Velocity Stacks & Airbox Prototyping.


This is going to be a big photo dump of my latest adventures into 3D printing, both for prototyping and hopefully end usage. I purchased myself a 3D printer, Wanhao Duplicator i3, and I'll do a separate post for that soon. For now let's talk about my experiences with the intake parts I'm prototyping ūüôā

I have no real knowledge in both 3D printing/modelling and engine intake theory, I'm just learning as I go, so there will be mistakes here and there. And therefore, not entirely sure if these parts/designs will make any measurable performance gains, but it's all fun anyway!

In my last post, I had just commissioned some prints of velocity stacks. Well I did some redesigns, and they can now be found on, again it's still all a work in progress and I'm not expert in the design theory.

The velocity stacks are 105mm tall and designed for Silvertop AE101 throttle bodies.


Next up was designing an airbox for the ITBs and 105mm tall stacks, I pretty much modelled it using the same external dimensions as my Pipercross filter. I did this because I know for sure that it would clear all the brake and clutch parts in the engine bay and I also wanted the ability to easily change from filter to airbox. I can and will make a better design once I have this design fitted and tested.

For the Pipercross filter and this airbox to clear the stacks, a new mounting plate needed to be made. So I chose to print out a spacer that would be sandwiched between two laser cut plates, you can see it in the previous screenshot.


Below is my ideal design, will work on that soon.


The printed spacer for the filter mounting plate, had to be printed in multiple pieces due to the limited build volume of my printer (200mm x 200mm x 180mm).


Before doing the actual prototype print I decided to use some rubbish filament for a test print without support material, just to see how far it could go. It failed pretty quick when it got to the dome part, it recovered slightly towards the end though.


Here you can see the rear section of the airbox being printed, tried to minimise the usage of plastic and support material. This was printed at mostly 200micron layer height and the curved sections were printed at 100micron layer height, varying the layer height like this helps reduce print time as well as reduce support material for the sections with overhang.


Mid section being printed, by far the easiest part. Only needed support material for the mount flanges, this was printed at 280micron layer height.


And this is the front section being printed, all printed at 280micron layer height. This part had some design modifications to improve print-ability, also to reduce plastic usage and support material.


Since this is a prototype for test fitting, sections are glued together using Cyanoacrylate. Final part will either be epoxied or plastic welded together, not sure yet. Or maybe just use the print as a mold for carbon fibre?


It's amazing seeing this all come together as one piece, nearly 500mm total length. So happy!


Photo trying to show the internal clearances with stacks installed, minimum distance to walls is 25mm.


Some lessons I learned during this entire print are that overhangs causes prints to look like crap. So I've made the following design changes to help reduce overhangs.

  1. I added a chamfer on the inside surface to reduce the overhang angles under the "dome", this allows me to print with minimal support material, and the chamfer being only 20% solid means I use less plastic overall.
  2. The highlighted flat sections at either ends of the flange remove the overhangs and allows my printer to simply bridge that section, which my printer does very well. This makes the print look cleaner and also reduce support material.
  3. I found that printing holes on a vertical plane produces nasty overhangs and causes imperfections in and around the hole, so I opted to print only dimples instead of a through-hole. This improves the finish and I can just simply drill the holes post print anyway.



I also modelled this catch can and printed it out for test fitting. Unfortunately, the filament ran out before it completed printing. Was still able to test fit though!



Toda High Compression Pistons!


Welllll than...... A couple new things in this update, and possibly a second post regarding some stuff I've been 3D modelling for the build.

First up, managed to install this 5V oil pressure sender and input it into the Megasquirt for full datalogging and dash display through Shadow Dash. The tablet mounted using two magnetic mounts clipped to the eye-ball vents. Works very well and has a very strong hold.

It was surprisingly easy to get working, the sender needs +5v, ground and signal return to the ECU. I happened to use the AD6 input on my Megasquirt, and TunerStudio has a built in wizard to configure your sender.


Developed a slight oil leak into cylinder no. 4 so took valve cover off to replace the gasket. Remember to go genuine valve cover gasket! I've had nothing but trouble with non-genuine valve cover gaskets.


Finally bought some new tyres and fresh alignment done! Hankook RS3 225/45 R15.


Received and installed my IL Motorsport bonnet lifts, not sure if I like them yet.


