Guide on how to make carbon fibre/fiber car parts (ITB trumpets)

That’s very interesting, I lost interest after lots of research left me at the point that the alloy will always oxidise and break the secondary bond it has formed. I read if you clean (sand) the ali in the resin so that it cannot oxidise this will work, but its messy and not always practical. I bet that resin is expensive but would definitely come in handy.


I roughed up the acrylic base plates so that the resin has something to grip when it cures. Bit of test fitting here so you can see how it all goes together.







The next stage was to coat the bases in resin and let it start to cure and layer the carbon weave over the top, the tacky resin sticks to the carbon so it can be shaped and bent around the bases. It is a bit of a crude way to lay up but I needed something for the trumpet to bond too and felt the small surface area of the contact patch between the trumpet and base was not enough.

Here are the bases wet with resin.





I laid the cloth flat over the top so it covered the hole and was careful with the resin not to wet this part of it. Once cured I cut the cloth pulled the fibres back and then inserted the trumpet – this was a bit tricky and I didn’t get any pics.

Once in place I wetted all the fibres and the roughed up areas that needed a repair and popped it into a vacuum bag. My first time vacuum bagging today, I cheated (left the bagging material at home) and used a plastic cover you put paper in, it worked ok but was not stretchy like good bag material is.



The four trumpets still curing but solid to the touch.



Lots of sanding awaits once the resin fully hardens, I will smooth back rough surface and remove the excess resin that the joining of the two required. Once sanded back smooth it will be time to seal them with lacquer again. I wont get chance to do this for some time but will post up when completed.

Tom.

 

To get the desired finish I sanded down the trumpets with 600 grade wet and dry. Once all the imperfections were removed I lacquered them using automotive clear coat.

The results are aesthetically pleasing and should work well too.





The trumpets bolt to the filter back plate which in turn bolts to a mounting plate that fixes to the ITB’s, the filter plate has now been made from ali instead of carbon fiber. This is purely because I needed a new filter (after setting the last one on fire from an inlet backfire) and the new filter was bigger and required a larger back plate. I did not have enough time to make a lay-up of carbon this time but I did have a sheet of ali lying around.



The plate that holds it all to the ITB’s was hand cut from stainless sheet.



With everything put together it was time for a test fit. The holes in the filter plate and holding plate are enlarged so that the trumpets can locate and centrilise themselves on the ITB’s. Once all is in position and the trumpets are pushed on tight all the bolts can be tightened up.









Ill lock tight all of the nuts and fit tomorrow. The holes on the end of the filter plate are for a Air Inlet Temp sensor and the crank case return from the catch tank – I do not like the smell if left open to the air.

Hopefully these will last some time and I look forward to taking her back to the dyno to find out if they make an improvement. Last time I ran her with not trumpets.

 

Wow !

Happened to click on this whilst I was just browsing the forum. I`m glad I did !

 

Possible useful link>

http://cstsales.com/tutorials.html

BG

 

I'm thinking of making an airbox, using my old kr airbox as a mould, will be hard but would like to give it ago. Not too sure on the types of carbon sheet, but is this ok, it's only cheap http://www.ecfibreglasssupplies.co.uk/p-2188-carbon-fibre-cloth-375gm-twill-weave-1-mt-width.aspx

Or could I just use fibreglass to get it even cheaper.

 

That is great stuff east cost are great on price and have loads of products, you can just use fibreglass and it will still be great just will not be quite as light and not look as nice.

If you want the 'look' then use carbon on the outside layer and then just use fibreglass this works really well.

I started making an airbox the other day, ill dig the pics out to show you how I went about making the mould - I have not finished it as I have run out of time and need to make it smaller as it touches my radiator.

 

Right I started by tracing around my back plate to make one out of MDF, this will give me a good 12mm lip that will help strengthen the end product.



I then milled down the tabs that hold it in place and then chamfers around this part.







I then made up a template for the side profile and worked out of the volume of the box, I wanted it to be at least 1.5 X the engine size - bigger the better.



Then I cut three out of MDF.



Tacked into place.





Then I glued and tacked a thin veneer sheet over the top and then made the side profile parts.





The aim was to then finish the sides of with styrofoam and shape then cover in filler and smooth to a perfect finish. Then I would add the intake pipe and split the buck up into sections with plastacine ready to mould.

 

Looking good! Take it that is all at work lol

Yer I may get some fibre glass to practice on as it's cheap, then do I need sealant and release agent ( That's where I'm confused, do I put them on at the same time?). My bay is not one bit tidy so a fibreglass airbox isn't going to hurt it!

I was thinking of using the kr airbox as mould itself. It's hard to explain how I'm thinking of doing it, but it may work.

Something like this http://www.ecfibreglasssupplies.co.uk/p-687-300g-chopped-strand-matting.aspx at 2 for 1.6sqm is cheap!

 

Chop strand matt is heavy and works well for mould making (cheap) and as a filler layer. The weaved matt is the best stuff really. Have a look at this There are loads of vids and advice around to help you, they recommend car body filler just as i would and then a good few coats of PVA release agent. You can apply the layers of carbon matt and GRP weave and chop strand all at the same time.

 

Nice one thanks smudge.

 

Smudge, how is it going to release off form? I know you have a cunning plan I haven't spotted, love the wood work, top job

 

very nice work

 

Thanks for making this thread,

In the above images why was the mould 'sectioned'? Does it make it easier for intricate forms?

 

Because of the shape with it's over over hangs and concave surfaces it would never be able to be 'released' from the mold if it was not sectioned.

 

Any updates on this?