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I understand your logic in respecting what he says.
I was monitoring that original thread as it unfolded.
It got to the point so many "not totally correct" statements about PCM function were being thrown around I just left it alone.
Not my nature to challenge his findings.
But before I took anyone's word as gospel I would ask for an explanation of how the PCM "learns" at WOT and in turn applies what it learned without a feedback loop?
Because unless it can do this (all other things remaining the same) there is no way for the car to lose power days, weeks or months later.
Originally Posted by Snorman
It's simply a matter of the PCM detecting KR. That's what this is all about. At a certain level the PCM moves to a low octane table and reduces timing, and thus power.
I'm not sure the fact that the PCM has low and high octane tables is in dispute, is it?
S.
@dar02081961 I think what you are asking is can the car learn based on AFR. The answer is yes it can learn and does remember. The car can lean/enrich the AFR based on the narrow band sensors.
STFT (Short Term Fuel Trims) = This item adjusts the fuel based on the most recent sensor information gathered after the car has been started.
LTFT (Long Term Fuel Trims) = This item adjusts the fuel based on an average of sensor information gathered over time and stored for each run event (I.E. start/stop engine).
Somewhat off topic, but something we have not mentioned is that we have sold close to 50 Stinger-RZs to one of the premier forum vendors for their special package.
They have not asked us to keep this QT, but based on what I have seen, they would prefer that we keep this under wraps.
I know they picked up close to 50 RWHP with our intake and specified our high flow filter in their purchase orders.
In addition to this, GM contacted us last year due to a referral from the GM engineer that tested our intake at the Milford Proving grounds Feb. 2014. He gave it the thumbs up, and now the Performance and Specialty Vehicle Division of GM is looking at Halltech's C7 products for their dealer network. You have to ask yourself this question. If GM has no concerns with our system on the C7 and C7 Z06, why would anyone?
Before and after. We have seen no less than 15 independent dynos showing over 45 RWHP with our Stinger-RZ, 10 over 50, and one at 60 on an engine dyno pull. Can your dynos vary? Of course they can. Every dyno and dyno operator have different protocol for testing, and I know for sure you can show almost any number you want to if that is the objective. I am sure that every dyno we have ever posted is exactly what was sent to Halltech, unsolicited, with no input from us. All but a handful were done without touching the ECU.
We have done extensive testing of the stock and Halltech Stinger and see virtually no degradation of timing with our system, short or long term. In fact, we have seen log files with the stock intake that show as much or more KR as our intake shows under various conditions.
The Z06 has very active knock sensors and are probably too sensitive, but they work well in keeping the engine alive.
Jim
__________________ "World Class Performance for your Corvette"
Intake Design and Engineering since 1999
Halltech Systems, LLC
262-510-7600
This car just ran 127-128 mph in pretty good air on a well prepped track (1.5 short time on DR's). That's 3-4 mph slower than what it ran stock. There is no possible way it gained 40+ rwhp and retained it over the last 1-2 months and ran 3-4 mph slower. The car should have ran 133-135 mph with the no-tune CAI.
S.
This car just ran 127-128 mph in pretty good air on a well prepped track (1.5 short time on DR's). That's 3-4 mph slower than what it ran stock. There is no possible way it gained 40+ rwhp and retained it over the last 1-2 months and ran 3-4 mph slower. The car should have ran 133-135 mph with the no-tune CAI.
S.
Didn't he say something about low octane fuel? If that's the case you're not comparing fairly. Low octane fuel or oil ingestion or humidity, etc all have an effect on performance.
Didn't he say something about low octane fuel? If that's the case you're not comparing fairly. Low octane fuel or oil ingestion or humidity, etc all have an effect on performance.
I have no idea what you're talking about. The owner only runs 93-octane fuel in this car. And it is extremely low-humidity here today. And now we're going to blame "oil ingestion"? Let's stop with the excuses and call this like it is.
S.
I have no idea what you're talking about. The owner only runs 93-octane fuel in this car. And it is extremely low-humidity here today. And now we're going to blame "oil ingestion"? Let's stop with the excuses and call this like it is.
S.
I read on another thread a while back and there was a guy running slower and having kr kick in because of bad fuel. I think he added fuel at the track but it didn't help. I was not blaming anything on oil ingestion just stating things that would cause kr to kick in. I am also not making excuses for anything. I was merely trying to find out if the results that you are talking about were with the same car, same fuel, same temps, etc. Not sure why you're so fired up about it but if someone can't ask you a question without you getting upset you will have a hard time convincing people. It seems more like a vendetta than research.
I read on another thread a while back and there was a guy running slower and having kr kick in because of bad fuel. I think he added fuel at the track but it didn't help. I was not blaming anything on oil ingestion just stating things that would cause kr to kick in. I am also not making excuses for anything. I was merely trying to find out if the results that you are talking about were with the same car, same fuel, same temps, etc. Not sure why you're so fired up about it but if someone can't ask you a question without you getting upset you will have a hard time convincing people. It seems more like a vendetta than research.
