SlowTeg

So before delving into the BMM stuff, I need to get the fuel stuff sorted first. Makes sense to just install the fuel pump and injectors first rather than running the stock injectors and changing things later. So first thing is the fuel pump. Installed a DW200 pump. Install was straightforward. You need to trim the pipe about an inch as the DW pump is longer.



For injectors I'm running FF640's. I've been told to clock them to 9 and 3 o clock. The NB won't allow the connector to go straight up and apparently they shouldn't be installed connector down. Again, pretty straightforward install.


Now, for the rats nest on the passenger frame rail and around it, all the stuff is no longer needed there (evap solenoid, and there's a vacuum line to a solenoid that goes to a map sensor). They can all be removed. I want a fuel pressure sensor (transducer) so I am mounting one inline where the stock fuel pulse dampener is and I'm removing it. I am making some -6 an line and fitting to mount it. The sensor is a Honeywell. I used a cheap pipe bender to bend down the oem fuel line so it comes forward parallel with the frame rail. This moves it a bit out of the way. Here is my first quick mockup. I made a simple bracket that will mount to some existing 6mm threaded holes on the frame rail. Also, this gives plenty of space for the radiator hose now and I will need to make a bracket for it.





Here are a couple shots making some AN line and the new line in place. I got a 180 degree fitting but I actually need a 150degree fitting to connect to the stock hard fuel line. To connect the fuel rail I used a 5/16" SAE fitting to AN line fitting. These fittings are nice as you don't need to use an SAE to AN adapter fitting. It cleans up the passenger frame rail quite a bit.





Once I get the 150degree fitting from summit I can reassemble stuff and start messing with the new ECU. I have been slacking working on the Miata. I've still got about 3 yards of mulch to spread for the yard and been doing a bunch of yardwork. Beautiful time of year now.

Z_WAAAAAZ

Fuel line project's looking good man! Are you gonna wire the EV14 connectors straight into your engine harness or run the supplied jumpers? On my car, the jumpers added too much length to be tucked away neatly and made the harness kinda rat nest-y.

SimBa

Excited to see how the fuel lines end up. I've always hated that mess of pipes/hoses.

What's the reasoning for rotating the injectors that way? Is that supposed to help with leaks or something? I'm running the same ones so I'm curious, I just threw mine in and ran.

SlowTeg

I thought about it but with the injectors rotated 90 degrees the oem plugs look like they'll be a bit short, so I'm just going to run these jumper harnesses for the time being. I don't want to take the time to mess with it now but down the road I will definitely think about it. With everything back on you won't see the rats nest as it's tucked underneath the rail.

A couple folks on the BMM discord said for the NB's they should be rotated 90 degrees. I'm deferring to them. Jesse said he checked it with a scope at 90 degrees and the spray pattern was good. Apparently with the FF640's they spray at a downward angle (opposite the connector). They obviously won't go in with the connector facing up on the NB's because of the head in the way. Ya it's really nice to clean that area up. It drove me nuts too with the radiator hose pressing against it. I can now make a proper mount for the radiator hose and not just have it wedged between things on the frame rail. Ideally at some point it'd be nice to make a hard pipe for that radiator hose but that'll be down the road.

SlowTeg

I got the 150 degree fitting from summit and was able to finish the fuel line. On checking the Honeywell sensors from Sager electronics they sent me two gauge pressure transducers rather than one gauge and one absolute. An absolute pressure sensor should be used for fuel pressure and gauge pressure sensor will be used for oil pressure. So, I simply installed a 1/8" npt plug into the fitting for the time being. The absolute sensor should read AAAX vs. SAAAX.




Now onto the BMM stuff. I opted for the BMM over the Megasquirt as it seems to be a few bucks cheaper, have some additional features (it has a built in wideband controller, built in map sensor, and supports DBW TBs, as well as some others), and have good support (there's a discord for BMM). It also has the option of adding sensors that can be read by the ecu and read on the CAN bus. The sensor I will be adding now is a fuel pressure sensor (transducer). You need a Bosch LSU sensor (part #17025) and you need to run a vacuum line to the ECU. The ECU comes with an aux harness for adding inputs to the ECU and a nice plug for the LSU sensor which makes it easy.

I've opted to mount the fuel pressure sensor in place of the pulse dampener on the passenger frame rail. It was nice to remove the rats nets of lines on my NB1 and clean up things on the passenger frame rail. I used a cheap tubing bender I had to bend the OEM 5/16" fuel line down parallelish to the frame rail. For a fuel pressure sensor, there are cheaper ones available on amazon, but it seems like a no brainer to pay a few more bucks and get a brand name like Honeywell. You want an absolute pressure sensor (not gauge) the one I went with was (Honeywell MIPAN2XX100PAAAX). This cost $55 from sager electronics. The corresponding harness for this sensor is CONN-75732 from ballenger motorsports. It has a standard 1/8" npt port and has 3 wires, +5V, sensor ground, and signal wire. Make sure to use sensor ground at the ECU not just a chassis ground on the car. The BMM ECU has the ability to add fuel to keep the car from leaning out should fuel pressure drop which is nice. Also, it's nice to be able to monitor fuel pressure.

