Keisler was nice enough to extend the alternator plug so I should have no problem moving it over to the passenger side. Engine harness gets here today, so it will be going on this weekend. The rest of the exhaust gets here next week.

Made progress on the Driver side downpipe and the passenger side is already mocked up and needs to be welded. Not thrilled with my stainless welds, but they are good enough. The Keisler downpipes are a work of art. Shame I had to cut them, but they were made for the RX8 and I wanted the 2.5" opening. Very happy with the trans mount I made. There were no off the shelf options since I'm using an MV7 trans and the exocet tunnel made it a bit challenging. Sent the trans mount out today for powdercoat. Just need to weld up the upper and lower coolant pipes and get the chassis wiring done and the car should be ready to run. I had my miata driveshaft cut and modified to adapt to the MV7. Ended up being only $350 so pretty happy with that versus a $1,000 new custom driveshaft.

https://cimg6.ibsrv.net/gimg/www.mia...24310e2338.jpg
https://cimg4.ibsrv.net/gimg/www.mia...5776125c7d.jpg

https://cimg7.ibsrv.net/gimg/www.mia...f1d9fa54b0.jpg
https://cimg8.ibsrv.net/gimg/www.mia...f237855d8c.jpg

Thanks! This is coming along nicely. It's been a shit ton of work, but that has actually made it a lot cooler since I'm fabricating a lot of parts.

Current to do list. Knocked a ton off of this recently and should be able to finish in the next 30 days hopefully!

To Do:
Weld Driver Side Exhaust Downpipe
Weld Exhaust Back Half
Mount Exhaust
Engine Wiring Harness
Chassis Wiring and Fuse Box
Clean Brake Rotors
Fabricate Clutch Mounting Plate
Change Spark Plugs
Transmission Fuild Fill
Weld Upper and Lower Coolant Pipes
Powdercoat Transmssion Mount
Install 6-Point Harnesses
Mount Coolant Overflow Can
Install MAF and Intake
Install Radiator
Fabricate Upper Bracket for Alternator
Order Front Driveshaft Bolts
Mount Drivehsaft
Get Shifter from V8R
Get Engine Cover from V8R

Making good progress this weekend. Engine harness is on, both downpipes are welded and on, alternator relocated with upper bracket, drive belt on, fresh oil in the motor, intake installed and driveshaft installed. I still need to finish the wiring and fabricate the upper and lower coolant pipes and then I think it is ready to test start. Pretty damn close!

https://cimg1.ibsrv.net/gimg/www.mia...f7978793d2.jpg
https://cimg2.ibsrv.net/gimg/www.mia...e972e09ad8.jpg
https://cimg3.ibsrv.net/gimg/www.mia...c8c2ed870a.jpg
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https://cimg5.ibsrv.net/gimg/www.mia...b1c9b295cf.jpg
https://cimg6.ibsrv.net/gimg/www.mia...a7e0c96804.jpg

Looking for some feedback on my proposed coolant routing. I've talked with a few people now and I believe this is correct, but just want to be sure. The Radium expansion tank will have a 22psi cap.

https://cimg7.ibsrv.net/gimg/www.mia...a2d426a830.jpg

Dark purple is the steam vent? Not sure what the mustard line is for.

Edit: Also, you'll need to cap off the miata radiator cap.

Sorry for the rainbow version. Just trying to differentiate all the lines. Radiator cap is removed and welded shut with a 6AN bung where the cap used to be for air to get out of the radiator (mustard line). And Dark Purple is the steam vent.

Don't think the line is required since expansion tanks are more or less self bleeding / the steam port does the exact same function since it's most likely higher than the cap.

I was looking through Ryan's build thread and he had added the bleed to the radiator so I figured it was necessary. Any idea why he would have it on there?

Edit: After looking at it again I think he has it because the coolant hoses sit lower than the top and wouldn't be removing air from the top of the radiator.

https://cimg5.ibsrv.net/gimg/www.mia...281fe87735.jpg

My guess is because he has that substantial rake and the upper hose position is much lower than it would be normally it'd be a bitch to purge naturally.

Awesome, thanks Brother! You just saved me some time and work.

How does the purple line attach to the green line? The green line is the metal tube that comes out on top of the alternator correct? (I believe gooflophaze found a different one that gives more room and exits below) Are you adding a fitting to the tube to connect purple line or does it attach some other way?

