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Old 02-05-2024, 10:51 PM
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Diesel911 Diesel911 is offline
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Originally Posted by carock View Post
What is the advantage of setting the boost to 10.5-11.0 psi? What is the disadvantage?
On a OM617.952 that is the high normal.

At a higher boost pressure, you get more fuel and use more fuel and in theory more fuel gives you more power but the higher boost in a sock set up will only give you a limited amount more power at the high normal end.

Let's suppose you have a stock setup fuel injection pump and managed to get 14 psi of boost. You are not getting any more fuel from the fuel injection pump than you got say at 12 psi so you would not have some surge of power.

To make use of the higher boost you need more fuel. So, some modify their pumps to get more fuel.

Before someone dabbles with that, they ought to have a full understanding of how the whole of it works and their engine and cooling systems need to be in great condition. Adding more fuel and boost increases the pressure in the cylinders, heat generated and stress on parts. And in the long run the engine pays for that.

One of the items that is monitored is the exhaust gas temperature.

However, I am not the one to ask about souping up the engines. There is a forum called the superturbodiesel forum where the more extensive knowledge is.

This is a slightly different area. Some people want better acceleration/power at lower speeds. No expert at that either but the general trick is to get the boost pressure to rise at lower engine rpms and the higher boost pressure causes more fuel to be injected at that lower rpm. I have a general idea that people have used different sized compressor wheels and perhaps exhaust turbines to do that, and they have something called variable venturi turbo chargers. They restrict the exhaust gas flow, and the higher pressure of the exhaust gasses causes the turbo to turn faster sooner. Later they open up and have a normal gas flow.

Anyway, there is a lot to learn.
84 300D, 82 Volvo 244Gl Diesel

Last edited by Diesel911; 02-05-2024 at 11:03 PM.
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