jap-si

I've just seen an old thread where some of you guys didn't rate a new fmic because of the maze of carbon pipework and bends, and some of you think the carbon's just a gimmic to sell the fmic. I'm thinking about getting some of these carbon pipes, and have spoken to the company that sells them. They tell me that they are made from a vacuum formed carbon (the same as Formula 1 stuff) and it's very different from the kind that bonnets etc. are made from. I thought there was only one kind of carbon.
The company says that if the pipes are used for a fmic, the carbon is better at keeping the air cold because carbon is a much better insulator than the alloy pipes i already have.(they also look quite trick)
Can any of you confirm that vacuum carbon is better than alloy and will it maybe get my induction temp down a bit?

scoobiestu

i think what most people were slating on that fmic kit was the amount of silcoln joints that it had causing lots of turbulance to the ar passing through it, like you say carbon is a lot better insulator than alloy but it costs alot more to make tubes with bends in as apposed to straight sections with silcoln joints. stick with alloy it does the job well enough

Chelspeed

The whole point of the intercooler is to reject heat from the charge air inside the cooler to the air outside. Most heat is rejected from the cooler itself as that's what it's designed for. But if you can lose a bit more from the pipework as well then that's got to be a good thing. So if alloy is a better heat conductor, which it almost certainly is, then that's a good thing not a bad thing.

Only time this won't be true is if the air outisde is hotter than inside, except close to the exhaust or turbo then I can't see this being likely.

scoobiestu

good point! didnt think of it like that but your right

jap-si

Thanks for that, the only possible flaw in your theory is that the ideal charge air temp would be 35 to 40 degrees or even less would be better, So what temperature do you think is under the bonnet around the engine? I don't honestly know but surely it must be higher than 40 degrees and if so, the alloy pipes would soak up that heat instead and transfer it to the charge air thus increasing the charge air temp after it's been cooled in the front mount.
Maybe i'm being a bit **** about this (all this for a few degrees) or maybe i'm just trying to justify spending my money!!!!

The other point you mention about extra bends and joints causing airflow problems, isn't that a bit daft when the air has to travel through a maze of little pipes in the intercooler itself...surely that causes more turbulance!

Thanks again though.

R19KET

Charge temps after the turbo, and before the IC, can reach in excess of 140C, depending on the turbo, and how hard you drive it.

Now try and work out what you want to do with the pipes

Mark.

jap-si

Thanks Mark, the point still remains though, fair enough the temp at the turbo end is going to be high but after it's gone through the fmic, that's when the charge air temp will (or should) be less than 40 degrees. And that's where i'm saying the carbon pipes will maybe keep the temp down where as alloy pipes might increase the temp by a few degrees.

Also as i originally asked, has anyone used or have any knowledge about this vacuum formed carbon, is it that much better than "wet lay up" ( which i believe is the other version).

Still confused!!!!

Adam M

I believe you are talking about autoclaved carbon as opposed to wet lay which is glorified fibreglass.

Autoclaved is also known as pre preg which is a better starting material. I requires far less in terms of material but requires an autoclaved to form it to the mould under a vacuum and at high temperatures. This process requires very very expensive machinery and the raw materials are also not cheap in the first place.

I have an autoclaved front bumper waiting to go on my car one day!

The strength to weight ratio of autoclaved carbon fibre is far higher than that of wet laid, but both are easily strong enough to with stand the pressures.

The temperature theory is all very well.

Ideally you want black aluminium pipes on the hot side with fins to increase their surface area to allow them to cool pre intercooler as much as possible. Then on the hot side, shiny carbon pipes with as few bends as possible to reduce turbulence close to the inlet manifold and prevent heat from the engine bay heating the cooler charge. The shiny carbon reflects radiation and reduces heat flow across its section.

jap-si

Cheers Adam
My goodness! at last someone who seems to know some serious technical info, unlike the usual " i know a mate who had one of these and thought it was crap....so that means it definately doesn't work!!!!" LOL

Thanks for that M8.