allow about 7 hours but if you work without interruption you will probably use less time.


What is next?

Here is the picture of inside of car after removal of dash. Here you can see the maze of wires and I must admit this can seem a little intimidating as this stage.

Dash removed and wire and more wires,

For lack of a plan I removed the seats. This was easy enough. Only 4 bolts per seat. My passenger seat required and extra bolt to remove for the shoulder harness. I believe I used a 24 mm socket. I now find the room to work has improved and since we are not going to reassemble our car, I would recommend making this the first step before dash removal as it will make working under the dash more comfortable and takes only 10 minutes.

Next up. As you can see in above picture the  the main wiring harness disappears  behind the heater core housing and blower fan housing. So these are my next targets for removal.



The donor car , and post #1.


transplanted parts will see better days in the VortX.


Pictured is the  1994 First Generation Miata ,Fastcraft motorsport is using for this Build. This car was purchased for a winning bid of $900.00 from the Copart on line auction service. Has 109,269 miles on the clock. The car starts and can be driven slowly. The model year of 1994 was my preferred year. This year and most all 1995 are ideally suited for turbocharging as the compression is lower at 8.8 :1  for these years and the block has blocked off NTP supply and return ports to feed the Turbo charger bearings. Also this year the transmission is more robust and 1994 was the first year I believe to use the larger 7″ ring and pinion. I still have not determined if  this donor has the rather rare Limited slip. Would be a great bonus to find out it is a Torsen LSD but I am not counting on it.Also 1994 and 1995 cars are the last two years before the engine management system has to be ODB 2 compliant. The engine starts easily and sounds good, very little blow by and oil looks good. You always are taking a chance when you buy with out seeing and inspecting in person but I  am pleased with this donor purchase and my winning bid was the max I had set for donor purchase. I wanted to buy the car this way for the experience of using this on line auction. As these salvage cars from Copart are often available for less than $1000.00 they may be a good donor source for our  builders, and at this price for a donor with serviceable engine and drivetrain we are on target to build the affordable performance car for around $15,000.00 target budget for a no frills build..