Bought from another member some supposedly 1300 cc (850 bored out by RCE I was told). They came with no paper but have a 1300 scribed onto them.

Sent them to KGP for cleaning and balancing. The data sheet shows good flow pattern and perfect balancing among the two, but the static flow is 390 cc over 15 sec @ 2.25 bar, which equates to 1560 cc/min.

I am not mistaken, std. injectors' capacity is normally specified at 3 bar, which means these are more like 1800 cc!

This is very puzzling. Either KGP gave me wrong test figures (which I doubt because my batch included also two 550; they came back in numbered plastic bags and the numbers match those in the test sheet). Or, there are 850 cc bored out to 1800 around, being sold as 1300 ?!

- Sandro

 

So, there has been a bit of correspondence back and forth between me and KGP and me and RCE.

RCE indicated the max they can bore out the 850 injectors is 1300 and offered to re-test the them. They tested at 1318 cc/min avg at 43 psi.

KGP test had showed 1560 cc/min at 2.25 bar (@ 32 psi)

- Sandro

 

I'd definitely have them retested. I'd probably send them over to RC since they did the boring.

 

Yes, that is what I did - second attachment of my previous post...

 

My bad. Not enough coffee this morning.

 

I'd be curious to see some real world lag tests for these bred out injectors at different battery voltages. Side feed injectors tend to be pretty sluggish already.

 

How to measure that?

 

Injector shops can do those tests. When you buy injectors for Subarus, they often come with a test sheet that shows the exact lag readings at various battery voltages. Then you reflash the factory Subaru ECU with the real-world numbers. It's very important to have accurate lag numbers to maintain a consistent tune on modern ECU's. Otherwise it will throw off the adaptive learning (fuel trims) and that can make the car drive like crap or possibly lean out under boost.

On my Power FC I use the actual lag vs battery voltage tables, I do not use the lag trim adjustments that everybody else uses (the ones you can set in the Commander). I didn't get my 720's and 1680's tested, but I did use the lag testing tables from injector rehab (Denso 720 and Ford 1680). The interpolation that people are using to determine their lag settings in the PFC is a method from the Commander manual, but no other ECU does it that way really. It does not reflect the way injectors work in the real world.

There are big differences in lag based on the solenoid design. Look through this chart here and you'll see what I mean:

http://injector-rehab.com/kbse/lag.htm

and look at the default lag numbers in the PFC lag vs battery voltage chart, the numbers that Apex'i obtained by testing the stock FD side feeds. In terms of injector response, from most to least responsive it goes:

top feed, low impedence
top feed, high impedence
side feed, high impedence

And the type of injector driver also affects it (saturated/voltage controlled vs peak&hold/current controlled). I have a bunch of Mazda and Toyota literature which explains all this. Side feed high impedence injectors are very sluggish, but they run a lot cooler, produce less fuel vapor (improve hot starts and evaporative emissions), and are simpler than low impedence systems.

 

Thank you very much for the information Raymond.

Exhaustive and comprehensive - as usual...

Lacking actual test data - I should have probably asked RCE to perform those - any suggestions on the values I could use in my PFC?

Thanks,

Sandro

 

on the PFC honestly I'm still not sure if it actually makes much of a difference whether you use the battery voltage table or the usual trim adjustments. But I guess using the battery voltage table makes me feel better.

Off the top of my head I think I have run .10 lag (using the normal adjustments) on 1300cc secondaries before without much trouble. transition was like .300 and overlap was 4-3-2? or maybe it was 7-7-4. i'll have to check when I get home

 

just checked, it was .10 lag on the secondary's with the 1300's. pri/sec transition was 30%, milliseconds .712, injector overlap was 7-7-4 if you go down the column

 

Thanks a lot Raymond.

- Sandro

 

perhaps you can guess via boost and duty cycle...
ive got 1300cc.. typically see high 70s at WOT on 12psi tuned to high 10s afr..

 

I know I explained the flow pressure to you... If I did not already offer (I believe I did) it, send them back and we will send you a video of them flowing so you can see the results or yourself as well as see the results on paper.

here is a video of modified 1300's flowing next to a set of unmodified 850's to see the difference in spray pattern

http://www.youtube.com/watch?v=yLbY5ZBo_FA

 

Is there a reason the 1300cc injectors are spraying more towards the sides?

 

Yes thanks, you kindly offered me already to re-test the injectors and send me a video. This was when RCE (whom I contacted to comment on their flow rates) indicated that they could not bore out the 850 cc beyond 1300 cc and made the hypothesis that the injectors might be leaking.

After that, RCE suggested to test them independently at their own premises. Their test data look consistent with their early statement about their modified injectors rating.

A few items I would like to point out:

1. From your test data sheet, it appears that your static test is carried out over 15 sec, while RCE indicated that their measurement is taken over a 60 sec period, which is intrinsically more accurate.

2. Still, the difference between the two separate tests is astonishing:

KGP: 1,560 cc/min at 2.25 bar or 33 psi
RCE: 1,318.0 cc/min at 43 psi

If your data are normalized at 43 psi, the flow rate becomes 1,791 - if I am not mistaken
That is 473 cc/min more than what RCE measured, a 36% difference!!!
well beyond any reasonable measurement error

Thank your for following this up.

- Sandro