Gday New User, First Post About NA6 Engine Swap

[Hammer]

Good luck on the project. Keep us updated with pix.

[Szemen]

Put an SVT engine in it!

[Fatty]

Flyin Miata sell a kit with all the parts needed for the engine swap.

[Jeo]

Welcome.

Mine had the swap done by a previous owner. The car was running when I bought it but it took plenty of stuffing about on my part to get it running correctly.

If there's nothing wrong with your current motor, I wouldn't bother. You'll get better value with other mods.

[Jeo]

SVT is a form of variable valve timing on the intake cam.

Basic explanation of an ECU, stolen from the all knowing wikipedia...

An engine control unit (ECU) is an electronic control unit which controls various aspects of an internal combustion engine's operation. The simplest ECUs control only the quantity of fuel injected into each cylinder or the spark timing in an SI engine. More advanced ECUs found on most modern cars also control the ignition timing, variable valve timing (VVT), the level of boost maintained by the turbocharger (in turbocharged cars), and other peripherals.

ECUs determine the quantity of fuel, ignition timing and other parameters by monitoring the engine through sensors, and reading values from multidimensional maps.

Before ECUs, fuel injection, ignition timing, and idle speed were directly controlled by mechanical and pneumatic sensors

By swapping over just the engine itself and leaving all of the 1.6 sensors and ecu, the new 1.8 will run, just not as well as it should. This was what was done with my car, which then took a decent amount of effort on my part to rectify. The most common solution to this is either swapping over all of the 1.8 wiring, sensors, ecu, etc; or going for an aftermarket ecu/piggyback (a piggyback sits between the ecu and the engine and then adjusts the signals before the ecu see';s them to get the desired results).

No difference between 89 and 90, the kit is the same for all 1.6 NA's.

Enlarged intake, CAI, extractor and exhaust should net you a good chunk more power. A 2 1/4" exhaust system should be acceptable.

[SuperMazdaKart]

bit of a waste of money in my opinion if theres nothing wrong with the 1.6 engine, you'll gain rwkw of about 73kw instead of the 1.6s 65kw. but hey, it's your money & time

money better spent on changing to the Torsen LSD instead.

[StanTheMan]

if you want more power with using same amount of fuel its going to be pretty hard.

extractors. CAI. AFM ajustment , Timing Adjustment will certainly make it run more powerful....and if you drive it correctly will make it more efficient. But I bet you when you have these mods you will end up using them for getting more power. As a well as using more petrol.

Maybe The only other way would be to replace your ECU with a brand spanking new one. Not one that's been sitting there for 20 years. An ECU which was built this year or not long ago. Our ECU's have been in service for 20 years. The silcone in the capacitors have probably leaked out or dried out. So our ECU's are probably not running as efficiently as they were 20 years ago. Of course this is not my own theory but i've been reading up on it. but it makes sense.
What do the experts think about this?
Lets have some Myth Busting.


& before someone say's ohh I've got a JDM ECU here it runs more powerfull. because its tuned for 100 ron. Don't believe them unless they can give you written proof from Mazda that they bothered to change the tuning for thier own Japanese market. & when the give you the proof.......post it here. So we can all benefit.

some more myth busting.

However at the end of the day this would prolly only freshen it up a little. If this was to work it woulnd be an earth shattering difference.

Just some thoughts.

[Jeo]

Didn't someone here post up not that long ago, back to back dyno results from the same car with both Aus and Jap ECUs?

I'm pretty sure there was no difference either way though.

[doogle]

if you want more power with using same amount of fuel its going to be pretty hard.

extractors. CAI. AFM ajustment , Timing Adjustment will certainly make it run more powerful....

I don't know much about the engine myself, but I'd also be looking for more power from my NA6 with simple mods and keep the fuel economy down. What can be done with AFM adjustment? Timing adjustment isn't a DIY job either is it?

For now just simple mods, but perhaps a better engine for me one day too watching this thread with interest!

[bruce]

It would have been easier and cheaper to have purchased a NA8 in the first place.
I would just keep the money in your pocket and wait until the current motor dies (which may be never).
I doubt driving a 1.6 and a 1.8, you could barely tell the difference between either.

[doogle]

funnily enough i actually put the mania enlarged intake on last friday. makes a fairly big difference in acceleration (perhaps a little more psychologically ), a very nice noise. looks nice, but fits horribly. the parts they supply makes it rest against the top radiator hose at the moment which heats up the intake (made of metal not plastic), kinda defeating the purpose of the CAI a little, although i wouldn't be sure if this is significant. but its probably not worth the money in my opinion.

[StanTheMan]

Inside the afm is a spring. It restricts the amount the flap opens at a certain point with a certain amount of airflow.
if you were to tighten or loosen the spring it would give the computer a diferent signal & make it supply a different air & fuel mixture.
The tuning of theses afm is reputed to be reasonably inaccurate from the factory & can be improved upon. I did it by the feel of the seat. (not very scientific) It did improve but hardly noticeable.

the NA's ECU also has a crystal which controls the RPM & indirectly influences the fuel flow. if you were to change the crystal to a different one within a slighly higher frequency. It would trick the computer into thinking the engine is reving at 7200 when in actual fact......its reving at 7500 rpm.
& because your engine is reving at a higher rate but fuel delivery is a a lower rate it increased top end power slightly as mx5 engine from the factory, run overly rich at high rpm.

you can find a big write up on miata.net about it All the information is in 1 particular thread. I can't recall all the specifics

Tread carefully. If you do both, you can run too lean & have fatal consequences. The crystal is only about $3-$5 at places like dick smith.

make sure you have access to a spare computer as a new one will cost a bit especialy if you are desperate for one if you stuff up the soldering.
clear as mud

[StanTheMan]

timing adjustment

at idle the spark happens 10 deg before top dead centre. Its the base timing. if you increase the base timing to say 14 or 16 deg. the spark ignites the fuel earlier. & there fore has a higher compression as the fuel has more time to explode. or something.

Its easily adjusted on the NA's but again you need to proceed with care. Some engines don't like it as much as others. I don't know the reason. so when you advance the timing be sure to watch out for pinging.

http://www.miata.net/garage/ignition.html

again its not an earth shattering difference but makes it a tiny bit livelier
have fun

[adherent]

It might not give you a lot of power but definitely do the timing advance and maybe the AFM trick because its simple and free, and you will notice the difference. And learn to love your engine above 4000 rpm.

[StanTheMan]

in that case you may find by reving past 4000 rpm that you actually have plenty of power.

by not reving past 4000 rpm you are not accessing about 20% of your power.