Siemens 80lbs injectors

Sluggonaut

Goblin Guru
We are talking about the same! I left it at GAS 14.7. So it shows me stoich at 14.7, BUT my ECU, Scanner,... all reads ECU stoich at 10.4. Which is the same, I just look at the gauge and know that I am not shooting for 14.7. It makes comparison from the gauge to the scanner data a bit more challenging. But I am using my gauge just for eyeballing that I am not to far off, so that works for me.
Makes sense. I am not a tuner so I am not dealing with the things you and Rauq are dealing with. For those of us that are just drivers, it doesn't matter what the gauge is set to as long as we know what stoich is for that setting and monitor accordingly.
 

mike_sno

Goblin Guru
I am in no way a professional tuner either. Just dig and dig, watch and watch and walk my way through it. That's why I said in my very first comment about your tune "I also wonder why...".

Did Al McClure, I guess that's the guy which work(ed) at ZZP tune your car?

It still makes me wonder, if there are any other reasons why he would not do the "obvious" thing and change the Afr. Maybe he wants his tune not comparable (achieved!) or maybe that works better with the injector data for the Siemens injectors he uses or maybe there are other advantages ?!?
 

Rauq

Goblin Guru
I have a couple guesses:

First, changing stoich in the tune has other hidden and undesirable consequences. No idea what they might be, but I would remind of the random Commanded AFR swings caused by removing the B1S2 HO2S and not being able to disable HO2S tests à la every other GM ECU.

Second, once they have a dialed-in tune for E85 with stoich set at 14.7 and compensations made in all the airflow/airmass tables, it makes no difference to them to fine-tune those tables. Side benefit is if you want to switch to a pump gas tune, you're incentivized to go back to your tuner rather than changing a single parameter for yourself (spark tables would still need touching, but still).

Third... something else?
 

mike_sno

Goblin Guru
I am not sure where the B1S2 Sensor sits. I would guess Bank 1 Sensor 2 (after catalytic converter). Did you removed that sensor completely?

I left my Sensor in my new exhaust, even without the catalytic converter. I don't see random AFR changes when I am MAF and SD. I am mostly commanding my set (10.4) unless I am in Power enrichment.

Idle is different. The ECU try to change AFR, sparc and TB position to make it idle. Based on those 3 things the engine should idle +/- 1rpm around target. My tolerance band is a big higher. LOL
I did my idle tuning in a longer process. Summarized: Setting AFR constant --> tuning TB, then setting sparc constant --> tuning AFR, then activating all 3 to the tuned values. Worked out half way decent.

I kind of which I had a stock engine, if all other variables are set, you can determine the Injector data pretty easy.
 

mike_sno

Goblin Guru
Side benefit is if you want to switch to a pump gas tune, you're incentivized to go back to your tuner rather than changing a single parameter for yourself (spark tables would still need touching, but still).
This is equal to lock your tune :D
 

Gtstorey

Goblin Guru
I kind of which I had a stock engine, if all other variables are set, you can determine the Injector data pretty easy.
There has been a bunch of people that thought this on HPT forum. I've never seen anybody actually do. It's not impossible to get an approximation close enough to get it drivable, it's what they did in the old days before injector data was available. But not easy and not exact.

Unless you are talking about flow rate only.
 

Rauq

Goblin Guru
I am not sure where the B1S2 Sensor sits. I would guess Bank 1 Sensor 2 (after catalytic converter). Did you removed that sensor completely?
Yes, I only have the B1S1 narrowband and a wideband in my exhaust, no B1S2. I think the random commanded AFR swings are because we don't have the Post O2 test toggle, screenshot below is from a stock '10 LAP tune.
49704



Idle is different. The ECU try to change AFR, sparc and TB position to make it idle. Based on those 3 things the engine should idle +/- 1rpm around target. My tolerance band is a big higher. LOL
I don't think +/- 1rpm is realistic on any engine. My completely stock B207R still in its original Saab home doesn't even hold that, more like +/- 100rpm

There has been a bunch of people that thought this [rauq: figuring out fuel injector settings] on HPT forum. I've never seen anybody actually do. It's not impossible to get an approximation close enough to get it drivable, it's what they did in the old days before injector data was available. But not easy and not exact.