I'm not getting "fired up" about anything. But why would you insinuate he had low octane fuel in the car?
And then to comment about oil ingestion?
The data and timeslips will be forthcoming, I'm sure. I already have them, but not my place to post.
S.
If I arrive at the track with this intake and fill up 100 octane, how long will it take for the ECU to learn the mixture and jump on a higher power map?
Somewhat off topic, but something we have not mentioned is that we have sold close to 50 Stinger-RZs to one of the premier forum vendors for their special package.
They have not asked us to keep this QT, but based on what I have seen, they would prefer that we keep this under wraps.
I know they picked up close to 50 RWHP with our intake and specified our high flow filter in their purchase orders.
In addition to this, GM contacted us last year due to a referral from the GM engineer that tested our intake at the Milford Proving grounds Feb. 2014. He gave it the thumbs up, and now the Performance and Specialty Vehicle Division of GM is looking at Halltech's C7 products for their dealer network. You have to ask yourself this question. If GM has no concerns with our system on the C7 and C7 Z06, why would anyone?
Before and after. We have seen no less than 15 independent dynos showing over 45 RWHP with our Stinger-RZ, 10 over 50, and one at 60 on an engine dyno pull. Can your dynos vary? Of course they can. Every dyno and dyno operator have different protocol for testing, and I know for sure you can show almost any number you want to if that is the objective. I am sure that every dyno we have ever posted is exactly what was sent to Halltech, unsolicited, with no input from us. All but a handful were done without touching the ECU.
We have done extensive testing of the stock and Halltech Stinger and see virtually no degradation of timing with our system, short or long term. In fact, we have seen log files with the stock intake that show as much or more KR as our intake shows under various conditions.
The Z06 has very active knock sensors and are probably too sensitive, but they work well in keeping the engine alive.
Jim
My tuner installed one on a members A8. He made less than 40 rwhp
on a mustang dyno.
but I think the A8 shows slightly less gain than the M7's. Still very good.
I have a mid February appointment for mine. so I'll get a dyno on mine. See just what it makes.
Then ARH 2inch Jet hot coated are going on with a tune.
I felt a nice increase in power with your intake over stock.
I have over 10 k on your intake.
My tuner installed one on a members A8. He made less than 40 rwhp
on a mustang dyno.
but I think the A8 shows slightly less gain than the M7's. Still very good.
I have a mid February appointment for mine. so I'll get a dyno on mine. See just what it makes.
Then ARH 2inch Jet hot coated are going on with a tune.
I felt a nice increase in power with your intake over stock.
I have over 10 k on your intake.
No matter what mods ya decide to get it will still be slow with you driving...
And, he was exactly right in what my car started to do at the track. Big power gains at first (in the heat of the summer), but after the CAI sat on the car for a few thousand miles and conditions got MUCH better, I lost tons of power at the track. As I previously stated, my car was stuck in the low octane table and was pulling tons of timing and seeing way too much knock. Put the stock intake on with a little more octane and bam, all better! You guys do what you want, but I saw it first hand.
I tend to agree with the PCM learning the leaner air flow after a CAI is installed and will shift to the lower octane timing map after KR is detected more rapidly in the KR Learn Factor.
Here is a base line of factory stock time slips at PBIR when my A8 car had 525 miles and 1st passes at PBIR May 2015. Note the 60 FT's at 1.70, 1/8mi at 100 mph and a 130 MPH pass in 80F with DA at +1200ft. Left Lane 0383 The HPT Scanner showed a Max KR of 4 degrees on 93 octane and Max delivered torque of 604lb/ft. Knock learn factor was 0.02
Then after waiting months for weather to cool down I went back to PBIR on Jan 20 with the Haltech CAI. The 60FT was still about 1.70 but 1/8mi at 104 mph and 129 MPH pass in 75F at +300ft. The HPT Scanner showed Max KR of 8 degrees on 93 octane and Max delivered torque of 562lb/ft. Knock learn factor jumped to 2.5. The car picked up about 4 mph in 1/8mi and loss -1 mph on top end. My guess is the leaner AFR picked up ~40hp until the 1/8 but leaned out on the top end slightly and the learn factor lowered timing. The whole time I have own the car, I never disconnected the battery to reset the PCM.
Then on Jan 24 I had another chance to test at PBIR. This time I thought I would try to reset the PCM by disconnecting the battery for 1 minute and try running on a fresh PCM reset. The 60 FT was still 1.70 but 1/8 mi was now 105.82 mph and 132.53 MPH pass in 57 F at -300FT. The HPT Scanner still showed Max KR of 4 degrees like stock but Max delivered torque was now 628lb/ft. The knock learn was back to 0.02.
