Are MAF's worth the money?
03-22-2004, 05:35 PM
#31
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I am happy with my LR MAF. I agree that it did not bring me a lot of peak hp, but it resulted in a better powerband. In low rpms the cars feels much better.
What brings a high peak hp figure with no low end power?
So I think the MAF is worth the money for a better powerband, but does not bring buckets full of extra peak hp.
What brings a high peak hp figure with no low end power?
So I think the MAF is worth the money for a better powerband, but does not bring buckets full of extra peak hp.
03-22-2004, 05:45 PM
#32
maybe a bit late to the party, but...
it seems there is no *fundamental* disagreement here. MAF/MAP system is certainly better than the stock AFM because it represents less of a restriction to the airflow. on its own, it prolly isn't going to net you a huge powergain - this comes from running higher boost and the chips to match.
the thing is, to get more power you want to get more air into the engine. the easiest way to do this on a stock car is to crank the boost and have remapped cihps to match. but beyond a certain point, on the stock turbo (or any other for tha matter) cranking the boost yields negligible performance gains because the turbo is out of its efficiency range and heats up the intake charge too much.
so another way to get more air is to decrease the restrictions in the intake system, and it seems one of the major ones is the stock AFM. moving to a MAF/MAP will net you greater air flow at any given boost level, which will result in more power. or another way, you can get the same power while running lower boost, which is generally a nice thing.
now whether any of this is 'worth' it is a personal choice. for myself, i'm only after modest power gains *atm*
, so a MAF/MAP is probably overkill. but later on, if i move to a new turbo, etc etc, it will probably make sense to upgrade various things to match, and the stock AFM will prolly go at that time. though to be honest, i'm wild keen on stand-alone atm. just trying to think of a way to justify it...always the way, 'i'll just chip it, that'll be fine'...
it seems there is no *fundamental* disagreement here. MAF/MAP system is certainly better than the stock AFM because it represents less of a restriction to the airflow. on its own, it prolly isn't going to net you a huge powergain - this comes from running higher boost and the chips to match.
the thing is, to get more power you want to get more air into the engine. the easiest way to do this on a stock car is to crank the boost and have remapped cihps to match. but beyond a certain point, on the stock turbo (or any other for tha matter) cranking the boost yields negligible performance gains because the turbo is out of its efficiency range and heats up the intake charge too much.
so another way to get more air is to decrease the restrictions in the intake system, and it seems one of the major ones is the stock AFM. moving to a MAF/MAP will net you greater air flow at any given boost level, which will result in more power. or another way, you can get the same power while running lower boost, which is generally a nice thing.
now whether any of this is 'worth' it is a personal choice. for myself, i'm only after modest power gains *atm*
, so a MAF/MAP is probably overkill. but later on, if i move to a new turbo, etc etc, it will probably make sense to upgrade various things to match, and the stock AFM will prolly go at that time. though to be honest, i'm wild keen on stand-alone atm. just trying to think of a way to justify it...always the way, 'i'll just chip it, that'll be fine'...
03-22-2004, 06:18 PM
#33
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Nobody has mentioned that the stock AFM will bottom out at some point of HP increase and make replacement necessary. Unfortunately I do not know at which flow that happens. Anyone?
Bengt
Bengt
03-22-2004, 06:37 PM
#34
Race Director
The flapper barn-door on the AFM hits maximum at about 300-325CFM or about 250-270rwhp. It outputs a fixed 4.6v signal at that point and the computer has no idea that air-flow is increasing afterwards. The MAF & MAP upgrades can go fully up to the 5.0v that's mapped in the chips for higher-flow fueling.
The following are trends that's been documented across numerous cars, so we do know that removing the AFM is worth at least 30-40hp:
AFM @ 15psi stock K26/6 turbo = 220-225rwhp
AFM @ 18psi stock K26/6 turbo = 235-240rwhp
MAP/MAF @ 15psi stock K26/6 turbo = 260-265rwhp
AFM @ 15psi stock K26/8 turbo = 240-245rwhp
AFM @ 18psi stock K26/8 turbo = 270-280rwhp
MAP/MAF @ 18psi stock K26/8 turbo = 310-315rwhp
MAP/MAF @ 18psi K27 turbo = 325-330rwhp
MAP/MAF @ 20psi K27 turbo = 360rwhp
There's no denying that getting rid of the AFM is good for performance. Also the tuning adjustments available with MAP/MAF upgrades allows you to optimze and extract the very last bits power possible from your configuration.
The following are trends that's been documented across numerous cars, so we do know that removing the AFM is worth at least 30-40hp:
AFM @ 15psi stock K26/6 turbo = 220-225rwhp
AFM @ 18psi stock K26/6 turbo = 235-240rwhp
MAP/MAF @ 15psi stock K26/6 turbo = 260-265rwhp
AFM @ 15psi stock K26/8 turbo = 240-245rwhp
AFM @ 18psi stock K26/8 turbo = 270-280rwhp
MAP/MAF @ 18psi stock K26/8 turbo = 310-315rwhp
MAP/MAF @ 18psi K27 turbo = 325-330rwhp
MAP/MAF @ 20psi K27 turbo = 360rwhp
There's no denying that getting rid of the AFM is good for performance. Also the tuning adjustments available with MAP/MAF upgrades allows you to optimze and extract the very last bits power possible from your configuration.
