Installed the MSD ignition coil wires and heat protect "booties". These were a pain as I wasn't sure the best way to install the booties - they wouldn't slide over the plugs very easily

Also didn't find the plug wire connections to be very positive. On other cars, the wires make a nice *click* when you push them on. One the spark plug side especially, I had to remove and reinstall a few times until I was sure they were on all the way. Guess the first fire up will tell... They also seem a bit longer than needed but not causing any issues here

Attachment 8754


Heat shield for the PCM

Attachment 8755

Still room for plug wires and shield to live together over here

Attachment 8756


Amazingly, I didn't need to make any modifications to make the Miata throttle cable work. At the TB side, looks almost stock to me

Attachment 8757

Here's how it routes from the firewall, just along the coil packs...

Attachment 8758

...and then makes an S-shape on top of the engine

Attachment 8759

Tested the pedal and due to the tunnel widening there is some touching of the pedal to the tunnel. No evidence of the pedal sticking but might not be worth the risk, so I may pound out the tunnel a bit here.

Attachment 8760

Made some final adjustments so that the "stop" on the pedal adjustment does its thing before the throttle is wide open so there is no stretching of the cable if you are pushing the pedal at WOT. When the pedal is in normal position, so is the throttle plate. Any final adjustments can be made once the engine is running and things start to "loosen up".

Still amazed that the cable just WORKS.

Pictures no worky!!!

I'll assume it was/is an imgur.com issue - they still work for me. Anyone else?

I looked at this thread a few times in the past few days and they've always worked for me.

This is a great read, plenty of V8 Miata content:
Miatagasm

Since the PCM now inhabits the area where the washer bottle was, I needed a relocation solution. Flyin Miata sells the alternative washer bottle:
https://www.flyinmiata.com/suzuki-ca...er-bottle.html

Last I had checked this bottle was about $130 I think, but they seemed to have lowered the price by half (!) to $70 as of this post. There were and still are a lot of cheaper options for the same thing from overseas.

I ordered mine from https://www.amayama.com/en/genuine-catalogs using part number 3845080F00. The price shipped was $46 and I got it within a week or two from Japan - not too shabby.

Attachment 8750

The oem motor fits right into the new bottle. The bottle is designed to fit in the cowl/drain area of the Miata. Capacity seems to be about the same. Strangely the picture on the FM site of this bottle shows it mounted with low point on the bottle where the motor sucks up washer fluid sitting too high in the picture. Any remaining fluid in the bottle will not get picked up very well. Maybe it’s me, or that bottle was shown for example purposes and not actually installed.

Anyway, I fab’d up some aluminum brackets to withstand the weather and will very securely mount the bottle in place. I extended the wiring to reach the new location. We will see once the hood is mounted if there are any clearance issues with the bottle or harness connector. The rubber hose might also reach, if not I’ll just extend it as well once the hood is installed. Seems like a nice option to clean up the engine bay in any case.

Attachment 8751

Attachment 8752

Attachment 8753

Everything looks great, you might want to add a wire loop at the bolt and another nut to secure the wires.

I was able to sort out the intake situation pretty cheaply using some pieces from Silicone Intakes Intercooler Pipe Fabrication

Here was my order:
1 x Silicone Reducer, 90° bend - 4.0" to 3.5" - Black (BRE000958) = $19.99
1 x 3.5" Silicone 45° Elbow, Black (SIL000408) = $19.99
1 x 1' Straight Aluminum Pipe, 3.5" (SIL000279) = $14.99
1 x Dual-Cone Air Filter - black, 3.5" inlet (AIR002008) = $14.99

You may want to measure the O.D. of your throttle body or MAF sensor plate for the right match. The 4” end of the 90° bend is not a perfectly snug fit on the throttle body, but with a hose clamp on it I think it will hold fine.

Unfortunately the 90° bend was not a perfect 90° either, more like 80°. When I brought this to their attention, they refunded the cost of the $20 piece from my order. Made the total price of this kit pretty reasonable ($50 + shipping).

Next challenge was to adapter the IAT (air intake temp) sensor to the intake. I picked up the correct two wire sensor and grommet from Amazon. Some later LS engines might have a 3 wire sensor or have the IAT integrated into the MAF sensor.

The IAT sensor (ACDelco 213-243) https://www.amazon.com/gp/product/B000C9JQVS
Grommet (Part# 14054892) https://www.amazon.com/gp/product/B00266IC06

The grommet is pretty important to create an airtight seal to the intake tubing an also space the part of the sensor so that it sits in the air stream at the right height.

Fitted up the silicone bends and MAF sensor to see where it put me:
Attachment 8741

After some measurements, I only needed about 6” of the 12” section of aluminum pipe to place the air filter in the right spot. Flyin Miata seems to think that putting the air filter near the shock tower works the best. I’ve got my bandsaw setup with a metal cutting blade already, which will help me down the road shortly with my exhaust system. Made some marks and cut it in half.

