AFR and Timing Tuning (02 Regal GS 223k!!!)

[PWNED]

I really don't know where to start on how to explain this car. Basically I bought the car from a friend and my mods are in the sig. Never seen a wideband in its life until today! Initially at wot it was running 10.6. Well I had to fix this. Now running 11.5-11.0 (redline)

Upon tuning I started seeing KR 2-4* 5200-6000rpm. I had the AFR's perfect 11.5-11.6 at wot. Now I started taking away timing to see if it would drop the KR down which at wot it was set to 13-14*. I dropped it down to 11-12* with no change at all. So I decided to add about 2% of fuel from 9500hz up. Initially its hits 11.6 and the closer to red line it gets its right around 11.0. With the timing untouched I get around 1* KR.

I will post up logs/tunes below. Now my previous gtp had an s1x cam and headers and running 18* timing at wot with a 11.3-11.5AFR.

Do I need headers to run a 11.5AFR and more timing? Or even rockers as well to get to 15* timing plus???? Is this a normal characteristic?

I spent a good 2hrs with the below logs/tunes. I wont post them all but I did 14 changes pretty much bit by bit.

----Note--- I have the wideband in the crossover pipe as there is a bung in it.

Below are screen shots of what I can hopefully call progress.

Any help is appreciated!

First is the current tune

Second is the tune before me adding that 2% fuel.

Last is what I started with pretty much.

Here is a link to the hpt forum.

http://www.hptuners.com/forum/showthread.php?45403-AFR-and-Timing-Tuning-(02-Regal-GS-223k!!!)

 

[91parkave]

You need to have that wideband in the right place before you try and make changes or else its useless

 

[PWNED]

You need to have that wideband in the right place before you try and make changes or else its useless

How is it useless if the front cylinders are the problematic poppers?? Most header company's put the bung in the crossover right before it meets the rear bank. Like W-Body Store for the actual 02 sensor so it only reads off the front. Unlike factory you get front and rear all in one. Yes you could crawl under the car and put it in downpipe exit but why if there is an easy access above?

 

[Z34Phoenix]

the rear bank is just as important as the front. you can have a very lean condition in the rear and never know if the front are rich. get a bung installed so you get a better more accurate reading on the over all af. not just half the engine.

as for tuning...

first i would add some fuel to your AE as when you step on it you are getting that spike of KR. depending on what tps it starts i would add some just before to stop it. I am running a diff maf then you, but the readings seem like they should be changing more. have you cleaned it lately? short of adding more fuel or pulling timing, more mods would help. you are running a 3.4 with just plogs and ported mani. you really need rockers or cam. also swapping to headers could help too. I am assuming you are also running 93 octane right?

 

[91parkave]

How is it useless if the front cylinders are the problematic poppers?? Most header company's put the bung in the crossover right before it meets the rear bank. Like W-Body Store for the actual 02 sensor so it only reads off the front. Unlike factory you get front and rear all in one. Yes you could crawl under the car and put it in downpipe exit but why if there is an easy access above?

Dude any wideband instructions and/or installs you see never have half of the engine to accept that as the engine AFR reading. Wbody store just did that for a unknown reason

 

[PWNED]

the rear bank is just as important as the front. you can have a very lean condition in the rear and never know if the front are rich. get a bung installed so you get a better more accurate reading on the over all af. not just half the engine.

as for tuning...

first i would add some fuel to your AE as when you step on it you are getting that spike of KR. depending on what tps it starts i would add some just before to stop it. I am running a diff maf then you, but the readings seem like they should be changing more. have you cleaned it lately? short of adding more fuel or pulling timing, more mods would help. you are running a 3.4 with just plogs and ported mani. you really need rockers or cam. also swapping to headers could help too. I am assuming you are also running 93 octane right?

