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the way i have been thinking is that 4bd1t revs to 3000rpm (as a easy figure) say the 4bd1t is running over 20psi boost pressure it will use more air or "require" more air than a td5 that has a gt2052s which is a smaller turbo.
i was thinking about a compound turboed cummins 6bt it may only run to 4000rpm but that secondary turbo will be sucking a considerable amount of air even compared to a motor that is reving to 6000rpm.
although i do talk alot of crap:D
and to get the flow rate for a Turbo diesel the formula is roughly
engine capacity+(engine capacity*boost PSI(g)/14.7)
So if i put the correct figures in the formula the airflow required for a 4bd1t will always be greater than any other diesel rover motor even at same boost pressure.
For airflow vs boost.
15psi is around 1.5 times the NA engine air consumption.
20psi is around 1.6 times
15psi with 60% intercooling is 1.75
20pis with 60% intercooling is 2 times
These numbers are on the conservative side. With a well matched and very efficient turbo you can do better, with more than 60% intercooling better again. But the returns diminish fast.
my airbox had 4" inlet and outlet, so i made up a 4" s/s snorkel, then 4" reducing to 3" for the turbo feed. 3" exhaust running behind the starter motor near firewall and in between the chassis rails as i had the winged sump and couldnt be bothered changing it.
ok prove that for me.Quote:
Originally Posted by Dougal
No.:pQuote:
Originally Posted by Blknight.aus
The Donaldson book gives the following formula for airflow with a naturally aspirated four stroke engine.
(engine size in cubic inches x RPM/3456) x volumetric efficiency.
Donaldson uses the following factors for volumetric efficiency-
NA diesel = .9
Turboed diesel = 1.6
On a related issue i have done a bit of research on intake designing and an interesting fact i have found is that a rough surface flows better and has less resistance than a polished smooth intake....off to do some bead blasting now :D
Wow, that is very counterintuitive.. source?Quote:
Originally Posted by c.h.i.e.f