Flyin Miatas guys are out of the office obviously for the weekend so let's talk about it here, just because
I wonder, I’m close to pulling the trigger on a 1.6 turbo setup for my 1990. What I wonder about is if in the future the 1.6 gets replaced with a 1.8, how much of the turbo swaps over? Obviously manifold and down pipe would need to change.
Being that the newest 1.6 engines are 27 years old, I feel like if the motor fails I’ll have better luck finding a 1.8 to replace it with. Would a voodoo box and the 1.6 computer still work for a turbo 1.8? I already have a 1.8 swapped 1.6 car, running the stock 1.6 computer.
thanks!
Nope.
I'm pretty sure very little swaps over.
Why not swap to the 1.8L now?
1.6 manifolds won't fit the 1.8.
If you were running it on megasquirt you should be only looking at changing the manifold and possibly down pipe depending on clearance. I don't have any experience with how the voodoo box works.
Turboeric said:
1.6 manifolds won't fit the 1.8.
Yeah, those would definitely not work.
SVreX (Forum Supporter) said:
Nope.
I'm pretty sure very little swaps over.
Why not swap to the 1.8L now?
Well, I don't plan to go 1.8, but if in the future the motor does need to go, I feel the likely 1.6 candidates are dwindling.
Hey, I've done this! But I did it the hard way, I also converted the car to effectively be a MSM from a wiring perspective. This is not something I recommend. IIRC, I had to change the manifold but I was able to retain the downpipe with some hammer time. Because I changed to a 1.8 throttle body at the same time, I needed a new throttle body inlet pipe.
The Voodoo Box will not have a problem if you run the 1.8 on the 1.6 ECU with 1.8 injectors.
Keith Tanner said:
Hey, I've done this! But I did it the hard way, I also converted the car to effectively be a MSM from a wiring perspective. This is not something I recommend. IIRC, I had to change the manifold but I was able to retain the downpipe with some hammer time. Because I changed to a 1.8 throttle body at the same time, I needed a new throttle body inlet pipe.
The Voodoo Box will not have a problem if you run the 1.8 on the 1.6 ECU with 1.8 injectors.
Thanks Keith that's exactly the info I was hoping for! Sounds like if I retain the 1.6 throttle body like I did in my other 1.8 swap I'll be good with just a manifold swap
I'll try to confirm that. I seem to recall telling myself that I wish I'd picked up a new downpipe, and I have a 1.8 downpipe in my stash for the next time I find myself in that area with a wrench.
This is based on the FM turbo stuff. There may be differences in other vendor's products.
EvanB (Forum Supporter) said:
If you were running it on megasquirt you should be only looking at changing the manifold and possibly down pipe depending on clearance. I don't have any experience with how the voodoo box works.
Just to reiterate this... the initial learning curve with Megasquirt is a bit intimidating, but once you learn it EVERYTHING turbo becomes so much easier. Moving to a 1.8 should be as simple as a manifold and tune, maybe a downpipe. The 1.8 will spool up the turbo a lot faster than the 1.6, and if you get Megasquirt 3 you can also control the VVT on the later 1.8 motors.
The downside is that you are now responsible for everything: cold start, AC idle compensation, etc. All the nasty corners of the map that take 80% of the time to figure out and sort out. It can certainly be done, but simple posts like this one really, really, really underplay the amount of work it takes.
The nice thing about a piggyback is that you get to keep all the factory programming which has thousands of hours of work in it. I've owned both and done conversions with both - a 1.6 conversion with a stock ECU is not a challenging prospect.
You will get better spool with a well-tuned Megasquirt than with a fuel-only piggyback regardless of engine capacity.
^ fair comment, and I agree that it is a lot of work to learn how to deal with MS. I do think it's worth pointing out though that the stuff that takes all the time (idle tuning, compensation, etc.) is "nice to have" stuff that isn't required to drive the car. It did take me a few months to get my idle tuned as well as the OEM idle tuning. However, the car started and ran safely and reliably on the day that I put the Megasquirt in. From there I just tweaked it whenever I had the time.
The time you put into learning how to tune is a crash course in engine management. The benefits of understanding it went way beyond the tune itself for me.
The other big advantage of running an aftermarket ECU is being able to safely run bigger injectors. If you really want to reach the power potential with the turbo, this is an unavoidable step and to my knowledge you can't do it with a stock ECU.
Of course, a programmable ECU unlocks all sorts of potential. If you want to make twice the horsepower of a stock engine, it's a requirement. You're basically making the car into a factory turbo car. But getting that "nice to have" stuff going is a lot of work and a lot of learning and if done right, will take quite a bit of time. I've driven enough cars with half-tuned ECUs to not want to do it anymore. Turns out that tuning ECUs well is basically a career. And forums (1000 guys who have all tuned one car and may or may not have bothered with the nice to have stuff) are no substitute for pros (one guy who has tuned 1000 cars and examined datalogs from them all under all conditions). I just want anyone considering an aftermarket ECU to go in with their eyes open. Chances are, your car will never really run as well as stock under all conditions.