Attachment 8742

Cut a hole in the aluminum pipe with my big step drill
Attachment 8743

A hole of an appropriate size
Attachment 8744

Installed grommet
Attachment 8745

Installed the IAT. Needed to use the heat gun a bit on the grommet to loosen it up and slide the IAT in
Attachment 8746

Attachment 8747

Final install
Attachment 8748

Attachment 8749

If you are referring to the washer bottle wiring, I left it loose/incomplete until the hood can go on. I have a feeling there might be some clearance issues with the hood. If not, then a final trim to the right length and a crimp connection will seal the deal. I will then secure the wires. Thanks

Still making progress on the build. Alot of the wiring is done, so I'll write up a post that goes over in pretty good detail my thoughts on the wiring stuff. I have to make the fuel pump relay connection and the car *should* start. I also want to verify I have oil pressure before I start it as well.

I was able to turn the engine over a few nights ago. At first I had nothing when I turned the key but I ultimately traced the problem to bad connection at the starter solenoid. I used the LS1 connector, but it seems the metal contact inside the connector was slighly bent out of shape, and was not making contact with the single pin on the solenoid. It's a tight fit with the oil pan dipstick there. I have a shorter starter than stock to clear the headers, so I'm wonddering if this tight clearance is normal. If the starter was 1/4" or more longer at the solenoid, I'd need to move the dipstick to get the starter solenoid connection plugged in.

Other than that, I also bypassed the clutch interlock so that I could turn it over w/out sitting in the car - since I don't have seats installed. I verified there were no strange noises from the engine as I cranked it, as I had not been able to do this in the almost year I've had it. No blown fuses or strange smells, etc.

I decided to fill up the engine with various fluids.

• Mobil1 5w-30 for the engine, which I have on hand for other cars.
• Redline D4 ATF for the T56, which I have on hand for my M3 trans, and Subaru gear oil.
• Prestone coolant in a 50/50 distilled water mix for the cooling system.
• Royal Purple 75w-140, plus the required Ford Racing friction modifier for the Ford 8.8 diff

Attachment 8737

Attachment 8738

Attachment 8739


Installed the T56 shifter to keep the gear oil sealed in there. New shifter boot since I tore the old one during the engine removal WAYYYY back in September.

Attachment 8740

In preparation for the engine startup I decided to work on the exhaust system. Most of the work I do on the car right now is during weeknights so I didn't want to wake the dead with the first startup. :firedevil:

So far this has been going swimmingly. The result of two nights and 6 hours of work:

Attachment 8729

I'm using the 2.5" Summit Racing Universal Rod Builder Exhaust Kit SUM-670146
https://www.summitracing.com/parts/SUM-670146

The crossover pipe is a Flowtech Universal Off-Road X-Pipes 53620FLT
https://www.summitracing.com/parts/BIG-53620FLT

I would like to do something in stainless, but I don't have a TIG welder. This is my first exhaust, so MIGing a regular steel exhaust seemed like the natural step. The car will be a fair weather car, kept garaged, etc. so I'm not worried about it lasting over time. I will be coating it with some exhaust paint once it's all done.

The car will be registered as a Modified vehicle in Pennsylvania, so there are no Emissions restrictions and some guidelines around limited usage b/c of lack of emissions requirements. So there will be no catalytic converters on the car.


Sorry for the lack of detailed pictures on this step, I think things were moving along so quickly that I forgot. I started on the driver's side with a large straight pipe from the kit and then eyeballed two bends to zig-zag to line up with the half round cutouts on the trans crossmember.

I used a carpentry angle finder gauge to get a rough idea of what angle I needed and where I needed it on the pipe. I then made some pie cuts on the pipe to make the bend. The metal cutting blade on my bandsaw didn't seem up to the task and I didn't feel like forcing it, so I reverted to using a large metal cutting blade in my grinder. Once I was happy I tacked the pipe together on the ground and reinstalled it.

You can see in these pictures I used a clamp to hold it in the right position against the crossmember.

Attachment 8730

Attachment 8731


On the pass. side I started at the crossmember by making a little zig zag around the transmission towards the front of the car. Then I clamped it in place to fit up the crossover pipe. I just used the 45 degree pieces from the kit to meet up with the crossover pipe on either side and cut them at the right length to line up. What's nice with the slip joints is that depending on how tightly you push them together, you can still rotate them and wiggle them to get a 1/8" or 1/4" sometimes of movement so you line up with other pipes. Welding the connections together will seal up anything that doesn't perfectly line up.

To finish up the pass. side and meet up with the header required a bit more thought. I took one of the 90 degree pieces from the kit and marked off the pipe in sections at 45 degrees, 22.5, etc. I just used some cardboard to bend around the inside and outside curves and made markings on the cardboard at the halfway points, and then worked my way down until I had the smaller sections marked off.

Attachment 8732

Attachment 8733

This is after the cut was made, using the angle finder and a machinist square to judge where the cut line would be that would match up with the angle I needed.

Attachment 8734

If the cut was square to the pipe you should not see any gaps when a normal section of pipe is fitted up

Attachment 8735

I measured what I needed for the short straight section of pipe and made sure it all lined up. It did, so I tacked it in. If you put at least 3 or 4 tacks around the pipe in a butt connection, it shouldn't move at all I've found.

Attachment 8736


That was enough doing geometry and welding on my back for one night, so I called it quits and pulled the exhaust system off the car for a full welding of the joints tomorrow night. Trying to take advantage of some warmer weather the last few days.