Also, is a recovery tank needed? or are you using that as an extra precaution since track car? I thought (probably wrongly) that the expansion tank also filled the role as the recovery tank.

And thanks for diagraming this out. That has already helped me with thinking about all of this / understanding it.

Less joints - less potential for leaks. :)

If I had to do ours over again, I'd just lop off and weld the rad cap neck closed (we didn't have the ability to weld aluminum during the build) - and we'd start with an aluminum expansion tank instead of the Cadillac plastic tank I documented but have since upgraded. Every time I've opened the cap since, our coolant is at the very top of the radiator.

If you have the expansion tank overfilled, it'll purge - generally just the first time it's filled. If you have a loss of pressure, the coolant will boil and that's what the overflow catches - instead of laying coolant down on the track. We just ran a hose down to the subframe to purge it out of the engine bay (since it's right next to the fuseboxes). And I think tech inspectors want to see an catch for the track..

Purple and green don't mix - purple and red exit from the same point though - mixing manifold on the front of the engine.

The radium tank I'm using is pretty bad ass but not cheap. Looks like an excellent solution for this swap paired with the recovery tank I'm getting off of summit.

Coolant Expansion Tank, Universal

https://www.summitracing.com/parts/BSP-BLK77109

That's a real nice looking piece, but I'm a little leery of the "vortex" claims. Optimally the expansion tank shouldn't see any "flow", just expansion and somewhere for the steam to condense edit: (at least in the LFX application. In my LS3 I've a repurposed FM Moreoso overflow tank I've welded bungs in that see heater core flow).

OK, we are on the same page with the expansion tank. Thanks for the explanation! I was going to just run the purge hose, but I need to put in a recovery tank too, since building for track. That's a smart move.

I still don't get the Light Purple & Green lines. They look like they are being "T" off from each other in the diagram. How are you attaching the Light Purple line from the expansion tank to the Green line (which is the black metal tube that runs from the back of the block to the front if I'm understanding this correctly.) <-- If this is starting to become a thread jack because of my ignorance, let me know and we can start a new one / discuss when I finally get to this point.

@LukeG -- I like the looks of both of those tanks...They will look great in your car.

Here is a revised version with some more notes added.


https://cimg1.ibsrv.net/gimg/www.mia...49b74203c6.jpg

Light purple is the "expansion" line, shouldn't see any flow. How I did it on ours: https://www.miataturbo.net/build-thr...3/#post1308784

All good. Sorry for the chaos on the diagram, but if the lines are a different color they do not touch or connect in any way, unless there is a black connection block on the image.

The light purple line will go to an 8AN steel bung that will be welded on the LFX steel coolant pipe that comes out of the back of the engine. Check the Portabull build thread (link below) for pics showing this. Got the idea from him.

https://www.miataturbo.net/build-thr...x-build-87186/

Got it! Thanks for the info. And I just re-read the Portabull build thread. I now see what gooflophaze did / what you are going to do.

Thanks again for the diagram! & thank you both for the write up. It's a huge help!

All good! Keep in mind the expansion tank must be the the highest point in the system for this to work properly.

Because of where I'm putting the intake I have to extend my MAF sensor wires about 6". I looked at the wires before cutting and they all seemed like standard different color wires. Fast forward 30 minutes later when I go to solder them all back together and there are two wires that are exactly the same damn color. Doh! Pin 1 and pin 8 wires on the MAF sensor are a solid light blue with no markings, and they are EXACTLY the same color. Which seems odd because they are two completely different functions. Pin 1 is the IAT sensor signal and pin 8 is the humidity sensor signal. I tried the multimeter on the two ends of the wires that go back into the harness looking for anything that would differentiate them, and nothing to note (harness doesn't have power yet).

Any ideas on how to figure out which wire goes where? I'm not at the point of starting the engine yet, so it may have to wait until then.

https://cimg4.ibsrv.net/gimg/www.mia...608d30c00b.jpg
https://cimg5.ibsrv.net/gimg/www.mia...da38927f4a.jpg

Gotchu.

