AustenW

For Nasp, very good, for Turbo its a no no

AustenW

RUPERT THE BIG HAIRY BEAR

looks like a plastic mani for a set of throttle bodies

AustenW

Its a fibreglass Airbox I made for my car

I make them for 4 and 5 cyl

RUPERT THE BIG HAIRY BEAR

well it looks good

dunketh

I'd guess the reason you never see them is because they're a pain in the arse to make.
Layering up composite materials is a much longer 'faffier' process than simply sand casting a load of molten metal or pressing some plastic into a mould.

Its less forgiving too - if you get a rough patch you can't 'smooth' it with a dremel without opening up potential air pockets/holes and the like.

andy escos

iTrader: (1)

go for it fella would be interesting to see if it works

xr-stu

collecting a zetec xr2i in a few weeks, i might try and pick up a shitload of fibreglass matt and resin from somewhere and try and knock something up for it in my spare time, just to see if it works. if it shits itself and the engine gets written off its no real drama, a new un would only be a few quid from a scrappy and a day to replace.

AustenW

Ive got a 4cyl airbox for sale on ebay at the moment similar to my other post

Search for Airbox

cjwood555

Surely an airbox 4-5mm thick would be heavier than a factory ABS one, as well as being less strong, less well designed, and offering the above opportunities for catastrophe???!

Chris

cjwood555

will a focus abs manifold fit the 2i?

AustenW

Its all about volume and inlet diameter so the flow isn't restricted

SuperStoker

I think you've got the wrong end of the stick on this one.

there is a common misconception that tube is stronger than solid bar under torsional stress
the primary reason for drilled shafts is to reduce weight as the worst weight in a car is rotating weight and un-sprung weight, you can safely remove a large amount of material without significantly reducing strength but strength is reduced however:

From wikipedia...

In solid mechanics, torsion is the twisting of an object due to an applied torque. In circular sections, the resultant shearing stress is perpendicular to the radius.
For solid or hollow shafts of uniform circular cross-section and constant wall thickness, the torsion relations are:
where:

• R is the outer radius of the shaft.
• τ is the maximum shear stress at the outer surface.
• Φ is the angle of twist in radians.
• T is the torque (N·m or ft·lbf).
• ℓ is the length of the object the torque is being applied to or over.
• G is the shear modulus or more commonly the modulus of rigidity and is usually given in gigapascals (GPa), lbf/in2 (psi), or lbf/ft2.
• J is the torsion constant for the section . It is identical to the polar moment of inertia for a round shaft or concentric tube only. For other shapes J must be determined by other means. For solid shafts the membrane analogy is useful, and for thin walled tubes of arbitrary shape the shear flow approximation is fairly good, if the section is not re-entrant. For thick walled tubes of arbitrary shape there is no simple solution, and FEA may be the best method.
• the product GJ is called the torsional rigidity.

The shear stress at a point within a shaft is:
where:

• r is the distance from the center of rotation

Note that the highest shear stress is at the point where the radius is maximum, the surface of the shaft. High stresses at the surface may be compounded by stress concentrations such as rough spots. Thus, shafts for use in high torsion are polished to a fine surface finish to reduce the maximum stress in the shaft and increase its service life.
The angle of twist can be found by using:

[edit] Polar moment of inertia

Main article: Polar moment of inertia
The polar moment of inertia for a solid shaft is:
where r is the radius of the object.
The polar moment of inertia for a pipe is:
where the o and i subscripts stand for the outer and inner radius of the pipe.
For a thin cylinder
J = 2π R3 t where R is the average of the outer and inner radius and t is the wall thickness.




so the only way you can acheive the "stronger and lighter" claim is to use a larger than standard diameter shaft that is drilled.


a variable not taken into account here is heat treating, where having drilled shafts is an advantage if treated after drilling as there is more surface to treat..


hope this is of use to you.

Chip

iTrader: (3)

Superstroker, you misunderstood my comments, apologies if it was worded badly as reading it back I can see that I should have put more time into that reply than just a quick one liner, my point was meant to be that a larger diameter drilled shaft (this shaft is a larger diameter than a standard nova one) is stronger and/or lighter than a smaller diameter solid one.
I didnt mean that it is stronger than a same diameter solid shaft, I meant its stronger than a same weight solid shaft, or lighter than a same strength solid shaft or of course a combination of the two depending on the exact dimensions of the two shafts.

Great input though mate, thanks for clarifying

AlexF

Why are you worried about heat transfer?

At over 100 litres per sec passing through your inlet (taking a guess at the engine your aiming this for) there's not much chance its going to heat the air up!!