quick chrome injector scale question

just getting started tuning and tried setting the injector scale to 525 as recommended for the delphi 550cc and have the latencies set per recommendation of chris @ rvenge Performance but car is running 20 afr and o2s will not cycle. only way i got them to cycle was to lower the injector scaling to 420. then the o2 started to cycle and fuel trims are all around 6% front and rear. Wondering if this is the right approach to start or should i leave them at the 525 and start messing with the ve smoothing tables

Did you just swap injectors? Was it working correctly with stock injectors?

Yes car was running fine on stock injectors and 15 psi boost and stock ecu. Just added some billet 15g turbos and the 550cc injectors and the chrome ecu. I have been messing around with the ve smoothing table and have all the trims with in 5% but injector scale is still at 420. Had to add like 20 or so on the ve smoothing table 100hz and below and a few on the mid to get trims with in spec. Im assuming my injector scale needs to be way closer to the 550 but car will barely run its so lean when set to that.

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Originally Posted by mc24

Yes car was running fine on stock injectors and 15 psi boost and stock ecu. Just added some billet 15g turbos and the 550cc injectors and the chrome ecu. I have been messing around with the ve smoothing table and have all the trims with in 5% but injector scale is still at 420. Had to add like 20 or so on the ve smoothing table 100hz and below and a few on the mid to get trims with in spec. Im assuming my injector scale needs to be way closer to the 550 but car will barely run its so lean when set to that.

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If the car was fine with stock injectors, and you had pressure tested, and know it to be solid, then obviously something you bolted in is what changed... (Just stating the obvious, because we want to make sure you don't have something wrong in the car throwing everything off before trying to fix a tune)

There's about a hundred ways to get there between scaling, lag time VE table, and actual fuel tables. My preference is to start with a known good stock setup and work from there. I like to have the VE table start at stock or zeroed out, all other tables stock, and don't touch them until I'm happy with the injector scaling and latency. Get a scaling that lets the car run, and work your way up to dialing it in at high load. (latency is pretty irrelevant at high IDC when the injector is almost always open anyway) Once you have the sizing right, work on the latency. I usually add/subtract latency on the entire scale by a percentage basis until I get it right.

At that point You'll be able to do any minor fine tuning with the VE, and have your target A/F tables extremely close to actual. (which I kinda like personally, some people could care less...)

Pulled the engine to install transmission bellhousing brace and everything else so going to make sure I didn't miss getting something back together right. The injectors I installed were from a friend that never got his car running before a hail storm totaled it out. So they r not new but never really run. I flushed them out and replaced the filters just incase. Something just isn't right did a boost leak test nothing major there. Confused. This is a spare car I'm working on have another one set up with dr650 and 550cc injectors but running maft and neo. Chrome may have been a bad choice always want to try it out seems sweet but I'm not off to a good start.

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Originally Posted by mc24

Pulled the engine to install transmission bellhousing brace and everything else so going to make sure I didn't miss getting something back together right. The injectors I installed were from a friend that never got his car running before a hail storm totaled it out. So they r not new but never really run. I flushed them out and replaced the filters just incase. Something just isn't right did a boost leak test nothing major there. Confused. This is a spare car I'm working on have another one set up with dr650 and 550cc injectors but running maft and neo. Chrome may have been a bad choice always want to try it out seems sweet but I'm not off to a good start.

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I wouldn't quit on Chrome... I like it. It just a bit of a learning curve. (and figuring out your own tuning style that works for you) for me personally, I like having everything organized and repeatable. Many people are simply concerned with the end result.

It might work better for you to toss the stock injectors back in it, and flash the stock tune back in just to test your setup. Then you could install the injectors and tune the sizing and latency to fit, knowing they are the only variable.

I would not count on the injector size always being what you expect... I've seen some pretty far off of what I thought would be correct.

are they the "fat" 2 tone delphi injectors? are they high impedance or low?

They where bought from 3sx ya id say fat type silver and black low impedance. Im going to mess around alittle bit with the latency values and hope thats the problem. I have pulled these motors more times then I like. I pretty sure everything is hooked up right. Have 4 turbo cars now ive been playing around with. Have been reading on the evo flashing tuning site seem some there set the scaling then go do a full throttle pull and see the scaling is close then start tuning fuel trims. I havent done that but with the current scaling set to 420 i have the trims pretty close now. Have done a mild boost pull for a couple seconds enought i seen the afr drop to like 12 afr open loop so thats close. Maybe these injectors just are way off like realMccoy stated. Anyone else here have to set it that far off? Chris at rvenge performace suggest to set them back to 525 and add to the latency scale which is my project today. I may just pull them off and get them flow tested and cleaned and see if thats the problem and throw the stocks in. Here are the current latency settings. One quick question which i dont think is the problem but i have installed the egr pipe blockoff plates but have not removed the egr yet as i didnt want to change a bunch of things at once incase i had problems will be removing it later anyways. Cant see that causing and issues. Thoughts? Thanks
4.69 = 3.825
10.99 = 0.810
12.01 = 0.675
12.96 = 0.585
13.99 = 0.510
15.01 = 0.405
18.68 = 0.300

Do they look like this: https://www.injector.com/cart/pc/cat...481_detail.jpg

Or this: https://www.3sx.com/images/thumbs/00...cc-1000cc.jpeg

Top ones you set to 525 (assuming they are 50lb/hr, they can also be 45, 40, 30), and you may have to add to the latency values because those style injectors are slow as shit, so your idle flow rates are way leaner than cruise and full throttle flow rates. I suggest getting rid of those, I hate them. Another thing they do is lock open or closed at 50 psi of fuel pressure, which having an injector hang at 20 psi is a sure fire way to blow up an engine.

Bottom are newer style and I don't have the data in front of me but they are (can be) actually 550's. There are several websites that list common injector types and their latencies.

There's a ton of other things to consider, but with your latency already boosted like that I'd check to see if the injectors are clogged from sitting. The stock mitsubishi tables are pretty damn on when it comes to stockish cars, so whatever your injector size is, is what your injectors are actually flowing. This is of course assuming you didn't dick with all the other tables. You also didn't say anything about your fuel pressure so I'm assuming all that is stock?

They are the ones in the second link (3sx). I changed the injector scale back to 525. I even added 25 percent and then another 25 percent to the latency and idle trims still plus 12.5. All other tables left alone for now. Stock fuel pressure setup. I'm going to do some more research on scaling and latency setting I guess and mess around with them. If things don't start getting better the injectors are off for testing and cleaning.