Metal vs. Plastic Boost Tubes

[s2avant]

I was wondering aside from cosmetic reasons whether there are any advantages to the plastic boost tube which according to ETKA is fitted on RS2's and later ABY's?

My ABY has the metal one fitted which seems fine apart from being scratched although I imagine it's fairly easy to bend the ends of it when removing and refitting the turbo hoses.

Do the plastic ones have any advantages? i.e less heat retention

On my engine that pipe gets ridiculously hot. Is this normal? I would have thought that having a high temperature in this pipe would undo the work done by the intercooler.

Ben

[S2central.net]

I have noticed the plastic pipe on Jim's MY96 car and often wondered was this done for cost or performance reasons.

I don't have any data to compare the two with regards air temperature.

Think I was talking to Greg or someone at the weekend about this - he was talking about removing the black paint to make it less likely to absorb heat from the surroundings. Quantifying those kind of gains would be errr fun !

Paul

[blu_s2]

Certainly my plastic pipe is one of the few places on the engine you can touch without removing skin after a run.

I suspect it was a cost save. There were plenty of other cheap things Audi could have done to improve the car in later years that they chose not to do - Mark's IC Hose Mod for one

[Greg_S]

Yeah probably make very little difference to temp, but maybe just a little. Will polish the pressure pipe up more for cosmetic reasons though.

Greg

[Doug_RS2]

I was asking people at the weekend about plastic ones - i was told AMD changed the plastic one on my car to a metal one and never beleived it until I saw Blu-S2s picture and saw it at the weekend.

I think a custom one with an outer cavity, with water pumped though it, to cool the inlet, could be a cheap way of cooling the inlet air - What does everyone think??

[SteveH]

Sounds like a good idea Doug, however, there's all the hassle of pumping water and cooling it. What about a bit of heat insulation wrapped around it? Like the metalised cloth you can buy for exhausts.
The other problem is the location of the pipe - right next to the head. I'm sure some insulation between the pipe and the rocker cover would also reduce temps by a degree or so.

I'm going to spend the rest of my working day looking at insulation on the web

Cheers
Steve.

[s2avant]

Sounds like a good theory, could be a little hard to put into practice though.

I am thinking of lagging the pipe in that heat reflective sheet they use on race engines. Should do a similar job. Any thoughts?

Ben

[s2avant]

Steve,

Great minds think alike. I've been doing some investigating of heat wrap on the internet. SWR Motorsports sell thermotec 'cool it' in sheets and in sleeves. It's supposed to be the best but it's not cheap. £30.60 + VAT for a 3ft length of 2.5in sleeve.

Cooltek produces similar stuff. It's bit cheaper but not a lot. It's sold through proven products.

It might be best to use a sheet cut to fit around the various fixings held with jubilee clips as the tube isn't smooth all the way along.

SWR Motorsport

Cooltek

[Doug_RS2]

http://www.merlinmotorsport.co.uk/catalogue/heat.htm

You can download their catalogue - it has more stuff in that.

[audiman]

If you do polish that metal pipe, remember that it is mild steel and will go rusty!!

[Dr H]

Tom

Is it mild steel or aluminium? Last time I had mine off I seem to remember it was pretty light

Leigh

[audiman]

It is steel, but its paper thin. When i welded the stub for my dump valve on to it, the welder was turned right down and it was still a bitch to do. It is so thin.

[Greg_S]

Originally posted by audiman
If you do polish that metal pipe, remember that it is mild steel and will go rusty!!

Will probably have to have it plated instead then, not sure what that would cost though. Heat wrap sounds like an excellent idea however. Did think about using some of the exhaust wrap you can get.

doesnt look v nice tho.

[s2avant]

the problem with heat wrap is it is desgned to keep heat in. The aluminium surface on heat barrier is designed to keep heat out.

They will both do the same job although in theory but i would imagine the reflective stuff is better.

Not entirely sure though

Ben

[Audi Parts Guru]

I'd personally look at something similar to the tin foil that you find in your kitchen.I know that there is stuff out there that is wafer thin but is good for temps of up to 110c +,i know that this temp doesn't leave much of a margin but hey it's gotta be worth a shot.
It's at times like this that i'd wished i'd not thrown away my Demon Tweeks catalogue