Injection Timing

Hi can someone confirm please that in the attached photo that the negative numbers are before top dead centre thank you

Adam,

It looks like the data in that map is represented in ATDC, not BTDC like you're expecting. The (-) data is more advanced and would be an injection event starting BTDC. The (+) value is one more retarded, starting ATDC.

What vehicle is the map from, out of curiosity?

Nick

Thanks for the reply. It’s a stock map from a 2012 Mazda bt50. So a larger negative number would be advancing the timing? Also these numbers are SOI numbers?

That's correct from what I can tell. -10* would indicate SOI 10* BTDC

Nick

I´d like to add a little bit of wisdom here. Don´t believe every number in those maps. They have to be taken with a grain of salt. Not uncommon for the drivers (definition files) to be wrong.

Hi, I having the same confusing on how to retarding degrees. From my Map Table I had minus number (BTDC) show up.

Example: -2 degrees advances by 1 degrees is -1 to get peak torque or not retard early like -2 degrees advances by 1 degree is -3.

Talk about peak torque of SOI, is that center TDC is a peak torque? Or correct me if the peak torque is at the higher number ATDC 26-27 degree?

My vehicle is 2016 Ranger PX2 3.2

(1st posts)

Danny,

Your map looks to be listed in the traditions 'Deg BTDC'. The punctuation in the example you've listed makes it difficult decipher exactly what you may be experiencing on the scan tool.

On the map you've attached you should be able to add timing to advance SOI and subtract timing to retard SOI.

-Nick

Hi Nick,

Thanks to straight up my head got confusing. I also notice that from HP Tuners MAP if you add timing to advance SOI. The number will closer to center TDC.

But not with other MAP from WinOLS that I work with is came from other vehicle 2013 Ranger PX1 is showing me upside down number. By commonsense the higher number is a peak. But I believe some error or "mirror" number I think. But I will do the test first and see if it make any changing torque by expend further more down that minus? no good, then back up again.

See the attached snipping picture SOI Table. Weird formulas capture from Damos itself.