I like how things look for getting the pipe around the differential, as I had intentionally tried to get the diff is high up as I could for clearance reasons. It's pretty much a straight shot back to the diff and then a 45 degree up to meet up with whatever mufflers I decide to go with. I'll work on exhaust hangers later as well.

Thanks for doing a well detailed install with lots of pictures. It will be extremely helpful once I get a drivetrain bought and cleaned up.

I definitely like the build notes and pics of the exhaust work. Pipes are looking good and well thought out. Very cool.

Continue...

One thing I forgot to post was how I did the heater hose connections. I did some research and found some hoses that I think worked really well for the ls swap applications.

It mainly consists of molded bends that come off the water pump and heater box to allow some clearance with the frame of the car or engine, and also the right diameter for the outlets. You can then swivel these to fit your swap, and all are reasonably priced pieces.

This was used on the right side, water pump inlet:
ContiTech 1027AMZ8653


Left side, water pump outlet:
URO Parts 64 21 1 394 292 Heater Hose


Then I used two 90 degree molded heater hoses of the right diameter to come off the heater box connections:
Gates 28466 90 Degreees Molded Heater Hose



To help with the connections between the heater box and pump, I used four of these. I went in favor of brass as I didn't feel comfortable adding plastic to the system for longevity. They do make plaster heater hose couplers, which would certainly work fine here
Anderson Metals Brass Hose Fitting, Union, 5/8" x 5/8" Barb


The heater hose itself:
Gates 28491 5/8 Inch Polybag Heater Hose


The LS water pump connections are:
Inlet on the right, towards front of the car
Outlet on the left

Miata heater box connections are:
Inlet on the left, passenger side
Outlet on the right, driver's side

The final product installed:
Attachment 8726

Attachment 8727

Attachment 8728

Still plugging along, with the finish line in sight.

Motor runs, though w/out any o2 sensors. I'll post a proper video of it when I can get some good video over the weekend. Getting some light lifter ticking but never really gave it a chance to warm up.

Exhaust is done and fitted. I have some Flowmaster Super 40s I borrowed from a friend that I've tested. Seems loud but that was with no clamps on them and the exhaust not fully welded. Pretty happy with the way it turned out. Getting the final bends around the diff and rear subframe brace was a bit of work.

I would recommend anyone doing this to buy a decent metal chopsaw. My bandsaw and blade were not up to this task, and using a cutting wheel worked ok, but doesn't guarantee decent square cuts. Good square and accurate cuts will make your life and welding much easier.

First startup was very loud and produced some evil looking smoke out of the pipes
Attachment 8719

Bulk of the system is painted
Attachment 8720

pieces that go around the diff
Attachment 8721

Rear subframe brace was used to make the exhaust hangers and was repainted
Attachment 8722

Closeup of DIY hangers. I used some 1/2" rod (I think) and some older rubber mounts from my Subaru. Then once I had the position right for the donuts I welded little beads on the hanger to keep the donut in place. Obviously don't do this with the rubber mounted
Attachment 8723
Attachment 8724

Found a good place for the o2 sensor bungs and welded them in
Attachment 8725

Will have final pics once all buttoned up

I'll be posting much more on the whole wiring setup as I complete that.

I have 15x9 6ULs in Tungsten with Toyo Proxes R1R 225/45ZR15 coming to me soon from Flyin Miata. They sell wheel/tire packages which are a good deal vs buying separately I think. Many places were out of stock on the 6ULs. A fender roller should arrive in the mail by the weekend and they might need massaging

Was also able to do any final application of seam sealer under the car and on other spots. Then installed the fenders and the hood. I needed to tweak the oil dipstick tube a bit for hood clearance and dent the hood for sufficient clearance for the oil filler neck and the clip that holds the hood prop. Car is looking like a car again from the outside.

On the interior I have the carpet, dash and center console back in. I have some new ebay rear deck and wall carpet coming as the original ones were pretty faded and beat up. Need to finish wiring CEL for the dash, OBD connector wires and some other little stuff on the inside, as well as the airbags and steering wheel, seats, etc.

Nice update! What diameter exhaust tubing is that?

2.5" pipe. This was the Summit Racing Universal Rod Builder Exhaust Kit
SUM-670146
https://www.summitracing.com/parts/SUM-670146

I also used their bungs:
WLK-88103
Fitting, Bung, Weld-In, Oxygen Sensor, Female 18mm x 1.5, Steel, Each
(Mfr. #: 88103)

One comment on the crossover, I liked the crossover pipe that creates an X-shape, vs. those that are more like an H-shape. You can make fewer bends in my opinion with the X-pipe. Since each pipe comes off the X at a 45 degree angle, you just need another 45 degree pipe to make another pipe that will end up straight with the body of the car, front to back.

Also you can just shorten your 45 degree pipe to adjust whether you want both pipes coming off the X-pipe to be closer or farther from each other.

Hope that makes sense.

Thanks for the info. I'm curious to see it all mounted up in the car with the hangers. I've just started thinking about how I want to mount the hangers, but I like your solution!

Absolutely, more pics to come.

Great write up and pics. I'm interested in how you are hanging the mufflers.