The Haltech CAI does consistently show an increase over the OEM unit with 4~5 mph gain in the 1/8 and plus 2 mph on the top end with the factory stock tune. There may be more gains using a blend of 93/100 mix to eliminate the 4 degree KR.
Lesson learned, "Reset the PCM when looking for maximum performance at the strip!"
This plug chop was done today on our 6122 mile Z07. We have done more high speed and full on throttle testing with our intake on our mule than any car we have ever owned.
From Andy Pilgrim running the Autobahn Track in Joliet, with 2 full days of racing, many dyno pulls, tons of fun, and 44 RWHP, the plug tells the story.
Perfect color, showing no lean condition at all, zero detonation specs, and almost black colorization around the plug perimeter, you could not ask for better proof of our intake air fuel ratio.
The gap should remain close to stock for 100,000 miles plus.
I tend to agree with the PCM learning the leaner air flow after a CAI is installed and will shift to the lower octane timing map after KR is detected more rapidly in the KR Learn Factor.
Here is a base line of factory stock time slips at PBIR when my A8 car had 525 miles and 1st passes at PBIR May 2015. Note the 60 FT's at 1.70, 1/8mi at 100 mph and a 130 MPH pass in 80F with DA at +1200ft. Left Lane 0383 The HPT Scanner showed a Max KR of 4 degrees on 93 octane and Max delivered torque of 604lb/ft. Knock learn factor was 0.02
Then after waiting months for weather to cool down I went back to PBIR on Jan 20 with the Haltech CAI. The 60FT was still about 1.70 but 1/8mi at 104 mph and 129 MPH pass in 75F at +300ft. The HPT Scanner showed Max KR of 8 degrees on 93 octane and Max delivered torque of 562lb/ft. Knock learn factor jumped to 2.5. The car picked up about 4 mph in 1/8mi and loss -1 mph on top end. My guess is the leaner AFR picked up ~40hp until the 1/8 but leaned out on the top end slightly and the learn factor lowered timing. The whole time I have own the car, I never disconnected the battery to reset the PCM.
Then on Jan 24 I had another chance to test at PBIR. This time I thought I would try to reset the PCM by disconnecting the battery for 1 minute and try running on a fresh PCM reset. The 60 FT was still 1.70 but 1/8 mi was now 105.82 mph and 132.53 MPH pass in 57 F at -300FT. The HPT Scanner still showed Max KR of 4 degrees like stock but Max delivered torque was now 628lb/ft. The knock learn was back to 0.02.
The Haltech CAI does consistently show an increase over the OEM unit with 4~5 mph gain in the 1/8 and plus 2 mph on the top end with the factory stock tune. There may be more gains using a blend of 93/100 mix to eliminate the 4 degree KR.
Lesson learned, "Reset the PCM when looking for maximum performance at the strip!"
Thank you Jim for a proven product!
Mark
Pretty much exactly what some have been saying. Initial gains are good, then the PCM settles into a low octane table and it pulls power.
S.
I've had the Halltech installed for about 6 months now.
I have no idea if I'm out to lunch on this... But I took my car to the dealer for a number of warranty/maintenance issues (all software updates, alignment, etc), and when I picked it up... it felt noticeably faster than when I dropped it off. Is it possible they reset something in the ECU, making it go back to the high octane tables? The difference was shocking.
I feel like I might need to look into a tune if it really makes that big of a difference.
Jim: I think folks would really like to see some long-term dyno comparisons. I know it's tough to control all variables, but if you annotate temperature and density altitude for each test and attempt to test in comparable atmospherics on the same dyno, I feel like good data could be obtained. Lots of folks are starting to question if intake gains are short-term. I'd love to see the numbers.
@dar02081961 I think what you are asking is can the car learn based on AFR. The answer is yes it can learn and does remember. The car can lean/enrich the AFR based on the narrow band sensors.
STFT (Short Term Fuel Trims) = This item adjusts the fuel based on the most recent sensor information gathered after the car has been started.
LTFT (Long Term Fuel Trims) = This item adjusts the fuel based on an average of sensor information gathered over time and stored for each run event (I.E. start/stop engine).
That should clear up your question.
Thanks for your explanation. However the car (PCM) learns virtually nothing in open loop (WOT).
LTFT and STFT learning is only applied in closed loop when the O2 sensor feed back is being used to trim fuel to attain a desired AFR.
So yes the car learns. But at WOT it does not. The PCM retains nothing from WOT run to WOT run simply because there is no (very little) feed back to the PCM under WOT to be learned and retained.
This is why anyone that truly understands and has studied the operating logic of the modern PCM like yourself knows that any gains from a CAI at WOT will remain.
By the way I am very familiar with you from HP tuners. I am a regular there as well and have been for over 10 years.
Your knowledge of the E92 and other modern controllers is without question.
