Z06 MAF Center Bar Removal???
Thread Starter
TECH Fanatic
iTrader: (1)
Joined: Jun 2003
Posts: 1,876
Likes: 1
From: Mount Dora, Fla
Z06 MAF Center Bar Removal??? I just bought a Z06 MAF and it has a bar that is 16mm wide that goes right through the center of the MAF. I have a LS1 MAF with Whisper MAF ends on the engine now, that does not have the center bar in it. If you figure the area of the LS1 without the bar and the Z06 with the bar tha Z06 actually has less area. This does not take laminar peripheral flow into consideration which would restrict the Z06 MAF even more. Has anyone cut out the bar on the Z06 MAF?
I've got a 408 and am going with a Fast 90, thus the reason for the 85mm MAF. I'm wondering, if in actuality, the old LS1 MAF will flow more CFM's?
I've got a 408 and am going with a Fast 90, thus the reason for the 85mm MAF. I'm wondering, if in actuality, the old LS1 MAF will flow more CFM's?
Last edited by bigdsz; Oct 6, 2007 at 06:00 PM.
Our bench testing showed that a completely ported MAF (using our Fast Toys MAF ends) outflowed a 85mm MAF with the screens. However, with the screens removed from the 85mm MAF, it did outflow the ported stock size MAF.
Any time you modify the MAF, you will need to rework your MAF PCM table.
Any time you modify the MAF, you will need to rework your MAF PCM table.
i'm using the vinci ends on my stock maf with my 408. had to rescale the MAF table to fix the lean condition from it. so, that says it's flowing more air through it.
if you are refering to the wedge looking divider, you can remove it. personally, i think the whisper ends are going to end up with about the same overall inner diameter as the Z06 MAF has. do you have a way to measure the overall diameter of each one?
if you are refering to the wedge looking divider, you can remove it. personally, i think the whisper ends are going to end up with about the same overall inner diameter as the Z06 MAF has. do you have a way to measure the overall diameter of each one?
Thread Starter
TECH Fanatic
iTrader: (1)
Joined: Jun 2003
Posts: 1,876
Likes: 1
From: Mount Dora, Fla
I figured the modified LS1 MAF that I have on the car now at 75mm. I'll pull it off tomorrow and mike things.
A friend of mine asked about the LS7 MAF, which never occured to me. Has anyone tried it, and I wonder the diameter is.
A friend of mine asked about the LS7 MAF, which never occured to me. Has anyone tried it, and I wonder the diameter is.
I wouldn't get so hung up on "CFMs". That's marketing
hype type numbers, they look good and mean nothing.
This is because your motor is a fixed displacement
pump and moves a fixed amount of air naturally, from
which you only see a short-fall varying with components.
What you really need to know, is your BARO (outside
pressure) and your big-end MAP (manifold pressure).
BARO-MAP is where it's at. (BARO-MAP)/BARO is your
percent of not-realized horsepower.
The thing is, when vendors talk about CFM it's CFM at
an inch or three of water. That's like 0.25%, an inch of
water is, of atmospheric pressure. So if you rate flow
at 500CFM @ 2"H2O that means, at 500CFM the piece
is costing you 0.5% of ideally-realizable output. So
swap it for a 1000CFM piece and knock that 0.5%
down to 0.3% for a big 0.2% gain? Yeah.
If you do arithmetic for a hobby you can kind of back
meaningful pressure-drop numbers out of the brag-CFM
but if you start with that you'll buy a lot less stuff.
Good for you, bad for them. Not easy though to get
the test conditions out of the blurbs, usually, though,
so you have to assume they stuck to "normal" basis
(whatever that may be for EFI air-side plumbing).
Upping the "H2O testpoint is an easy way for them
to make their stuff look better, for free.
My take, if it's a 1000CFM machine then it'd help but
by then the meter is off the scale and you're done
with MAF based control. So fuggedaboudit.
hype type numbers, they look good and mean nothing.
This is because your motor is a fixed displacement
pump and moves a fixed amount of air naturally, from
which you only see a short-fall varying with components.
What you really need to know, is your BARO (outside
pressure) and your big-end MAP (manifold pressure).