If you're looking at the same power level that you can get with a Voodoo Box, you don't need those bigger injectors. That's for if you want to go further.
ShinnyGroove (Forum Supporter) said:
^ fair comment, and I agree that it is a lot of work to learn how to deal with MS. I do think it's worth pointing out though that the stuff that takes all the time (idle tuning, compensation, etc.) is "nice to have" stuff that isn't required to drive the car. It did take me a few months to get my idle tuned as well as the OEM idle tuning. However, the car started and ran safely and reliably on the day that I put the Megasquirt in. From there I just tweaked it whenever I had the time.
The time you put into learning how to tune is a crash course in engine management. The benefits of understanding it went way beyond the tune itself for me.
The other big advantage of running an aftermarket ECU is being able to safely run bigger injectors. If you really want to reach the power potential with the turbo, this is an unavoidable step and to my knowledge you can't do it with a stock ECU.
With a turbo, some of thoes "nice to haves" are actually requirements. Like transient fuel and transient spark- those being wrong can actually blow up the engine. Especially if the hope is to take it on the track or autocross it.
BTW, once you reach 100 cars that you've done, the 1000's of hours can be condensed quite a bit on a single car- as you double and triple up things being calibrated at once. But for the first car, yea, 1000's of hours. And for a fleet of 800,000 tucks per year with all the varitions in the market, 1000's of hours and hundreds of thousands of miles.
I feel weird pointing to the document Keith probably wrote in a thread with Keith in it, but here's a nice starting point if you're not going full standalone:
https://www.flyinmiata.com/tech/1.8_conversion.php
In depth doc:
https://www.flyinmiata.com/support/instructions/misc/1.8swap.pdf
Miata Turbo VVT (1.8) swap.
https://www.miataturbo.net/engine-performance-56/definitive-vvt-swap-into-90-97-chassis-megathread-80469/
Some is specific to doing a VVT swap, but most is the same if I'm remembering correctly. I have a VVT engine I plan on plopping in one of my cars shortly so I've been down and around this rabbit hole. All my chassis/parts are na6. I think part of the fun of doing a swap with a standalone is playing with the tuning. In the n/a form miata are pretty forgiving and when boosted so long as you're careful they're not too crazy. Yes, the OEM ecu is probably going to be smoother than you, but it kinda depends on what sort of car you're playing with. I'm not taking my exocet or miata out when it's freezing or raining, doing a lot of crazy starting conditions, etc. So it's a fine compromise in my. book. You'll have to assess how the compromise stacks up for you.
You didn't say what your end goal is for power etc., but I'll offer these thoughts if you're thinking more on the mild side and grassroots budget. My sons and I have built several 1.6 and 1.8 boosted Miatas in the 150-170WHP range. I know everyone wants 200+, but these Miatas are fast and bulletproof. We've built them with cheap used turbos and cheap used superchargers and while the torque/HP curves vary a little bit, they're all just a hoot and you wouldn't know whether they're 1.6 or 1.8 without popping the hood. Our latest one was with an older Greddy kit we got for cheap. We used the manifold, turbo, intercooler, etc., but ditched the piggyback ECU and 5th injector, so no fabrication, just tuning on a Megasquirt after we put in larger injectors.
Around here in Michigan, it's pretty easy to find used 1.6 engines in usable condition, or parts cars, because everyone is looking for a 1.8. 1.8s are hard to find and sell fast. So if you're not planning on rebuilding, 1.6s are a value.
We've put Megasquirt PnP's on the cars, so some of the savings by using old stuff goes into the ECU. The base tunes are very good/conservative: experimentation, data logging, and an hour of dyno time gets them dialed in nicely, usually with a pickup of 10+HP.
If you're not interested in fabrication or tuning, buy a ready-made setup. But I thought I'd throw this out if you're up for some of that kind of work.
By the way, My son Jack has a 1.8 car with FM turbo at 220+WHP, former GRM project car, and it's a hoot+. But it's also had a few more issues since it's stressed more.
In reply to Carl Heideman :
Interesting path- when Doc was making his fuel economy 1.3l Miata, I had thought a lightly boosted 1.6 with a very modified gearbox and final drive would actually net some amazing fuel eocnomy with good performance.
(back when someone had a mazda gearbox web page- I had thought I found a set where it was a special RX7 gear set with the lowest final drive for a Miata that one could find in the world- which woud have lowered 5th gear by 25%. 1-3 would be really close to stock, 4th would be something like 10-15% lower, too).
