Circumsized Stock Injector Fueling - Rock Steady Idle - Perfect Fuel Trims - FREE map

[MRF582]

So after wasting minutes of my life arguing with retards who think the modified/circumsized stock injectors are hard to tune, or are 'too' big for their application, I've decided to just go ahead and post the values I use to get them to run right. I don't think a lot of vendors that sell aftermarket injectors or even those that modify injectors would appreciate the info posted in this thread. Now there is less of a reason for people to WASTE their money buying STi pinks, PEwhatever, any other injector that flows less than ~800cc.

Follow these simple steps:

Step 1: http://forums.nasioc.com/forums/showthread.php?t=478921
Step 2: copy-n-paste my MAF table and injector scalar value
Step 3: ???
Step 4: profit

Myth 1: Hard to tune
What a joke...I've already done the 'hard' work for you. So now to get the circumsized injectors to idle perfectly and match target fuel maps within .1 or .2 all you have to do is copy and paste. So much for that excuse injector vendors.

Myth 2: Don't use injectors that are too big for your application
Another idiotic argument meant to persuade you, the uneducated consumer, to shell out money for aftermarket injectors. However, after reading this thread you should be a bit more knowledgeable. I ran these modified injectors on my stock TD04-13T. Overkill to prove a point? Yes. Did the car idle perfectly, run target AFR properly? Yes.

Myth 3: Circumsized injectors don't atomize properly
Refer to http://forums.nasioc.com/forums/showthread.php?t=478921. Kingpin reports that the spray pattern is a fine disk pattern. I've also heard it being described as a 'nice conical' pattern. Some idiot was trying to tell me that the fuel 'drips' out of the circumsized injectors so that's why he was going to go for the $300 pinks. Keep in mind that static fuel pressure on the WRX is about 43psi. Show me a video of an injector where the fuel is dripping out in droplets at 43psi and I'll buy you a chili dog. In short, these atomize the fuel adequately.

And now for the part you've been waiting for.

MAF Volt 0.94	0.98	1.02	1.05	1.09	1.13	1.17	1.21	1.25	1.29	1.33	1.37	1.41	1.48	1.56	1.64	1.72	1.8	1.87	1.95	2.03	2.11	2.19	2.27	2.34	2.42	2.54	2.66	2.77	2.89	3.01	3.12	3.24	3.36	3.48	3.59	3.71	3.83	3.95	4.06	4.18	4.3	4.41	4.49	4.57	4.61	4.65	4.69
grams/sec 2.2	2.4	2.64	2.89	3.16	3.62	3.86	4.16	4.25	4.39	4.61	5.12	5.69	6.56	7.85	10.3	12.3	14.2	15.92	18.22	20.88	22.7	25.87	29.42	33.27	35.72	40.25	44.93	52.2	60.07	68.57	77.68	87.56	98.37	110.08	122.7	136.19	150.67	166.2	182.84	200.64	219.7	240.03	254.22	269.09	276.82	284.7	292.74

Injector Scalar Value
Enginuity 0.3.2 - 783 cc/min
StreetTuner - 3450

Injector Latency
Keep the same as stock

This MAF table has been known to work with DeatschWerks 680s as well. Just input a different injector scalar.

I still recommend you guys get yours flow tested after modification/circumsicion. I didn't.

No-no Note : Only tested on a completely stock WRX intake with completely stock fuel pressure and rails.


Update - 05/02/2007
Attention - Due to recent developments thanks to pioneering trailblazers, new sh** has come to light. My band-aid fix of modifying the MAF table at low volts is obsolete. For details on why we should keep the MAF table stock and modify the injector latency is best described in the following thread started by the venerable ride5000. http://www.enginuity.org/viewtopic.php?t=1722

After a few iterations of testing on my own car with modified (decapitated) wrx injectors with stock intake, and fuel pressure/rails, I have arrived upon the following values that seem to work very well. Actual AFRs match target AFRs and LTFT is less than +-3%.

I did have to bump my injector scalar to 835cc.

Injector Latency for decapitated wrx injectors
V    6.5   9.0 	11.5	14.0	16.5
mS  4.02  2.14	1.42	1.14	0.60

Completely stock MAF table.

5/15/2007 - Updated the latency and injector scalar after a bit more long term testing. I will update this thread again as I gather more data.