Might be awhile before I do anything permanent with the mufflers. The mufflers aren't mine so I'm not going to make any modifications to them. I think on the passenger side I would use the existing body hanger and then DIY a hanger from the muffler case to it.

For some reason Youtube is not liking my uploads tonight, so not able to post video yet of the engine running. But it does sound badass.

Here are some random pics of the exhaust hanging situation:

Attachment 8707

Attachment 8708

Attachment 8709

Attachment 8710

Attachment 8711

Attachment 8712

Attachment 8713

Attachment 8714

Attachment 8715

Attachment 8712



Seems like I'm not getting a full seal on the exhaust clamps:

Attachment 8717

It should look like this:

Attachment 8718




The two exhaust hangers I have now are enough to hold the system in place happily for now, even with the mufflers installed. I'm using FlowMaster Super 40s in 2.5". I'm not going to do any muffler hangers for now until I decide what I want to use and will then weld in some hangers using the stock locations where possible.

With the engine running now there are a few issues I need to address:

- The cooling system was literally being "pissy" with me. The coolant reservoir overflowed once the temp gaug hit 12 o'clock. Might be that the thermostat is not opening. What a shock to have finicky thermostat on a car that hasn't been run in awhile :vash:
- I couldn't get my bluetooth OBD reader to work. So not sure if it was the reader (which was cheap) or if the port was not functioning. I got a CEL shortly after the car was running so I know the PCM is able to throw codes, and the dash CEL was working. :-)
- Engine idle seemed high at 1000 or above. Need to verify using the OBD port that the PCM idle reading is matching the dash idle reading


This was my clearance with the accessory belt and the existing thermostat housing flipped around towards the radiator. It ran fine with no rubbing but I knew this wasn't sustainable.

Attachment 8705

So I had to go all out on this one. I could have just flipped the thermostat back to it's original location facing away from the radiator, and reconfigured my hoses. I liked the way my hoses were routed so I researched another thermostat housing that might give more clearance and went with this one:

CSR 912LS1-1.5: 90° Swivel Thermostat Housing - Clear Chevy LS* | JEGS

and the matching thermostat: JEGS Performance Products 53220: HP Thermostat Pre-LT1 GM, Ford, AMC | JEGS

Yeah, I know, the price is a bit ridiculous. But as far as clearance it will do the job:

Attachment 8706

In order to make the muffler fit easily I decided to remove the rear tie down points. I'm hoping I don't regret this in the future, but you can always use the rear subframe to tie the car down. <<Update from the future>> Removing these will prevent you from using some trailer hitches that bolt in between these mounts. But Bethania Garage/Hard Dog sells a Class I hitch that mounts to the bumper mounts - this worked great for me.

These are pretty bulky and really not in a good spot if you are trying to do a dual muffler setup. Plus I lost about a few pounds in the process.

My fear was that I'd put alot of effort into routing the muffler around it, only to have rubbing or clunking from the rear in high G corners. Just some work with a grinder and big hammer to knock them out, and touched up the bare metal with some black paint.

The hunk of metal removed
Attachment 8702


The cutaway area
Attachment 8703


Alot more room to fit this muffler or another one
Attachment 8704

One thing I tried to put a little thought into was the emissions/fuel tank vent situation.

Since I had the room I decided to install the charcoal canister in the stock location. There is some tight clearance with the passenger side exhaust pipe:

Attachment 8701

Starting at the top of the fuel tank my thought was to remove the tank pressure check valve (TPCV) since there is no longer any control signal coming from the Miata PCM. Though I'm not sure it gets a PCM signal, maybe it just needs power to open when there is enough pressure from the tank pressure sensor? I would also remove the check valve between the charcoal canister and the air filter underneath the car. There won't be any line running to the engine to burn off gas fumes so that could be left open to the air using the port on the charcoal canister.

Curious what others are doing.

I was able to upload some video finally. Here is the startup video. Not the very first startup but we'll call it that since everything on the car was mostly functioning by this time.




Next was after the car had warmed up a bit there was a bit smoother idle and throttle blips. You can see I had the fan going on the trunk b/c of all the stuff burning off the engine and exhaust smoke.



One thing I wanted to share was the belt tensioner seemed busy. This is a new tensioner, does this look normal to anyone? Seems to be moving around alot but appears to stay near the two marks that I assume are to check it's in the proper adjustment range?



As mentioned before need to figure out the check engine light I'm getting, and the coolant overflow issue before I do any more testing.

I have much of the interior back together too but leaving alot of it loose in case I need to get back into the top of the fuel tank area. See my earlier post on the emissions/tank venting if you have any input on how to do that. I'll be doing some research to see what hot rodders do that don't need to pass emissions 100%.

Maybe I just missed it.
What mufflers are you running?

Back on 3/1 I posted, they are Flowmaster Super 40s.

Figured out my OBD port issue pretty quickly, turns out I needed to repin the OBD port as the data connection wasn't in the right place on the connector.

This post DIY: LS1 OBD2 Port Install - ClubRoadster.net was helpful in figuring this out. Basically you need to move the wire that carries the data connection to the PCM to pin 2.

Attachment 8694

You'll need to remove this white plastic piece from the back by just undoing a clip on one side and lifting it up
Attachment 8695

On my 99 Miata, the green/yellow wire was the data line which was located over on pin 7. In order to depin it just look at the pin from the front side of the connector and use a small pick to lift up the plastic tab I pointed to with the arrow.

