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Doc Brown
Doc Brown Dork
5/6/18 5:16 p.m.

Y'all might remember my Miata project from before the great photobucket disaster of 2017.  Whelp, I reckon its time to post an update.  The original build thread is FUBAR, however if your curiosity get the best of you,  then you can read through the original build adventure and see the pictures.  Yes, the photobucket links are all cut but the photos are still available to view with a clever plug-in.  I'll post the details on how to access the original build thread including the color photos in a moment...... 

A quick recap for the folks that are too lazy to read the original post....





Way back in the summer of 2011 I picked up a rust free Miata that hailed from the state of Arizona.   The car was everything you would expect from a Miata, but I wanted to try something different.  I wanted to put together a commuter car that handled great, stopped great and delivered 50 MPG.  In retrospect, those were some pretty ambitious goals.  Luckily my ignorance  to the overwhelming, monumental, colossal, and immense  hurdle it would take to realistically achieve that sort of fuel mileage goal was pretty strong.   Really, how hard could it be?






...so here is the finial solution....... The engine was replaced with a 1.3L powerplant gleaned from a lowly ford Festiva.  Although this engine bolts right up to the Miata gearbox,  a significant amount of Miata  specific parts had to be swapped over to make the little 1.3 engine fit the RWD platform.  In the end this engine was one of a kind.    Once the engine was in place  and running, I embarked on a six year odyssey to tune the engine to make the maximum amount of power and the least amount of fuel.    Making power is simple... just add more fuel and air... Making power economically take a bit more finesse.  During my journey I encountered admirers and hatters.  The hatters perplexed me, because this was a honest high performance endeavor using every hot rodders trick to boost performance but somehow this was insulting to them.  Meah, I do things my way, I often take the road less traveled.

Performance is subject to debate.  The engine produced a E36 M3load of low end torque exactly where you wanted it to be  Acceleration  was on par with a 1.8L Miata ....up to 4500 RPM.  After 4500 RPM the engine sort of stopped making any sort of usable power.   For the street this was the perfect solution.... defiantly not a track car by any means.  Most of the modifications are covered in the original build thread.






Modifications were not limited to the engine, the gearbox was rebuilt using an early RX-7 fifth gear set to boost overdrive.  Every little bit counts...






Along the way, a 3.90 Torsen replaced the 4.10 Torsen.  





                                                                              Zoom Zoom everyday in a completely custom built car for 70,000 miles!





                                                                                          The little B3 engine took me on countless journeys. 







...Because I don't like to suffer, the interior was tastefully trimmed in leather and the air conditioning system was fully functional.







To date, the best I have gotten was 52.25 MPG... not too shabby.  Realistically the car delivered an honest 45 MPG during the daily commute.   No special tricks or techniques.... just jump in and drive.  





The clutch has been problematic for the past year or so.  I like to think the engine makes too much low end torque, but honestly I don't have a clue why the clutch wont hold after 70K miles.  The car was still very much drivable, but was no longer able to launch when I mashed the pedal to the floor with extreme prejudice.  ... so out came the engine for a lookie.






Not looking good boys... looks like we got issues with the spinny things.sad  





An engine is fitted with a new clutch and slid back into the bay.





Whelp, almost done.  Needless to say I have learned a thing or two over the past six years.  I say let's kick it up a notch and see what happens...devil



OK folks, that brings us up to date.  If you wish to see the beginning of the story, you will need to install a plug-in for your browser to repair the damaged links to the photos.

For instance, if you use Firefox as a browser, just google 'firefox photobucket plug-in' and install the plug in.  Plug-ins are available for Chrome, Internet explorer, Opera and others.

Original build thread.

Alternative build thread from day 1 of the build

The B3 dyno used to develop and fine tune the engine.

  Stay tuned!

wheelsmithy GRM+ Memberand Dork
5/6/18 7:40 p.m.

I love this build. That is all.

Mezzanine Dork
5/7/18 8:16 a.m.

One of your admirers here - I'm a little sad to see the 1.3 go, but always up for following along with a new adventure.

dherr Reader
5/7/18 8:20 a.m.

Glad to see where this has progressed to. I can't imagine driving my MX5 only to 4500 RPM, so I am pretty certain you will be pleased with the difference. If you want fuel economy, just keep you foot out of it smiley

Great looking car by the way!

Doc Brown
Doc Brown Dork
5/7/18 10:47 a.m.