In reply to Carl Heideman :
Solid advice, it's what i stuck with in my Exocet. I went with a rotrex, but same principle. Lowish boost on a 1.6 and it'll buzz around all day like that without breaking transmissions or rear ends and the heat is much more manageable at those levels.
alfadriver (Forum Supporter) said:
With a turbo, some of thoes "nice to haves" are actually requirements. Like transient fuel and transient spark- those being wrong can actually blow up the engine. Especially if the hope is to take it on the track or autocross it.
BTW, once you reach 100 cars that you've done, the 1000's of hours can be condensed quite a bit on a single car- as you double and triple up things being calibrated at once. But for the first car, yea, 1000's of hours. And for a fleet of 800,000 tucks per year with all the varitions in the market, 1000's of hours and hundreds of thousands of miles.
Maybe my experience is different from everyone else's, but I found the base maps to be quite conservative and safe. With turbo Miatae, whatever you're doing has been done a million times before and answers are easily found on the web. Putting in bigger injectors was as simple as changing ReqFuel and dwell times. The Autotune feature that comes with TunerStudio worked wonderfully to get the fuel table dialed in to 90% of optimal. Acceleration enrichments took a few tries, but once you understand how PID controllers work it's fairly easy to experiment and data logs tell you clearly what you need to do. No danger to the motor while doing it, it just affects how the car feels coming off of idle. Speaking of idle... yes, it took a while to get it dialed in so it didn't oscillate up and down at stop lights, but again- no danger to the motor. I never touched the spark table until I took it to a pro tuner and put it on a dyno. Those adjustments netted me 7-8hp and brought me to 205whp, 195wtq. I drove the car like that for three years, including track days, without a single issue.
I do have an engineering background but I don't think I'm exceptional. I think that most people who can succeed in installing the hardware can learn this stuff witha little diligence and research. The performance difference between a 150whp car and a 200whp car is night and day, and the 200whp car can be every bit as reliable.
In reply to ShinnyGroove (Forum Supporter) :
A lot of people struggle with the transinents. So that could be binned into the "nice to haves" if people struggle.
And making sure idle does not stall the car is also super important- having a car constantly stall when stopping can be dangerous.
The point is that there are some very important development outside of the map that has to happen to make sure the car can be used reasonably well and safe. Some people can deal with that quickly, others- not so much.
Not to discourage anyone from doing that, as like you say, it's very rewarding and fun. Just making sure people are aware of the work. It's also not an endorsement of the piggyback designs.
Thanks guys.
I really don't expect more than 150-160 hp. I've fooled with megasquirt a couple times and know it's not for me. I have to many hobbies sucking up my time to spend a ton of time chasing that extra 20 hp. Maybe someday but I'd still have a shop tune it, I'd really rather the car drive like stock except when under boost. But I respect guys who put in the effort! Got to love the modern stuff where you can plug in a oft and be off and running lol.
thanks to everyone who chimed in!
Carl Heideman said:
You didn't say what your end goal is for power etc., but I'll offer these thoughts if you're thinking more on the mild side and grassroots budget. My sons and I have built several 1.6 and 1.8 boosted Miatas in the 150-170WHP range. I know everyone wants 200+, but these Miatas are fast and bulletproof. We've built them with cheap used turbos and cheap used superchargers and while the torque/HP curves vary a little bit, they're all just a hoot and you wouldn't know whether they're 1.6 or 1.8 without popping the hood. Our latest one was with an older Greddy kit we got for cheap. We used the manifold, turbo, intercooler, etc., but ditched the piggyback ECU and 5th injector, so no fabrication, just tuning on a Megasquirt after we put in larger injectors.
Around here in Michigan, it's pretty easy to find used 1.6 engines in usable condition, or parts cars, because everyone is looking for a 1.8. 1.8s are hard to find and sell fast. So if you're not planning on rebuilding, 1.6s are a value.
We've put Megasquirt PnP's on the cars, so some of the savings by using old stuff goes into the ECU. The base tunes are very good/conservative: experimentation, data logging, and an hour of dyno time gets them dialed in nicely, usually with a pickup of 10+HP.
If you're not interested in fabrication or tuning, buy a ready-made setup. But I thought I'd throw this out if you're up for some of that kind of work.
By the way, My son Jack has a 1.8 car with FM turbo at 220+WHP, former GRM project car, and it's a hoot+. But it's also had a few more issues since it's stressed more.
Thanks Carl! I'd be happy with about 160 for now, I think. I don't need crazy fast, but just quick and nice to live with would be fine. I had a turboed 96, and while a rocket, it never ran super well, especially hot starts. I didn't build it either. I'd give up a few ponies for it to just...work