BARO-MAP is where it's at. (BARO-MAP)/BARO is your
percent of not-realized horsepower.
The thing is, when vendors talk about CFM it's CFM at
an inch or three of water. That's like 0.25%, an inch of
water is, of atmospheric pressure. So if you rate flow
at 500CFM @ 2"H2O that means, at 500CFM the piece
is costing you 0.5% of ideally-realizable output. So
swap it for a 1000CFM piece and knock that 0.5%
down to 0.3% for a big 0.2% gain? Yeah.
If you do arithmetic for a hobby you can kind of back
meaningful pressure-drop numbers out of the brag-CFM
but if you start with that you'll buy a lot less stuff.
Good for you, bad for them. Not easy though to get
the test conditions out of the blurbs, usually, though,
so you have to assume they stuck to "normal" basis
(whatever that may be for EFI air-side plumbing).
Upping the "H2O testpoint is an easy way for them
to make their stuff look better, for free.
My take, if it's a 1000CFM machine then it'd help but
by then the meter is off the scale and you're done
with MAF based control. So fuggedaboudit.
Last edited by jimmyblue; Oct 7, 2007 at 01:51 PM.
Thread Starter
TECH Fanatic
iTrader: (1)
Joined: Jun 2003
Posts: 1,876
Likes: 1
From: Mount Dora, Fla
Thanks Jimmy, so I guess what you are saying is to use the Z07 MAF on my 408 even though the area of the opening is slightly less than the area of the opening on my LS1 Whisper end MAF. And I shouldn't remove the bar on the Z06 MAF, right?
What about the LS7 MAF any experience with that? Thanks
What about the LS7 MAF any experience with that? Thanks
Trending Topics
If you leave the Z06 you get to use or mildly tweak a
GM stock table from that platform. Remove the vane
and all bets are off. Though, I can see if you had a
stock reference MAF and frequency meters, you
could port it slowly until you got to general agreement,
ported 85mm will come up toward stock airflow/freq as
you remove material. There's no guarantee, and low odds
that you'd totally match more than a couple of points
on the curve. But worth a try maybe if you've got the
gear and the spare time.
First order, though, if your MAP reading at redline is not
below 98% of your midband WOT MAP then all the intake
tract is "good enough". Only if it's fading more than that,
do lid/MAF/hose/TB have any big 2% contribution to offer.
GM stock table from that platform. Remove the vane
and all bets are off. Though, I can see if you had a
stock reference MAF and frequency meters, you
could port it slowly until you got to general agreement,
ported 85mm will come up toward stock airflow/freq as
you remove material. There's no guarantee, and low odds
that you'd totally match more than a couple of points
on the curve. But worth a try maybe if you've got the
gear and the spare time.
First order, though, if your MAP reading at redline is not
below 98% of your midband WOT MAP then all the intake
tract is "good enough". Only if it's fading more than that,
do lid/MAF/hose/TB have any big 2% contribution to offer.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo Thread Starter
TECH Fanatic
iTrader: (1)
Joined: Jun 2003
Posts: 1,876
Likes: 1
From: Mount Dora, Fla
This is confusing, is manifold air pressure, from the sensor on the back of the intake a Tech 2 reading or LS1 Edit? Really all I'm trying to figure out with out having alot of dyno and tuning time which adds up, am I better off keeping my modified LS1 MAF or going with the Z06 MAF and not removing the "vane"?
The modified LS1 MAF has more open area, but if I understand you correctly, that is not the real, valid parameter in evaluating MAF flow, and ultimately performance. Thanks
Also any comments on a LS7 MAF would be appreciated.
The modified LS1 MAF has more open area, but if I understand you correctly, that is not the real, valid parameter in evaluating MAF flow, and ultimately performance. Thanks
Also any comments on a LS7 MAF would be appreciated.
FormerVendor
Joined: Dec 2001
Posts: 2,444
Likes: 2
From: WWW.SPEEDINC.COM
IMO no maf should be hacked up or ends replaced. Nevermind not having an accurate maf table, the worst part is the loss of repeatability. (maf readings will no longer be consistent from run to run) On most setups it is not a restriction, but if it becomes a restriction it should just be tuned speed density.