In reply to Mezzanine :

I was a bit worried that no one would realize I switched engines.  I guess its kind of obvious, but 'ya never know.  Anyway the adventure continues.

Doc Brown
Doc Brown Dork
5/7/18 11:20 a.m.

The new engine.....



So along with the new clutch, I also replaced the engine.... if you haven't noticed already.

Anyway the new engine is from a 2000 Miata and has 40K original miles on it.  This engine is no pig in a poke,  I had it running and drove the car it came from.  Its a solid base to start with.  As some of you folks may or may not know, the 99 and up engines feature 9.5:1 compression ratio, solid lifters and a very desirable intake manifold.  The only downfall of the 99-2000 engines is the clunky cast iron exhaust manifold....  Apparently they flow like E36 M3  and aren't even good for a boat anchor.   The good news is this engine is rated for 140 HP in stock trim.  The bad news is most of that HP comes in above the RPM range I normally drive at.   I'll need to sort this out.



Very clean!



The exhaust manifold was replaced with a $74.00 header that I got on Amazon (free shipping).  The header is NFG out of the box if you wand a direct bolt in.  Apparently this header has the converter flange welded in the wrong clock position and the EGR bung is angled wrong.  Meh, no big deal.  

What I like about this header is that it is a 4-2-1.  Should be good for a bit more torque on the low end.



The crank trigger EDIS-4 ignition system from the 1.3 was a direct bolt on.



The engine is tarted up with a cut down red cam cover (good for 10 hp) and a pair of OBX cam sprockets.



Stay tuned!



pres589 PowerDork
5/7/18 11:23 a.m.

I do look the look of that cam cover in crinkly red.  

Interested to see where you take this.

Doc Brown
Doc Brown Dork
5/20/18 2:53 p.m.

Thanks for the comments!    of course I read every one, but sometimes I forget to answer them.  I more or less suck at internetting.

OK,  its been a long two weeks.  I have been sorting out exhaust issues and whatnot, but finally the day has come to turn the key and see what happens.  ....but first a few pictures.


The old exhaust was too small for the new engine and I didn't feel like fabricating something .... so I picked up this shinny bit of kit.  It is a Yonaka fully polished stainless steel system that weighs significantly less than a stock NA system.


The new exhaust is what I would call El-Cheapo... and it is.  The welds actually look pretty good, color me impressed.


The El-Cheapo header and the El-Cheapo exhaust were not compatible with each other so  a bit of fabricating was in the works...


I like using these V-clamp thingys.  The trouble is, the good ones are not good and the cheap ones are sometimes better...if that makes any sense.   


Yeah, no weld porn here.  My welds get the job done, but ain't so pretty.


Here is a little pipe I made to connect the header to the rest of the exhaust.


And last but not least, the all important first start video.... enjoy!


Stay tuned!



Dusterbd13 MegaDork
5/20/18 3:00 p.m.

What brand of exhaust is that? My nb needssomething better for the supercharger...

Doc Brown
Doc Brown Dork
5/20/18 3:25 p.m.

The exhaust is a Yonaka and was sourced from Amazon for $319.00.  The fitment is good and easy to install.    The OD of the pipes is 2.5 inch.   There are a bunch of reviews on YouTube and the takeaway is the exhaust is not too farty and generally has a good sound.

Doc Brown
Doc Brown Dork
6/6/18 8:24 p.m.

Wow, summer is legally here and I'm still driving the Saturnsad.  I reckon we need to do something about that...  Anyway, my goal is to get the car back on the road by next Wednesdaysmiley



So, here is a funny story.  Last summer the young girl at the drive through said... 'this looks like a car a younger person would drive' ...  Whelp,  I hate to say it, but there is some truth in that statement.  Anyway, now that I have an awesome engine I really don't need the racing stripes...  I guess that's sort of bassackwards ... welcome to my world.

Getting the strips off was no easy task.  The paint on the front clip is still original and looks fine,  the last thing I wanted to do was to damage the paint by removing the decals.  It took several days of effort to remove the decals and residue.  The bulk of the sticker residue was removed with soap and hot water.   This takes forever to do....

On the other hand, the trunk lid suffered a bit when the decals were removed.  Since Im an optimist, I saw this as an opportunity  to try various chemicals ......

This E36 M3 works the best, unfortunately it also scratches the paint.  Meh the paint was already FUBAR so no big deal.  Interestingly enough 3M adhesive remover is #2 choice but there is a huge gap between fast orange and the 3M product.   I think the difficulty stems from the fact the decals were some E36 M3 brand with some crazy unknown adhesive. 