Attachment 8696

Pull the wire from the back as you lift the tab and it should come out. Put it back on the pin 2 location so it should look like this from the back.

Attachment 8697



My CEL was related to both oxygen sensors having "no activity". It threw the code a few minutes after the engine was started, and I did verify the O2 sensors were both working fine when I started the car. I'll need to look into this a bit more and see if I have a bad connection. One of my sensors is new, the other is original to the engine.


I'm still having a cooling issue where the overflow tank goes from empty at startup to almost overflowing at full warm, the rad cap starts to emit steam. All the hoses are getting warm so I'm thinking the thermostat is opening. But I wasn't getting any heat from the hvac system. My fans were also not kicking on at any point.


My tach is reading about double the RPM of the engine speed. I'm not using a resistor as Flyin Miata describes, but I have one so I think I'll need to install it.


Did a couple small jobs like make a plug for the firewall hole previously was used for the engine harness. Just found a rubber plug and coated in some RTV and let it set.

Attachment 8698

Attachment 8699


Also I rerouted the rubber line for the windshield washers. Since my new reservoir is on the driver's side, I just flipped the hose routing to the other side of where it mounts to the hood and trimmed the rubber line.

Attachment 8700

As I near the end of the build, the problems seem to be mounting.

1. I think I'm going to try a manual belt tensioner vs. the OEM spring-loaded one that seems to be moving quite a bit. For track cars, it would seem this would be the way to go anyway: Billet Belt Tensioner ? Katech Performance Online Store

2. I'm not convinced the DIY power steering pump bracket will hold up to long-term use/abuse. After putting some torque on the tensioner it seems the PS pump bracket moves a bit too. It's only mounted in two places vs the ideal 3 mount points (triangulated). Going to give Turn One a call and see about the CTS-V pump with the restrictor for Mazda flow rates.

3. After some OBD scans it seems my car is not going into closed loop. The o2 sensors are tripping a CE light a few minutes into the car warming up. I'm going to check the o2 sensor heater connection for 12v+ or ground issues. Car seems to run great otherwise.

4. With the Flyin Miata tachometer resistor fix the RPM is still double what it should be. Hmmm.

5. Not entirely sure my cooling system is filled, I have my doubts.

6. Fans are not kicking on so need to check wiring there.


We are getting 18" of snow over the next day or two and temps are almost single digits.

Fun fun fun.

Let me know what you get on #4, my car still does this, and I'm tired of taking the dash out to expirement

I cant help with much else, but as for #6. I noticed the same problem during my first warmup cycle.

I verified my wiring was correct by providing 12v signal to the relays, and the fans came on, so I knew the PCM was not triggering them.

Now, I dont know if you guys are using HP Tuners. But I had to go into the tune and make some changes to the fan settings.

I will try and grab a screenshot this week of my exact settings. But for some reason , the PCM wants to verify AC refrigerant pressure before triggering the fans on. I had to play with a couple things, as well as tell the PCM what type of fan setup I was using for it to work (ie single fan, dual fan, single fan dual speed etc. ). After that, everything worked as it should.

All is not lost!

Also, for #4, did you wire the resistor in PARALLEL with the GAUGE? I know some people were having issues with that due to some misleading wording on that install. The resistor should not be in series with the signal, but in parallel to get gauge iirc.

I would prefer a picture to go along with Flyin Miata's description, but I think it's pretty clear when they say to "tee" into the tach wire. Unless their description is actually wrong, I think I have it right. Maybe some testing with a multimeter would confirm it.

Flyin Miata:
"The Miata tachometer is expecting a different voltage input than the GM ecu puts out, so we need to fool it. A 2200 ohm (2.2K) resistor needs to be jumpered in between switched 12 volts (Mazda 12v wire listed below) and the tachometer input lead (white wire in GM bulkhead connector) going from the GM harness to the Mazda instrument cluster.

The white GM wire will connect to the Mazda tach wire going in to your instrument cluster (below). The 12v -> 2200 ohm resistor -> will “T” into this tach wire. An easy way to visualize it is to just think of the 2200 ohm resistor as a jumper wire between the 12v wire and the tach wire where it plugs into the instrument cluster. Make sure you cover the resistor with heat shrink tubing to protect it from shorting! What you’re doing here is “pulling up” the tach signal voltage so the Mazda tach can read it.
• 90-93: 12v is 2K black/yellow, tach is 1H yellow/blue.
• 94-97: 12v is 2K black/yellow, tach is 1H black/white.
• 99-05: 12v is 1C black/yellow, tach is 2K green/orange."

The mention of the white GM wire is a bit confusing, when below that they describe three different color combinations for the tach wire.

What I've read is that when the RPM is double, it's because the tach is seeing twice as many engine rotation signals as it should, or a different frequency to put it another way. I'm not sure how a voltage strength change would alter that though. Maybe the resistor is intended to fix a different problem altogether?

Anyway, this Baker Electronix - Tachometer Adapterwould fix it for $40 but they are not shipping until 3/27, so not sure if I want to wait two more weeks, or go for this Universal Tachometer Signal Interface for twice the money.