Pin 1 - L-BU - X2 pin 49
Pin 2 - GG/WH - X1 pin 5
Pin 3 - TN - X2 69
Pin 4 - YE/WH - X1 pin 4
Pin 5 - PK/BK - +12v
Pin 6 - YE - X2 pin 52
Pin 7 - BK/WH - ground
Pin 8 - L-BU - X2 pin 15

So.. it's pin 1 and 8 you'll need to tone out to the X2 (which iirc is the gray connector - I doublechecked it's the black) on the ECM to either pin 49 or 15.

You are the man!!! Thank you so much, I seriously owe you big time for this!

Just to confirm, is this the same orientation for pin 1 and 8 you are seeing?

https://cimg5.ibsrv.net/gimg/www.mia...1af08bf927.gif

I pulled the info from this which doesn't have pin orientation - but you should be able to match the colors from the plug to figure the order (a lot of GM plugs have a orientation mark embedded in them). Black/White is 7, Gray/White is 2.

https://cimg2.ibsrv.net/gimg/www.mia...871936513c.png

Got the transmission mount back from powder coating. Last thing I needed before I can finish the exhaust.

https://cimg8.ibsrv.net/gimg/www.mia...b9d5b95185.jpg

Tunnel removed and trans mount installed. Added rivet nuts for the tunnel bolts and got the new harnesses bolted into the car. Working on the coolant pipes now and almost done. The new shifter from V8R (redesigned) should be here soon.

All that is left:
Mount expansion tank/recovery tank and run coolant hoses
Install V8R shifter
Mount and weld back half of the exhaust
Chassis wiring (the big one)

https://cimg7.ibsrv.net/gimg/www.mia...7b442df768.jpg
https://cimg8.ibsrv.net/gimg/www.mia...219114b754.jpg

Mocking up the exhaust and getting ready to tack everything in place. I'm digging the side exit even more once I saw it in person!

https://cimg6.ibsrv.net/gimg/www.mia...e7cfe93d06.jpg
https://cimg7.ibsrv.net/gimg/www.mia...0087868aa7.jpg

Exhaust components laid out for mock-up and awaiting my latest order of pie cuts from stainless bros. Pro tip, get the 4.5 degree 1D 5-piece kits. I've found those are the easiest to work with out of the four different versions and give super clean bends. I have to give it to Spintech, the owner Ron outdid himself on making the custom flat ovals for me along with the transitions to 2.5" round tube. And the muffler is gorgeous! I had never heard of spintech (https://spintechmufflers.com) and found them after searching for a compact dual inlet/outlet 2.5" stainless muffler. For any exhaust I do in the future, I'm calling them.

Also got the Radium expansion tank and recovery tank mounted up. Need to get the coolant hard line bead rolled that goes to the back of the motor and then the coolant system is done.

Water bottle for scale.

https://cimg1.ibsrv.net/gimg/www.mia...040cf24f52.jpg
https://cimg0.ibsrv.net/gimg/www.mia...689761a7c0.jpg
https://cimg3.ibsrv.net/gimg/www.mia...90ab2f3388.jpg

Few questions for the guys that have been down this path before me.

I'm using a derale fan controller with a temp sensor tapped into the outlet on the front to tun on the fan. Can I piggyback off the sensor to get a coolant temp reading displayed elsewhere? (AIM Dash in my case)
Or can that be pulled from the LFX ECU?

What data other can be pulled from the LFX ecu to display?

For E85, can the % ethanol be pulled from the GM sensor to display that somewhere as well?

Thanks for any help!

E39 has pretty substantial OBDII PID support. I don't know the AIM specifically, but I do recommend grabbing Torque app for android and a cheap ELM327 bluetooth OBDII adapter - it does look like there's a mode22 (extended diagnostics - OEM specific, not well documented) GM pid for ethanol content. I'd rather pull coolant info from the ECU.

Awesome, thanks as always!

A bunch of pics. Exhaust is almost done. Driver side finished and the passenger side is just missing the muffler to side pipe joiner which I'm going to make tonight. Also need to add an H-pipe before the muffler. Coolant system is done, you can see the routing in the pics. I welded on tube extensions for the upper and lower coolant pipes so I don't have to run long rubber hoses. I mounted the derale fan controller's temp sensor on the bottom of the coolant outlet at the top of the engine.

https://cimg2.ibsrv.net/gimg/www.mia...515fbef9d4.jpg
https://cimg3.ibsrv.net/gimg/www.mia...7d25682bc7.jpg
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https://cimg9.ibsrv.net/gimg/www.mia...ee6325669e.jpg
https://cimg0.ibsrv.net/gimg/www.mia...084e3a550c.jpg
https://cimg1.ibsrv.net/gimg/www.mia...5e5029e459.jpg

So close! Looks great.

