View Single Post
snowman snowman is offline
snowman's Avatar
Join Date: Feb 2003
Location: So California
Posts: 3,787
Back to a basic question- just why did Porsche introduce the restrictor? To keep to much oil out of the top end and consequently keep the bottom end alive at high rpm OR to boost the oil pressure at low rpm? I suspect the first is the correct answer.

PS that small hole still looks like it has more than 16 times the volume capacity of the very small holes in the squirters. Remember the volume goes up as the square of the radius so a hole that is only 4 times larger (dia or radius) than the squirter would support 16 squirters.

But again even if the restrictor is working, ie supports less flow than the bigger one, and actually reduces the output of the squirters, the pressure is still essenctially the same for all the squirters. Please!, try this with a garden hose and you will see what I mean. Unless the garden hose is really reallylong all the spray will be about the same.

Lets get a bit more technical to prove the point. Using electrical analogys, which are exactly equivalent, draw series resistors for in line restrictions, and parallel resistors for spray holes. Using a battery to represent emf or pressure you go thru a very big buss with no loss to the first restrictor, a series resistor of significant resistance. Then you travel thru another buss, the oil tube with low but non zero series resistance. How low? much much less than the restrictor. You could even proportion it using the diameter or the restrictor and the diameter of the oil tube. Then place parallel resistors along the oil line represented by very small series resistance between the parallel resistors. Do this until you have all the holes repersented. THen calculate the emf or pressure at each hole or parallel resistor. They wil be almost the same, ie very very close. This is true because the oil lines are not restrictive.

Give me the sizes of the holes and oil lines and I will give you the values to use for resistance as well as the relative pressures.

PPS that 246 hp is still 20 or more hp short of my 3.5L BMW M635 as measured on the same dyno, and its still stock. Lets get with it there.

Last edited by snowman; 03-19-2005 at 10:30 PM..
Old 03-19-2005, 09:44 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #26 (permalink)