3.2 Turbo Build

[greglepore]

Nice solution to the oil drain. Nothing holds my turbo in place other than the exhaust plumbing, but its old style 5 bolt flange and very substantial.

[Dieter9]

Wow just WoW !!

[Coultl]

The 3D printed stainless exhaust pieces came in today. Can’t wait to get this all welded up. These were not cheap, and there is some warping. It will require a couple hours of fitting, but they will be perfect with some work.

I’m also getting through the intake manifold design. It’s such a challenging assembly but it’s getting there.

[Coultl]

What is this, an intake manifold for ants?!

Making progress on the intake manifold design. I ended up printing a few 50% scale versions to get the joining features right (it’s four prints that will be glued together).

I’m really excited about ‘cartridge’ intercooler. I had to buy new cores but is so nice and compact. Will share more on that once I have all the parts.

The full scale one in the PPA-CF will be about $150 in plastic. I’d really like to find all the design screw ups before I print it for real.

[moparrob]

That is coming along really nicely Have you checked in to the cost of having it 'professionally' printed in one piece in PPA-CF or a similar filament? Just curious.

Looking forward to seeing the final design and the intercooler that you have selected.

[Coultl]

Good call, just checked. It's $5,400 to it printed in SLS in Hong Kong...the only place I saw that could do a part this large. If I had the 4 components printed in China it's $1,600. Good news it that it's only $11k in aluminum. Ha.

I also think the PPA CF material I'm using is far superior to SLS PA12.

Gluing nylon is not straightforward. I will flame treat and then use Plexus MA310. I will also have the joins extensively tabbed for additional strength. I'd like to use fasteners but there's not really enough room.

Lastly, there's the open question of whether or not I can print parts this large without warping. I'm printing on a H2D which will help with it's heated build chamber....but this is still pushing pretty close to the edge of what's possible. We will see.

[moparrob]

WOW! Those prices seem really excessive. Your initial plan is looking better and better.

One other thought (also not cheap) if you haven't looked into it is to have it printed with/by Markforged performance filaments which have the option of a continuous carbon fiber thread inserted in the stress areas that require it. I would be curious as to the estimate you receive for a one piece build from Stratosys (I think that is the name of one of their vendors).

[Coultl]

While I’m finishing the intake design I’ve been testing various adhesives. This started with some basic tests but quickly escalated to more precise heated shear testing of the bond.

I’m not done with the testing yet but a few things have become apparent:

- Nylon is tough to bond to and there’s only a handful of industrial adhesives that are made for it.
- Flame treating dramatically improves bonding and it’s easy to do.
- As temps go up the adhesives weaken. At 80 C they have lost 30-50% of their room temp strength.
- JB Weld PlasticWeld is no joke. For $5 a tube this stuff is crazy strong and even bonds to Nylon. That said, it loses a lot of strength at 80 C.
- The front runners are Plexus MA8110 and 3M DP8910DS.
- Testing so far is showing something like a 15X factor of safely on the intake manifold joints. This stuff is strong.

[quattrorunner]

You should make a youtube channel. I'd watch it.

[mikedsilva]

Originally Posted by quattrorunner

You should make a youtube channel. I'd watch it.

agreed

[kamaro]

Originally Posted by quattrorunner

You should make a youtube channel. I'd watch it.

It will be 10000 times better than the clown car mechanics we see there.

[Coultl]

I’ve wanted to do YouTube for a while. Appreciate the vote of confidence!

The prototype PLA manifold is printed and assembled. Leaned a lot while printing and assembling it. One funny thing, the manifold is about 2mm too narrow. Not a huge deal. It’s very stiff but can flex that much without issue.

But the cause? I ran 1.2mm base shims which pushed each cylinder bank out by 0.7mm and the manifold is based on the 3D scan of the engine before the rebuild. Forgot to account for the thicker base shims. Guess it’s pretty accurate…


Most importantly, I really like how it looks. Ha. Looks muscular and to me the aesthetic feels like it fits the car. The final manifold will be finished to remove seams and painted in a textured black. The logo plate will be 3D printed in aluminum.

[Coultl]

I also wrapped up the glue testing. I created a setup to get shear testing data using Knipex pliers (20:1 lever ratio). The handle is pulled with a scale and the force on sample should be 20X the force at the end of the handle.

There’s plenty of room for error but the end result was that I have a 50X factor of safety at 100C (100X at room temp). So yeah, this stuff is strong. Still some risk with heat cycling and unexpected loads, but I’d be comfortable with a 10X factor of safely….nice to be 5X that.

The Plexus MA8110 and 3M DP8910 were both similar in strength at room temp, 80C, and 100C. They both lose about half their strength at 100C vs room temp. I’m going with the Plexus bc I have used their stuff with success before.

For reference, the glued area is 8mm X 8mm and it held roughly 400lb at room temp and 200lb at 80C for both glues.

For kicks I tested crazy glue on PLA plastic. I have lots of hands on experience for how strong that is from prototyping, making 3D printed RC planes, etc. It’s a really strong bond but these adhesives on nylon were 4X stronger. Nuts.

[moparrob]

Looking good. I am interested to see the final version with the intercooler installed.

[quattrorunner]

You should rename this thread......

[Coultl]

Finally finished the manifold 3D print in PPA CF. Total print time was 150 hours, about $300 worth of fancy plastic, and the total weight is about 7.5 pounds. It is stout!

I ended up needing to reprint one section. Thankfully I realized right away that the prints shrink in the z axis by 0.5%. It’s a small amount but it would add up to 2mm across the manifold.

Next up is bonding it together and then finishing and painting it. The intercooler ‘cartridge’ is all designed and now I need to order the 3D printed aluminum parts.

I’m a little worried about the size of the Intercooler cores. They just feel small but they should be good for 500hp (~150hp more than I’ll run). I’ll only really know how they perform when the car is on the road…

[quattrorunner]

sick

[quattrorunner]

You'll have access to the triangle area

[mikedsilva]

Originally Posted by Coultl

Finally finished the manifold 3D print in PPA CF. Total print time was 150 hours, about $300 worth of fancy plastic, and the total weight is about 7.5 pounds. It is stout!
t

while you've got your scanner out, I wonder how difficult it would be, to scan and design an airbox centre section, to convert 3.0SC to efi "on a budget"...

Even if it is just to use something like a Holley Sniper efi unit..

[Coultl]

The SC is begging for a better intake manifold. Well, honestly, I don't really know if the stock one performs poorly. It could look cooler at least!

The CIS system is still port injection and I'd be hesitant to move to a sniper or similar EFI throttle body. I'm not sure it would be better as I'd guess you would have issues with fuel condensation on the runners. But, who knows, maybe it would work great.

It's really a shame the EFI systems are so expensive. I just bought the ECUMaster Pro-8 for this build and my wallet is still smoking...