So. Talk to me about this new "SOI offset".

***cleatus12r*** · #1 Fri, December 25th, 2009, 12:36 PM

Now I have problems. Not major of course....I'm a sharp guy

.

I just got used to "SOI Delay" in my old definitions.

Now with the new definitions I have "SOI Offset".

The "SOI offset" is 1/2 of the "SOI Delay".

I have already made an "SOI Delay" calculator.

Why the change?

It's not a big deal, I have since altered my calculator to work with the "SOI offset" of the new definitions but I was just curious of why and how.

Thanks!!

***907DAVE*** · #2 Fri, December 25th, 2009, 08:15 PM

Quote:

Originally Posted by cleatus12r

I have already made an "SOI Delay" calculator.

Not to derail but I would like to know more about the calculator. Does it basically convert time(ms) to crank angle(deg. or SOI) at certain rpm's?

***cleatus12r*** · #3 Fri, December 25th, 2009, 09:44 PM

Yes. Uh.......

Bill attached one in a post so let me see if I can find it. It's similar to mine except that it is a "SOI OFFSET" calculator instead of an "SOI DELAY" calculator. It will depend on whether or not you have "OFFSET" in your definitions or "DELAY".

Here it is....Just download and enjoy. I'd attach mine, but it's not nearly as inclusive as this one. Mine is simply a "plug-in-a-value-and-it-does-the-math" spreadsheet. I mean, the one Bill attached does it too in the upper right corner, but it's got a huge table in it that simply lists it all for an at-a-glance lookup.

http://forum.gopowerhungry.com/showp...5&postcount=24

***907DAVE*** · #4 Sat, December 26th, 2009, 01:42 AM

Nice, thank you. More stuff to play with......

***Power Hungry*** · #5 Sat, December 26th, 2009, 07:04 AM

Cody,

Those values were a boo boo. I'll get you new definitions today. Sorry about that.

Only the TOAA and VKAE definitions were affected. The VDAB0 is fine.

***cleatus12r*** · #6 Sat, December 26th, 2009, 10:23 AM

Quote:

Originally Posted by Power Hungry

Cody,

Those values were a boo boo. I'll get you new definitions today. Sorry about that.

Only the TOAA and VKAE definitions were affected. The VDAB0 is fine.

I noticed that the VDAB0 was still OK.

I am not upset, just kind of curious why I ended up with a VDAB0 instead of an FM20P402 and a VKAE3Q3 instead of VKAE4P8. The VDAB0 definition is not really that big of a deal since all of my existing ALF6 binary is totally supported in the VDAB0 definition anyway. However, I had to transfer all of my ZHL1 stuff to the VXY2 family. I got it taken care of though so no worries!

Any word on the VIAF3G4?

Thanks Bill. Good thing I didn't understand what was happening with the "new" (boo boo'd) offset. I'm glad I asked.

Hope you had a very merry Christmas!

soutthpaw · #7 Sat, December 26th, 2009, 11:29 AM

I am still trying to see the benefit of a SOI offest as changing a global parameter.. I can see the benefit in live tuning for being able to shift the whole SOI a couple of degrees esp when working at elevation. But there seems to be much better ways to set the SOI..such as with the Injection delay map.... when we say delay are we talking retarding the SOI. where as the SOI offset would advance it??? can u use negative values in that setting delay

***cleatus12r*** · #8 Sat, December 26th, 2009, 11:36 AM

Sorry for the confusion, DJ. The maps are THE SAME MAP. It just so happens that I was confused since I have definitons that have it listed as either one and that the new ones that are listed as "offset" do not contain correct information.

The MAIN advantage to using the SOI Delay map is the fact that the SOI can be changed based on engine oil temperature. A side benefit (or detriment) is that it is an indirect way of getting a greater SOI advance at higher RPM.

***cleatus12r*** · #9 Sat, December 26th, 2009, 11:43 AM

Quote:

Originally Posted by soutthpaw

when we say delay are we talking retarding the SOI. where as the SOI offset would advance it??? can u use negative values in that setting delay

The "delay" is a calculated value that the PCM uses to get the injection timing just right. The injectors do not begin spraying as soon as the PCM tells the IDM to do it. There are electronic, and more importantly, mechanical delays (as well as oil viscosity) that would cause a retarded injection event if there wasn't a compensation.

The "delay" values cause the PCM to anticipate for the injectors' inherent delay.

I wouldn't know about the negative values in the map. I would have to guess that you'd end up with some severe white smoke all else being the same.

soutthpaw · #10 Sat, December 26th, 2009, 03:07 PM

Just got done doing an oil change on my truck... with synthetic so it will be good to go when we get back to CO in Jan for the rest of the winter... Noticed a big dent it my steering stabilizer but took it off to check and it still works... anyway, Under parameters there is a SOI offset too though....

so the Delay map is actually giving the PCM an estimate of the time between commanding SOI and the actual physical event taking place??? is that correct?? I don't plan on messing with that though as I think I can accomplish what I want keeping things a bit more basic...