I am running 93 octane, all the car has ever seen its entire life. As for the maf it is a brand new gm lq4 item. As for the PE this is what it is set at. In the screen shot I opened what the values are. All the other items in that file are at 0. Yes you do have a valid point of locating the wideband to read all the cylinders. I would really like to get the stock injectors on the car as well. Being at 70% duty of 42#'s though may be close. Not to mention I would like to put a stock maf on as well as I bought the car with this setup.

 

[darkhorizon]

Dont listen to the kids talk about wideband placement...

Anyway.. you are going to live in the 10s afr wise without a real mod to speak of. Headers may let you run a degree or 2 more timing, but I wouldnt count on it.

 

[91parkave]

Dont listen to the kids talk about wideband placement...

Anyway.. you are going to live in the 10s afr wise without a real mod to speak of. Headers may let you run a degree or 2 more timing, but I wouldnt count on it.

Well please professor school us on wideband placement so we can learn

 

[PWNED]

Dont listen to the kids talk about wideband placement...

Anyway.. you are going to live in the 10s afr wise without a real mod to speak of. Headers may let you run a degree or 2 more timing, but I wouldnt count on it.

I am one to listen to what others have to say. I will try a more downstream placement. It was just super easy to put in in the crossover. For forced injection 11.5 seems to be the afr people say to run. But in the w-body world why does the current car hate it? What do others tend to run? 11.5-11.0? I would like to be out of the 10's as I would like to try to put a stock injector back in. What should I target for the initial throttle hit on the wideband? But then pops up another question. For flow vs kpa I really don't know how to scale this down if I want to richen/lean it out to lower the duty cycles. I know how to do so via the maf table. But considering they are 42's shouldn't the offset table be fixed as well? I mean in reality it should be I think but I guess that's where the term of the 3800's being hacked comes from. Along with some misleading info about how to tune these cars.

 

[91parkave]

Smaller numbers =more fuel.. larger = less fuel.

I can email you the injector spreadsheet so you can get the right info

 

[matt5112]

OP: My suggestion for your car is switch back to the factory injectors, TB, MAF, and tune. See how that works with the 3.4. If it doesn't, get a larger pulley.

Ramblings:

Tuning injectors is apparently voodo magic in the 3800 world.

Some injector companies will give you someone else's data to shut you up.

Some injector companies test their product and give you that data.

Some tuners care, some don't.

Some tuners suggest adjusting the IFR and leaving the MAF as is.

Some suggest finding out your fuel pressure, making sure your fuel pressure doesn't bleed off, then putting in a constant value for IFR, as it should be if your FPR is working correctly and the fuel pump can keep up. This is because the FPR is boost/vacuum referenced 1:1, meaning the delta pressure across the injector should never change. Unlike the LSx stuff where the FPR is fixed. In other words, do not use LSx injector values as is, you need to find the delta 3.5 BAR value and use that across the board. That is only if your fuel pressure actually changes as it should. Once you figure all of that out, tune your MAF to get your trims back in line. I presume you have an intake or elbow right in front of the sensor. They'll all change the calibration of the MAF. Yes, you can tune around it by changing the IFRs, or you can change the MAF.

The issue lies in only having one unknown constant. If you change your intake/MAF and injectors, then you have nothing to compare against. Making all changes just guesses. If your tune changes from season to season and your fuel isn't changing, then something is off. E85 is an entirely different battle. The fuel changes all the time.

There is no known manufacturer data for offsets for your injectors if you have the Lucas 42s. Any data anyone promises you, was found experimentally. As a result, it will have error associated with it. If you choose to use it, then expect to have to dial it in further. Make sure you consider both the voltage offset and the injection time offset tables.

As for the O2 placement, I ran my upstream narrow in the crossover, and the WB in front of the cat. I never had much of a problem with it. Arguably, running a WB that you do not calibrate regularly will cause your values to drift as the sensor wears and buildup on the tip occurs. If you can't trust your WB explicitly, then what was the point?