EDIT: Im an idiot, I wrote this in reference to the speedo.

I honestly dont think I did anything at all for the tach and it just worked? Ill have to go back and look at some of my pictures to remember which wire from the PCM I used.

Thought I'd also share this bit of weirdness. My OBD scanner shows that I appear to have 4 O2 sensors, but I don't, I only have 2. Per the instructions on lt1swap.com when my PCM was sent to him for modifications, I should only be seeing readings from the front sensors (BNK1 #1 or BNK2 #1) as I just moved the wires for the rear sensors to the front pinouts. Rear pinouts are empty.

Is this typical behavior if one has had the rear sensors (BNK1 #2 or BNK2 #2) removed?

Edit: A buddy with an LS has the same symptoms as this, so I'm assuming it's normal, at least with the PCM programmer we both used.

Attachment 8692

Attachment 8693

Confirmed. I just connected WHT Pin 10 on Red from the PCM to 1H yellow/blue on the cluster.

stng_96 and I have 99 models, I wonder if something changed that year.

What year LS PCM? I am using a '99 cluster if I remember correctly. I read somewhere that you only need the pull-up resistor if its a 2003+ PCMs

Alternatively, you should be able to scale the tach output with software. But I suppose that doesnt do you much good.

It's a 98 PCM, and I did read about the later PCMs working out of the box.

My guess is that my PCM guy didn't read my instructions about what car it was going into or this might not be an issue.

I went with a manual tensioner from KaTech, which seems to be doing the job quite well. Very nicely built piece, easy to adjust, looks good.

Billet Belt Tensioner ? Katech Performance Online Store

I'm also going with a different power steering pump, from the CTS-V, which is a pretty common choice among swappers. Turn One steering was nice enough to take allow me to return the F-Body pump I was using, which had very little actual use, just a few minutes idling. They will charge me a restocking fee, but the refund should work to about the same or more than I would get for the pump on the used market. New pump should ship this week I hope. I have the necessary parts for the pump coming to me as well, which would be the mounting bracket, reservoir, cap and rubber feed line.

I have the used but in new condition aluminum Turn One FBody pump pulley wheel for sale, if anyone is interested before I post it for sale.

My take on the OBD scan codes are that b/c I'm not driving the car or putting it through a drive cycle within a certain amount of time after starting the car up (for the first time) the PCM is telling me that something is wrong. So I'll have to see if the code reappears after I take the car for a drive. I verified the o2 sensor heater circuit is working, wiring is good, etc.

My cooling fans are working, I just had to wait until the LS temp sensor hit 200F before they kicked on. Yay.

I've ordered a Dakota Digital module to fix the tachometer being off, should arrive tomorrow. http://www.dakotadigital.com/index.c...127/prd127.htm Good thing is I can just borrow or T off the power and ground wires I'm using for the Dakota speedometer module and just tuck them behind the instrument panel.

Other options to fix the tach signal would be http://www.bakerelectronix.com/products_tsd/ The "1/2 multiplier" TSD would fix a tach signal showing double the correct RPM. Baker Electronix isn't shipping til next week so I passed on waiting for that unit, though it would be cheaper.


In other news, my new wheels/tires arrived and look amazing. These are 15x9 949 Racing 6ULs in Tungsten. I ordered them from Flyin Miata prefitted with Toyo Proxes R1R 225/45ZR15. I think it was a good deal, and I also don't need to make the extra trips to get the tires mounted if I bought them separately.

Attachment 8687

Next to my 15x6.5 Silver 6ULs. Makes the silver ones look kind of boring now. I hope in the daylight they will really "pop".

Attachment 8688

I had to cut the caps off my lug nuts for the rear as the wheel studs were too long. Might need to invest in some new lug nuts as mine are showing a bit of rust and look downright nasty next to these new wheels.

Also bought some exhaust tips to use, though I'm going to wait to make sure I like the mufflers enough before I put the work in to fit them.

They are from Flowmaster
Attachment 8689

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I think I'm going to go commando with the rear exhaust for now. I still need to fab up the hangers for the rear mufflers before I take it out for a drive.

Attachment 8691

Nice tire/wheel combination.
How is the fit?

Thanks. Based on my research, it should fit an NB Miata with very little fender rubbing. I bought a fender roller so I should have no issues, but I won't know til I get the car on the ground and set the ride height and drive it.

There is a bit of tire stretch with this tire on a 15x9, but Flyin Miata approved, and others have no issues. If over time there are no issues, I might move to a 235 or 245 on the rear for more grip. We will see.

Front sway bar clearance might be an issue if you are using certain bars. I don't think I will, but I have heard of others.

The Dakota Digital Tach interface did the trick to fix the RPM. Here's how I wired it. OUT3 halves the signal which worked fine for me, the other outputs can be adjusted up or down in increments. Very nice piece with clear instructions.

Attachment 8682

Since I don't have my new power steering pump yet, and I sent the other one back for a refund, and I wanted to idle the car to test things out, I made a quick pulley out of the old water pump tensioner I pulled off the engine when I bought it. Guess it pays to keep old junk around.