Your lack of heat shielding stands out to me.

Please elaborate. Where should there be heat shielding specifically? There is heat shielding on the bottom of the tunnel that is removed in the pics, but not really anywhere else. There wasn't any on the previous setup with the miata turbo motor (except around the turbo) and I didn't have any issues from it. I could wrap the downpipes and exhaust pretty easily.

Thanks man, it is really close. Talking with a local race shop to finish up the chassis wiring and then it is ready to start testing at the track.

I'm looking specifically at the exhaust running within the tunnel cooking legs and other parts of both occupants. And the spot immediately under the seat might melt the jellybeans in your pocket.

Got it and thanks for the input! Just ordered Summit's 100ft x 2" lava heat wrap. Should be enough to wrap both sides from the engine back minus the muffler. Do you think the exhaust wrap will be enough to tone down the heat a bit?

https://www.summitracing.com/parts/sum-350212-1

It helps but a metal shield with an air gap is ideal. That is why the OEMs do it. The shield can be on the exhaust or mounted on the chassis, whichever is more convenient.

Exhaust is finally done. Massive progress on my stainless welding from beginning to end. The H-pipe ended up being a bit of a frankenstein tetris experiment because of the location, but came out good and I'm happy with the big collection chamber. Mounts to the frame on the muffler and sidepipe ends to keep it in place. I'll be using some specialized high temp rubber washers from Mcmasterr Carr to keep it from melting the powdercoat, but the exhaust is rock solid and doesn't move at all. I need to get the engine running before I wrap the exhaust as I need to be able to find any leaks. I still need to get the new shifter from V8R and mount the fuel/brake lines in the tunnel. After that I'll be wrapping up a few small things like the ecu mount and then it goes off to the shop to finish the wiring.

Oh, and thanks for the feedback sixshooter. Just ordered some high temp heat shielding from summit for the tunnel and rear floor panels where the exhaust runs.


https://cimg4.ibsrv.net/gimg/www.mia...d2b5fb43e7.jpg
https://cimg5.ibsrv.net/gimg/www.mia...868f310b58.jpg

A bit of a change of direction on the wiring. I talked to the guys at Rywire and I'm getting a chassis harness from them and their PDM12 and doing this myself. One of my big concerns was how long it would take to figure out all the wires and what goes where. But once I created the spreadsheet and got everything on it, it only took a few hours to map everything out. The Rywire universal chassis harness is awesome too because it comes with everything I need already wired up. They also confirmed it is very easy to shorten if I need to since the car is fairly small. PDM12 and Harness should be here friday. Will post more updates as I get into the install process this weekend.

If you aren't familiar with the PDM12, it is a pretty crazy little box.
"This solid state 12ch Power Distribution Module is a state of the art fuseless system that distributes up to 15amps per channel." You can bridge channels for high power items like the fuel pump too.

You Tube

Looking for some advice on running the battery cables.

Positive Battery Cable:
What does the positive battery cable need to connect to directly?
I'm assuming a run to the alternator, starter and engine harness. Is there a preferred order where I can run to the the starter, then from starter to alternator and then to the engine harness?

Negative Battery Cable:
I'm doing a short run from the battery to the disconnect switch and then to the chassis.
Where does the negative battery cable need to connect to on the LFX engine block? I never saw the engine in the car, so I'm not sure how it was setup from the factory.

Thanks for any help!

We ran 2awg to starter, 8awg from starter (crimped in same copper lug as 2awg) to main fuse, 8awg from alt to other side of main fuse. I'd recommend 6awg but I couldn't find it in txl. 2awg from battery to body, then body to block. Just bolted it on, no specific location on block.

Awesome, thanks!

Do the starter and alternator have ground wires going to them? If so, are you just connecting them to the block?

Negative on ground wires. Alternator has the main 8awg stud and 2 wires to the ECU in a plug. Starter has the starter lug and a.. I wanna say 14-ish gauge purple wire for the starter solenoid that goes to your key. No grounds.

