I have some stock fuel injectors which proved handy for plugging the holes in the intake manifold where the fuel injectors would normally go.  I suspected that in terms of overall air flow, that is with all of the runners open, the inclusion of the fuel injectors to block the holes would have little to no affect on the airflow value for the intake manifold.  The reason being that the holes are less than an inch from the runner outlet and due to the orientation the air flow would have to reverse 180 degrees to exit via the fuel injector hole.

It will be necessary to have these fuel injector holes plugged during single runner tests so putting the fuel injectors in place now was beneficial beyond simply answering the question of whether or not they made a difference to the overall flow.

The results at 10″ of H2O were not a surprise:

Intake manifold without fuel injectors: 360 CFM

Intake manifold with fuel injectors: 362 CFM.

Because the air flow reading fluctuates as much as 3-4 CFM, even with the bench operating at steady-state, the results for air flow in the different configurations are essentially the same.

I’ve been working on a new adapter so that I can flow test intake manifolds.  My hope is to mess around some with porting the intake manifold and not hurt the performance of the part during the learning process.  The new adapter is not quite finished, there’s a little bit of air leakage around the base that should be taken care of with a gasket.

I wanted to try and measure ‘something’ and just measuring the pressure loss through the entire manifold seemed like a boring test at this stage, especially since the leakage at the base would throw the results off slightly.  While running some air through the manifold I thought that it felt as though the air pressure coming from the runner to cylinder 4 was weaker than the runners for cylinder 5 and 6 so I hooked up the velocity probe to measure the air velocity at the manifold runner outlet.

The velocity probe is a pitot-static system that will measure the pressure at the probe end and feed the pressures, static and dynamic, to the digital manometer so that the pressure can be recorded or the readings can be converted to an airspeed.  The airspeed reading at the outlet for each runner are shown below.

Interesting results.

Background:

When I purchased the AMD intercoolers AMD had informed me that they do not offer shrouds.  I inquired as to why that was and they explained that there had been negligible difference when they had tried using shrouds.  The thought was that because of the large frontal area of the core, the AMD frontal area is larger than any other SMIC I have got figures on except for the Wagner RS4 – which requires extensive modification to the car to fit, this larger frontal area leaves little room for air to go anywhere except through the core.

The Setup:

After driving with the AMD intercoolers for a few days I became curious to see if I could record any difference in IAT with a shroud in place.  I wasn’t willing to spend a couple hundred dollars on a set or ER intercooler shrouds, the only ones I thought might be close to covering the AMD core, so I decided to use my stock IC shrouds.  This was not the ideal setup, but if shrouds were to make any difference I thought stock shrouds may be sufficient.

I had a well laid out course to drive where speeds could be tightly controlled.  Part way through, at about 25 minutes in, I parked on the side of the road with the motor running for two minutes, then resumed the drive for four minutes whereupon I rolled into a FATS pull.  From there I spent a few minutes driving the car back to the garage.

The Results:

The results of the two drives are shown below:

Conclusion:

Results look mixed to me.  At the start the setup with shrouds shows a slight improvement over the non-shrouded drive, and the ambient temperature was a couple of degrees warmer when the shrouds were installed.  But around the midway point of the drive the difference disappears and never returns.  This could possibly be attributed to the type of driving being done, the first half was steady state cruising while the second half had some significant dynamic changes and an overall slower pace.

The main question I have is how the results would have looked if a larger shroud had been used.