Attachment 8683


Here's a quick pic of the Miata wire I used to grab 12v power for the O2 sensors. Just two black/white wires near the driver's side left foot. The wire normally goes under the driver's seat and through a grommet in the tunnel to the rear O2 sensor on the stock Miata exhaust. I just routed it back up behind the dash and split it off to each front LS1 sensor. It's already fused in the Miata fuse box.

Attachment 8684


Unfortunately my Miata Nardi airbag wheel got some damage in storage. I had used blue painter's tape to hold the airbag module to the wheel, but when I removed the tape it took some of the "leather" with it. This is before I tried some leather conditioner on it, so I'll have to see about what I can do to fix or hide this. :(

Attachment 8685


Finally, I had been waiting to do this little mod, and it seemed like the right time. Got these from Amazon for a song, one for each side. Comes with adhesive backing. They were a bit big to put on the back of the car, so I went with the side. Guess that removes any guesswork about what engine's in the car. Stealth be gone!

Attachment 8686

Hoping to put the car on the ground and pull it out of the garage this weekend. I have 100 ft. long driveway, so may just do some testing of gearbox, brakes, set ride height, and rough set the alignment. Once I have the PS pump I should be able to take it for a test drive.

Couple questions for anyone listening:

- Does anyone have short lengths of header wrap they would like to sell me? I need to wrap about 8" or so of the 2.5" header where it transitions to my exhaust system that I couldn't cover with the wrap I had bought. I'm not sure exactly how much I need but was wondering if anyone had more than they needed?

- What are people doing for oil temp sensors? I had a temp sensor mounted as the oil drain plug on the Miata engine, and I don't feel like tapping the pan right now for a sensor. Is anyone using the oil pressure sender hole to make an adapter for the oil pressure and temperature? I've done some searching, but figured I'd ask here.

The car moves under its own power and sees daylight for the first time in 7 months.

Attachment 8680

It was obvious the front ride height was too low, and the front VMaxx coilovers were at their max ride height. This would be obvious when you consider the extra weight on the front of the car with the LS engine. Turns out FM sells a specific spring for this problem https://www.flyinmiata.com/fm-v8-v-m...nt-spring.html Order placed.

Installed a fire extinguisher, the harness bar on the roll bar makes for a pretty good location. This is a project car and will see some track work, so better safe than sorry.

Attachment 8681

Hoping this time next weekend the car will be ready for it's first test drive.

so close!

Coming together nicely. I'm of little use to you in these last few posts with no header wrap or help with the tach and such. But, the V8M looks and sounds great! Keep the posts coming, it's fun watching you button things up.

Ah yes… wiring. The often feared, much maligned, misunderstood wiring. Mysterious electrons flowing over copper strand at the speed of light.

Anyway… there are some good guides out there for the Miata swaps, and some good “filler” info on ls swaps in general that helped me out.

Wiring guides:
Nathan’s site is NA Miata specific, but gives a good overview of the steps, including a summary of the harness mods:
Nathan's LS1 Miata

Flying Miata’s guide is laid out a bit better and has more specifics on one generation to the next:
http://www.flyinmiata.com%2Fsupport%...structions.pdf

LS PCM “pin out” guides:
Chevythunder - scroll down half way for pinout guides for various LS models:

LS1 97-98 specific pin out guide (what I used):
1997-98 LS1 PCM pinouts

LS1 guide to different engine components:
LS1 page 1

Brendan at LT1 Swap was who I used to reprogram my PCM. Their site also provides good info, similar to chevythunder.com. His guides give a good overview of the different options available for PCM programming if you are new to that.
1997 1998 Corvette Camaro Firebird PCM Pinouts

I would not recommend LT1Swap.com for any PCM work, I’m sure there are others who have had good experiences with him, and I did as well for what I was expecting. I would not say he is very good at timely communication or answering questions. It's possible he created some other problems for me in the mods he made, or didn't make, but it's hard to know b/c I can't inspect the PCM, and he has not replied to my questions in many weeks.


The wiring harness:
I found some open floor space in my finished basement to lay out the harness and start to pick over it, labeling each connector with what it does. I’d recommend a space where you know the kid/cat/dog etc. won’t get in your way, step on delicate connectors, or chew on those delicious wires.

The pictures here are a good guide to IDing each connector (download picture and zoom in)
Wiring information for 1998 to 2002 Camaro & Firebird LS1

This site has more of a DIY step by step guide on cleaning up a LS harness, with pictures:
http://www.thirdgen.org/forums/ltx-l...rt-finish.html

The two PDF files linked here were the most detailed at showing the connector locations on the engine and trans, and on the harness itself. Very helpful if you are unfamiliar with LS engines:
http://www.norotors.com/index.php?topic=175.0

You will want to think about what sensors or features you will not need. If you are using a manual transmission but have a harness from an auto trans car, you will remove connectors for an auto trans as there are a few more of them. If you are deleting EGR, remove those connectors by looking up the PIN numbers that relate to those sensors and remove them completely from the PCM. You can remove the whole wire from the PCM connector by de-pinning it and pulling it through. Youtube has some guides on how to depin the LS PCM, though you may be able to figure it out yourself.