Edit: This is our positive battery cable at the starter. Took a large-ish copper lug, crimped it with the 8awg and 2awg together, heatshrunk with triple-wall shrink, and then put it through split loom and heat barrier. Also put it in a vise and bent it over so it wouldn't run into the exhaust. Copper is plenty soft.
https://cimg2.ibsrv.net/gimg/www.mia...b60116feb9.jpg

Thanks! Which post on the starter is for the positive battery cable and which one gets the purple wire from the harness?

https://cimg9.ibsrv.net/gimg/www.mia...632d762563.jpg

Purple wire is plugged in (top left) - Battery post is the stud on the right.

Edit: Found another picture taken with a potato.
https://cimg4.ibsrv.net/gimg/www.mia...95c74cf716.jpg

Thanks!

In the middle of wiring, so please excuse the mess. Got the headers wrapped. Heat shielded the entire tunnel and underneath where the exhaust runs. Fabbed up a custom ecu mount because I couldn't figure out where the hell to put it. Got the E85 sensor installed with a DSX tuning double ended quick connect adapter, battery cables and battery are done, RYwire PDM12 is in, and V8R got me a kick ass MGW shifter they built for this application (should be for sale soon). The shifter is drool worthy and it is a fuckin tank! When I bought my trans it didn't come with the clevis pin for the selector rod to shifter and I can only get it from GM by paying $134 for the whole shifter assembly. So I'm taking the selector rod to a friend on monday to see if he'll make me a custom clevis pin.

https://cimg2.ibsrv.net/gimg/www.mia...ea0794a61b.jpg
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Question about the Miata (99) white/red wire from the ignition... if I am reading the wiring diagram right, the white/red wire is receiving constant power. Is that correct?

https://cimg7.ibsrv.net/gimg/www.mia...e67df4e8b3.jpg

FSM wiring guides are superior.
https://cimg5.ibsrv.net/gimg/www.mia...c20fc6a6fc.png

Okay, so it looks like the white/red wire on the ignition does indeed get battery power and as you activate a switch with the key, it sends power to that circuit. (I think!?). The Rywire PDM12 unit is ground switch activated. How do I get the miata ignition system to activate a ground switch? I am a bit lost here, so any help would be very grateful!

Looks good! For sure, you can make up a clevis, or substitute the right size bolt for the shifter; $134. just to move on from that is BS. On your question on grounds, I like to have a heavy gauge ground going from chassis to one of the starter bolts, like a mount to the bell housing, of engine/bell housing bolt, because when cranking you are pulling a shit-ton of amps, and providing a nice fat ground close to the starter helps make it's life easier (than a electrically long path around the engine bay, chassis back to the battery. Going overboard to have the engine, chassis, and battery well grounded to each other stops a lot of potential electrical problems from developing. Yes, the white/red wire has constant 12 V, and feeds the Ing. Sw. with power. The Ing. Sw. then passes it on in switched mode.

I'm afraid I need more context of what you're trying to do -

The ignition switch has 3 (4) states - ig1, ig2, app, and start. When you move the switch to start, IG2 and APP don't pass power, just IG1 (to save power for the starter motor).

Thanks!
Ended up running a short fat 2awg ground cable from the chassis to the upper back of the block. Battery to chassis is the same, short fat 2awg.

If the PDM12 power distribution system I'm using requires a switched ground from the ignition, can I just hook the white/red wire to a ground? Not sure if it is that simple.

Okay, let me explain this is in more detail. I'm using a Rywire P12 instead of fuses and relays.

Universal Chassis Harness W/PDM System

It is basically a solid state power distribution module. The instructions for the P12 say that the inputs from switches are ground activated.

The miata ignition switch positions all send power, not ground. So how do I activate the P12 unit's inputs with a ground and ideally keep the miata key ignition?

I may also be completely misunderstanding this. Not quite sure yet.

"Ground activated" means that you have the input wire from rywire - switch - ground. When the switch is closed, the power is enabled on the rywire output. This is similar to how ECU's provide the ground for a relay. But man, that looks like an expensive solution for what a relay does..

The other way to switch a ground to positive input is .. with a relay. 4 terminals on a typical relay - 85 86 and 87 and 30. 85 and 86 power an electromagnet that closes a switch between 30 and 87. To change the polarity - you ground 85 (or 86), run the positive to 86 (or 85) - that will close the switch that you can run between ground (on 30 or 87) and the rywire input (87 or 30).