I’m looking for info about cyclonic air pre cleaners for Toyota D4Ds (particular a 120), but this applies across the board.
More specifically:
What are engine airflow requirements per Toyota standards or actual measurements? Does Toyota publish this? If volumetric efficiency (VE) is 1.85 (a reasonable guess), airflow would be ~ 2.5 m3/min @ 900 RPM and 9.7 @ 3500 RPM. VE could apparently be 1.5-2.5 so the possible range is large.
What is an acceptable intake restriction (vacuum) downstream from the air filter, and as a contribution from a pre-cleaner? Operational intake restriction is inexpensively and routinely measured on heavy equipment with “filter indicators” (e.g. see Donaldson catalog). Why aren't these aren’t used on Prados and the like in dusty Oz conditions? Does anyone have experience with these measurements for a Prado D4D?
Appropriate restriction varies; 20-25 inches-water seems common. Is this a suitable range to indicate changing a D4D air filter?
Donaldson posts performance data (airflow vs restriction) for some of their pre cleaners. But not the Full View, which is a popular model for Prados. I didn’t find airflow vs restriction data for any other manufacturer. Donaldson pre-cleaners have published upper restriction ranges from ~ 5 - 12 in-water, depending on model and size. Has anyone measured actual performance (restriction at a specific RPM) of installed FullView and TopSpin pre cleaners, or for that matter, any other cyclonic pre cleaner?
I found the following pre cleaner specifications for airflow (min-max, m^3/min) and size (height x diameter, inches):
Donaldson TopSpin 002437 2.5-6 m3/min (5.75" x 6.4”)
Donaldson TopSpin 002426- 6-13 (9.4 x 9 .5)
Published TopSpin airflow capacities vary between Donaldson catalogs & web sites, and whether units are m^3/min or CFM
Donaldson FullView - max. 5 m3/min (~7” dia). (I could not find min airflow for FullView models)
Donaldson FullView - max. 9.5 (~10” dia).
Engineaire 4-150/465 4.3-13.2. (5.4 x 9.4)
Engineaire 3-75/250 2.1-7.1. (4.5 x 7)
Sy-Klone 9001. 2.8-7.8. (4” inlet 5.8 x 8.5)
The Sy-Klone appears to best fit my driving range, but no advertised airflow range fully covers 900-3500 RPM. Users consistently recommend going sizing down (e.g. FullView 7” rather than 10”) while many manufacturer and after-market dealers recommend sizing up for maximum RPM. Cyclonic filtering is clearly inefficient at too-low airflows. Airflow restriction increases when flow exceeds the maximum (> 5”-water for Donaldson’s), but does cyclonic filtering drop off at high airflows? I.e., is the maximum airflow specification set by a filtering efficiency standard, by an airflow restriction standard, both, or something else? For most designs, does the relationship between airflow and restriction remain relatively linear at high airflows?
I know this is a bit over the top, but I found very little quantitative information or actual performance data in the many threads on these pre filters. Let me know if this info is somewhere and I've missed it!
More specifically:
What are engine airflow requirements per Toyota standards or actual measurements? Does Toyota publish this? If volumetric efficiency (VE) is 1.85 (a reasonable guess), airflow would be ~ 2.5 m3/min @ 900 RPM and 9.7 @ 3500 RPM. VE could apparently be 1.5-2.5 so the possible range is large.
What is an acceptable intake restriction (vacuum) downstream from the air filter, and as a contribution from a pre-cleaner? Operational intake restriction is inexpensively and routinely measured on heavy equipment with “filter indicators” (e.g. see Donaldson catalog). Why aren't these aren’t used on Prados and the like in dusty Oz conditions? Does anyone have experience with these measurements for a Prado D4D?
Appropriate restriction varies; 20-25 inches-water seems common. Is this a suitable range to indicate changing a D4D air filter?
Donaldson posts performance data (airflow vs restriction) for some of their pre cleaners. But not the Full View, which is a popular model for Prados. I didn’t find airflow vs restriction data for any other manufacturer. Donaldson pre-cleaners have published upper restriction ranges from ~ 5 - 12 in-water, depending on model and size. Has anyone measured actual performance (restriction at a specific RPM) of installed FullView and TopSpin pre cleaners, or for that matter, any other cyclonic pre cleaner?
I found the following pre cleaner specifications for airflow (min-max, m^3/min) and size (height x diameter, inches):
Donaldson TopSpin 002437 2.5-6 m3/min (5.75" x 6.4”)
Donaldson TopSpin 002426- 6-13 (9.4 x 9 .5)
Published TopSpin airflow capacities vary between Donaldson catalogs & web sites, and whether units are m^3/min or CFM
Donaldson FullView - max. 5 m3/min (~7” dia). (I could not find min airflow for FullView models)
Donaldson FullView - max. 9.5 (~10” dia).
Engineaire 4-150/465 4.3-13.2. (5.4 x 9.4)
Engineaire 3-75/250 2.1-7.1. (4.5 x 7)
Sy-Klone 9001. 2.8-7.8. (4” inlet 5.8 x 8.5)
The Sy-Klone appears to best fit my driving range, but no advertised airflow range fully covers 900-3500 RPM. Users consistently recommend going sizing down (e.g. FullView 7” rather than 10”) while many manufacturer and after-market dealers recommend sizing up for maximum RPM. Cyclonic filtering is clearly inefficient at too-low airflows. Airflow restriction increases when flow exceeds the maximum (> 5”-water for Donaldson’s), but does cyclonic filtering drop off at high airflows? I.e., is the maximum airflow specification set by a filtering efficiency standard, by an airflow restriction standard, both, or something else? For most designs, does the relationship between airflow and restriction remain relatively linear at high airflows?
I know this is a bit over the top, but I found very little quantitative information or actual performance data in the many threads on these pre filters. Let me know if this info is somewhere and I've missed it!
Comment