To argue you need to monitor the rear bank as well as front actually introduces more error. If the rear bank is running lean causing your WB to read 12, you richen it up until the WB reads 11. Now the front bank is running 10 and the rear at 12 which might magically average out to 11. So yes, monitoring everything is ideal. However, making blind changes to your AFR without first looking to see if you don't have a mechanical issue first is dangerous.

I ran everything from 10's to 12.0 for an AFR. I found the car to be fastest when running 15-16* of timing, 11.0 AFR, and the smallest pulley that wouldn't cause knock. I was also top swapped, so I have no experience tuning an L67 bottom end. They may like more timing due to the lower compression. But I have a sneaking suspicion, as long as you're still running a dinner plate on the M90, smaller pulley is where it's at.

As a side note, I did not find that rockers helped with the amount of timing I was able to run in the slightest. They did add some top end. Nowhere near worth the cost though. Consider saving for an intercooler instead. Much better investment.

 

[PWNED]

OP: My suggestion for your car is switch back to the factory injectors, TB, MAF, and tune. See how that works with the 3.4. If it doesn't, get a larger pulley.

Ramblings:

Tuning injectors is apparently voodo magic in the 3800 world.

Some injector companies will give you someone else's data to shut you up.

Some injector companies test their product and give you that data.

Some tuners care, some don't.

Some tuners suggest adjusting the IFR and leaving the MAF as is.

Some suggest finding out your fuel pressure, making sure your fuel pressure doesn't bleed off, then putting in a constant value for IFR, as it should be if your FPR is working correctly and the fuel pump can keep up. This is because the FPR is boost/vacuum referenced 1:1, meaning the delta pressure across the injector should never change. Unlike the LSx stuff where the FPR is fixed. In other words, do not use LSx injector values as is, you need to find the delta 3.5 BAR value and use that across the board. That is only if your fuel pressure actually changes as it should. Once you figure all of that out, tune your MAF to get your trims back in line. I presume you have an intake or elbow right in front of the sensor. They'll all change the calibration of the MAF. Yes, you can tune around it by changing the IFRs, or you can change the MAF.

The issue lies in only having one unknown constant. If you change your intake/MAF and injectors, then you have nothing to compare against. Making all changes just guesses. If your tune changes from season to season and your fuel isn't changing, then something is off. E85 is an entirely different battle. The fuel changes all the time.

There is no known manufacturer data for offsets for your injectors if you have the Lucas 42s. Any data anyone promises you, was found experimentally. As a result, it will have error associated with it. If you choose to use it, then expect to have to dial it in further. Make sure you consider both the voltage offset and the injection time offset tables.

As for the O2 placement, I ran my upstream narrow in the crossover, and the WB in front of the cat. I never had much of a problem with it. Arguably, running a WB that you do not calibrate regularly will cause your values to drift as the sensor wears and buildup on the tip occurs. If you can't trust your WB explicitly, then what was the point?

To argue you need to monitor the rear bank as well as front actually introduces more error. If the rear bank is running lean causing your WB to read 12, you richen it up until the WB reads 11. Now the front bank is running 10 and the rear at 12 which might magically average out to 11. So yes, monitoring everything is ideal. However, making blind changes to your AFR without first looking to see if you don't have a mechanical issue first is dangerous.

I ran everything from 10's to 12.0 for an AFR. I found the car to be fastest when running 15-16* of timing, 11.0 AFR, and the smallest pulley that wouldn't cause knock. I was also top swapped, so I have no experience tuning an L67 bottom end. They may like more timing due to the lower compression. But I have a sneaking suspicion, as long as you're still running a dinner plate on the M90, smaller pulley is where it's at.

As a side note, I did not find that rockers helped with the amount of timing I was able to run in the slightest. They did add some top end. Nowhere near worth the cost though. Consider saving for an intercooler instead. Much better investment.

Thank you for the info. As for companies giving you data. Back in my gtp days I sent out my stockers and had them made into 48#ers. (Fuel Injection Connection) Jon (owner) supplied me with the correct kpa vs flow rate data.

