Little Help - The Correct Way to Tuning Fuel Injectors?

[BigDaddyCool]

I'm wondering if a senior tuner can point me in a more detailed direction in tuning fuel for a V6 alloytech based engine.

I'm trying to add spark and also deal with knock but I dont know exactly which way to go on the fuel injectors.

Tuning Fuel Injectors:

INJECTOR MSEC vs STFT vs SPARK vs KNOCK

Can someone please explain to me how it works better.

1. When I add a few degree's of spark what should I do with the injector? increase the msec time, eg. 0.960ms to 0.980ms
2. When I have knocking occuring should I go up or down rather then pulling timing first?

It seems a little complicated to me as it's about timing the fuel.

[umrjmac]

I believe that the idea is to insert the correct data for the fuel injector, which wont change as a result of air/spark/etc.

1) you should leave the injector configuration alone
2) if you have knock, you've passed MBT, so you need to remove timing anyway.

[BigDaddyCool]

More opinions? ..... I have no comment on that post above.

[umrjmac]

Suit yourself There are many paths to get from A to B, but I believe that the one that is most correct is:

Model your fuel delivery (correct injector configuration)
Model your air flow (dial in MAF and/or VE)
Adjust timing for peak power/torque

We cant learn from your experience if you don't take the time to point out what you think is wrong with what was posted. You never know, you might start a debate and everyone can learn something. That's exactly why I watch these forums daily.

[04 Intimidator]

UMRGMAC is correct. Set the fuel injectors to their specifications and leave them alone. It's one of those items that is pretty static. It would be like changing tire size to comensate for .035" of wear.

[passingpower]

Daddy, you stipulated that you were seeking the correct way to "tune" injectors.
The short answer is in post #4 this thread; i.e. you calibrate them.
The long answer is in the HPT help file or pretty much anything Banish has written.

[BigDaddyCool]

The injector multi table is where you essentially adjust the fuel timing to richen or lean it out....... The idea of saying put it at "specification" sounds stupid, obviously it's that way by stock.

I'm at work at the moment, when I get home I'll post up some pics of the area i'm talking about.

I am dialing in the VE/MAF etc as well as spark........ but I've come down now to where the injectors need to be adjusted along with MAF Reversion.

If you keep pulling timing and it keeps knocking........ u obviously need to attack it with a different approach, things must be done as a whole so.

Adjusting the VE, SPARK etc....... and it still knocks, need to go after fuel.

[passingpower]

Don't overthink and complicate fueling. If you're TRULY at an appropriate PE value, and experiencing knock that's not false, The fueling is STILL appropriate! The trouble is too much timing. See point 2, Post #2 above. If you're struggling with reversion then 1)bump idle until you're not, 2)accept a cruddy idle. Failing 1 and 2, scrap the MAF based control and set up for a full time SD strategy.

[BigDaddyCool]

Sometimes I think I'm the only one trying to achieve real power gains when it comes to tuning...... not just 'tweak it so it's nice'. That aside....

Cheers for the info on the maf reversion, never thought of tackling it via idle.

As for the fueling...... I dont get all of you. Here's the thing my stock tune knocks like a ****..... it's like a knock fest, and everything is fine with the car....

But because I have a heap of mods, it throws out my stock tune 'concept' functionality. I even half wonder if my revs per mile or something may be throwing out the cars 'calculated load' and grabbing the wrong spark off the wrong load level sometimes.... eg. 30% load spark when it should be 35% load spark (which is lower spark).

So ...... because it knocks to start with I'm trying to fix a few things like eg. my car bumps lean into the 8's average in the 2000-4000rpm range (mid range, mid throttle), it spikes lean when jumping into PE.........

Things just arnt accurate and constantly 'injector msec timing' comes into my mind as it's a constant thing.

The way I see it, my car in particular with Torque Management (which is cyclinder management), torque set to 68 originally......... all being bumped to 100, torque management off etc.......... obviously ur gunna need more fuel!......

It was designed to run at alot lower power correct? ........ more torque etc requires more fuel.

-=-

On another comparison, my dads 05 VZ...... runs longer injector times eg. 14ms is 1.040 etc for say 3000rpm........ where mine at 14ms is like 0.970 for example.

Mines stock 172kw at engine, his is stock 175kw at engine, same cam profiles etc....... his Optimal Torque Tables run higher then mine which from what I've read to pump more torque u need to add more fuel etc....... to do it the correct way essentially.

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I'm going off topic, either way it's all somewhat relative. Same goes for disabling COT, if no matter what I'm spiking lean in runs on certain area's when the cars cold or normal temp........u cant afford to be running like that when the engines hot....

I could go on and on, ...... if someone wishes to give me their thoughts on all this, i'm certainly all ears.