Since the car is so close to being R -spec, a trunk spoiler needs to be installed... 'ya know, to keep the car stable whist I drive through the urban jungle.   I was kinda hoping the spoiler would cover the damaged paint, but no such luck.


Under the hood, things are progressing.  For now I'm going to try and cobble up something to filter the air.  The OEM E36 M3 almost works... a few parts are needed to  connect the NA filter box to the NB intake pipe.  Parts are on order.... 

Stay tuned!




mhdelano None
6/7/18 1:00 p.m.

What are your plans for the new engine?  What kind of tuning strategy? Maximize power with your custom engine management?  Love the build!

Doc Brown
Doc Brown Dork
6/7/18 4:09 p.m.

In reply to mhdelano :

That's a great question!

When looking at the big picture, the car is now sort of "stock"..... what I mean to say is it's more or less just another Miata with a 1.8 BP.

Once you take a closer look and add up all the little details I think the car is still unique.  The modified transmission and the 3.90 Torsen should help out on the highway... and that's where the bulk of my miles are accumulated. 

The BP engine will get tuned a few different ways.  I'm going to try a power tune, a torque tune and an economy tune.  Ultimately I'm still a 12 year old at heart and would like to do donuts and other shenanigans.  I'm not necessarily interested in track performance, however 0-60 performance will be addressed. 

AWSX1686 GRM+ Memberand Dork
6/8/18 2:36 p.m.

Following along! I need to look back and check out the RX7 gear in the miata trans thing...

Doc Brown
Doc Brown Dork
6/8/18 4:01 p.m.

In reply to AWSX1686 :

The RX-7 fifth gear swap is here RX-7 fifth gear.  It starts about half way down the page. 

Doc Brown
Doc Brown Dork
6/8/18 9:06 p.m.

Since everyone like pictures and picture hosting is free, let's clog up the internet with useless photos.

OK,  today's project is connecting the airbox to the rest of the intake tract.


Connecting the intake tract to the airbox could be simple if I wanted to use the mass air flow sensor aka MAF.  ....But since I'm rocking the megasquirt, I don't need the MAF and somehow I feel like it would restrict the airflow. Anyway, I'm stubborn and I decided to build something to replace the MAF.

These joiners and whatnot were sourced through Amazon.  I went ahead and got stainless steel joiners because MIG welding was definitely going to happen.  The stainless parts were about half the cost of the aluminum parts. I'm not sure what the logic is with the cost, but cheap is always better.  

Fast forward a bit and now we have a perfect replica of the MAF, but without all the crap that restricts air flow.  Nice!  


Fits like a glove!   I was also able to salvage the O ring from the MAF to seal the new part to the airbox.  


Everything was going to plan.... then I discovered a problem.......


The El Cheapo header gets dangerously close the the airbox.    Now I reckon this won't end well no mater what I do, however if I do nothing then things won't end well a lot faster.


I forget what this stuff is called, it's a lot like fiberglass but it's made for heat.  I seem to recall it's sort of flame proof or something.  I guess if nothing else, smoke is better than fire.


Pop rivets to the rescue!  Although you cant see 'em, there is a short stack of washers between the heat shield and the airbox.  The washers stand the shield off a bit and provide an air gap that should make the heat shield work good'er.   We'll see.   Anyway, pop rivets are awesome.  back in the day I rebuilt my Chevy truck with pop rivets.   I like to think pop rivets are the sophisticated gentleman's version of duct tape.


I have a feeling we will re-visit this soon.....  


Now that we have a sealed intake tract, lets drill holes in it...'ya know , so we can mount the intake temperature sensor. aka IAT.  I poached this nugget from my 96 Saturn SW1.  This was probably the last good part on that car.  Sadly the car was sent off to the crusher a week ago.  A moment of silence for Uncle Buck, the greatest car ever made.


I'm not sure if this is the best place to mount the sensor, but it seems logical to put it as close to the throttle body as possible.    Speaking about the throttle body, this is the stock TB that came with the engine.  I cut off the plumbing for the coolant because hell no....  Heating the throttle body is bad M-kay.  I also eliminated the idle control valve because it was ugly and got in the way.   The TB is equipped with an air bleed screw to set the idle... and that's good enough for me. 


Stay tuned!



Doc Brown
Doc Brown Dork
6/13/18 8:41 p.m.
Doc Brown
Doc Brown Dork
6/25/18 6:20 p.m.

