Heat Shield Experiment
So I decided its time for some science. Cause I was bored.
Assuming standard laboratory conditions:
1 mol of gas = 25L
1 mol of "air" is about 15g
So 1.67L/g of air.
At 200g/second air intake that is 334L/second of air. Since 1L=1000cm3 that is 334,000cm3/second.
a 3 inch intake has a cross sectional area of 44cm2. To pass 334,000cm3 the air must travel at 7,590cm/second or 75m/second.
a 4 inch intake has a cross sectional area of 78cm2 meaning air will only need to travel at 43m/second.
All these number to say air has to travel fast through pipes and the air in the engine bay will be depleted pretty fast - sucking new ambient air into the engine.
THE EXPERIMENT
Background:
After watching MCM test cold air intake etc and showing minimal improvements I started reading. I couldn't find any actual testing of intakes to prove they did anything.
However when cruising sales websites I often saw claims of 20-30hp increase from a simple short ram intake. Now mazda went to the trouble of installing that god feral front grill That actually routes air towards the intercooler dropping boost temps by about 15C when travelling at 60km/h (I tested this). I can't help but think they would have looked at the intake if it was that restrictive.
So I have decided to test it.
Hypothesis:
Larger air intakes/short ram intakes are more about decreasing radial heat adsorption and heat adsorbed by the air flowing through them (lower surface area to volume ratio or shorter flow path etc), and that airflow restrictions of the OEM parts will be minimal.
Methods:
Stage 1 - collect baseline data (ambient air temp, boosted air temp, intake air temp) at 40, 60 and 100km/hour.
Stage 2 - Wrap everything I can find in heat shielding from bunnings and redo stage 1 data)
Stage 3 - remove intake hose and test air flow using an industrial fan. Test an aftermarket intake in the same way to see if the OEM intake is restrictive.
Stage 4 - install AFM intake system and repeat Stage 1.
As a second experiment I will also do before and after Vdyno testing to see if there are any improvements in turbo spool speed or HP or Torque.
RESULTS
Baseline data
So I have enough data to be confident in my base line values.
60km/h.
intake - 12-15 above ambient
Boosted - 15-17 above intake
80km/h
Intake - 12 above ambient
Boosted - 13 above intake
100km/h
Intake - 10 above ambient
Boosted - 12 above intake
With Heat shielding on any available air pipe surfaces
No improvement to cruising temps, but it appeared to be slightly better when parked - but quickly returned to 'normal'
I should note that I did not fully wrap all the intake piping (planned to if this made a difference). I will be installing a SRI and plan to test wind speed (using an industrial fan) through the SRI and stock intake (filter not included).
Anyone who can lend me an AFM intake system (SRI or Larger intake) that fits a 6MPS would get a special mention haha.
Last edited by Fever; 22-08-2014 at 08:36 AM.
2005 6 MPS - Cobb AP - Auto tech HPFP internals - CorkSport RMM - 3inch ceramic coated downpipe - SRI - TIH - FMIC - Oil Catch Can - RayD tuned. 190kw@wheels, 410nm, 20psi.