Car = 83 euro GTV6, 3.0 12v motor, CB cams, CSC extractors, no center box, ansa rear, MegaSquirt ECU & big injectors (also from Greg btw). The car used to have the biggest available BMW ljet AFM pegged wide open (was just there for it's air temp sensor) fitted to a modified Alfa airbox with a K&N panel filter inside and more cold air inlets to the box. The air inlet side was already a huge improvement over the stock tiny AFM, but I figured it could be improved:
I bought Greg's non AFM version of the inlet tube complete with his "best" version of air filter and silicon connector elbow. Note that with the Megasquirt ECU and a laptop I can view all engine parameters in real time or datalog them for later viewing, so these are my measured findings for the product rather than just opinions.
When tested the ambient air pressure was 98 kpa.
With the AFM & air box arrangement in place at full throttle the ECU would show 98 kpa inside the plenum up to 3000-3500rpm, then gradually drop down to 95 by 5000rpm and 94 by 6500, all at wide open throttle. I figured this loss of 3 or 4 kpa at maximum demand was a symptom of residual restriction from the components before the throttle valve. Now the good bit.
With the Greg kit installed and ambient air pressure still 98kpa I find that full throttle low to mid rpm is still 98 kpa, so no change here, or expected.
At 4000 rpm where previous version is already showing losses the new version maintains 98 kpa.
Above 5500 rpm the plenum pressure now increases to 99 and then 100 kpa and maintains this right through to 6800 rpm.
In short measurements of air pressure inside the plenum chamber are 5-6kpa higher than the previous modified and pretty good inlet system.
Not only has the restriction vanished but there is now a measurable RAM effect ! I don't know exactly how this comes about but suspect that as the air filter base is the shape of a large "velocity stack" and merges perfectly to an unribbed tube and elbow the system is not only unrestrictive but generates some positive RAM effect at high demand.
In short this is a fantastic product. I've gained 5-6 kpa air pressure which ought to be some 5% extra airflow into the engine and Air = Potential Power !
The extra breathing requirements of a mildly warmed 3.0 make this a very worthwhile modification.
Nice one Greg !
