C5 Air Intake Modifications
Heel & Toe
Joined: Oct 2007
Posts: 18
Likes: 1
From: Helsinki / Florida
Proofs:
http://www.idavette.net/hib/02ls6/page4.htm
The two MAFs, screened and unscreened. That GM has done this for ’02 ought to prompt the folks who’ve yet to do it to older Gen IIIs to remove their screens. Removing the screen and using the ’02 air filter box together gets about 5hp at airflow levels such as the LS6’s.
Image: Author [Click Image for Larger View ]
"GM did what Idaho Corvette Page regulars have been doing for years with MAFs–remove the air flow straightener or "screen". What took them so long to figure that one out? The LS6 is not GM’s only application of that MAF. Any use of it with an air intake duct that curves just before the MAF (typical of most trucks), needs the straightener for the MAF to sense accurately and GM’s conventional wisdom was to leave it in on Corvettes. In part, the essence of the ruthless pursuit of power is whipping conventional wisdom which was, according to Dr. John, "....you gotta have it in there."
With the Corvette’s relatively straight passage between the air filter box and the MAF, the straightener isn’t needed. Juriga told us it wasn’t until the MY02 development that his people looked at that MAF in a Corvette-specific perspective. "The questions we continually ask are: ‘Do we need it?’, ‘What’s next?’ and ‘What if?’
"The low-hanging fruit is gone," Juriga continued, "as far as changes that make more power so you gotta start going higher–you gotta go to the edge. That’s what the Corvette is all about–pushing everything to the edge."
I compressed the net and here's picture of it and how much there is stuff before throttle body. I'm sorry about wrong currency.
Drifting
Joined: Jun 2008
Posts: 1,333
Likes: 32
From: cruising between USA and Canada... SAVE THE WAVE!
I think the argument being missed here is:
if you descreen a maf on a car that had one, a corresponding "tune" would be needed as the way the maf is meant to read the air with the screen has been changed.
It's not a matter of if the screened vs non-screened flows more or less, it's a matter of ensuring that things are paired up the way they're supposed to.
In the article you site, there's a clear mention of a tune that helps with the increased power levels.
The argument that everyone with an '01 or screened maf should chuck the screen fails to address issues with maf properties after the screen removal.
someone with the technical depth may be able to further elaborate.
I do stand corrected but that's my understanding after spending much time debating whether to descreen my '98. My conclusion was - no. Leave it alone.
HTH,
TG
if you descreen a maf on a car that had one, a corresponding "tune" would be needed as the way the maf is meant to read the air with the screen has been changed.
It's not a matter of if the screened vs non-screened flows more or less, it's a matter of ensuring that things are paired up the way they're supposed to.
In the article you site, there's a clear mention of a tune that helps with the increased power levels.
The argument that everyone with an '01 or screened maf should chuck the screen fails to address issues with maf properties after the screen removal.
someone with the technical depth may be able to further elaborate.
I do stand corrected but that's my understanding after spending much time debating whether to descreen my '98. My conclusion was - no. Leave it alone.
HTH,
TG
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I think the argument being missed here is:
if you descreen a maf on a car that had one, a corresponding "tune" would be needed as the way the maf is meant to read the air with the screen has been changed.
It's not a matter of if the screened vs non-screened flows more or less, it's a matter of ensuring that things are paired up the way they're supposed to.
In the article you site, there's a clear mention of a tune that helps with the increased power levels.
The argument that everyone with an '01 or screened maf should chuck the screen fails to address issues with maf properties after the screen removal.
someone with the technical depth may be able to further elaborate.
I do stand corrected but that's my understanding after spending much time debating whether to descreen my '98. My conclusion was - no. Leave it alone.
HTH,
TG
if you descreen a maf on a car that had one, a corresponding "tune" would be needed as the way the maf is meant to read the air with the screen has been changed.
It's not a matter of if the screened vs non-screened flows more or less, it's a matter of ensuring that things are paired up the way they're supposed to.
In the article you site, there's a clear mention of a tune that helps with the increased power levels.
The argument that everyone with an '01 or screened maf should chuck the screen fails to address issues with maf properties after the screen removal.
someone with the technical depth may be able to further elaborate.
I do stand corrected but that's my understanding after spending much time debating whether to descreen my '98. My conclusion was - no. Leave it alone.
HTH,
TG
Anything that you do to the engine to alter the air flow THRU the MAF, will effect part throttle fuel efficiency and throttle response during closed loop operation. Most of the time it's a NEGATIVE effect, meaning you will loose fuel economy and your throttle response will be soft or have a flat spot.
The biggest offender is adding a cold air intake like a VARARAM. They make GREAT power but,,,almost always need MAF tuning to make the MOST POWER!
If you look at your Long Term Fuel Trims before and after the modifications, the AFTER the MOD trims will normally be very positive. When there positive, they cause the air fuel ratios to go very rich.
All in all, you will not gain as much as you think until you retune the PCM. During that tune you correct the MAF tables and the LTFTs get back in the slightly negative region and you get your throttle response, fuel economy and power back.
4th Gear
Joined: May 2010
Posts: 4
Likes: 0
Ah,,,,,Your absolutely correct! Heres the deal and YES,,,Ive been down this road.
Anything that you do to the engine to alter the air flow THRU the MAF, will effect part throttle fuel efficiency and throttle response during closed loop operation. Most of the time it's a NEGATIVE effect, meaning you will loose fuel economy and your throttle response will be soft or have a flat spot.
The biggest offender is adding a cold air intake like a VARARAM. They make GREAT power but,,,almost always need MAF tuning to make the MOST POWER!
If you look at your Long Term Fuel Trims before and after the modifications, the AFTER the MOD trims will normally be very positive. When there positive, they cause the air fuel ratios to go very rich.
All in all, you will not gain as much as you think until you retune the PCM. During that tune you correct the MAF tables and the LTFTs get back in the slightly negative region and you get your throttle response, fuel economy and power back.
Anything that you do to the engine to alter the air flow THRU the MAF, will effect part throttle fuel efficiency and throttle response during closed loop operation. Most of the time it's a NEGATIVE effect, meaning you will loose fuel economy and your throttle response will be soft or have a flat spot.
The biggest offender is adding a cold air intake like a VARARAM. They make GREAT power but,,,almost always need MAF tuning to make the MOST POWER!
If you look at your Long Term Fuel Trims before and after the modifications, the AFTER the MOD trims will normally be very positive. When there positive, they cause the air fuel ratios to go very rich.
All in all, you will not gain as much as you think until you retune the PCM. During that tune you correct the MAF tables and the LTFTs get back in the slightly negative region and you get your throttle response, fuel economy and power back.
I Just read the install instructions for the vararam and it says that it will take 4 runs in the 1/4 mile or some driving at 50-60 mph for the system to reset MAS etc... No mention of 'tuning' Where would a hypertech programmer fit into this equation if VR themselves say it just takes some runs for the car to 're-adjust'?
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Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If your flowing more air the MAF calibration is going to be off. Not all that much that it will cause major issues, Just enough to make the engine run a little rich. Especially in WOT. Yes, some road time will smooth out idle issues and cause your LTFT to normalize (average out the change in Air Fuel Ratio as much as it can. Most of the time it more than the 25% that it can adjust.
You need a tuning shop to fix that issue. Hand held tuners wont do the job.
BC
You need a tuning shop to fix that issue. Hand held tuners wont do the job.
BC
4th Gear
Joined: May 2010
Posts: 4
Likes: 0
vararam water issues?
I've been contemplating a vararam intake, but am a little concerned with water intake, despite the updates and water channeling. I have to drive 180 miles to and from the track... has anybody experienced an issue with this? should i just go with an under the hood cold air intake to play it safe?
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
Almost any CAI will pull in some water/moisture but almost never enough to cause any problems. However, if you are heading toward a stream of water and can't tell how deep it is, turn around! It's not worth the risk.
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
This is not correct. You don't harm anything by removing it.
Proofs:
http://www.idavette.net/hib/02ls6/page4.htm
The two MAFs, screened and unscreened. That GM has done this for ’02 ought to prompt the folks who’ve yet to do it to older Gen IIIs to remove their screens. Removing the screen and using the ’02 air filter box together gets about 5hp at airflow levels such as the LS6’s.
Image: Author [Click Image for Larger View ]
"GM did what Idaho Corvette Page regulars have been doing for years with MAFs–remove the air flow straightener or "screen". What took them so long to figure that one out? The LS6 is not GM’s only application of that MAF. Any use of it with an air intake duct that curves just before the MAF (typical of most trucks), needs the straightener for the MAF to sense accurately and GM’s conventional wisdom was to leave it in on Corvettes. In part, the essence of the ruthless pursuit of power is whipping conventional wisdom which was, according to Dr. John, "....you gotta have it in there."
With the Corvette’s relatively straight passage between the air filter box and the MAF, the straightener isn’t needed. Juriga told us it wasn’t until the MY02 development that his people looked at that MAF in a Corvette-specific perspective. "The questions we continually ask are: ‘Do we need it?’, ‘What’s next?’ and ‘What if?’
"The low-hanging fruit is gone," Juriga continued, "as far as changes that make more power so you gotta start going higher–you gotta go to the edge. That’s what the Corvette is all about–pushing everything to the edge."
I compressed the net and here's picture of it and how much there is stuff before throttle body. I'm sorry about wrong currency.
Proofs:
http://www.idavette.net/hib/02ls6/page4.htm
The two MAFs, screened and unscreened. That GM has done this for ’02 ought to prompt the folks who’ve yet to do it to older Gen IIIs to remove their screens. Removing the screen and using the ’02 air filter box together gets about 5hp at airflow levels such as the LS6’s.
Image: Author [Click Image for Larger View ]
"GM did what Idaho Corvette Page regulars have been doing for years with MAFs–remove the air flow straightener or "screen". What took them so long to figure that one out? The LS6 is not GM’s only application of that MAF. Any use of it with an air intake duct that curves just before the MAF (typical of most trucks), needs the straightener for the MAF to sense accurately and GM’s conventional wisdom was to leave it in on Corvettes. In part, the essence of the ruthless pursuit of power is whipping conventional wisdom which was, according to Dr. John, "....you gotta have it in there."
With the Corvette’s relatively straight passage between the air filter box and the MAF, the straightener isn’t needed. Juriga told us it wasn’t until the MY02 development that his people looked at that MAF in a Corvette-specific perspective. "The questions we continually ask are: ‘Do we need it?’, ‘What’s next?’ and ‘What if?’
"The low-hanging fruit is gone," Juriga continued, "as far as changes that make more power so you gotta start going higher–you gotta go to the edge. That’s what the Corvette is all about–pushing everything to the edge."
I compressed the net and here's picture of it and how much there is stuff before throttle body. I'm sorry about wrong currency.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I've been contemplating a vararam intake, but am a little concerned with water intake, despite the updates and water channeling. I have to drive 180 miles to and from the track... has anybody experienced an issue with this? should i just go with an under the hood cold air intake to play it safe?
Have the C6 VARARAM on my wifes 06 Coupe. No issues there either.
BC
Instructor
Joined: May 2010
Posts: 230
Likes: 2
From: indianapolis Indiana
Team Owner
Joined: May 2006
Posts: 21,473
Likes: 356
From: Palmdale, Ca----- 2009 Cyber Gray 4LT A6 F55 452 RWHP 422 RWTQ- RIP 1998 C5 734 RWHP & 585 RWTQ-----
Dang this is old and got Resurrected! 
Perhaps he will post some other test results from way back then - I wondered what had happened to this Thread!
Thanks,Matt
Perhaps he will post some other test results from way back then - I wondered what had happened to this Thread!
Thanks,Matt
Safety Car
Joined: Aug 2011
Posts: 4,449
Likes: 409
From: Portland OR