But for my current 42's I really don't know where the current info came from. How do you actually know when/where to adjust in the offset?

As for afr I was just curious on what some members run. I will shoot for the low 11's. I will try the WB in the rear manifold this weekend to see what it truly is at vs just off the crossover. For the initial hit I am unsure what I should get it dialed too. (if 11.8-12.0 is too lean)

As for the intake, how did you know?

 

[PWNED]

Smaller numbers =more fuel.. larger = less fuel.

I can email you the injector spreadsheet so you can get the right info

[email protected]

 

[PWNED]

Smaller numbers =more fuel.. larger = less fuel.

I can email you the injector spreadsheet so you can get the right info

[email protected]

 

[PWNED]

Smaller numbers =more fuel.. larger = less fuel.

I can email you the injector spreadsheet so you can get the right info

What does everyone usually input for the pressures? At the end where it spits you the data it is no where near the actual numbers in the tune file. I must be doing something wrong.

 

[darkhorizon]

WHY is it my job to fix all this god awful information people love to spread around????? GAH here goes 20 minutes of my day:

I am one to listen to what others have to say. I will try a more downstream placement. It was just super easy to put in in the crossover.

Yeah, its fine. Reading "half" is the same as reading it all... If you have some major issue like a misfire on the front bank its going to still show up no matter where you have the sensor. Having it further back lets it run a bit cooler, but really its not a huge deal because its still within spec.

For forced injection 11.5 seems to be the afr people say to run. But in the w-body world why does the current car hate it? What do others tend to run? 11.5-11.0? I would like to be out of the 10's as I would like to try to put a stock injector back in.

Who said that 11.5 is right? It may be true for intercooled cars, but in the world of 300+ degree air temps you are going to need to run on the side of 10s for the amount of KR reduction you are looking for. In terms of what makes the most power.... I would check it at a dragstrip.

What should I target for the initial throttle hit on the wideband?

As lean as you can manage without KR... Typically you want to come in high 11s then quickly get it into the low 11s/10s as things heat up.

But then pops up another question. For flow vs kpa I really don't know how to scale this down if I want to richen/lean it out to lower the duty cycles.

You never adjust flow vs KPA.. for anything other than injector size.

I know how to do so via the maf table.

Maf table is not the place to do "tuning" either. You can do things in there if you want, but its usually not consistent with the overall goal of having a tuned car, so at best you can do "tricks" in the maf table. The only tuning you want to do here is compensate for the maf being wrong due to a different maf, cold air intake that is screwing you up... etc...

But considering they are 42's shouldn't the offset table be fixed as well? I mean in reality it should be I think but I guess that's where the term of the 3800's being hacked comes from. Along with some misleading info about how to tune these cars.

There is no offset table in the classic sense for a 3800 PCM. There are tables out there but they are completely useless and do not function as suggested. I've ran every type of injector you can imagine from stock to 110# high or low impedance without adjusting offsets and they idle and run just fine.

OP: My suggestion for your car is switch back to the factory injectors, TB, MAF, and tune. See how that works with the 3.4. If it doesn't, get a larger pulley.

LOL what a giant waste of time.

Tuning injectors is apparently voodo magic in the 3800 world.

No they are not... Its probably one of the easiest parts of tuning. adjust IFR values and go.

Some injector companies will give you someone else's data to shut you up.
Some injector companies test their product and give you that data.

Some tuners care, some don't.

Some tuners suggest adjusting the IFR and leaving the MAF as is.

This is probably true, only because they are actually the same injector. The fact that flow data is REALLY easy to obtain on a flow bench made out of a battery and bucket of fluid I usually find it easy to trust numbers on injectors.

Every tuner that knows what they are doing doesnt fiddle with a maf if the maf is stock... its stupid to think you are going to do a better job with leaky headers and some $100 wideband than engineers in controlled environments with great tools.