Per the LT1Swap.com site, most swappers use only two o2 sensors, one for each bank of the engine. He suggests that you take the rear o2 sensor harness wires and connector and just move them to the front o2 sensor PCM pin locations. You can eliminate the rear sensors by turning them off in the PCM. Though in my experience they aren’t really removed - in my experience you will still see a rear sensor show up in the OBD scan output. It seems the PCM is just tricked into thinking the rear sensors have the same o2 signal as the front. If you see a function related to a specific pin on the diagrams, just google for the name and you can usually get an answer as to what it does and whether it is applicable to you.

PCM functions you may want:
* OBD port wires - connect to Miata OBD port (if applicable)
* MIL light - illuminate the CE light on the instrument panel
* Generator warning light - going to hook this up assuming it will work. FM guide says it should.


PCM functions you may NOT want:
* Auto trans related stuff - TCC switch, park neutral switch
* Oil level sensor - most will have removed the oil level sensor when switching to a custom oil pan
* CAGS - T56 skip shift function
* VATS - you will have VATS disabled most likely as the car will not start without it
* Rear 02 sensors - you will only need the front sensors for most applications
* Anything EGR related


Harness connectors:
Part of the main harness, aside from the engine sensor connectors, fuel injectors, coil packs, etc. are the Cxxx connectors or whatever you want to call them (C101, C105, C220, etc). These would have connected inside the car the harness came out of. These connectors were for getting fused/relayed power from the car to power the PCM and other engine functions. They may also feed signals from the engine/PCM back into the car for gauges, OBD, water temp gauge, or other things. I left these as is and labeled each one with a marker or masking tape.

Attachment 8678

This url shows which connector is which on the LS1. If you use google image search for the connector name and your engine, year, etc. you will find plenty of info:
Attachment 8679

This url provided a good overview of harness modifications in general (the whole swap site has good info). I used the yellow boxes about halfway down the page “Connectors for 97-98 LS1 Engines”
LS SWAPS: Wiring Harness and Wiring Guide

The info above came from a book which is available free to read on Google Books, however many pages of the book here (for free) are not available on purpose, so be aware of that:
https://books.google.com/books?id=AP...cPC2YQ6AEIJTAA

If the link doesn’t work just search Google books for “How to Swap GM LS engines into almost anything”.

Installing Harness:
Once you’ve got your PCM location established (see an earlier post of mine to see what I did) and you have a working LS harness, my approach was to connect the harness to the PCM and bolt in both red and blue side connections, so it doesn’t pull out and damage the pins as you are tugging on the harness during install. It might be a good idea to make sure your battery is disconnected at this point, so your not sending power through the car or wiring by accident.

Lay the harness out on the engine and start making connections. For the most part this should be easy and satisfying - the positive click of a sensor connector going into place. This will start to give you an idea where the bulk of the harness will route. If you aren’t happy with it, you can con’t to pull it apart, extend or shorten wires, etc. to your preference.

I stripped off all electrical tape and plastic wire loom and used loose zip ties to keep things from getting out of control. Keep them loose so you can pull new wires through for later as you route things across the engine into the cabin.

First step was to make a good ground to the chassis by using an available bolt hole on the back of the driver’s side head. Connect the multiple black wire ground connections on the harness to this location with a ring terminal. Then add another 6-8 gauge connection from this bolt to the firewall or frame rail using the Miata locations.

On my car the 10 gauge (?) Black/Red cable that comes out near the Miata main fuse block, connects to the starter. The LS1 cable coming from the starter on my car was light purple, so I just connected those two securely with a crimp connector and weather seal.

Sidenote - For routing various things I’m using the corner of the engine bay on the passenger side, where you cut out the gussets early in your build, and where the tunnel, the firewall and engine bay frame rails meet. I have my fuel line, brake line and wires for the trans, o2 sensors, CKP (crank) sensor and starter connections going down here.



Power connections:
There are two orange wires in the LS1 harness that come out of the PCM, and then combine into one wire. This orange wire needs to be hot all the time so the PCM can retain its memory. I ran a wire with a 15A fuse through my own fuse block to the thick black wire from the battery. The black battery wire connects to the main fuse box where it bolts up with a ring terminal.

This isn’t my picture, but this is the main engine fuse
Attachment 8674

You can tap into this by using the existing bolt that holds each side of the fuel blades in. Use a ring terminal to tap into it or tee the two wires together and crimp on a new ring terminal:
Attachment 8675


There are 5 pink wires which all need switched 12v power (2 feed each bank of the engine for the coils and injectors. 1 is for the MAF, 2 are for the PCM). Some guides will mention just putting these all together and feeding it into a power source. If it requires switched power you should try to do that. Not saying it won’t work, but if OEM wants switched power, then there might be a good reason it’s done that way. Maybe so it won’t drain the battery while the car is off.

I purchased a small fuse panel that worked nicely
Attachment 8676

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On the 99 Miata, at the ignition switch is a thick black/red wire, maybe 12 gauge, that provides switched power. I cut this wire and reconnected with a heat shrink crimp connector and ran a 10 gauge red wire from it. It went out through the firewall using a small, unused grommet/hole above the steering shaft. I will be also be using the grommet for the wires from the PCM going into the cabin.

Route the 10 gauge red wire over to the main fuse box. This wire will feed 3 fuses for the PCM and both sides of the engine (injectors and coils). Connect your pink wires up to your custom fuse block.