The project took a slight detour when I damaged the paint on the trunk lid.  Let's take a look at what I have been doing...



This dent by the tail light has always bothered me.  Since the trunk was going to get repainted, I figured I would tackle some body work that I've been putting off.  Now, on a twenty four year old car, its easy to get carried away and start fixing everything.  Project creep was limited to both quarter panels and the trunk lid.  


Fast forward a bit and the dent is gone.  I think the dent has been there for at least eight years... even though the paint was damaged right down to the metal, no rust had formed.  keeping the car garaged most likely helped.


Five minor dings have been vanquished on this side of the car.


I'm not a big fan of spray can paint products, but this stuff is awesome! 


Its hard to tell, but both quarter panels and the trunk lid have been shot with white epoxy primer sealer.  While body work takes skill,  prep work makes a paint job.  


Shop-line epoxy primer / sealer.   Shop-line is budget friendly, however this E36 M3 is still expensive.  I have just over $300.00 locked up in paint products and another hundy in body work supplies.  When all said and done these minor repairs are going to cost just over $400.00.


The rear filler panel was shot with black epoxy / sealer.   In the past, I have used black epoxy sealer as a satin finish top coat.  The white area between the spoiler and the filler panel will also get shot with the black epoxy sealer.  This should give a nice black out look to the rear of the car.  The hard top and A pillars are going to be painted gloss black.   I'm planning on finishing the car over the 4th of July holiday. 


Once the paint and body work are finished, its time to bring out the new toy!  This little guy is a stand alone performance analyzer.     The car is still more or less set at baseline tune and with this analyzer we should be able to track  improvements.


Stay tuned!





badwaytolive Reader
6/26/18 1:00 p.m.

In for analyzed performance- nice work!

Mezzanine Dork
6/26/18 1:42 p.m.

What has your experience been with performance analyzers? I'm curious how well they work.

alfadriver GRM+ Memberand MegaDork
6/26/18 2:07 p.m.

Somehow I missed this new thread, and I TOO am very interested in how this turns out.

I've been thinking of the same 5th gear and FDR change in my '99, and now that we are older, the speed is less important than just enjoying the drive.  

Then again, IIRC, I found a swap page where the end result was 1-3 was almost the same engine-speed ratio, 4th was pretty tall, and 5th would be close to 75% of the original engine-road speed.  So at 70, instead of 4k, it would be closer to 3k.

If this work is easier- well, there you go.  One question- how did you deal with the speedo/odo?  Is that in the rear of the car or in the trans output?

Once I restore my car, that would be a worthwhile project.  Until then I will try to keep closer tabs on your project.

Doc Brown
Doc Brown Dork
6/26/18 6:23 p.m.

In reply to Mezzanine :

The Performance analyzer is still a big mystery to me.  I have actually taken it apart to see what sort of magic was  being done and still no clue.   Time will tell..

Before I purchased the unit I did check the internet  for reviews.  Here is one of many G tech PRO RR reviews  It would appear the device is fairly consistent and more accurate than a cell phone.  This should be fine for my application.  As long as whatever numbers it generates is consistent then it will show where performance improvements have been made.  I think it uses a lot of clever math along with its sensors to figure stuff out.   Stuff like 0-60 accelerations should be accurate and can be compared stock Miata data.  The other stuff like HP and torque may be subject to debate.  Anyway,  I'm pretty excited to try it out, but unfortunately the car is stuck in the garage for another week.  I guess I could try it out on the Saturn...LOL

In reply to alfadriver :

As I recall,the speedo has a 5% error due to the 3.90 axle.   Since the speedometer has always been a bit off.... it is slightly more accurate now.   The odometer on the other hand has to be corrected using a bit of math when calculating fuel consumption.  

I'm not 100% sure there is a legitimate fix for this.  My NA has a mechanical speedometer and the axle is out of a car with an electric speedometer.  I think it may be possible to take the  gear off the electronic speed sensor and fit it to the speedometer cable adapter in the transmission.  I have the parts to do this, but haven't tried yet.

Stay tuned!

alfadriver GRM+ Memberand MegaDork
6/27/18 6:37 a.m.

In reply to Doc Brown :

Given that my car is an NB, I'm betting that I have an electric speed sensor.  It would fit well with the digital odo.  

Run_Away HalfDork
6/27/18 6:49 a.m.

Excellent! This was one of my favourite builds.


I will say I was hoping for a turbo B3 though.

RossD MegaDork
6/27/18 9:00 a.m.

MOAR! please...

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