omgpham…
25Mar/173

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 🙂

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 thingiverse.com, 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.

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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.

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

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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).

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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.

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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.

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

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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.

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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?

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

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

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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.

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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!

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11Jan/174

3D Modelling & Printing.

 

Ahoy!

Lately I've been spending more time learning how to model parts in 3D, still new so bare with me. It's not a new concept to me, but I am using Fusion 360 mainly now and sometimes a bit of SolidWorks.

I've done some prints in the past, a good example would be the bulk head connector plate I drew up and printed. Had it installed in the car while I waited for the final piece to be laser cut from steel.

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And now I'm starting to move onto slightly more detailed designs. Starting of with "remixing" a design from Thingiverse.

4AGE Black Top Velocity Stack - http://www.thingiverse.com/thing:25207

And my "remixed" version, which is basically modified for Silver Top engines instead of Black Top and increasing overall length to 115mm.

4AGE Silver Top Velocity Stack - http://www.thingiverse.com/thing:2016083

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I than scrapped that design altogether and did one from scratch, increased the radius lip profile and removed the side bracing. The print below was done in ABS and I'll be testing it for clearance and heat resistance. If all goes well, I'll most likely print my final design in ABS. If not, other materials like Nylon and Poly-carbonate are alternative options for heat resistance.

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And this is another design I quickly modelled. Main differences being the bottom flange, length adjusted to 105mm and the dimpled internal surface. NO idea how that'll work for airflow, good or bad, but it's fun drawing these and 3D printing them! The idea is from dimpled surfaces on golf balls, and I've seen shops machine dimples onto the back of inlet valves and cylinder head ports.

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And this is how the print came out.... About halfway up the velocity stack, the wall was a tiny bit too thin and the dimples were too deep! Not something I was expecting, but I'll learn from this one and make revisions. This print was also done at 300 micron layer height, I think it needs to be 100-200 micro next time.

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And finally, this is an airbox/plenum that will mount to my current Pipercross filter plate. Still needs some work here and there, but I'm pretty set on the general shape of it and the inlet is 4.5" diameter. The final product could be moulded from the 3D print and made with carbon fibre, or possible printed entirely out of fibre infused nylon for strength and heat resistance.

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More to come!

11Jan/170

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.

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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.

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

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

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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.

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Garage Star Coil-on-Plug adapter acquired!

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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.

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Some close ups of the pistons.

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28Dec/151

Start Up!

 

This was not a smooth start up.... Ran into a few issues earlier on, car would crank over and sometimes nearly run but never more than than a fraction of a second. Went through and checked through the wiring and grounds, everything was good there, a quick visual inspection of the cam gear and cam lobes to see if they were in the right positions. And a whole bunch of things....

The ECU logs showed consistent sync loss, error no. 31. Something was wrong with the cam/crank sensors. In my particular case it was caused by the crank trigger wheel being installed backwards :P. And I actually did check it earlier on, but checked it incorrectly!

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Once I flipped that trigger wheel around, it started right away! Here's a quick video of it, more to come later!

23Sep/151

Back Home!

 

Happy day! Car has been towed back home and first thing we did was remove all the front panels 🙂 Storing them in a spare bedroom for now, don't want to scratch anything during assembly.

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Colour is Audi's Aviator Grey.

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The entire engine bay was covered in blankets during the engine install.

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Hnnnnggggggggggg!!!

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Colour looks amazing in sunlight, the Audi paint code has a bit of pearl through it but can only be seen in direct sunlight.

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The freshly powder coated radiator and sway-bar brackets fitted up with new bolts.

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A quick mock up panel for the engine harness Deutsch bulkhead connectors.

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I had the front lip painted gloss black, will be interesting to see how well it holds up from all the abuse it cops 😛

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11Jun/150

Head Unit Relocation 2nd Update.

 

Received some feedback and discussion on my head-unit relocation last week, and as I often find, I decided to change it up to the better option.

Below are photos of where the head-unit was mounted, I made a custom MDF piece for that spot too.

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But it was obvious that the better position would be in the other corner of the boot, and mounted from above. Overall it looks a lot cleaner and more out of the way.

Started off by half removing some of the rear carpet, I than removed the bottom four bolts of the rear parcel shelf cover. Made it a lot easier to run the harness.

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Harness fed through and the head-unit case mounted up!

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Everything mounted and connected, works just as well as before.

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10Aug/140

Engine Rebuild – Part 3

Update time!

After I gave the paint some time to dry, it was time to give the internals a wash down. For this I was advised to use dish washing liquid with water, once that was done everything was given a wipe with engine oil to prevent any surface oxidisation.


The crank journals were given a good clean and main bearings installed.

Before the crank can be installed, the clearances need to be checked using Plastigauge.