However this discussion centers around power gains from additional airflow provided from a CAI in open loop (WOT) being learned away over time. I would agree with this if we were discussing closed loop operations. But for this discussion folks admitting that the horsepower is there from the CAI at WOT and then after some period of time the hp just vanishes into thin air because the computer all of a sudden decides it doesn't like the extra air is nonsense.
It's simply a matter of the PCM detecting KR. That's what this is all about. At a certain level the PCM moves to a low octane table and reduces timing, and thus power.
I'm not sure the fact that the PCM has low and high octane tables is in dispute, is it?
S.
No it isn't in dispute. However the explanation you give above is over simplified.
Knock retard is detected within milliseconds. Timing is reduced until knock subsides and then continuously probed and increased until timing is within 1/2 degree or so of the "knock threshold". This probing is called "knock recovery". The PCM doesn't just jump to the lower octane table. It looks at knock and knock recovery over a period of time amoungst other things to determine the car is likely operating on poor quality fuel before going to lower octane table.
If the CAI produces power on day one any knock retard associated with this additional power would have shown up immediately within milliseconds. So any power gains shown are inclusive of the knock retard associated with additional air. It doesn't take the knock sensors days or weeks to figure out the engine is running lean and step the timing back. So this talk of learning away the gains after a few days or weeks is unfounded in PCM logic.
And we must be careful here, many folks make the false assumption that reduced timing always results in reduced power. This is often the case but in boosted engines reduced timing can sometimes actually result in more power. Simply put optimum timing advance varies depending on a lot of conditions. Just because the PCM applies a solution a few degrees less than you would normally see doesn't necessarily mean the engine is producing less power.
Last edited by dar02081961; 01-30-2016 at 05:48 AM.
I believe that only dyno before/after and also after few hundred miles will tell!
I don't buy into that ECM adjustment will take several thousand miles to adjust. If that was the case that will be terrible poor piece of hardware/software where everything else adjust in few tenths of a second!!!! ECM adjustment are done much quicker than that. Opposite will be dangerous for any engine.
Thanks for your explanation. However the car (PCM) learns virtually nothing in open loop (WOT).
LTFT and STFT learning is only applied in closed loop when the O2 sensor feed back is being used to trim fuel to attain a desired AFR.
So yes the car learns. But at WOT it does not. The PCM retains nothing from WOT run to WOT run simply because there is no (very little) feed back to the PCM under WOT to be learned and retained.
This is why anyone that truly understands and has studied the operating logic of the modern PCM like yourself knows that any gains from a CAI at WOT will remain.
By the way I am very familiar with you from HP tuners. I am a regular there as well and have been for over 10 years.
Your knowledge of the E92 and other modern controllers is without question.
However this discussion centers around power gains from additional airflow provided from a CAI in open loop (WOT) being learned away over time. I would agree with this if we were discussing closed loop operations. But for this discussion folks admitting that the horsepower is there from the CAI at WOT and then after some period of time the hp just vanishes into thin air because the computer all of a sudden decides it doesn't like the extra air is nonsense.
Thanks for the HPT props . Yes I was a touch off topic on the fuel side of things, just chipping in on the knowledge . I'm kind of on the fence on this one about loosing power over time (as to spark tables being manipulated by knock learn, burst knock learn). not so much on fueling. I have not yet had a chance to scan my C7 yet, did it change from the Gen 4's? With my '08 C6 if trims were actively adding fuel they would remain locked in from the moment you mashed the gas to go into WOT. So if it is still true then this could be what some people see on the dyno since they are going partial throttle till they reach the gear they want then go WOT. But would not explain a slower 1/4 mile since they should be going from idle to WOT immediately. It's all pretty muddled and puzzling with all these different results floating around
Just finished reading all the entries on this thread, all 4 pages worth. Wow, there is so much information here, for me at least, it is simply overwhelming! Have we reached any kind of consensus to the question...Is it worth spending the money to purchase and install a CAI? Not being a smart *** here, at all. For me at least, I really am confused! Provides more power, yeah but you lose it because the engine relearns, no it doesn't, leans out the A/F ratio too much, no it doesnt, only in cooler weather, etc., etc....YIKES! I have had CAI's installed in a number of my cars over the years and never experience any problems. Some I really believed increased HP (butt dyno), one of them I don't believe it did anything. Please, this is truly my honest question....is the consensus of the talented owners on this thread, that purchasing the CAI is a decent investment for a permanent HP increase of 30-40 HP in completely stock 2016 Z06? And my other question is, is it a decent investment to purchase and install a throttle controller to make the throttle more responsive to the accelerator inputs? Really appreciate everyone's thoughts and hope this doesn't start an argument!!! Thanks...
01-29-2016, 11:30 AM
. Yes I was a touch off topic on the fuel side of things, just chipping in on the knowledge 
