DIYPNP MegaSquirt – Step 2

Posted on September 18, 2011 | Leave a comment

Okay, time for an update. This step is essentially the initial assembly and build of the entire ECU. If you’ve ever done hobby electronics building, you’ll find this really easy as the boys from DIYAutoTune have done a great job in terms of marking everything and providing detailed instructions.

Considering the kit targets a large number of vehicles and models, the additional steps for my MX5 were mostly clear and available. I did find a few areas a little puzzling, but nothing where I had to specifically ask a question, as often the answer was available on a forum or a re-read of the guides eventually provided an answer.

I ordered the sequential injection add-on board which brings the total number of injector drivers up to four (4) from the default of two (2). I could have continued running with Batch injection, which at high RPM produces similar performance and ecconomy, but if I ever decide to upgrade to larger injectors (and I do) then having sequential will help with low RPM idle and fuel ecconomy – as firing a bunch of large injectors when the time for the next injection is long (as it is with low RPM) results in wasted fuel, wet walls and other bad things!

As far as assembly goes, the first thing to do is to fully read and re-read the entire assembly instructions including the additional application notes for the year/model MX5 I was building for.

I soldered and assembled in front of my study computer and left these two (2) websites open in front of me.

http://www.diyautotune.com/diypnp/docs1_5/main_assembly.html

http://www.diyautotune.com/diypnp/apps/n76/usdm-mazda-miata-9093-16b6-mt.html

That way I could solder/assemble and re-check the guides to ensure I was on the right path. As each component was individually marked and bagged, there really is little chance of doing the wrong thing – obviously this assumes you’ve used a solder iron in anger, and know your way around electronics – which I do/did.

In addition I also downloaded the Startup Maps zip file which contained a Excel spread sheet of the jumpers and hook-ups needed. This document helped explain what features you were taking from the standard harness and connecting into the MegaSquirt board. Obviously at this stage you are complete and really performing the final assembly/soldering steps.

I also grabbed an OEM ECU pin-out guide that I found on Miata.net, a copy of both are included here as images that you can click on to enlarge.

So after about 3-4 nights spending about 2 hours each I completed the entire kit and was ready to switch on and upload firmware etc. Next blog will cover off that process and further progress.

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DIYPNP MegaSquirt – Step 1

Posted on September 5, 2011 | Leave a comment

I’ve decided to embark on what will be a fairly interesting and lengthy project - to build and tune my own Engine Management System.

Based on the very popular MegaSquirt kit, I ordered a DIYPNP (do it yourself | plug-n-play) plus a few other bits from the guys at DIYAutoTune.com in the USA.

Specifically I ordered the following:

  1. a DIYPNP Nippon Denso 76pin (that suits the MX5) that is essentially a MicroSquirt module, mainboard and case that provides MegaSquirt2 capabilities.
  2. an Intake Air Temp sensor kit comprising a bung and all needed wires, connectors and something to simply plug straight into the existing MX5 harness (this will allow me to delete the restrictive Mass Air Flow meter).
  3. a sequential injection upgrade (that allows 4 injectors to be driven).
  4. a Serial-to-USB connector so that I can plug my notebook into the kit.
  5. an Innovate LC1 wideband O² sensor and controller (that allows me to measure the entire range of O² levels in the exhaust).

After parting with some ca$h, I waited just around a week for the package to arrive. Inside a neatly packed box was a well protected collection of plastic bags and boxes. Kit assembly seems to require at least basic soldering and some electronics experience – the required tools are fairly modest – a good quality soldering iron, digital multi-meter, a collection of tools for cutting/stripping and perhaps wires etc.

No instruction manual or guide book was included, but a link to a website where you can follow instructions for assembly. Considering the low cost nature of the kit, and the fact that it limits the killing of trees, I’m actually glad they didn’t!

The on-line instructions essentially direct you through each phase starting with low height components (resistors) and then ending with the tallest components (being the MicroSquirt daughter card).

A nice feature is that all components are neatly bagged and bundled with quantities outlined, so that each is essentially individually labelled. As they are marked, you simply just have to find the part on the PCB, insert correctly and then solder. So the kit is fairly easy to follow, and if you take time, should be a simple assembly process.

For my next post, I’ll hopefully looking at assembling the case, adding jumper wires and powering up the ECU for initial firmware and software configuration…

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Superlight Strut & Bleep-bleep

Posted on August 28, 2011 | Leave a comment

Over the past few weeks I installed a few things…

First things I tackled was the 10 minute installation of the Super Light IL Motorsport Strut Tower Brace Bar. This was the simplest and a very effective upgrade to the car – you can honestly notice the front end is now stiffer and doesn’t crash on bumps like before. The steering feels more solid and the more stable in tight bends - yes, very nice. Shock tower braces became standard on later special edition models.

The next thing I installed was a central locking kit and a basic alarm. Unlike the strut brace, this took over 10 hours to install. Mainly due to the large number of wires and existing old wiring that I neatened up, tied back and made good.