[passingpower]

“never thought of tackling it via idle.”
A cam, regardless of duration or overlap nearly never reverts at anything but idle. Forward flow is the goal of all cams especially the wilder ones.
“my revs per mile or something may be throwing out the cars 'calculated load'”
Doubtless, your calc. load is off. But, not due to revs per mile. It’s the ‘or something’ part. More specifically, your MAF calibration er-ah, tune. The MAF numbers dictate to the PCM what engine load is in a MAF system. (MAP numbers in a Speed-Density system) change those and voila! You’ve altered your indicated load.
“my car bumps lean into the 8's”
There’s a jewel of hard info. You’re correct, increasing your 'injector msec timing' WILL compensate for that.
You might’ve opened the thread by letting us know you’re not concerned with 'tweak[ing] it so it's nice'. Being that you’re not striving for streetability, “tuning” becomes a breeze. Your goal at this point is to quench cylinder heat by adding petrol to act as a cooling agent, that is to say, you’ll be targeting an AFR that is richer than optimal for your setup, allowing you to run more timing.

There any number of ways to fatten up fueling, nearly all of them involve deceiving the PCM such that it increases fuel injector duration based on a condition that doesn’t exist.

• Increase the MAF numbers. Fake out the PCM so it adds fuel to air that’s not in the chamber.
• Decrease the IFR table. The PCM will hold the injector open longer if you tell it the injectors are smaller than they actually are. (Disregard Bernoulli’s flow equation. Scaling gets close enough.)
• Pick an AFR modifier table and fiddle with it until the knock goes away.
• Bump up the PE table. Not exactly deceptive, you’re just telling the PCM to richen things up.
• Occasionally, I see tuners add fuel to the cylinder skew table such that there’s a global increase in fueling that occurs AFTER all the calculations have been performed. The PCM will always deliver more fuel than its commanding.

Since ‘it's all somewhat relative’ you have the option of picking one of the above or any combination of them to get the thing to spray more gas. You can “scale” the tables for a quick fix or, spend some time scanning and adjusting them for the times when you’re seeing knock. If you need specific process for these tuning methods, use the SEARCH function; the number of opinions is overwhelming! There again, you have the option of picking one or any combination thereof. Good luck!

[BigDaddyCool]

Believe me when I say i'm listening all ears.

What I take away from what you said is this:

1. Incorrect Load = MAF generally speaking...
2. Injector Skew = Might be a good way to go as there's no way to overall command a different AFR
3. IRF Table? Dont beleive I have that on mine.
4. ATF Table... yes if I set Lamdba 1.0 to -0.08 it helps knock alot but fuel use goes up a bit and power goes down somewhat overall....
5. PE I'm trying to raise it so it's not so rich but compensate with injector msec table.

Ultimately I think it would be heaps easier at this point without a stupid maf controlling things ......

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On my car a pro dyno tuner said I need to be trying to archive 25 degree's of spark on a dyno run ....... my car atm will average 24 which isn't real far off.

But i've modified an American Cadillac STS tune designed for one with variable exhaust cams and it's heaps more powerful, virtually no knock an easily pulls 25-29 degree's of timing at wot......... the power difference when taking off on the highway is phenomenal ....... but daily driving it's not really designed for my car so.

But it's just changed my view on making the power, obviously my car can produce upto 29 degree's at WOT.

So I'm trying to bring my tune upto closer to the 26/27 mark.

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Ultimately i'm trying to hit the 160rwkw on my next dyno run virtually 40kw above my last one before i had my high flow cats added, some exhaust stuff changed and my ss inductions kit put in.

A reasonable goal is 140..... But I want to defy the ECU and tuning laws to get the result I'm after.

I attached a tuning log from my run home from work ......... if you wanted to have a look at my yoyo effect i'm trying to smooth out. You'll need the latest beta to view it.

[vz_calais_190]

is there a way to make PE run all the time? i set mine to come on at 0 or 0.100sec but there is always a longer delay.
iv been playing around with mine to run lean below 30% load and rich 80% on but there is always a few sec delay before it runs rich.
PE shuts off too quick to run lean
if there was a way to get it to run all the time you be able to get it to add fuel in your trouble area since i cant find any other way to change fuelling without the ecu trimming back to stock after a 10 min drive

[BigDaddyCool]

Try adjusting your PE Axes

[vz_calais_190]

yeah done all that worked that little trick out a few weeks ago lol
iv set PE delay to 0.1sec
min dev 0.008
enrichment time 0.100sec
seems to take 2.5 to 3 sec for PE to kick in

iv got load 85,100% at 0.80 and it seems happy there but the delay is a pain in the ass

[BigDaddyCool]

.80? That seems a little rich doesn't it?.... and personally I found PE better at the stock ratings....... I haven't really gone back to playing with PE just yet.....