IS HIGH AIRFLOW CHOKING MY DIESEL?

The old saying ‘Bigger is Better’ has been around for ever. When this age old saying is applied to the inlet airflow of your Diesel, bigger may not be better.

Take a look at how a Diesel works and you could nearly say, “It’s just a big air compressor.” It sucks air in on the induction stroke and pushes gases out on the exhaust stroke. Traditionally this inbound air is compressed to, depending on the engine model, 500 PSI and when atomised Diesel fuel is added combustion begins. Get more air in and more fuel can be added for more Power. For so long, getting more air into the old Diesel engine had been a mandatory area to look at for power gains. One common side effect commonly witnessed during these times was many a dusted Diesel engine coming from poor filtering or easily blocked aftermarket hi-flow oiled air filter. A lot of aftermarket air filters were either straight poor quality due to the supplier cutting costs at point of manufacture or, as we would commonly see, made for a market unlike our unique Australian dusty conditions. These filter shortcomings would make these higher flowing air filters, turn into a quite restrictive ones.

Step up to modern EFI controlled diesels and other areas must be considered. One key point is the effect airflow changes will have on sensitive sensors such as the ‘air mass sensor’. Bigger air filter lids and again hi-flow air filters can alter air flow measured by the air mass sensor potentially inhibiting power across the rev range.

Remember to always chat with your Diesel Expert about changes you’re considering making to the airflow on your Diesel. More may end up being less if applied to the wrong conditions.

Safe Fourwheeling

Andrew Leimroth

Berrima Diesel- The Diesel Experts