The alarm was installed for convenience (enables the central locking) and hopefully to distract would-be-thiefs or larks from messing with the car. I’ve also install a hidden disable switch that will kill the alarm. This was mainly so that I can work on the car, or just leave it secured in my garage and not have the alarm on, draining the battery, or chance it going off in the middle of the night ;-)

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Fuel Filter, Oxygen Sensor and Diff Axle Seal

Posted on July 17, 2011 | Leave a comment

Decided to replace a few things this weekend, being the fuel filter, O² narrow-band sensor and the differential axle-shaft seal. The car was sometimes idiling roughly and blowing black smoke when stomped on… so me thinks the O² was original (they only last about 6 or so years). The diff was leaking and you would have noticed this on my photos of the new exhaust system – the smell of burnt diff oil isn’t pleasant!

Fuel Filter: was fairly straight forward and I followed the well documented guide on Miata.net here > http://www.miata.net/garage/FuelFilterChange/index.html

Oxygen sensor: was also simple, but a bugger to get at due to where the new extractors and exhaust system had relocated the sensor – in small space between the gearbox and the body tunnel – not easy but I eventually removed the old sensor, cut the wires and solded a new sensor in-line. After starting the car noticeably idles smoother and was more quickly able to reach a stable idle when first started. I’m expecting my fuel economy to improve also… as it was kinda thirsty (and that isn’t just my right foot!).

Diff Axle-Shaft Seal: completed in about 1 hour and was easier than it seems. As I couldn’t find many guides with pictures, thought I’d add some here.

Step1 – get the rear in the air (the car that is) and take off the wheels. Remember to loosen the wheel nuts before you raise the car. It is way safer to strain on the wheel when the car is on the ground – once loose, you can raise the car and place on stands. I used axle stands, but did so near the jacking points – this let me work on the diff/axles without interference. Now is a good time to drain the diff oil and let it drip out whilst doing everything else.

Once you’ve removed the wheel and undone the four nuts (14mm) attaching the drive shaft to the diff flange you will realise you can’t remove the shaft off the flange unless the wheel hub can move away. Be careful when pulling/pushing on the shaft and flanges – the CV joint ends can pop open and it is possible for the ball-bearings to fall out etc.

Step2 – To make it easier to get the axle shaft off the diff flange, you can just remove the top nut and bolt that attaches the hub to the upper wishbone A-arm. If you can’t get the bolt out, just raise the hub slightly releasing pressure on the top bolt. Once the bolt is removed, you should be able to now pull the hub out slightly enough to release the shaft from the diff flange.

Step3 – The flange is securely held inside the diff, retained by a circular c-clip. It requires a lot of leverage to push the flange out, and I found using a lever between the flange itself and the diff housing to be the only way. After a lot of swearing and cursing, it eventually popped out. Be careful here not to damage anything, but in saying that, I exerted a lot of force and all was OK.

Step 4 – With the flange removed, carefully clean the edges around the diff housing being careful not to let any dirt or grunge enter the diff insides. The flange can be wiped clean where the seal would be seated. You can see the flange with the new seal. You can now also remove the seal attached to the diff. I used a flat blade to slowly edge the seal out, careful again not to scar or mark the diff housing.

Step5 – Now that the old seal is removed, grab the new seal and coat edges with fresh diff oil. Use plenty of oil and even consider coating the flange at this time, at the areas where the seal would rub/seat. Insert the flange into diff housing and use a block of wood and hammer to squarely locate back into the diff. Make sure the seal is fully homed and flush against the diff housing.

Step6 – Final steps are to insert and locate the flange back into the diff. Push as far as it will go, and then use that wood block and hammer to drift back and locate the clip. It should fall flush like before it was removed. Reassemble everything ensuring you remember to tighten securely and replace the A-arm top bolt. Replace with clean fresh diff oil.

Easy :-)

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HSD Install Step 2

Posted on July 4, 2011 | Leave a comment

Finally got some time to finish the installation of the HSDs. The fronts are installed, but need the height adjusted, and yet the rears still need to be installed – so here goes!

Getting the rear coils and shocks out is probably a littler easier than the front. The suspension seems to be more willing to drop and the bottom shock joint was easier to unlink from the lower arm. Unfortunately the same can’t be said for the top towers! Inside the boot area way up the back isn’t as great a place to work compared to the front – which comes as no surprise I guess – the MX5 boot isn’t that big!

Once again, the spring compressors were used in anger, but this time you don’t have to unhook the sway bar as the suspension arms move down far enough to enable the sets to be removed. After adjusting both new coilovers to the same height, they were both installed and wheels returned to the car.

I took the time to adjust the front height, and much to my relief, adjusting the front was really, really easy to do… 1) jack up the car, 2) remove the wheels, 3) undo the locking ring, and 4) wind up or down the entire shock tube – job done in minutes!

Final heights are:

  • Fronts – 310mm from wheel centre to arch
  • Rears – 320mm from wheel centre to arch

Plan is to let the suspension settle for a few weeks and then remeasure everything and decide on any further adjustment. I think it might be a little low (as the lower arms are slightly angled up at the wheels – but only ever so slightly!)