Unless you are talking about flow rate only.
I had decent results playing with start of injection/end of injection (SOI/EOI) on an LS1, basically clicking them up and down and gauging based on sound and idle quality what was better and worse. I made zero progress trying to adjust Short Pulse Limit/Adder and Min PW on my Goblin, I couldn't tell any difference changing them at idle or driving or anywhere. I have a good feeling I got good data on Offset vs Voltage vs VAC... once I figured out that negative manifold vacuum pressure.
 

mike_sno

Goblin Guru
There has been a bunch of people that thought this on HPT forum. I've never seen anybody actually do. It's not impossible to get an approximation close enough to get it drivable, it's what they did in the old days before injector data was available. But not easy and not exact.

Unless you are talking about flow rate only.
You know me, the guy who wants to eliminate all tolerances in the process. That's not matching well to "look out of the window and guesstimate the injector data" LOL
 

mike_sno

Goblin Guru
I don't think +/- 1rpm is realistic on any engine. My completely stock B207R still in its original Saab home doesn't even hold that, more like +/- 100rpm
+/-1 was sarcastic from me. It's just: at least 3 things which change to have to hold idle at target... This should point to a fairly good idle result.

I don't recall the actual tolerance but +/- 100 rpm on complete stock seems to high. I want to say that at my old LAP engine and the unmodified LSJ I never saw the rpm moving if I look at the instrument cluster.

@Rauq If you get a chance, not that I have the 80 lbs injector yet to send me your tune, that would be great. It's more the curiosity to see and compare what I got from the guy from facebook. I can forward you what he sent me as well, if that's of any benefit from you.
 

mike_sno

Goblin Guru
One thing I didn't test was, if you change the Stoich AFR in the tune, what does it do to the Commanded AFR PID in the scanner? As I recall, that data is reported as gas AFR (with a 14.7 stoich tune) with no option to change it to Lambda or any other scale (except by creating a math parameter). That may have been what Al was getting after.
I found in this post a screenshot where you see the AFR commanded. My mouse is over the Power enrichment.
 

Sluggonaut

Goblin Guru
Did Al McClure, I guess that's the guy which work(ed) at ZZP tune your car?
My donor was turbo swapped before I bought it and ZZP did the tune on it.

After I finished my Goblin, I contacted Al who tuned the donor, and explained my situation to see what they would charge to check the tune. Al sent instructions for pulling a log and he looked it over for free.

Long story short, I was set for Lambda, he answered a bunch of my questions about the tune, he identified the problem that had me question the tune to begin with, and he confirmed the tune was working fine in Goblin trim after I fixed the issue I caused during the build.
 

Rauq

Goblin Guru
+/-1 was sarcastic from me. It's just: at least 3 things which change to have to hold idle at target... This should point to a fairly good idle result.
Check out this LSJ tune vs the last LS1 I tuned...
LSJ:
49706

49708


LS1:
49709

49710

I don't recall the actual tolerance but +/- 100 rpm on complete stock seems to high. I want to say that at my old LAP engine and the unmodified LSJ I never saw the rpm moving if I look at the instrument cluster.

@Rauq If you get a chance, not that I have the 80 lbs injector yet to send me your tune, that would be great. It's more the curiosity to see and compare what I got from the guy from facebook. I can forward you what he sent me as well, if that's of any benefit from you.
The needle doesn't move on my Saab, Goblin, or even my Duramax, but with a fast enough scanner, I can see fluctuations in the reading. I should've said +/- 50rpm, I'm seeing swings of 100rpm total.

I'll take you up on the injector data swap. I'd estimate early next week on that.

I found in this post a screenshot where you see the AFR commanded. My mouse is over the Power enrichment.
Good to know, thanks!
 

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