timing changes

anyone mess with the timing on the hd300 tune? i notice that it gets to about -6 degrees while some other tunes get to -9, whats the advantages or disadvantages of changing the timing

There is a lot to timing. I haven't messed with mine. But with more timing comes more cylinder pressure. I'm by far not an expert, but I would be careful with timing changes and do small increments at a time. I could be wrong but I think with less timing makes more drive pressure but less cylinder pressure. But I'm sure somebody with way more knowledge on the matter will chime in.

-12 is the most you really ever want to see unless you plan on turning a bunch of rpm

More timing while cruising will give you better mileage but like stated cylinder pressure goes up with timing

Dzchey21 said:

-12 is the most you really ever want to see unless you plan on turning a bunch of rpm

More timing while cruising will give you better mileage but like stated cylinder pressure goes up with timing

Click to expand...

So would running 8* to 9* btdc be a good to set for highway speed? I notice that when my hd300 gets to around 2100-2200 Rpms that the timing goes to 0

no thats probably too much timing for cruising, small changes like 1 or 2 degrees will net some gains

whcih timign tables do i change? there is about 20 LOL

I've been changing 0, 0

Kind said:

I've been changing 0, 0

Click to expand...

And that effects it no matter the coolant temp, or other variables?

pretty sure hes referring to the temp 0 tables, which are when the truck is full operating temp. you'll need to change all the tables to have your change take effect for all engine temp conditions

I was looking at the timing tables a few days ago and I saw that at the time at idle was +4*, would it effect anything to out it at zero or btdc, maybe help with cylinder wash at idle? It's just a thought

Has anyone confirmed what Configuration timing map we are using when the engine is at normal operating temperature. (temperature 0). When I monitor "Timing" with the Mini, it really doesn't match any of the tables.
Here is an example of what I see on the tuner:
RPM----------------------------TORQUE------------------------------- TIMING
1250------------------------------300----------------------------------- -1
1500------------------------------250----------------------------------- -2
1800-1900---------------------400-500-------------------------------- -4 to -5
2500------------------------------600----------------------------------- -9
3000--------------------------- 600-700-------------------------------- -9

idle--------------------------------84------------------------------------ +4

downhill no load
2000-------------------------------0------------------------------------- -5
1800-------------------------------0------------------------------------- -4
1600-------------------------------0------------------------------------- -3

0,1 & 4 are the configurations that H&S makes adjustments to in the “INJECTION TIMING” maps for the MILD & HD300 files.

are you WOT or cruising?

Various throttle positions, which equate to the commanded torque values read from the tuner. I was basically climbing a long 6% grade and pushing the truck to different RPM & torque values and then reading what the corresponding Timing value was.