Start of Injection Delay

[cleatus12r]

It was great talking to you again Bill. Somehow I always feel kind of special when we talk like old friends (who aren't really that old and who have never met). I'm getting excited since we're down to less than a month before SEMA. It'll be nice to put person-to-person faces with you and Corey's names.

In the grand scheme of things, it was nice of you to take the time to 'splain to me what that map does and how it relates to SOI.

Thanks a million!

[Power Hungry]

As Corey will tell you... "Bill has never met a stranger." I've always talked to people like old friends. Some may find that a bit unprofessional, but I think it's just a nice way to be. In the hustle and bustle world of today, people just don't seem to take the time to actually talk to people anymore. Of course, being a chatterbox has its drawbacks sometimes and I frequently have Corey reminding me that I have work to do. :whistle:

Corey and I are quite excited to be seeing you guys (Jack and Janet included) in Vegas and are glad that we could help out. We're gonna have a blast for sure.

Anyway, if there's anything else I can help with or any questions I can answer, I'm happy to make myself available.

Take care.

[907DAVE]

So basically the higher the number(ms?) the more advanced the SOI will be? Or am I backwards, seems like the higher the delay more advanced timing is needed to compensate for it?

[cleatus12r]

Dave,


Bill and I had a discussion a few months ago about SOI Delay and there's a reason he wanted to talk me through it on the phone....it's complicated but not really at the same time.

It's Ford's way of compensating for the mechanical and electrical delays in the injectors at different oil temperatures and injection pressures.

The reason it makes sense to change this map is because for regular injection timing, you've simply got a map based on RPM and MFD. That's ok but there is no temperature compensation for the injection timing (save for the SOI vs. EOT but that's a fixed adder) except for the SOI Delay map.

The higher the value, the more the PCM is going to compensate and the more advance you'll see. It is time based (in milliseconds) so there is an obvious injection timing advance going on at higher RPM since time is fixed and RPM is not. See where I'm going with this?

[907DAVE]

Just came back here to re-read this thread and I think there is a few posts that are missing.

For an "all out" program would you be better off setting this at a low number across the board?

Like the actual delay at full temp, which I guess will be around or less than 1ms. Of course the program would ONLY be used at full operating temp.Would this add a timing safety net?

[cleatus12r]

Originally Posted by 907dave

Just came back here to re-read this thread and I think there is a few posts that are missing.

For an "all out" program would you be better off setting this at a low number across the board?

Like the actual delay at full temp, which I guess will be around or less than 1ms. Of course the program would ONLY be used at full operating temp.Would this add a timing safety net?

Personally for my own programming I usually only alter this map by a half a millisecond or so at the most....and it's never at the higher ICP levels (high load).

You will see that most of the time in aftermarket tuning, the higher the ICP, the higher the delay is set. There are a couple of reasons for this, the biggest being that the amount of fuel being injected is higher for a higher injection pressure. By programming in an advanced SOI based on load and RPM (basically higher ICP and higher RPM), the burn is hopefully initiated sooner and it keeps the fuel from burning too much past TDC.

The nice thing about the delay map is that it is based on EOT. My programming will leave the stock delay at low temperatures (below about 120F) and at high temperatures (above about 240F). I usually incorporate the same temperature changes in the PW multiplier map too.

If you're worried about any effects due to a time-based SOI map, then it's best to leave the map alone.

[907DAVE]

I just had another random thought pop into my head.

With large injectors with big nozzles fuel is able to be delivered faster, meaning more fuel in less time, regardless of RPM's and possibly EOT and ICP.

If you were to adjust for this faster delivery rate (less delay) would it be better to use this map to do it, since it is a time based map? Just an "across the board" change to accommodate for the big, fast nozzles.

I am aware this is no where close to the only change needed with large injectors.

What am I missing, its early and I haven't had my coffee yet.