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Nexuscocker wrote:Sorry about the side note:

Is it for effective to port the inlet of a M90 rather than the outlet? Based off that data I would think that porting the inlet would lessen the heat that was created, but in not and engineer.

On the M90, don't PORT anything. You can improve efficiency by simply smoothing and polishing the inlet and outlet (replace the needle bearings afterwards) to get all the bumps and sharp edges out without enlarging either feature.

Paul (bullet), I know it doesn't make sense, and I've mulled it over ever since I ran the data and found the other data, but the data is what the data is. The only thing I can put a finger on is that the inlet is rather rough in stock cast form, and the air reaches a restriction in the inlet, and has to turn upwards to enter the compressor chamber at that point.

Could it be friction of the air as it's being restricted through the TB and inlet?

Could it be the 500 F EGR ?

Before I removed it I couldn't hold my hand on the TB it was so hot.

Now with both EGR and coolant disconnected, it is cold. With no intercooler.

When your engine is warm try to grab that TB at the EGR entrance and feel for yourself.
All that heat will conduct into the casing and hence warm the air.

Paul, neither set of data I posted accounted for the EGR, and as I said before, my modeling showed a very minor effect from it.

I was wondering if your modeling was only accounting for the effect of the EGR gas temp on the air temp in the intake or if it accounted for the heat soak in the charger where the EGR enters the air flow that would also heat up the air.

It's the coolant that is making that thermal map hot at the inlet. Unless the laws of physics no longer apply in Minnesota, there is no way that the inlet temps are hotter than the compressed outlet temps of the air charge...NO WAY! I will bet my car on it!

What tools did you use, willwren, to collect this data?

You last two posters missed two key points. It's not the coolant. That passage was set to coolant temp before the test was run in my model, and unaccounted for in the older model. I did not allow the coolant temp to rise above normal in the test. That heat came from elsewhere.

Neither my model (shown) nor the older model accounted for the EGR at all.

The old model shown (black and white) was made in CAD, and various known temperatures were constrained before the test.

2: Constraints

The bottom surface was constrained to 120° Celsius (250° Fahrenheit), the intake (the hole in the trapezoid) to 36° C/ 97° F, and the other surfaces exposed directly to the engine bay were set at 76° C/169° F. Surfaces exposed to the engine bay that shared an edge with the bottom mounting plate were left unconstrained.

I did the same, but with some differences. I made my own 3D model based on an empty housing, and constrained the bottom surface of the supercharger and the coolant passage to known temperatures off my cars when warmed up, then began the test with a typical CFM of air through the inlet.

My model was created in CoCreate Solid Modeling (hp designed it originally under UNIX as ME30, then sold it to CoCreate who now license it back to us as a discount under windows). I used the finite element analysis module for my thermal testing.

One possibility for the odd rise in temperature is that the lower area of the inlet isn't exposed to engine bay air. Their model was more simplified, causing the entire inlet to rise in termperature. My model was far more advanced, and showed a specific rise in one area.


I did my modelling quite some time ago, and don't recall the results of every test. I varied alot of the parameters including coolant on/off, coolant temp, LIM surface temp, air temp, etc. Every time, whether the EGR or Coolant was on or off, the lower surface of the inlet was always hot. In some tests, the outlet did rise in temp, until I smoothed off the edges in the model (which is why I port/smooth my inlet and outlet the way I do now).

Bill ported my Gen5 SC using his knowledge but I insisted on him filling my EGR hole with JB weld and I plugged the coolant ports in the LIM.

EGR block off works for me.

It's a personal choice.