Injector Dynamics

[IH8TOADS]

I read a lot about injectors and I took a liking to this thread.....probably because of their fancy break-in bench, pic of a 2000cc spray pattern and the fact that the part number for my dream injector is quoted.

http://www.supraforums.com/forum/showthread.php?635568-2000cc-FACEOFF-How-to-compare-injectors

[XYZ]

Good read... Always hard to get my head around all the different EV14 injectors on the market...

[Vevapower]

I use a fiveomotorsport injector toad.

Best injector we've used.

Best idling injector by far.

"."

[IH8TOADS]

Yeah I remember you saying they were good.

My only convern is the lack of data. Having data on the slope, deadtimes, min pulsewidth and breakpoint makes dialing in the tune much easier.

Simply modifying the slopes to meet your fuel requirements is primative and this method has been used in 99% of tunes I've acquired.

With a big injector you end up spending a fair amount of time running off the low slope. In this region the deadtime makes a big contribution and the breakpoint trigger to switch between slopes is very important.

Closed loop cleans a lot of this up, but I have often seen problems when it comes to open loop cold starts.

[discostig]

How's the deviation/pulsewidth graphs of every 10th squirter from a batch of ID2000s vs the flow matched (by ID) ones!

I don't pretend to understand the details... so all this thread really gives me is more want for ID injectors

[IH8TOADS]

Traditionally, injectors (if at all) were matched on their linear flow rate (injector hi slope in Ford calibration speak). However as you can see in the graphs, the injectors show a high variation in the low flow / non linear area (injector low slope and battery offset table in Ford calibration speak). The bigger the injector the more likely you are going to be in the low flow area (where the fuel mass delivered per intake stroke is below the breakpoint) and therefore matching across the entire pulsewidth range becomes increasingly beneficial (stress beneficial and not essential). Idling, low rpm cruising, and closed loop decels (if your tuner has culled torque mgt completely) all hover in the low slope area of the injector curve (with these bigger injectors that most people are now using).

[Ralph Wiggum]

^ post needs more (...)

[discostig]

I was always concerned about choosing my injectors; I wish I had the cash for new ID1000s (or 725's perhaps). That's why I went the green top 42lb Bosch over the Dekas though, concerns over the low flow performance and knowing the 42lbers would get me to the 300 zone which is plenty fast but also a safe level for stock gearbox.

The graphs in question

Picking every 10th 2000cc injector from a batch:

Flow matched set

just spotted this on the ID site Application Data page

On that subject, we would like to thank Mick Egan from Pit Lane Performance for working with us to sort out the Australian Fords.

Edited 24/01/13 11:06 AM by -SteveR-

[IH8TOADS]

Yeah ages ago Mick was tuning Bels car with the 725's and I was doing mine with the ID1000's. Because the Aussie fords have a speed density airmass calc and a mechanical return style fuel system it was fairly different to the MAF style (and returnless fuel system) American set-up, that Paul Yaw was familiar with. Paul Yaw was kind enough to supply Mick and myself with the 4bar raw data (not publicly available at the time). Mick also spotted some technical errors with the SCT software (wrong units). Never met Mick but he's certainly a helpful guy as is Paul Yaw and Tony Palo. Edit...spelling

Edited 24/01/13 11:43 AM by IH8TOADS

[discostig]

Yeah I always pay attention to ratter's posts that's for sure! Ultra helpful to this forum on his own time too.

Fascinating reading on the ID site even if like myself you aren't knowledgeable in cars... currently working through this little pearler - " The same as Injector Dynamics but cheaper"

http://www.injectordynamics.com/size14.htmlhttp://www.injectordynamics.com/size14.html

Good equivalent to a popcorn thread that one.