Some suggest finding out your fuel pressure, making sure your fuel pressure doesn't bleed off, then putting in a constant value for IFR, as it should be if your FPR is working correctly and the fuel pump can keep up. This is because the FPR is boost/vacuum referenced 1:1, meaning the delta pressure across the injector should never change. Unlike the LSx stuff where the FPR is fixed. In other words, do not use LSx injector values as is, you need to find the delta 3.5 BAR value and use that across the board. That is only if your fuel pressure actually changes as it should. Once you figure all of that out, tune your MAF to get your trims back in line. I presume you have an intake or elbow right in front of the sensor. They'll all change the calibration of the MAF. Yes, you can tune around it by changing the IFRs, or you can change the MAF.

No... Just adjust your IFR by the difference in injector size.. Injector constant is a CONSTANT size at that pressure, GM already tuned the curves in use it.

The issue lies in only having one unknown constant. If you change your intake/MAF and injectors, then you have nothing to compare against. Making all changes just guesses. If your tune changes from season to season and your fuel isn't changing, then something is off. E85 is an entirely different battle. The fuel changes all the time.

Dont talk about E85 like you have ran it. It may change slightly but the small rich/lean swings will be offset by the fact that you can run it leaner or richer without penalty. You also dont "guess" with changes.. The narrowband is VERY good at reading 14.7 so use the information your narrow can give you about that. The wideband is also quite good, within a .1 or .2 tolerance normally.

There is no known manufacturer data for offsets for your injectors if you have the Lucas 42s. Any data anyone promises you, was found experimentally. As a result, it will have error associated with it. If you choose to use it, then expect to have to dial it in further. Make sure you consider both the voltage offset and the injection time offset tables.

Injector offset data is a farce at best for GM pcms. People that think they are geniouses at it dont know how the GM PCM works as it uses many many tables to determine offsets.. when you put in raw data measured in a lab it still means nothing.

I ran everything from 10's to 12.0 for an AFR. I found the car to be fastest when running 15-16* of timing, 11.0 AFR, and the smallest pulley that wouldn't cause knock. I was also top swapped, so I have no experience tuning an L67 bottom end. They may like more timing due to the lower compression. But I have a sneaking suspicion, as long as you're still running a dinner plate on the M90, smaller pulley is where it's at.

This is probably somewhat true on his setup. it probably doesnt matter enough to worry though.

 

[PWNED]

WHY is it my job to fix all this god awful information people love to spread around????? GAH here goes 20 minutes of my day:



Yeah, its fine. Reading "half" is the same as reading it all... If you have some major issue like a misfire on the front bank its going to still show up no matter where you have the sensor. Having it further back lets it run a bit cooler, but really its not a huge deal because its still within spec.



Who said that 11.5 is right? It may be true for intercooled cars, but in the world of 300+ degree air temps you are going to need to run on the side of 10s for the amount of KR reduction you are looking for. In terms of what makes the most power.... I would check it at a dragstrip.



As lean as you can manage without KR... Typically you want to come in high 11s then quickly get it into the low 11s/10s as things heat up.



You never adjust flow vs KPA.. for anything other than injector size.




Maf table is not the place to do "tuning" either. You can do things in there if you want, but its usually not consistent with the overall goal of having a tuned car, so at best you can do "tricks" in the maf table. The only tuning you want to do here is compensate for the maf being wrong due to a different maf, cold air intake that is screwing you up... etc...



There is no offset table in the classic sense for a 3800 PCM. There are tables out there but they are completely useless and do not function as suggested. I've ran every type of injector you can imagine from stock to 110# high or low impedance without adjusting offsets and they idle and run just fine.



LOL what a giant waste of time.



No they are not... Its probably one of the easiest parts of tuning. adjust IFR values and go.



This is probably true, only because they are actually the same injector. The fact that flow data is REALLY easy to obtain on a flow bench made out of a battery and bucket of fluid I usually find it easy to trust numbers on injectors.

