3.2 Turbo Build

[quattrorunner]

Aluminum isn’t meant to bend back n fourth. See if you can it can aneal it before trying to bend again.

[quattrorunner]

I see cracks already.

[Coultl]

Definitely not ideal to bend aluminum…even once. Hard to tell from the photos but I was happy to find that it took very little bending to get the old tanks off and the bend spread out over a large area. I does look like cracks in the photo but that’s some kind surface finish from when the aluminum was formed. Was there before I removed the stock tanks.

Good idea to anneal the aluminum. That could help!

[moparrob]

The scans look great after processing them with Fusion. What type of scanner are you using to achieve those results?

[Coultl]

I use and Einstar scanner. I’ve had others and this one is so much better. Pretty amazing that this tech is cheap enough to have at home now.

[Coultl]

After mostly finishing the design of the BMW intercooler end tanks, I’m thinking about going another direction. It would have worked and worked well but I just don’t love how it’s sitting on top of the engine. It doesn’t feel well integrated.

We’ll see if I actually finish this new direction but I’m thinking I’ll make a new intake manifold with the intercooler integrated into it. Certainly more complex to engineer this, but it’s also a fun project. It’s possible I start with the BMW intercooler and then go this route later.

The design is far from complete but this is how it’s shaping up. (It’s rendered in carbon but it will be 3D printed nylon and/or aluminum)

[quattrorunner]

Awesome

[ToySnakePMC]

Wow. So glad I stepped in here. Got caught up on this most creative turbo build. You’re really good at juggling multiple balls at one time. Glad you post all the action here on the Pelican.

[Coultl]

Appreciate the feedback! I’ve been working on the aesthetics of the intake. If I’m going to do all this work it better look good! After a lot of different directions I’ve ended up with a shape that I like. I think I’m good to start the engineering work on it.

This is again rendered in carbon fiber but the real part will be 3D printed nylon.

[moparrob]

That is coming along really nicely. I look forward to seeing your future iterations on the intake.

Out of curiosity, are you going to be able to print that in nylon in one piece, yourself? Or will you need to send that out to an outside service to have it printed?

If you are printing it by yourself, what type of FDM machine will you be using thathas the build volume to handle that?

[Coultl]

I’d like to print it myself so I designed it around my small 256mmx256mm print bed of my Bambu X1C. Each runner will be a print and the center section will be two prints. The plan is to bond it all together. Not ideal but there will be very large bonding surfaces so I think it will be quite strong. I may add some fasteners too.

[moparrob]

That should work out well.

I have been checking out this new Creality Ender-5 Max for some prototyping, which has just hit the market. It has a 400 x 400 x 400 build area and it looks like it can handle the technical filaments like PA6-FG, PA6-CF, and PAHT-CF with it's high(er) temp print head and heated chamber.




What filament do you expect to use for the final product?

[Coultl]

That looks like a really nice printer. I could make the manifold in three pieces with that build volume. There seems to be a surge of progress in 3D printing right now.

I’ll use Bambu PAHT-CF. I have some PPA-CF which would be better but would also cost a fortune.

[moparrob]

That PAHT-CF prints nicely, and is amenable to post-processing.

You can sand it and polish it with Tripoli rouge (and others) to give it a really nice surface finish.

[Coultl]

Really good to know moparrob! I have not printed with it very much. I'm mostly worried about keeping warping in control as there are big parts. I also not sure what glue to use and what filler to use when I assemble the intake.

I've been busy getting the car ready for paint. Details on that HERE. I have also been working on engineering the intake manifold.

- The "throttle body adapter" is hopefully done. This is a really complex part of model in CAD and I also wanted to make it as strong as possible given how critical it is. At 14 psi of boost it will see about 700 lbs of force.

- The water to air intercooler will be sourced from Bell. They say it good for up to 500hp so should be perfect for my 350hp target.

- The intake is a work in progress. I sill have a lot of work to do. I'm having to design it around the limited build area of my 3D printer but so far that has not required any major compromises. The intake flange / fuel injector geometry is done and the intake trumpets are done. The trumpets are all the same length to within 2mm and they are about 60mm longer than stock. I also tapered them from 41mm to 50mm. I'm hoping that the length and taper helps torque at lower rpms when the turbo is not active. I have done no math on this as it seems like testing is the only good way to dial it in. Going with the educated guess. Runner resonance is a nice bonus but not a huge deal on a turbo car.

I have a lot more work to do on the intake and then I'll start the test prints. I have two week to get the car ready for paint so that takes priority. Going Bali Blue!

[moparrob]

Wow that is coming along nicely. I am definitely envious of your CAD skills and appreciate the work that goes in to the many iterations.

I have never had to glue 2 parts together, but I bet the techs at the filament manufacturer would have some valuable input. Also, the folks at 3M never seem to be short of solutions. Keep up the great work.

[Coultl]

Made some progress in CAD and I have what I hope is the final plumbing arrangement.

Now that the engine is out of the car I scanned the engine bay and dropped that into CAD. That gave me a much better idea of the space I have to work with and I'm able to fit the charge pipe inside the engine bay. It's much shorter and nicer this way. That said, this whole setup is going to make changing spark plugs a full day job...

[Coultl]

The engine is finally rebuilt. It took a little longer than expected, but went really well.

Now I can shift to the final development of the turbo system. I started mocking things up on the engine and found a couple issues.

First when you twin plug the heads, the lower plug on the 1-3 side of the engine is very close to the exhaust flange. I can still mount the coil, but it is way too close to the exhaust. I don’t think I can keep it cool enough even if I add insulation. My plan is to create a 12 inch extension wire and mount the coil on top of the engine. I have not really seen people do this before with coil on plug coil. I don’t see why it wouldn’t work though.

Also, when I added the thicker cylinder base gaskets (1.2mm) this made the exhaust flanges misalign. The crossover pipe flange is now about 2 mm back from the heat exchanger flange. I think I’ll just double up the gaskets and that should work fine.

Now I’m focused on building the CAD, prototypes, and test fitting. It’s a little tempting to put the turbo where Porsche put it, but I still like the side mount and I like that it puts the weight further forward. I’m sticking with it!

[moparrob]

Wow, that is coming along rather nicely. Job well done.

Are you going to have the prototype exhaust pieces powder metal printed, or laser sintered, or...?

[Coultl]

Yup, they will be laser sintered stainless. Pretty incredible how affordable that has become. The two parts that connect the exhaust to the turbine inlet are about $200 each. If these were mass produced Porsche parts they would be double that…at least.