Another thing that is highly recommende is a 36-1 crank trigger wheel. OEM Mazda part: part # ZM0111408. It cost me $26. Also a license for Tunerstudio software.

One thing not mentioned in the install guide for the BMM ECU is that you should install a microsd card at time of installation as you have to open up the ECU to install it. It'd be a pita to have to remove the ECU to install it as you have to open up the case. You just open up the case, slide the mechanism to unlock it, and pop the card in. I used an old 32GB microsd card I had which I've been told should be plenty big. By default the ECU will log to the SD card if the ECU is powered up via +12V (with the key). If it's connected to the laptop first via USB, it doesn't log to the SD card.




Here's the orientation of the BMM ECU. It uses the OEM brackets which is nice and the USB port and vacuum line point up so they don't interfere with the pedals. I also repurposed a vacuum joiner from the Evap solenoid or somewhere which allowed me to use a slightly larger vacuum line than he specified (it's what I had on hand). The vacuum hose was run through the hole where I believe the cruise control something ran through. I just needed to open up the hole a bit. The vacuum line goes to a barb I installed on the back of the intake manifold.







The wideband harness I fed in through the main/big grommet by the brake MC. Used a coat hanger and like running an amp wire for a stereo. Of course the O2 sensor had to be a little b**ch and didn't wanna come out but no big deal I don't plan on using it again so mutilated it removing it.





The crank trigger wheel it's recommended to install AFTER the first start not before. In hindsight you probably could just do it before. After this everything should be installed and ready for the first start.

Z_WAAAAAZ

Solid progress, man! Seems like you’ve thought everything through really well before pulling the trigger. Interested to hear about your experiences with the BMM ECU. The integrated wideband controller is a really cool feature.

Again, the fuel line setup looks super clean

SlowTeg

So regarding the first start. I'd say it's probably covered well in a bunch of other places so I'll try to summarize it very briefly for anyone new and not put anyone to sleep. Load a base map and try to start the car. Once the care runs/idles, set the base map to use static timing (this allows you to set the base timing so the computer and mechanical readings are synced). Use a timing light to verify the timing is correct. Then reset the timing back to dynamic. Then calibrate all your sensors (mainly TPS or any others). Then it's all tuning. I'm not at all familiar w/ Tunerstudio so have been looking up videos on it. OGPedXing has some great info and a series using Megasquirt. A lot of the same stuff applies to the BMM ecu. I won't delve into tuning as there's plenty of info out there it looks like and OGPedXing does a great job explaining everything.

With all that said, the car started up fine on the first start. I set the timing and surprisingly didn't have to change the offset timing angle at all. Apparently NB's are usually pretty spot on whereas NA's usually need it offset/changed. After that I installed the crank trigger wheel. Car starts up OEMish or faster now. I drove it around and tuned it a bit. It needs some more tuning but it's not terrible. I will mess with tuning it over the next week and then probably get to installing the turbo. One thing I'm thinking/debating about is turning the IAC valve duty cycle down and mechanically opening the throttle plate more on the junk2 TB to hopefully avoid the TB sticking but I'm not sure.



I realize I forgot to comment more on the BMM ECU. It seems like a solid solution and is basically plug and plug for an NB. For the NA's you have to do some minor wiring changes but for the NB it's basically plug and play. You don't need to wire up an external wideband and wire it into the ECU which is nice, and Jesse shipped out the ECU configured fully for my NB1 (like the sensor settings/etc) so I just plug it in and it's ready to go. There are some minor things like updating the firmware with the latest firmware (FOME software) but it was pretty straightforward. For those that don't know the BMM ECU is based off of the FOME open source software. It stands for Free Open Motorsports ECU. I guess it originally started as RUSefi or some other previous name but has branched or changed since then. It is still getting software updates and is supported which is nice.

SimBa

Garage sandals are the GOAT. I'm running around the garage in flip flops way more often than I'd like to admit.

I'm surprised the car is starting up like OEM. That's been one of the most difficult things for me so far with tuning. Warm/Hot starts are dialed in fine, but I usually spend some time cranking on cold starts. The BMM unit looks cool. I'll be interested to see how your experience with it continues to go.

Roda

Congrats on the first start!

I'm really hoping to fire my K swap for the first time this week... still not quite finished with wiring.

SlowTeg

I'm pleasantly surprised as well. I know cold starts are usually a problem w/ standalones but this thing has better cold starts than warm starts. Warm starts it blips higher (which is normal I've read) and hunts ~1500rpm for a few seconds then settles down. I drove it around a bit yesterday tuning the fuel which is decent now and I used some existing timing maps out there to set the timing map and it drives well. I will probably tune it a bit more but I'm pretty happy with it and will probably get to installing the turbo pretty soon. I don't drive it much on the street so having a perfect warm start doesn't bother me as I'll fix it eventually but no rush. Being a long time honda guy I'm definitely missing the vtec up top but the turbo should help.

SlowTeg

Thx. You are definitely doing a whoooole lot of stuff. I've been watching your thread and it's coming along nicely! Hopefully my turbo setup can be reliable on track. I'm going to keep the boost down and just drive it and have fun.