[brandonbeeb]

bump this for a great guy helping the community out

[cdvma]

The injectors are weird in that they act like a stock injector at idle but don't at higher line pressures. People usually attribute it to hard because they don't see how changing the MAF scaling will change fueling. It really is a bandaid but it does work...problem is that it doesn't work on all intakes or blow-though setups as well. Also I'd put a bit no-no note for those not running a 2.0L stock intake and MAF...people do crazy things and someone will blow their motor from this post if you don't warn them.

[Tgui]

Good info, thanks. Here comes the onslaught. Also, are circumsized injectors less sensitive to their enviroment and less prone to premature edripulations?

[xolosis]

Great infomation here! Nice of you to share such invaluable knowledge.

Free bump!

[Spec C Wannabe]

Originally Posted by Tgui

Good info, thanks. Here comes the onslaught. Also, are circumsized injectors less sensitive to their enviroment and less prone to premature edripulations?

Excuse me for my poor English, but what does "edripulations" mean?

[MRF582]

Originally Posted by Tgui

Also, are circumsized injectors less sensitive to their enviroment and less prone to premature edripulations?

So I've heard.

[LastResort]

Hmmmm........this makes moving too full on 100% E85 that much more possible. Between OpenECU and this, about the only real cost would be a fuel pump.

[akira02rex]

I don't think this will work that well for everyone...it MAY but look into this:

1) We have seen modded stockers flowtested that range from 700 to 900cc.
2) Part of ^^^- Companies use different ways of flowing injectors that manipulate the numbers.
3) I have my MAF scaled much differently than yours, with a different injector scale value and my A/F is within .1 - .2

But all-in-all, thanks for helping out the community!

[MRF582]

Originally Posted by akira02rex

I don't think this will work that well for everyone...it MAY but look into this:

1) We have seen modded stockers flowtested that range from 700 to 900cc.
2) Part of ^^^- Companies use different ways of flowing injectors that manipulate the numbers.
3) I have my MAF scaled much differently than yours, with a different injector scale value and my A/F is within .1 - .2

But all-in-all, thanks for helping out the community!

Points 1 and 2 pretty much cancel each other out. at 40psi these flow ~740cc at 43.5psi they flow ~810. At xxpsi they flow 900cc

Point 3 - I'm assuming you have the stock intake and stock fuel pressure. PM me your MAF table and what injector scalar value you use. I'd like to compare it in excel.

[scoobdude]

a few more questions:

1) does tip in need to be adjusted (applies more to the reflashes i think)

2) in ST some people say they need to adjust the MAF voltage table. Any news on this?

3) Is there any way you can add a pic of the teh fueling maps for ST and Enginuity?

Thanks for your contribution. I can make the pic of ST if needed, I just need waht to put in there

[MRF582]

1) Yes (a little bit) but my values are stock. I need to tune that table better. I haven't quite figured out exactly what values work well but when I do, I'll post them. The car drives just fine for now and transition into WOT is smooth.

2) Don't adjust the MAF volts.

3) Do you mean the target AFR map? I'll try to post it sometime but I only have Enginuity not StreetTuner.

[scoobdude]

Originally Posted by MRF582

1) Yes (a little bit) but my values are stock. I need to tune that table better. I haven't quite figured out exactly what values work well but when I do, I'll post them. The car drives just fine for now and transition into WOT is smooth.

2) Don't adjust the MAF volts.

3) Do you mean the target AFR map? I'll try to post it sometime but I only have Enginuity not StreetTuner.

1) cool. My thought on the process was to change them by the same percentage as the injector scale (ie take out 50% of fuel on the injector scale, do the same for the tip in cells)

2) Some peopel have done this.. but I think i am confusing this with E85 (which can run lean up top due to the stft and ltft not being fully adjusted)

3) My bad, I meant tip in map. This might change for 2.0 to 2.5 though.

p.s. "tip in" "circumsized" "premature edripulations" ... are we still i na car forum?

[xolosis]

Originally Posted by scoobdude

1) cool. My thought on the process was to change them by the same percentage as the injector scale (ie take out 50% of fuel on the injector scale, do the same for the tip in cells)

2) Some peopel have done this.. but I think i am confusing this with E85 (which can run lean up top due to the stft and ltft not being fully adjusted)

3) My bad, I meant tip in map. This might change for 2.0 to 2.5 though.

p.s. "tip in" "circumsized" "premature edripulations" ... are we still i na car forum?