Next up, I had some spare parts accumulating and was able to put together this LED bar kit. It's operated via RF remote control that looks like a bomb detonator, the LED light bar and associated electronics (now enclosed in water-proof case) are mounted just behind the front bar.


Garage Star Coil-on-Plug adapter acquired!


Toda forged pistons!!! They are 11.0:1 compression ratio and +3mm overbore, made from a special alloy with very littler thermal expansion which allows it to run factory Mazda piston-to-bore clearances. Toda also designed the skirt to allow usage of factory oil squirters. I also ordered the matching overbore head gasket from Toda.


Some close ups of the pistons.




ITB Build – Part 14

Dropped my engine off last week at the Auto Xperts, they did an excellent job and degreed my cams to the recommend specs. Final adjustments will be made on the dyno.

Picked her up this morning and have been on it since than.

After the crank bolt was correctly torqued, I started on assembling the timing cover and ITBs.

Some close-ups of stuff.

Lightened flywheel and clutch going in.

Engine going back in ūüėÄ




Thought I would do a quick post about this great piece of software called MSDroid.

From their website:

"Android + MegaSquirt
msDroid is an application for Android smartphones and tablets being developed for use with the MegaSquirt¬ģ range of electronic fuel injection controllers. It aims to provide logging, fully customisable gauge dashboards, tuning, and graphical log viewing. This shall remain a completely free application. This application is presently in alpha development."

It has the ability to connect to your Megasquirt via Bluetooth or USB OTG. Your phone/tablet must have USB OTG support and you simply connect your existing USB-to-Serial RS232 adapter into your phone. USB OTG cables can be found on eBay for a couple of dollars.

Quick proof of concept below. I will be wiring in oil pressure and oil temp sensors soon. They will go directly into the Megasquirt's ADC inputs and I will be able to display them in MSDroid as well as data log. Cool thing about the MSDroid software is that it runs off the standard Tunerstudio INI files ūüėÄ

I did a quick guide on the Bluetooth module, link below.

Bluetooth x Megasquirt


Megasquirt DIYPNP Rework

Last week Josh asked me to help him update the firmware on his DIYPNP Megasquirt ECU, he also needed a base map loaded. So he posted it from Melbourne to Brisbane and I got it early this week.

Josh purchased the ECU second hand off the forums, was told it was working (and I don't doubt that it was) but the surprises came when I opened up the case for a closer look... This is what I found:

  • at least half of the solder joints throughout the board were beyond terrible
  • about a dozen pins/legs had no solder at all
  • the ends of wires were snapping as I was de-soldering
  • a handful of lengthened wires which weren't heat-shrinked
  • tape had fallen off one of the lengthened wires and fully exposed the connection against the metal case
  • loose solder and component pins on the underside, could have easily causes short circuits
  • component pins bent towards each other, more possibility of short circuits

Even if the ECU was working fine, I wouldn't be surprised it failed very quickly in a car environment (heat and vibrations).

So I fully stripped all the wiring off the board, re-soldered every joint, cleaned/removed all the flux, re-wired the connector board, updated firmware and loaded a base map.

Below are some before and after photos.

The wiring was a huge mess, lengthened wires and a lot of fatigued joints which eventually resulted in snapped connections. In the center of the photo you can see the joint that was exposed because tape fell off.

Was difficult to take a clear photo showing the bad solder joints. Looked like a lot of cold joints and not enough solder was used. Quite a bit of flux too.

The wires that snapped clean...

These next photos were taken after I re-worked the ECU.

Re-soldered and board cleaned up to remove all the flux.

The pins on the Microsquirt Module re-soldered and cleaned up.

New jumper wires installed.

My preference is to have the jumper wires on the component side because it places less strain on the wires, helps reduce any fatigue. It also allows easy view of the connections without removing the entire circuit board.


COPs Bracket

Just some quick photos of the COPs Bracket installed on my engine, I gave it a quick coat of satin black enamel paint too. Came out great and really suits my painted valve cover.

Now with the COPs bolted onto the bracket.


Bluetooth x Megasquirt

This is something I've been wanting to do for a long time, implementing Bluetooth connectivity for my Megasquirt ECU.

No more cables for tuning and data logging, I can even use my Android smartphone/tablet for data logging and digital gauge/dashes. The Android App is called Shadow Dash MS, free of charge from the EFI Analytics.

You can buy "off the self" devices that are plug and play, around $50-$100, but I've decided to take the DIY route which cost me $12!

