Timed my truck tonight

[david85]

Do you guys have any recommendations for the Snapon MT480 (w/lummy)? Mine was intended for the 6.2 and 5.7 but the 5.7 lumosity probe fits the 6.9. Unfortunately, the kit only has instructions for the GM diesels.

 

[Trevtron]

ou were extremely advanced running the clapped out injectors.

Retarding your timing back to STOCK spec it ran WORSE until you got the injectors swapped out?

Exactly, and running so far advanced had masked the symptoms of the whacked out injectors.

 

[Trevtron]

That’s exactly what happened. Truck didn’t start well on stock spec and killed all the mosquitos in the camp ground, didn’t go on the road like that but I’d be surprised if it got above 50 mph the way it sounded

Yeah I fogged that campground out, sounded raspy too. But, you got me on the right track by identifying the troubled injectors. And everything got better from there because you reinforced that there is a right way and a wrong way to run our trucks, crazy part is how they can actually run so far out of time.

 

[chillman88]

Thanks guys. That's what I was afraid of though lol.

killed all the mosquitos in the camp ground,

Would you send me a set of those wasted injectors please? I have quite a decent population here to deal with lol!

 

[Trevtron]

Ha ha!!! They help dissuade tailgaters too!!

 

[pastorjeep]

This ia all good information to chew on. There is a difference between optimal setting and good setting that only a dyno can identify. There are a few vids on the tube that highlight this. One in particular is a factory 093 setup run at 8.5* and then the pump was turned up and a wicked wheel installed and several runs showed that it wanted 6.5* now that it was pushing 20+ psi. Backing off on the timing gave a 20hp and 80trq boost! So the factory turbo did want the factory timing but as the cylinders were filling with more air and faster the factory timing was detonating and loosing hp.

 

[Thewespaul]

This ia all good information to chew on. There is a difference between optimal setting and good setting that only a dyno can identify. There are a few vids on the tube that highlight this. One in particular is a factory 093 setup run at 8.5* and then the pump was turned up and a wicked wheel installed and several runs showed that it wanted 6.5* now that it was pushing 20+ psi. Backing off on the timing gave a 20hp and 80trq boost! So the factory turbo did want the factory timing but as the cylinders were filling with more air and faster the factory timing was detonating and loosing hp.

That has more to do with the fact that stock turbo had so much back pressure that and the cylinder pressures were so high that it needed less timing overall, if you put a turbo that could actually flow efficiently at that lb/ft amount then you would need to bump the timing back up. With a better turbo even with the same boost level it would be making more power because it’s doing so more efficiently, past 15 psi all the main turbo kits become a major choke point on the hot side.

Fyi a diesel won’t detonate or have preignition. Technically it’s constantly detonating just idling because it runs on heat caused by the compression of the gasses in the cylinders which ignites the diesel being injected. The knock or pinging that you tune to avoid in gas engines is what makes these engines run.

 

[79jasper]

Iirc, retarding the timing will actually spool faster. At the expense of less "top end."
How did the egt compare?

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