2) I've done this recently - rescaled my MAF Table grams/sec values (not volts) and took -20% as I'm running a FPR with upped pressure. Then -20% out of the Fuel Enrichment Map (Tip In) and car feels smoother.

[JoshP]

You get a little too excited about modded stock injectors

[jamesfacts]

Hmm.. what's the rest of your setup? Great work with Enginuity!

[akira02rex]

Has anyone tried these values with good results?

[subaruwrx420]

I have the Deaschwerk 650cc injectors and should have listended to this guy and modded my stockers. I have also adjusted the MAF table by about 12-20% from 0.94 to 2.19 volts...car runs about +6% AFR correction and pretty close to 0% at WOT.

I have the stock intake, minus the snorkle.

Bump for some valuable info.

[MRF582]

^^ If you look at the map your car is running, you'll realize your MAF table looks eeriely similiar to the one at the top of this thread Oddly enough, that's what my car runs too with just a different injector scalar.

So yeah, this MAF table works with modded stockers and Deatschwerks 650s. Btw, I thought you said they were 680s earlier? Are yours 650s or 680s?

[subaruwrx420]

^Yeah that's why I posted...I don't know how to copy the MAF values in that nifty table like the one you posted.

BTW, my injectors are 650cc...I should have gotten the 750cc for an extra $20...goes to slap himself upside the head

[Homemade WRX]

when I test it out, I'll let you know how it turns out. Adding to the test base.

[tmarcel]

Originally Posted by MRF582

Myth 1: Hard to tune

Myth 2: Don't use injectors that are too big for your application

Myth 3: Circumsized injectors don't atomize properly

#1 Hard to tune, no. Some folks have had problems with them but they did many mods at once for example. This happened to me more than two years ago on my WRX. It was due to the MAF sensor in a short intake (rotated turbo set up). I've seen numerous other issues on other Subarus too that were not caused by the injectors themselves.

#2 I agree BUT why put up with a 'potentially' poor idle with 1000cc injectors when you don't need to go there. If a set up requires that large of an injector then it's necessary. 800cc injectors are not excessive though.

#3 There's something about these injectors you're not mentioning. They don't have a good spray pattern. It doesn't mean that they don't atomize well (sounds like mixed words). I'm no fuel injector expert only going by what I've seen on reports and from a company that does testing.

See this from my injectors...the pattern says "fair" and just about all other reports from other companies state the same thing.




Fuel flow shows much more than what they flow for gasoline. This is because the fluid is lighter. They technically flow (on mine at least) 804cc -/+

[jblaine]

IMO, the "poor spray pattern" argument is moot from anyone.

It's different.

It works fine. There are simply way too many cars with these modded injectors making great power just fine to argue that it's an issue at all.

[akira02rex]

I tried this MAF table posted here and let's just say it didn't work out too well. I have the mods stated for this to work: stock intake box, modded injectors.
Target AFR was 11.33 and I ended up logging a 12.2:1 lol.
Go figure..like I said before it's not universal for all cars...
I was previously using an injector scale value of 660..maybe I'll change it back.

btw..the reason for trying this table:

I recently thought I had my MAF/scaler set really good. Target and Logged AFRS were within .1 of each other.
I checked the engine again over a week later after it had some good time in to learn things quite a bit...the datalogs were spot on with my fuel maps! Wow I guess I had it pretty good then!

NOT!

Just today..probably 3 weeks later, my datalog is showing 11.9 - 12:1 toward redline where I am targeting 11.33:1..
UGH! How is this supposed to be done when my tune COMPLETELY changes after several WEEKS?

Well tomorrow I'll try my old injector scale value and keep the MAF table the same..old value was 660cc.

On a side not, would being 1/8th or less on gas make the car go lean possibly? I also have 40k now on the odometer, when do fuel filters need changed?

[MRF582]

Originally Posted by akira02rex

I was previously using an injector scale value of 660..maybe I'll change it back.

You need to use my MAF values with my injector scalar value.

And you're doing pulls with an 1/8th tank or less? Come on man, of course it's going to go lean. Be careful dude.

Anyway, I disagree with your coment about the MAF not being universal. If this works on 3 different cars but doesn't work on the 4th car (yours), I'm likely to think that there is something wrong with your car.

Don't do pulls on an 1/8th tank.