CF Charge Pipes, Need Insight

General Composites Discussions Composites Talk
#1

I’m looking to make charge pipes for a turbo car.
There are 2 pipes, a hot side and cold side. Cold side will be less than 100f; hot side can be north of 300 but probably never over 450* [I need to verify].
These pipes will constantly be in between 10 and 20 PSI.

[ul]
[li]So I need sources for some real high temp epoxy? I have had poor luck finding one[/li][li]Is it worth even making the hot side?[/li][li]What should I use for connectors, I’m thinking silicon adapter style “bead roll” at the end? How would you accomplish this in CF? Other suggestions?[/li][li]I’m thinking I will make the mold by heating up PVC pipe and bending it to the exact shape I need; then maybe cutting it down the middle and laying CF in either side, trimming it off with a razor when it sets, then binding the two sides together with more resin. Then either wrapping around it with another layer and off-setting the seam? or maybe getting one of those pipe wrap “Chinese finger toy” style deals to finish them?[/li][li]How many layers of CF do I need to hold pressure like that?[/li][li]Anyone ever experiment with using some fore of automotive ceramic temp spray to keep heat out of the CF? like for headers[/li][li]When molding in PVC how do I need to prepare it? Keep in mind for the previous resin request that PVC deforms at 140*[/li][/ul]I hope that wasn’t to dense ha, lots of questions.
First post!
I have used fiberglass a good bit, I have never worked in CF…

#2

Your car will have a “user manual” after installing a carbon pipe on the hot end. After stopping the engine the red-hot turbo (I presume it is a high-pressure type) will radiate its heat, destroying many things in its way.

However, silicone seems to survive (265 degrees C) so a resin with a Tg of 230 degrees C should be doable.

With Huntsman I get to 210 degrees C, which is not enough, but getting close. This is the LY8615/HY8615 type.

#3

This is a custom turbo setup im building that I have 90% of the parts to or else id know the exact temperature.
The charge pipes connect to the compressor side of the turbo ,“cold side”. which have no direct interaction with the exhaust gasses. The air coming out of the compressor is less than 300* on most setups if i remember correctly… using a silicon coupler it would give the pipe some insulation from the slightly hotter metal…

So as you said I would like a resin that was happy up to the 230 - 265 range
210c would probably work…
If it has a tg of say 410f/210c and it has 300f/150c air flowing through it, at pressure, does that push its limits?

I need also consider the worst possibilities and re-ask the previous question, worst case air temps are something like 400f/205c and would that push the limits of the resin? - i would imagine so… im thinking 230c+

#4

http://www.cotronics.com/vo/cotr/pdf/4460.pdf
Lookey there?

#5

I have never ever seen a composite hotside, except the can portion of a muffler, where temps are MUCH lower, and have the outside air to keep it cool. I also have not seen silicone used on the hotside either, are you sure this is possible? You can try a ceramic coating, but if that flakes off, it will enter the engine!!!

#6

Not the hot side of the turbo, the charge pipe before the intercooler… the hot charge pipe… much cooler than the hot side of the turbo.

#7

this is very interesting for high temperature…but I don’t know if it’s for sale

http://www.pyromeral.com/doc/jec-magazine-nb53-dec-2009.pdf

http://www.high-temperature-composites.com/high-temperature-composites-and-fire-barriers-pyrosic-pyrokarb.htm

#8

BMI and maybe phenolics should work well. But, AH, the intake side, FROM the turbo…First off, yes, get a good and realistic temperature profile of your system. Even if you have to get a wire thermocouple and reader, and slide it in the tube at some fitting, etc. Make sure you have an extreme safety ratio as well…just because your max temp at testing is 300f, doesn’t mean you might not hit 375…so use a resin that is good for 400 working. etc etc.
I think there should be several epoxies with high temp applications, but they will be expensive.
As for pressure…I can’t say exactly, but 10-20psi isn’t that high. I would think, as long as you have continuous fibers in the tube (ie: use a sock braid, or wind the fabric around the mandrel. No cuts and reglues!!), 4 layers should be ok. Someone might be more knowledgeable here about it.

#9

lol @ turbo knowledge

I don’t think a charge temps would pose that much of an issue for cf. I think proper construction, considering the burst pressure will be more of a concern.

I’ve seen many streetbikes run shorty, cf pipes directly off 2’ long primary tubes and bouncing off limiter for extended periods of time.

For the flanges, I think silicon would be the best to allow for flex. Carbon v-bands would be way cool though… to look at

#10

cf v bands…Sounds awesome would likely get beat up quick after a couple installs and removals…I have worked on a bunch of aluminum stuff that gets beat up pretty easily.

I would love to see a how to or “how I did it” cf tube job. Using sleeve or whatever…

#11

Do CF v-bands exist???
I was considering just molding in vbands…
I am thinking a mixture of v-bands and silicon couplers to give it just a hair of flex.
@gab981 I bet that stuff is insanely expensive… cool find.
@Riff I was thinking three layers, maybe i should do more… As for no cuts, what about a seam along the pipe that I lay over with a wrap from the opposite direction?

#12

1: What is a V-band?
2: Watch out for what the pipe is next too as well…the air flow might be cool, but if it runs next to a hot engine part, the outside can fry.
3: You can TRY that, but not really recommended. you can do, maybe 2 layers, cut to get off the mold, glue the seam shut, and lay up 1-2 more layers around it (full wrap, not pieces) and then recure that. Peelply and sandblast the first tube before adding the rest. You can use a heat shrink wrap, or just tightly wound mylar tape to get compact outer layers.

#13

I was thinking lay one layer and let it set remove from mold so I have the pipe I want. then wrapping two full layers or one layer and a “chineese finger trap” wrap around it?

what do i need to do to add layers after something is solid?

V-band:

#14

well, you would only need to make one flange, bonded to the charge pipe. I really wouldn’t suggest it though.

check out this guys method http://www.carbonfiberdiy.com/2010/12/diy-how-to-carbon-fiber-tubes-piping.html

more importantly the last pic of the mold with bladder

#15

why would you not suggest bonding a metal flange to a cf pipe?

#16

Would bonding aluminum flanges to carbon fiber have issues with temperature changes and cracking the tube?
what about corrosion?
Could I put the flange on the outside of the cf and get better flow and possibly other benefits?
what about nodizing the aluminum before bonding it?

#17

Take some Ir readings at your local dyno. I seriously doubt the temps will reach that high. I had carbon intercooler piping before the intercooler on my civic with no problems made with west systems. Also had a hard 90* bend right after the compressor. I used 2 layers of sleeve and miter cut angles from a tube. Sanded them smooth and then wet layup third layer over that. I used run of the mill five minute epoxy to bond the miter cuts together.

I cleaned the inside of the bends with a dremel.

Bonding a vband with an aluminum sleeve would work fine. You will however need a 4" section of reinforced silicone coupler to allow engine dampening or it will break stuff. Unless you have solid motor mounts.

Good luck

#18

Btw I bonded an HKS aluminum BOV flange to my piping with no issues… No leaks. :wink:

#19

dallasb84…PICS!!! LOL

#20

yeah, I was talking about making a composite flange for the the pipe, not bonding an Al flange to a carbon pipe