Emissions time is here

[Dieselfuture]

I would guess so, I don't see how unburnt fuel can spool anything it's the explosion that produces pressure that should move some air through turbo, but I could be wrong there too. Just makes more sense this way 

[Me78569]

retarding timing will move the flame front later into the stroke, this will cause more heat energy to be pushed out the exhaust valve and into the turbo.  it will result in less downward force on the piston however.  

[Dieselfuture]

I think we're splitting hair if we only talking about few degrees of timing but at same time I'm stuck on stupid lol, plus I don't get enough beauty sleep for my brain to function properly. 

Anyways after compression stroke where both valves are closed comes power stroke where both valves are still closed, it's not till exhaust stroke when that energy leaves cylinder. So in my mind time we benefit when we get more complete burn so we're not losing energy and it forces other pistons harder to push exhaust gas out and forget what I was going to say. Oh its Friday. 

[jlbayes]

Retarding timing forces the burn to happen in the manifold/turbine housing. Why egts go up when retarding timing. It physically moves the burn around. Advancing timing keeps the burn in the cylinder providing more work to act on the piston.

[AH64ID]

Advancing timing puts more power to the crank, but retarded timing makes for a cleaner burn. It's less efficient but cleaner.  It's much easier to see the effects with a pilot injection. Too much timing and the CRs smoke easily and sometimes the difference is really just a degree or two. 

 

Around 1000 rpms advancing timing should reduce black smoke, as the crank speed is slow, but it doesn't take much to go too far. So from idle to 1200 a little advanced it good, but by 1600-1800 advancing timing will increase black smoke. 

 

With different injectors it can also alter the normal reaction. I've had to retarded timing to clean up idle - 1200 low load black smoke. 

 

 

The chart on this page is a good general rule of thumb. 

 

http://dodgeram.org/tech/dsl/FAQ/timing.htm

Edited August 11, 2017 by AH64ID

[Mopar1973Man]

@AH64ID

 

Since you are tuner guru of Smarty what would be the optimal timing for cruising state? (Of course 24v engine)

[Me78569]

The CR ecm tuning is just worlds more complex than the vp stuff.  I drool over the CR stuff lol

[AH64ID]

20 minutes ago, Mopar1973Man said:

@AH64ID

 

Since you are tuner guru of Smarty what would be the optimal timing for cruising state? (Of course 24v engine)

 

With the pilot injection, pressure differences, and differences in the delay from start of injection to start of ignition it's difficult to correlate the CR to a VP. This is the main reason I don't tune VP trucks. If I had one local I could drive for a couple weeks and learn the setup that would be different.  

 

I rarely use more than 8° of main injection timing at 2000 rpms on a CR. 

[Mopar1973Man]

Darn... Thanks for the try though... I was hoping to find some information on the timing yet...