Where Should I Set My Timing
 

I was researching the possibility of increasing the timing on my truck. It appears that advancing the timing will decrease my EGT's and increase some power, among other things.

What is a good point to advance it to. I read between 15 and 15.5 is a good point for a slightly modified 5 speed.

Any opinions???

Is this something the average guy can do or should I take it to the Stealership.

I set my sons 94 at 15.5 and it made a big difference

i was thinking about this too, im not sure if its something that i can do though

Not too up on this myself. I only went to 14. It's a good middle of the road number I was told. I was at 10 so it made a big difference.
I thought at 16 or higher it got a little risky?? Have heard of a lot in the 15 range though.

most people will tell you that about 16.5* is max for a stock headgasket.

it is my personal opinion that if you are towing/working the truck than you shouldn't go higher than 15* for reliablity reasons. remember that increasing your timing increases cylinder pressures. at the same time, towing/working the truck also increases cylinder pressures. this math equals out to a lot of increased cylinder pressure with increased timing while towing/working the truck. that is without taking into account the other mods you've done to increase fuel and boost. those also increase cylinder pressures. if pressures get too high then something gives. usually the head gasket. most likely this is going to happen when you're in the middle of bum-f***with a load on and no way to get the truck or load to its destination.

like i said, this is just my personal theory. i have no scientific info to give you on what is the maximum amount of timing you should run.

15-17 is a good target. With the mods in your sig, the rpm gain with springs as well as the plate would be better utilized with more aggressive timing. HG problems from increased timing shouldn't be an issue, even at 17, providing you keep that boost elbow limiting the turbo to 35-37 psi. More than that and the drive pressure to manifold pressure ratio becomes very lopsided, and the high drive pressure could be risky for a stock HG, not to mention that turbo doesn't like 40+ psi for very long anyway. You WILL lose EGT, and you WILL gain mid and upper range power....and even mileage...but you WILL also lose some bottom end and turbo spool time because the combustion is occuring earlier in the stroke, and converting more of the cylinder heat into force energy rather than letting it out of the hole as wasted heat (hence lower EXHAUST gas temp). This drop in EGT means the turbine also sees less heat, and since a turbine is theoretically a "heat engine" in itself, less heat will mean less drive energy. But the sacrifice is worth the gain, and it may not even be noticeable. If it is, find a good number you can live with on both fronts. My .02

Remember, DC knocked the timing out of these engines to get into EPA standards for passenger vehicles.....these engines live a lot farther advanced life in the industrial and marine environment...advancing them just brings them closer to their power and efficiency potential they should see anyway.
Chris

Is there a procedure or a write up on how to change the timing?

You need the tools to do timing, which Snap On sells an entire set for. I'm sure if you dug through tool flyers and places on the web you'll find somthing cheaper than ol' Snappy though. They're a bit overpriced.

Yeah I think mac has a set as well. Thanks for the info fellas.