Once you have the clearances checked and within recommended specifications, it's time to pull it apart, clean and than re-fit using assembly lube.


In the next episode, I hope to have updates on the ring gaps and final assembly =).

15Jun/141

Engine Rebuild – Part 1

Hey guyyyyyyyyyyssssss!

My goal has always been to build my bottom end, forged high compression pistons, forged rods and maybe a decent over-bore. As everything with my car, I would prefer to learn and do it myself. So this rebuild is more of a refresh using stock pistons and rods, a learning exercise/practice before I attempt the forged build.

So over the last week I've been slowly pulling apart my spare block, getting it ready for the machine shop. I'm also wire brushing and prepping the block for a fresh coat of paint.

Pulled the head and sump off, and quickly checked the side-to-side clearances, crank thrust and bearing clearances.


Everything out and ready for the machine shop.



1Jun/140

Boot Light

Just a quick update, I've installed a boot light and it's amazing! Please excuse the image quality, they were all taken using my phone.

Install doesn't take very long and everything is plug-and-play. Kit comes with a LED mounted on a stainless steel bracket, boot switch and wiring harness.

Boot Light Kit - http://omgpham.com/store/interior/boot-light-kit


Photo taken without flash at 9PM.

I also removed my tombstone to give it a quick coat of Plasti-Dip, the surface was a bit too rubbery/grippy for my liking so I gave it a quick wipe with some interior detailing products. Worked out very well 🙂


26May/145

Radio Delete

Been wanting to do this post for awhile now. It's been a combination of research and a lot of testing to get to this point. Quite pleased with the outcome but would like to make some changes later on, more on that later.

A few goals I had for this project:

  • Delete radio/head-unit.
  • Keep everything as simple as possible, think minimal.
  • Nexus 7 tablet to display all the Megasquirt gauges via Bluetooth.
  • GPS with offline maps, pause/resume music on power off/on, wired tether to phone.
  • Maintain charge with full brightness, GPS, music and gauges running.
  • Easy to remove tablet from the car, one cable to dock.
  • Amplifier install that is compact yet has tone controls (bass/treble).

To make it possible for the tablet to dock with just the one cable (USB), and not have to plug the headphone/Auxilary cable in as well, I had to use the tablet's USB OTG Host feature. This basically allows you to plug heaps of USB devices to your Android device, keyboards, mice, thumb-drives, USB DAC, etc...

However, while in OTG Host mode Android doesn't allow the tablet to be charged at the same time. This is where the software comes in to make it all possible. Check out Timur's website for details on his custom built ROM. It is optimised for car installs and enables charging while in USB OTG Host mode, deep sleep mode when power loss is detected (huge power saver), and hot-plugging of audio devices.

You will also need a USB OTG Y-Split cable, I picked up mine off eBay for not much money. While you're there you'll also need a USB DAC, again very little money for these. The USB DAC basically plugs into the tablet via USB and outputs sound for the amplifier.

We're very lucky with Megasquirt when it comes to Android software. MSDroid allows tuning as well as gauges, still in the beta with a new major release soon. ShadowDash is by the same creators as TunerStudio and is a lot more stable but only allows gauges and no tuning features.

http://omgpham.com/msdroid
http://omgpham.com/bluetooth-x-megasquirt


For amplification, I decided to go the DIY route. This consists of a pre-amp so that I could have bass and treble control. For the power-amp stage I picked a DIY kit that is built around a IC chip that is commonly used in car radio.



Took me literally under ten minutes to build the power-amp, pre-amp took a bit longer. I than stuffed them both into a plastic case with the USB DAC. The case was picked up from JayCar.


Sound wise, this combo worked very well. The pre-amp gave me plenty of tone adjustments and power-amp was able to keep up with the volume levels I usually listen at. But it did suffer from a "pop" noise on power up, and I may have blown the IC chip because of insufficient heat-sinking!

So the other option I'm look at is this little amplifier, Pyle PLMRMP1B. It's very compact, plenty of power, remote gain control and anti-thump turn on. I'll re-use my current DIY pre-amp though, need those tone controls!

My initial install of the tablet wasn't very successful. Couldn't use my hazard/retractor buttons without removing the tablet, very flimsy, and blocked both centre vents.

I than found a company called ProClip that produce a Nexus 7 holder that was perfect for my requirements.

I used a custom made radio panel, available through my store, and made it a complete blank. This would allow me to hard mount the ProClip tablet holder. Very happy with the qualilty from the holder, sturdy and easy to dock/undock from the car.


For the wiring part, I used new connectors. 4-way connector for the outputs to the speakers, and a 3-way connector for ground, accessory and constant 12V power.

Photos of the finished project!



Parts list: