[TSloper]

I'll try to explain this. If it is unclear don't be afraid to ask questions.

When GM designed their intake they didn't just go create plastic prototypes and hoped it all worked out. They did a lot of modeling well before a prototype was ever produced. One of the most critical items is to keep the airflow over the MAF sensing element as smooth as possible. If the airflow is turbulent you will not be able to get accurate mass air flow measurements. Ultimately once they decided on a design they had to create a mass air transfer function (i.e. Lookup table) that converts the frequency output of the MAF to a flow rate (i.e. grams/second). If everything is calibrated properly the O2 sensors will add the final minor tweaks necessary to keep the air/fuel ratio where it needs to be.

So on to an aftermarket CAI...

Anything an aftermarket CAI changes from the stock intake can have the potential to upset the airflow behavior over the MAF sensing element across the RPM range and load range. A very slight deflection in the air path or a larger diameter tube can wreak havoc on the MAF output. This will lead to an inaccurate reporting of the actual mass air flow at that moment.

When your fuel trims change in this scenario you can't assume it is because of more airflow. It is likely it is not more airflow. It is likely it is a misreporting of airflow causing the change. How much one CAI changes the trims versus another is irrelevant to determining the performance value. A CAI if designed properly should have minimal changes on the fuel trims. If the air flow is being reported accurately the trims shouldn't change even if more air is truly coming in. Thats the whole point of the MAF. More air less air. It should all calculate out to the proper fueling regardless. If it doesn't something has upset the calibration.

Under WOT you don't have the benefit of the O2 sensors to keep the fueling on track if the calibration gets upset. So a CAI that causes a significant error in MAF output will have a significant error in AFR. This may show up as a power advantage if things lean out a bit but it is not correct. The CAI guys should be providing a recalibrated MAF table for their unit. But they don't because they hide behind the O2 sensors and fuel trims. If you are going to get a CAI you really should have the MAF table recalibrated.

When I get the Roto fab unit I will provide the properly calibrated MAF table on the forum. It really doesn't take that long to do.

[JANNETTYRACING]

Originally Posted by raptor5244

Good stuff. Question, I used to tune my 2002 Z06 a few years back and when I installed my Halltech CAI I saw the fuel trims shift about 7-8% leaner via HP Tuners data logging. I then used that info to tune trims as close as I could back to zero. The question is when you guys are testing or looking for CAI intake gains is it correct to say that a CAI that causes your fuel trims to go leaner than another is better or will makes more power due to the increased airflow? For example, if I slap on my Halltech I saw 7-8% shift in fuel trims but if I reset and slap on another model that showed a 10% shift in fuel trims then is that one better?

Thanks

The shift in fuel trims is not a product of better or worse, it has more to do with how the air crosses the little sample tube in the MAF and the size and shape of the MAF pipe.

[JANNETTYRACING]

Originally Posted by Intimidator

My last questions for T and T....

On the tunes for my GTO and 2012 Camaro, the AFM (4cyl mode) was shut off for maximum performance gains, because "it was not needed" to reach optimum mpg...supposedly when you tuned for performance, you also reached the maximum mpg...is this still the case for the 6th gen?

I'm older, I still check my mileage with a pen and paper! lol
My 84 year old Mother taught me how to do it when I first started driving! lol
Both 970 mile trips down and back were within .2 mpg of each other.

The Whistle is being construed as a by-product of elimination of a factory restrictions and the silencer??, and the noise is now showing and audible because more air is being sucked into the Manifold due to reduced turbulence of those factory restrictions?????

Ted
Do you have a mail order tuner ready yet for the 6th Gen?....my baby is ready for your love!

Again it really depends on Region you live and drive, If you live in the Desert where it is completely flat AFM is your Friend.

If you live where there are hills and it is constantly switching back and forth from 4-8-4-8-4-8 there is no benefit and in many cases hurts economy vs staying in 8 cyl mode.

Where I live here in the Northeast it is beneficial to stay in 8 cyl mode and pull a higher gear, my mileage has improved since I turned of AFM.

The whistle is a product of the factory TB and Intake manifold and is no indication of added air flow or not more like Muffling it or not.

Yes I have Custom tunes available via the SCT X4, AFM off is still standard in my tunes unless you request otherwise.

Ted.

Originally Posted by TSloper

I'll try to explain this. If it is unclear don't be afraid to ask questions.

When GM designed their intake they didn't just go create plastic prototypes and hoped it all worked out. They did a lot of modeling well before a prototype was ever produced. One of the most critical items is to keep the airflow over the MAF sensing element as smooth as possible. If the airflow is turbulent you will not be able to get accurate mass air flow measurements. Ultimately once they decided on a design they had to create a mass air transfer function (i.e. Lookup table) that converts the frequency output of the MAF to a flow rate (i.e. grams/second). If everything is calibrated properly the O2 sensors will add the final minor tweaks necessary to keep the air/fuel ratio where it needs to be.

So on to an aftermarket CAI...

Anything an aftermarket CAI changes from the stock intake can have the potential to upset the airflow behavior over the MAF sensing element across the RPM range and load range. A very slight deflection in the air path or a larger diameter tube can wreak havoc on the MAF output. This will lead to an inaccurate reporting of the actual mass air flow at that moment.

When your fuel trims change in this scenario you can't assume it is because of more airflow. It is likely it is not more airflow. It is likely it is a misreporting of airflow causing the change. How much one CAI changes the trims versus another is irrelevant to determining the performance value. A CAI if designed properly should have minimal changes on the fuel trims. If the air flow is being reported accurately the trims shouldn't change even if more air is truly coming in. Thats the whole point of the MAF. More air less air. It should all calculate out to the proper fueling regardless. If it doesn't something has upset the calibration.

Under WOT you don't have the benefit of the O2 sensors to keep the fueling on track if the calibration gets upset. So a CAI that causes a significant error in MAF output will have a significant error in AFR. This may show up as a power advantage if things lean out a bit but it is not correct. The CAI guys should be providing a recalibrated MAF table for their unit. But they don't because they hide behind the O2 sensors and fuel trims. If you are going to get a CAI you really should have the MAF table recalibrated.

When I get the Roto fab unit I will provide the properly calibrated MAF table on the forum. It really doesn't take that long to do.

Great explanation Tsloper, you are one of very few people who understand fuel trims.

[Intimidator]

Originally Posted by JANNETTYRACING

Again it really depends on Region you live and drive, If you live in the Desert where it is completely flat AFM is your Friend.

If you live where there are hills and it is constantly switching back and forth from 4-8-4-8-4-8 there is no benefit and in many cases hurts economy vs staying in 8 cyl mode.

Where I live here in the Northeast it is beneficial to stay in 8 cyl mode and pull a higher gear, my mileage has improved since I turned of AFM.

The whistle is a product of the factory TB and Intake manifold and is no indication of added air flow or not more like Muffling it or not.

Yes I have Custom tunes available via the SCT X4, AFM off is still standard in my tunes unless you request otherwise.

Ted.



Great explanation Tsloper, you are one of very few people who understand fuel trims.

TO YOU BOTH!
Thank you VERY much...you have made it VERY understandable for someone like myself, that has very basic knowledge!

Ted, I will be in Contact soon...I actually want to see intake testing or someone provide real data before I decide on a final intake for my DD, then get my exhaust, then I will have it tuned!
If possible, all 3 will come from you again.

[Fraxum]

I am watching the Rotofab. Even if I can get 10 real HP with that one it will be worth it since I love the sound. And will there be a Big Gulp option?

Even though I know nothing about fuel trims I do know one way to make your M6 SS faster. Just drive it. In the spring in good air I was happy with a 12.5. Now 4,000 miles later my car is at least a tenth faster I am getting PBs (low and mid 12.4s) in crappy air. Soon I will be loooking at clutches. I know we all want to mod, but it is fun to see what you can do stock. I am still learning. If a CAI helps me I will know it. On my 5th gen 1LE I added a CAI and DRs and gained .5 secs in the 1/4. Mostly the DRs I know, but the sound you get from a CAI is the best part. No need for piping it into the cabin.

Looking forward to Ted's tests. And If it works out I will buy a CAI from Ted. It's only fair. There are a number of good tuners. But Ted shares more than most. Pay it forward.

[JANNETTYRACING]

Originally Posted by Intimidator

TO YOU BOTH!
Thank you VERY much...you have made it VERY understandable for someone like myself, that has very basic knowledge!

Ted, I will be in Contact soon...I actually want to see intake testing or someone provide real data before I decide on a final intake for my DD, then get my exhaust, then I will have it tuned!
If possible, all 3 will come from you again.

Originally Posted by Fraxum

I am watching the Rotofab. Even if I can get 10 real HP with that one it will be worth it since I love the sound. And will there be a Big Gulp option?

Even though I know nothing about fuel trims I do know one way to make your M6 SS faster. Just drive it. In the spring in good air I was happy with a 12.5. Now 4,000 miles later my car is at least a tenth faster I am getting PBs (low and mid 12.4s) in crappy air. Soon I will be loooking at clutches. I know we all want to mod, but it is fun to see what you can do stock. I am still learning. If a CAI helps me I will know it. On my 5th gen 1LE I added a CAI and DRs and gained .5 secs in the 1/4. Mostly the DRs I know, but the sound you get from a CAI is the best part. No need for piping it into the cabin.

Looking forward to Ted's tests. And If it works out I will buy a CAI from Ted. It's only fair. There are a number of good tuners. But Ted shares more than most. Pay it forward.

Thank you gentlemen, I appreciate your support.

Ted.

[raptor5244]

Originally Posted by TSloper

I'll try to explain this. If it is unclear don't be afraid to ask questions.

When GM designed their intake they didn't just go create plastic prototypes and hoped it all worked out. They did a lot of modeling well before a prototype was ever produced. One of the most critical items is to keep the airflow over the MAF sensing element as smooth as possible. If the airflow is turbulent you will not be able to get accurate mass air flow measurements. Ultimately once they decided on a design they had to create a mass air transfer function (i.e. Lookup table) that converts the frequency output of the MAF to a flow rate (i.e. grams/second). If everything is calibrated properly the O2 sensors will add the final minor tweaks necessary to keep the air/fuel ratio where it needs to be.

So on to an aftermarket CAI...

Anything an aftermarket CAI changes from the stock intake can have the potential to upset the airflow behavior over the MAF sensing element across the RPM range and load range. A very slight deflection in the air path or a larger diameter tube can wreak havoc on the MAF output. This will lead to an inaccurate reporting of the actual mass air flow at that moment.

When your fuel trims change in this scenario you can't assume it is because of more airflow. It is likely it is not more airflow. It is likely it is a misreporting of airflow causing the change. How much one CAI changes the trims versus another is irrelevant to determining the performance value. A CAI if designed properly should have minimal changes on the fuel trims. If the air flow is being reported accurately the trims shouldn't change even if more air is truly coming in. Thats the whole point of the MAF. More air less air. It should all calculate out to the proper fueling regardless. If it doesn't something has upset the calibration.

Under WOT you don't have the benefit of the O2 sensors to keep the fueling on track if the calibration gets upset. So a CAI that causes a significant error in MAF output will have a significant error in AFR. This may show up as a power advantage if things lean out a bit but it is not correct. The CAI guys should be providing a recalibrated MAF table for their unit. But they don't because they hide behind the O2 sensors and fuel trims. If you are going to get a CAI you really should have the MAF table recalibrated.

When I get the Roto fab unit I will provide the properly calibrated MAF table on the forum. It really doesn't take that long to do.

Thanks for the great explanation.

[Code 6]

talk to
www.youtube.com/user/Lethalhammer hes been buying different ones and testing them

[laynlo15]

I guess I'm not really worried about if it makes more power, if it does I'm good with that. I also like the looks when I open the hood. The majority of those who are worried about it whistling or make more power won't get a tune or take it to the track. I haven't had mine on the dyno or to the track after my CAI, but it feels stronger and the sound is amazing. If you buy a set of wheels and tires to make it look better you probably won't go faster at the track or on the street, but you'll spend 2000 for wheels and tires, but your worried if you'll will pick up 10 hp and 15 lbs of torque for 400 bucks. I did both and I'm happy with it and when I open the hood after I'm done with my wash it looks bitchin being able to look inside the plexiglass lid to see a nice looking filter instead of a black box from GM. Just think about it. They are all gonna make a few horse and sound good so go for it.

[TSloper]

Man things sure have changed. 20 years ago no one would have installed a CAI for sound or looks. People were porting their MAF housings with a dremel to gain 10 HP. If all show and no go is the bar for what is to be a performance modification then knock yourself out.

[raptor5244]

Originally Posted by TSloper

Man things sure have changed. 20 years ago no one would have installed a CAI for sound or looks. People were porting their MAF housings with a dremel to gain 10 HP. If all show and no go is the bar for what is to be a performance modification then knock yourself out.

Lol, remember when folks were removing the screens from their MAF housings?

[crabman]

Not sure it is entirely relevant but I would pay for something that doesn't lose power but sounds better. I'm old and grew up in a headers and open element air filter world so induction sound matters. Now I'd like to get more power, don't get me wrong. I'm only saying that sound matters.

Just a thought here but who really expects to get much power out of an air filter assembly on a high horsepower car in a CAFE world? It seems to me silly to think that GM would leave that efficiency on the table when they are struggling for every bit of help they can get with CAFE. Consider the fact that C7s in the wild with NPP dyno at exactly the same power on average as those that do not have it despite the 5 rated horsepower. Just saying...

[raptor5244]

In general does the new LT1 have a lot of power left of the table vs the LS series motors? I remember with LS3 cars you could do air intake, long tube headers and tune and folks claimed 50hp gains. Is this the still the case with the LT1 motor considering the new Tri-Y header design plus NPP, etc.? When I modded my 2002 Z06 that had the LS6 motor I didn't notice any really power increase until I cammed it, which is why I won't waste my time and money on simple bolt ons anymore. If I decide to mod again I will go straight to forced induction this time.

[LibertyHill]

Originally Posted by raptor5244

In general does the new LT1 have a lot of power left of the table vs the LS series motors? I remember with LS3 cars you could do air intake, long tube headers and tune and folks claimed 50hp gains. Is this the still the case with the LT1 motor considering the new Tri-Y header design plus NPP, etc.? When I modded my 2002 Z06 that had the LS6 motor I didn't notice any really power increase until I cammed it, which is why I won't waste my time and money on simple bolt ons anymore. If I decide to mod again I will go straight to forced induction this time.

Same here.

The only exception to that rule now seems to be the newer turbo cars like the 335 and S4 where a tune will get you 100+HP and shave a second off your 0-60.