Hey guys, apologies in advance for being wordy but I want some input on my plan with my build to see if I'm being too noob and not making sense.

Just to summarize, I have a 92 with the end goal of swapping a BP4W 1.8 I'm currently building with an EFR and MS3Pro. The new block has been machined with the forged internals waiting in my garage to assemble and add the turbo and supporting stuff. My 92 engine is bone stock right now, I've been picking away at the chassis with full suspension stuff, 3.9 torsen, Supermiata crossflow rad, buckets/roll bar/harnesses etc etc for supporting stuff for a fun street/light track car. I'm very comfortable wrenching on stuff and have done basic wiring stuff but ECUs and tuning is going to be new to me.

When possible I like to try and change only one thing or as little as possible at once for the inevitable issues and troubleshooting that eventually happens with stuff. That being said, I'm hesitant to go straight from stock 92 engine to a BP4W fully built by myself with forged internals, a turbo, sensor changes, coilpacks etc. etc since I don't want to be troubleshooting a bunch on initial startup/break in. I also am still saving for the turbo and supporting goodies. I've been parting out miatas for 3-4 years now to scavenge parts and make back money for my build. Most recently I've been parting out a rusted 2001 NB2 with a running VVT and 6 speed (I just got it for the drivetrain) so I happen to have a known good well running 1.8 VVT engine with the 6 speed mated to it.

Now for my plan to make this transition:
1) Order the MS3Pro for the 90-93 chassis, hook it up and make sure it runs my stock car fine. (is this a waste of time?)
2) Swap the VVT engine w 6 speed into my 92, make wiring changes per the VVT megathread, and adjust basemap accordingly
3) Get used to tunerstudio and tweak stuff to make sure everything runs well for the rest of the fall, keeping VVT engine all stock. I don't want to make any permanent modifications to this because I want to sell it whole later.
4) Come springtime, get my R8 coils and get it running and switched to sequential spark. (Maybe wiring for sequential fuel too on stock injectors?)
5) Finish building the turbo setup on the built 1.8, swap it in and sell the stock VVT.
6) Get the turbo setup tuned.

I understand I'll have to do some changes to IAT, TPS, wideband, etc. and wondering at what point this would be best to do as well.

Please roast my overcomplication and overthinking, and especially tell me if anything I'm doing won't work, or should do differently or any steps I could add in. Am I correct that the MS3Pro should be able to run all 3 of these setups "easily"?

 

Install the ECU first on the 1.6, and no it's not a waste of time. I would immediately modify your injector harness for sequential fuel, there's no point in not. You'll just swap your wideband over to the 1.8, same with injector harness and IAT sensor. Unplug your 1.6 "TPS", and use MAP accel enrichment, then when you go 1.8, you'll wire the TPS, crank sensor, cam sensor, and coil packs. Biggest thing you may have to do is extend the IAT sensor to a different location for turbo.

 

Thanks Curly, especially on using MAP accel enrichment to run the 1.6 engine, forgot about that. Would you suggest I switch right to using the NB2 VTPS once I have the VVT engine in or could I run it on MAPdot first?

I also did not realize NBs already ran sequential fuel so makes sense to switch to that right away in preparation for it. I assume it will be easier to modify my 1.6 batch injector harness or even make a new one rather than try and harvest the one on the VVT engine.

 

Your plan makes a lot of sense, and I think you’re taking a smart, step-by-step approach. Starting with the MS3Pro on your stock engine is a great idea, it’s definitely not a waste of time. It gives you the chance to figure out wiring, tuning, and any potential hiccups in a low-stakes setup before introducing more variables.
Swapping in the VVT engine is a solid next step since it’s a known good motor, and you’ll be able to learn how the MS3Pro handles VVT control. The basemaps should get you started, but you’ll need to tweak them to get things running smoothly. Running the VVT engine stock for a bit will also help you get familiar with tuning before diving into the turbo build

Adding R8 coils and switching to sequential spark and fuel during the VVT phase makes sense, it’s good practice for the built motor and turbo setup. Plus, doing the sensor changes (IAT, TPS, wideband, etc.) during this phase will make the transition to the turbo setup much smoother.

Overall, I don’t think you’re overcomplicating things, it’s actually a really well-thought-out plan to avoid troubleshooting everything all at once. The MS3Pro is fully capable of handling all three setups, so you’re good there.

 

I like LS2 truck coils from a junkyard best.

 

Thank you! I ended up a bit tight on time before putting the car away for the winter so didn't get to swapping to sequential fuel and spark, (still NA coil/wires temporarily) but everything else I did according to plan. VVT engine feels soo much better compared to the 1.6, especially the low-mid range torque. Looking forward to getting back to it as soon as spring hits, building my own cam/crank/vvt sub harness and re pinning all the connectors was surprisingly enjoyable.

 

Thanks sixshooter, any particular reasons? I know they seem pretty tried and true, I just hate how messy they look (stupid, I know).
Seems like a lot of people are starting to run the R8 COPs and that they're better than the Toyota COPs and similar options for a good price point

 

http://sadfab.com/prod%209005%20miata%20i.html