These can be found on eBay for about $12-$14 shipped to Australia.

There is a bit of work to do like adjust settings as well as some soldering.

1. The module needs to be jumpered temporarily so settings can be applied.

Used some copper wire and soldered it from 3.3V to PIO (11), these are pin 12 and pin 34 respectively on the main circuit board.

2. Use some paper to insulate pins 6, 7, 8 and 9 on the DB9 Male connector. And than solder a wire from pin 9 to V+ pad, this is next to the break-out pins.

This wire takes +5V from pin 9 of the serial connector (Megasquirt side) and supplies it for the Bluetooth module.

3. An external +5V supply has to applied to the break-out pins.

This temporarily powers the device so settings can be applied.
NOTE!! I wired the power wires incorrectly here, switch the black and red wires!!

So that completes most of the modifications needed, now on to software. I used Microsoft Hyper Terminal, which is available on Windows XP machines. You can download it below:

1. Connect the module to your serial port, or your USB-Serial adapter.

2. Open up Hyper Terminal and create a new connection. Select your serial connection's COM port., mine was COM4. The settings below should be applied.

3. To confirm that the connection is correct, quickly type in AT. It won't display what you've typed but it should display the response OK.

4. Open up Notepad and type the following AT+NAME(insert the name you want here), in my case I typed . CUT all the text, go back to your Hyper Terminal window and click on "Paste to Host". You should than get a response saying OKsetname.

5.  Next up we'll set the PIN Code. So back to Notepad and type in AT+PIN(insert your 4 digit pin here), eg. AT+PIN1234. CUT all the text, go back to your Hyper Terminal window and click on "Paste to Host". You should than get a response saying OKsetPIN.

6. Finally, we'll set the baud rate. By default it's 9600 but this needs to be set to 115200. So in Notepad you'll type AT+BAUD8, CUT all the text than go back to your Hyper Terminal window and click on "Paste to Host". You should than get a response saying OK115200.

The reason we have to cut and paste commands from Notepad is because Hyper Terminal needs commands to be typed completely in under a second. Stupid? Yes, but ah well.

So everything software wise is now done, this next part is optional and it involves removing the female DB9 connector which is used for applying settings. It's the connector that plugs into your computer's serial port.

Connector removed and heat shrink applied to protect the circuit board.


Testing Coils


Had a chance to try out TunerStudio's "Output Test Mode", basically allows you test fire your injectors and coils. Something I really wanted to do because I wired my coils for sequential fire.

Firing order is 1-3-4-2 so they are wired as such:

  • Cylinder No. 1 - Spark A
  • Cylinder No. 2 - Spark D
  • Cylinder No. 3 - Spark B
  • Cylinder No. 4 - Spark C

I initially wired them in the wrong order but luckily I caught on this error early.

Tried to take a photo of the spark but that nearly impossible so I've uploaded a video below.

I also had a chance to change the transmission front seal and gasket.


ECU Mounting Revisited

So my first attempt for the ECU mount was a failure, it sucked and was messy looking. This next mount attempt is so simple, not sure why I didn't think of it first. Checkout the photos below.

Used my spare dash to plan my bracket, much easier when flipped upside down.

Had some some left over angle aluminium, perfect for the task at hand.

Quickly positioned to make sure it clears everything.

Stickered my ECU because it's so awesome.

Marked all the holes and drilled everything.

Double checking that all the holes lined up.

Done! Very very happy how it turned out, the bracket is strong and holds it at a good position. The glove box closes up fine, still emptied out so no real use but it'll be locked up anyway.


ECU Mounting


I've been dreading this part of the build, was never sure how I would do it and make it neat. But everything is coming together now and so I had to do something.

Because my custom fuse/relay panel sits where the ECU normally goes, I've had to install the ECU in the glove box. It's not a bad spot to put it, just my solution isn't "clean" for my liking.

I had to remove all the internal sides of the glove box, gives much more room for the harness to hook up. I'll also make a short serial cable "pig-tail" so I can hook up the USB connection.

All the studs were epoxied into place, not very clean and not sure if it'll be strong enough. So I might go over everything with some fibreglass, any thoughts?

Test fit was good too, but I'll let it cure overnight before I tighten up the nuts.

I also decided to use the stock tombstone, goes much better with the rest of my interior. So the KG Works tombstone will be up for sale soon.