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HSD Install Step 1

Posted on June 25, 2011 | Leave a comment

I finally had some spare time to start the installation of the HSD coilovers. I decided to start with the front pair, and began with putting the car up on jack stands and remove the wheels.

The old suspension had busted shock boots, cracked bump stops and didn’t handle road irregularities very well. The original 20+ year old dampers and rubbers were old!

The task required compressing the springs to reduce the height of the coil and shock set so that you can remove it from the lower suspension A-arm. The only problem was that the expanded size of the spring was quite a bit taller than the space between the top tower (above) and the lower arm full extension. So the only way to reduce the height was to employ coil compressors!! I’ll admit I hate dealing with coil spring compressors – they scare me – the thought of a sudden and fatal failure of the compressors constantly remains in my mind.

The trick with removing the MX5 coilovers is that you need to allow the lower arm to drop far enough, and the easiest way is to remove the sway bar link from the arm. This removes the last amount of resistance enough for you to push down on the arms, and then with the compressors reducing the height of the coils, you can slot out the coilover top hat and remove the set as one piece.  I used a bit of coat-hanger wire to ensure the top part of the compressor remained attached to the springs. The compressors I had were slightly too big and didn’t easily match the radius of the springs, and so for an added “false sense of safety”, I thought the weak coat-hanger wire would save me from sudden finger loss should the compressor jump off??

Anyway, once finally complete I was able to add the new coilover into position after adjusting the initial height and spring pre-load. I was expecting that I wouldn’t be able to judge the height correctly,  and accepted that at some future point I would need to re-adjust again after the car has settled and I can correctly measure the road height with the wheels on etc. After another hour, both sides were successfully finished and the first step of the job was complete – leaving me to do the rear next week end (I like to work slow).

As you can see below, the front is fairly low, and what I can only describe as “down in the weeds” and clearly not something I can leave as is. I think it was 290mm (wheel centre to arch) which is 20mm lower than I’d like it to be. Oh, and the lower arms were beyond horizontal, and now facing upwards (pointing up to the wheels) which is another clear indicator the height is too low.

Like any inner-boy, I had to go for a drive and see how it handles…. and for those unsure, trust me, it doesn’t handle well at all! No surprise considering the rear was stock height with 20 year old worn shocks, and the front too-low with brand new stiff springs and shocks. MXV79 is staying indoors for now until the rears are done.

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A bright spark

Posted on May 29, 2011 | Leave a comment

I took the opportunity to replace the coil pack, ignition leads, and spark plugs today. Job took about 1.5 hours as I took my time explaining the steps, and letting my son help.

When replacing the coil pack, I realised that the new unit didn’t have the same rubber ring that the original had – so even though the replacement coil pack was OEM, I couldn’t seem to figure out how to transfer the old locating ring & rubber. It was stuck really firmly and not going to budge. I tend to think the perhaps the new unit wasn’t as OEM as I thought it was….?

Anyway, after deciding the lower locating ring probably wasn’t critical to the mounting of the coil pack (it is held firmly by upper locating bolts) I proceeded to install it with the original lower locating bolt installed, but clearly not tightly securing the coil pack.

 Next task was the four (4) spark plugs and new ignition leads.

I’d ordered some Magnecor Competition leads with an 8mm core along with a standard set of NGK plugs.

After removing the old plugs, setting the gap on the new, I was connecting the new blue leads and wrapping up the job.

The final job with new leads, new plugs and the new coil pack. I’m hoping the ignition system remains trouble free for the future ;-)

Looks nice, and me thinks I’ll buy an old rocker cover and paint it… maybe bright yellow!!

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Like its on rails

Posted on May 27, 2011 | Leave a comment

Just bought this funny sticker for when the HSDs get installed… me gonna be on rails !!

 

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HSD HR Unboxing

Posted on May 21, 2011 | Leave a comment

My HSD coilovers arrived the other day and I’ve decided to take my time and document everything I do – starting with an unboxing.

Main features of the HR coilovers for MX5 NA6/8:

  • 9kg/mm Front, 6kg/mm Rear Spring Rates
  • 16 stage adjustable damping.
  • Seperate height and preload adjustment.
  • Anti-corrosive zinc damper plating and rubber dust boots.

I ordered them online from Otomoto in Australia. Ben was great to do business with and considering I was driving a hard price, he was a pro to deal with.

Ok, on with the unboxing. Upon opening the box you find 4 smaller boxes each containing a coilover wrapped in bubble wrap.

In the above shot you’ll see the rear coilover with the special designed cup top mount to allow damper to have full travel.

A close up of the front coilover.

Also included was some C-spanners, an allen-key, some HSD decals,  and what looks like some green caps for the adjustable damper key.


There was also a loose bit of paper with tips and warnings for the installer, but no real instructions for installing are included. That’s ok, as I wasn’t expecting a guide or any particular detailed instructions with the kit. (BTW – HSD have a good YouTube video on how to install coilovers into a MX5. Watch part1 and part2.)

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The HSD’s arrive!

Posted on May 18, 2011 | Leave a comment

Oh my gosh! 25kg of suspension arrived at work today!

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