Every tuner that knows what they are doing doesnt fiddle with a maf if the maf is stock... its stupid to think you are going to do a better job with leaky headers and some $100 wideband than engineers in controlled environments with great tools.



No... Just adjust your IFR by the difference in injector size.. Injector constant is a CONSTANT size at that pressure, GM already tuned the curves in use it.



Dont talk about E85 like you have ran it. It may change slightly but the small rich/lean swings will be offset by the fact that you can run it leaner or richer without penalty. You also dont "guess" with changes.. The narrowband is VERY good at reading 14.7 so use the information your narrow can give you about that. The wideband is also quite good, within a .1 or .2 tolerance normally.




Injector offset data is a farce at best for GM pcms. People that think they are geniouses at it dont know how the GM PCM works as it uses many many tables to determine offsets.. when you put in raw data measured in a lab it still means nothing.



This is probably somewhat true on his setup. it probably doesnt matter enough to worry though.

I truly do appreciate your insight. I never took into consideration that not being intercooled and having things richer will help with KR. I will be sure to get this in check tomorrow. This explains my KR issue after leaning it out. In my above post of Flow Rates (in the tune) what do you think I should do there? In that I mean in terms of richening/leaning it out/ Where should I start tweaking? I have been meaning to get a stock maf so I can put my maf table back to stock. But being an LQ4 I cannot do this as it is much bigger and must be compensated for i would think.

 

[PWNED]

Ok guys/gals we all know how I had the WB in the crossover pipe. With only minor changes from 7500-9500ish in the maf (1% more fuel was added) But initially beyond that I did not touch anything. Before I was hitting 11.1 afr in the crossover. Now in the rear manifold I hit 11.0. On the initial hit I get 11.8 afr and then taper to 11.0. With a few timing tweaks I am happy enough where it sits for what it is. I may or may not leave the lQ4 maf in (meaning if I go stock maf I need to redo everything, but by then I may just leave the stock maf table alone and tweak the IFR table if I get some insight on that)

 

[darkhorizon]

In my above post of Flow Rates (in the tune) what do you think I should do there? In that I mean in terms of richening/leaning it out/ Where should I start tweaking?

Those numbers are probably fine. if you plan on using a narrowband, I would use that to tune in the IFR numbers better.

General "afr at wot" tuning will be done in your PE tables.. pick your poison there it really doesnt matter. This will change your requested afr (which I noticed you are not scanning, why?)

I have been meaning to get a stock maf so I can put my maf table back to stock. But being an LQ4 I cannot do this as it is much bigger and must be compensated for i would think.

LQ4 is a nice maf, no reason to ditch it really. Make sure you have the "right" LQ4 table out there and go for it. I cant really gauge from your posts what maf table you are currently using.

 

[PWNED]

Those numbers are probably fine. if you plan on using a narrowband, I would use that to tune in the IFR numbers better.

General "afr at wot" tuning will be done in your PE tables.. pick your poison there it really doesnt matter. This will change your requested afr (which I noticed you are not scanning, why?)



LQ4 is a nice maf, no reason to ditch it really. Make sure you have the "right" LQ4 table out there and go for it. I cant really gauge from your posts what maf table you are currently using.

What is this requested afr you speak of not in the scan? Is actual not ok when the wb is hooked up? In the table it is displayed as seen. I am trying to un-hack tune the car but there is not an actual lq4 maf file in the pcm as I asked the previous owner. He just modified the stock file to work. It looked like a roller coaster. It is much better looking now. I am not flowing 11500 plus so I really see no need for this lq4 or any gains it would give me. Right?


Also how am I hitting 10500 hz on tis setup? My gtp was on spray/cammed and hitting 10,000hz at times seen here.


http://www.grandprixforums.net/showthread.php?t=51024

But why use NB to tweak the IFR's? I mean if I have the WB hooked up that is the best unless I misunderstood.

Would shrinking my 104s from .054 to .050 net me any possibility to add more timing?