Here is a LINK
to Thermal expansion coefficients for some common materials. The higher the number the more prone the material is to thermal expansion. Take a look at both the Poly Carbonate and Rubbers coefficients of thermal expansion compared to that of aluminum. I feel confident in assuming that the material wrapping the rubber braided piping is produced of a polymer base. Since we know that the material wrapping those piping isn't reinforced, when you look at even the lowest coefficients of thermal expansion for the polymers based material its about it's a little greater than 50 m/mk compared to that of aluminum which is is 22.2 m/mk.
The seat belt example is a good one. What if that fiber wrapped around the rubber is made from the same stuff a seat belt is made of? Seat belts don't give. You can tug on them like a mofo and they're not going to stretch. If the nylon or whatever is in seat belts is the same stuff that's tightly woven around the UICP, why would it expand?
I get what you are saying completely and in theory this sounds like a good idea but the truth of the matter is that this has nothing to do with the fluid properties of the flow with in the pipe. You are also ignoring that mentioned that the hard pipe is more resistant to deformation than the stock piping. Should we also start talking about how the rubber hose is more prone to turbulent flow to do a the rubber being a less dense material that that of a hard pipe?
Why would that rubber section expand? It's not 100% rubber. It's braided nylon shit. You keep avoiding that and saying "it's rubber, it'll expand."
This is just common sense to anyone who knows anything about cars. To further bring home what I am saying Here
is an in depth explanation about the friction losses of air through out a rubber hose. as well as an excert from the Doctors conversation. Even though it's for a different application they modeled the experiment using fluid properties of air.
"In lean phase the pressure losses in rubber are higher due to a number of reasons.
1. The wall friction between particle and rubbers hose is very high as compared to steel. This causes increased losses.
2. Due to the soft nature of rubber hose when the particle impacts the hose the rebound energy is less then steel pipe.
That explains the 50% higher pressure drops in lean phase as stated above. In dense phase the most materials will have very high wall friction with rubber hose and it will not move on the hose wall and instead will have an outside stationary layer and the plug will slide on this stationary layer. If you want to quantify this the increase in pressure drop will be the difference between the wall friction of the material with steel pipe and internal friction of the material. Which when correlated to pressure drop will be in agreement with Dr Mills observations."
I have also included a graph of the Moody diagram
which is a graph in non-dimensional form that relates the Darcy friction factor, Reynolds number and relative roughness for fully developed flow in a circular pipe. It can be used for working out pressure drop or flow rate down such a pipe.
So what we have learned to day is that the softness of the rubber increase the friction factor which has an impact of the flow of fluid, in our case its air and we experience what they call in the industry a "pipe loss". So like I said the hardness and higher density material is more resistance to deformation which allows for a less turbulent flow to develop with in the pipe and overall increase performance.
I really didn't want to get into the affects on laminar flow and friction loss in a rubber hose but you left me no choice. The studies have been done and are proven and I don't need to watch the pipe expand or do a dyno pull to understand this. So to sum everything up on the debate of Stock UICP vs. after market hard pipe hard pipe, after market hard pipe hard pipe is better than the OEM UICP. the Now close this thread lol
Quod Erat Demonstratum