So, this is a subject that I have read many different opinions on. Some say to advance the timing a little and some say to retard the timing a little. I have been in the advance the timing group but I want to get the facts before I install my turbo.

What I would like to hear from everyone here with a turbo is what your timing is at, how the power and economy is and your boost numbers. I want to compile a definitive list of real-life results.

 

Well i have no numbers for you, but pre turbo i was running advanced, it liked it. Once the turbo was on there i ended up retarding it quite a ways to find its "happy place". The reason for this is since there is so much air the fuel continues to burn quicker, whereas in NA form the combustion chamber starts running out of O2 and thus the combustion rate tends to slow down, especially noticable at higher rpms. I have noticed a 2mpg drop since the turbo and retarding the timing, but im chalking that one up to my perpetually heavier right foot.

 

Definitely advanced. Most 5.9 guys run 12-15 advanced. My Cat is set at 12 advanced. No idea what the PSD's are running since their computerized but I know for sure its advanced. Advancing the timing will get you more boost and better mileage. I only know of ONE turbo IH motor that wasn't factory advanced and that was the 407 I-6 in the 1456 tractors, they ran a straight 0 advance.

 

What you say about the PSD must be be true. They have a loud diesel knock and lower compression, so it seems to make sense, bar the completely different injection system. I have only recently heard of retarding timing after installing a turbo. I was always under the impression that about 2 degrees advanced was optimal for the IDI engines.

 

completely irrelevant. 5.9's and PSD's are measuring a different timing event than the IDI is, so the numbers do not mesh.

You also misunderstood him when he was asking about advancing or retarded. The accepted norm for an IDI is 8.5* btdc. So that is where the "advance it, or retard it" comes into play.

An engine like mine runs @ 6*, this is because it can burn the fuel, injected in closer to TDC. The closer to TDC you can get, while still burning the fuel = the most power.

Elevation also plays a big roll. On a stock turboed engine you are going to find somewhere between 8.5 - 10* is where it will be happy.

 

I guess I should have asked was the op asking about the static timing of the pump or the mechanical advance over the rpm range, my bad.....

 

I'm talking about the timing of the pump on the 6.9/7.3 IDI engines. Advanced being anything over 8.5BTDC and retarded being anything less than 8.5BTDC. I am assuming timing is set with a pulse meter @ 2000 RPM with -20 degrees offset.