[335MRod]

I’m currently looking for some info on how I can run a cone intake at my inlet. I would do Maf delete, but also need an option for an occ so I can delete the hose from pcv to intake. I saw mishimoto occ but it uses the connections on the intake and I would need to get rid of that all together and only use occ. Anyone running an intake on their inlet ?? Looking for some guidance. Thanks in advance

[Divbetic]

Originally Posted by 335MRod

I’m currently looking for some info on how I can run a cone intake at my inlet. I would do Maf delete, but also need an option for an occ so I can delete the hose from pcv to intake. I saw mishimoto occ but it uses the connections on the intake and I would need to get rid of that all together and only use occ. Anyone running an intake on their inlet ?? Looking for some guidance. Thanks in advance

It's been done before. Back in 2018 Twisted Tuning was working on a maf-less solution for us e-series n55 but not sure if anything came of it. Here's a link to the IG post.

[drwillb]

That's just about the hottest part of the engine bay. Not sure how that can yield positive results.

[fortywater]

Originally Posted by drwillb

That's just about the hottest part of the engine bay. Not sure how that can yield positive results.

Same way any other intake setup yields positive results. The air is still passing through the inter-cooler. As long as your IATs aren't rising during a pull you will benefit from increased airflow depending on mods.

All the single turbo N54 guys run their cones in the same location. Maybe not as far crammed down, but close

[TheGoodTheBadTheUgly]

The stock design will be more efficient, I am certain of it. Sure the intercooler cools the passing air but it can only do so much. When compressing air, thermodynamically the temperature increases at the outlet in a very intense manner that many people ignore.

A compressor is considered a reversible device thus making it an isentropic process yielding the derived equation of the second law of thermodynamics: TOut/Tin = (POut/PIn)^(k/k-1). "In" is the inlet of the compressor (air intake) while "Out" is the outlet (before intercooler) and the temperatures are taken in Celcius.

K is the ratio between Cp, the specific heat of the fluid taken at a constant pressure which in our case is air while Cv is the specific heat of air taken at a constant volume. By doing the ratio of various Cp and Cv measures or simply by assuming that air is a diatomic molecule since it is mainly composed by dinitrogen and dioxygen (~79% N2 and ~21% O2) you get a gamma (K) value of 1.4.

Thus the formula can now be shrunk to: TOut = TIn*(POut/Pin)^3.5.

Right, enough maths even though probably none of you followed this. Lets take these following measures. The pressures will be absolute, meaning that to the car's TMAP reading will be added the atmospheric pressure.

Lets be conservative and assume the turbocharger has an efficiency level of 70%.

Inlet pressure as the ambient pressure: PIn = 14.7 psi = 101.325 kPa
Outlet pressure at a tuned pressure of: POut = 16 psi + 14.7 psi = 30.7 psi = 211.669 kPa

In the first case, we will take an intake temperature of: TIn = 20 Celcius which is a normal reading. Thus, by putting all the known values in the formula, the result is TOut = 263.52 C. By applying our efficiency loss, this would render a true outlet temperature of TOut = 184.464 C

In the second case, let's imagine the air intake is near the turbo and in the hot region of the car. The material of the pipe will get heat soaked pressure fast. Let's suppose that this would affect the inlet air by raising its temperature by 5 degrees which could be possible considering the advection of the hot air of the bay. Thus, TIn = 25 Celcius. The outlet temperature will then be TOut = 329.41 C. By applying our efficiency loss, this would render a true outlet temperature of TOut = 230.59 C

In conclusion, for a very small intake temperature increase of 5 degrees Celcius, the outlet temperature at the compressor increases by 46.126 Celcius. This is a very theoretical calculation but pretty close to the real values. Even if the values are not the same the principle and correlation remain.

What is important to get out of this is that a small increase in the intake temperature results in a huge increase in the outlet temperature. Now crank up the intake temperature or generated outlet pressure and you will see how fast the outlet temperature can increase and why we have certain limitations with our turbocharging systems. I am not saying that that location for air intake is horrible because we would have to study the heat transfer between the hot area of the engine and the intake pipe to see if it would make a 5 degrees difference.

So this was more of a post for fun and to make you realize the importance of the intake air temperature. It doesn't really mean anything for you other than to argument the fact that the stock engineered air intake system is optimal since it ensures high air intake and at a minimal temperature.