Last edited by Danno; 03-22-2004 at 11:28 PM.
03-22-2004, 08:25 PM
#35
originally posted by the danno meisterAlso the tuning adjustments available with MAP/MAF upgrades allows you to optimze and extract the very last bits power possible from your configuration.
03-22-2004, 08:59 PM
#37
The flapper barn-door on the AFM hits maximum at about 300-325CFM or about 250-270rwhp.
Seems I said that about a page ago...at least I was close to right.
BTW - the APE chips are PERFECT for their application, i.e. NO other mods. Damn good product. The problem is that people like to make crazy mods then blame the chipset because it didnt compensate.
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Seems I said that about a page ago...at least I was close to right.
BTW - the APE chips are PERFECT for their application, i.e. NO other mods. Damn good product. The problem is that people like to make crazy mods then blame the chipset because it didnt compensate.
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03-22-2004, 09:05 PM
#38
Nordschleife Master
Originally posted by mwc951
NZ.......aren't we all "annoying and pointless"??
BTW......I'm a paying member, so I can flame you more now, right??
NZ.......aren't we all "annoying and pointless"??
BTW......I'm a paying member, so I can flame you more now, right??
There's no reason to beat around the bush.
03-22-2004, 09:25 PM
#39
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Danno, I am a bit confused...
and
So for the 26/8, you can acutally max out the AFM?? So then how does your chips kit know how much air is being flowed if you just have a chip set??
TIA for your explanation.
The flapper barn-door on the AFM hits maximum at about 300-325CFM or about 250-270rwhp.
AFM @ 18psi stock K26/8 turbo = 270-280rwhp
TIA for your explanation.
03-22-2004, 10:37 PM
#40
Rennlist Member
2 + 2, let me try to answer that , and then somebody else can correct me.
Your RPM signal that's going into the DME is independant of the AFM, so with different programming of chips you can still make adjustments via RPM even though the AFM might be maxed out.
On the subject of MAF: trying to make more power in an engine is all about addressing the bottle neck in the airflow and some have said that here in a roundabout way. If the demand for more airflow increases and the air metering device happens to be the next bottle neck then that's the component that needs to be upgraded. The trick is to know at what stage your at and what's the next bottle neck; maybe it's the AFM, maybe it's not.
Your RPM signal that's going into the DME is independant of the AFM, so with different programming of chips you can still make adjustments via RPM even though the AFM might be maxed out.
On the subject of MAF: trying to make more power in an engine is all about addressing the bottle neck in the airflow and some have said that here in a roundabout way. If the demand for more airflow increases and the air metering device happens to be the next bottle neck then that's the component that needs to be upgraded. The trick is to know at what stage your at and what's the next bottle neck; maybe it's the AFM, maybe it's not.
03-22-2004, 11:32 PM
#41
Race Director
"Your RPM signal that's going into the DME is independant of the AFM, so with different programming of chips you can still make adjustments via RPM even though the AFM might be maxed out."
Yes, that's correct. The DME uses two variables, air-flow voltage and RPM to look up a 3D table to get fuel-values. Under WOT/full-throttle, it switches to a 2D table that has less weighting on the AFM-voltage. It's still used, but doesn't make as much of a difference as under partial-throttle. And RPM takes on a larger weighting.
I agree with Matt H, the plug-in APE chips are fine if used in exactly the same configuration they are shipped from the factory. That is with their banjo-bolt restrictor rather than an adjustable manual controller. Once you introduce variables that the designers never anticipated, all bets are off.
Yes, that's correct. The DME uses two variables, air-flow voltage and RPM to look up a 3D table to get fuel-values. Under WOT/full-throttle, it switches to a 2D table that has less weighting on the AFM-voltage. It's still used, but doesn't make as much of a difference as under partial-throttle. And RPM takes on a larger weighting.
I agree with Matt H, the plug-in APE chips are fine if used in exactly the same configuration they are shipped from the factory. That is with their banjo-bolt restrictor rather than an adjustable manual controller. Once you introduce variables that the designers never anticipated, all bets are off.
03-23-2004, 12:26 AM
#42
Once you introduce variables that the designers never anticipated, all bets are off.
Except here where everyone and their brother is able/willing to say that their product is crap. Shame because as intended they do a fine job. However, they are what they are. I.e. when used incorrectly not that great. Kind of like prying with a screwdriver. Yep, it works but at some point it will fail since it isnt meant to pry with.
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Except here where everyone and their brother is able/willing to say that their product is crap. Shame because as intended they do a fine job. However, they are what they are. I.e. when used incorrectly not that great. Kind of like prying with a screwdriver. Yep, it works but at some point it will fail since it isnt meant to pry with.
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03-23-2004, 01:15 PM
#44
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Wow. Great posts! I am installing my LR MAF today. I also am installing 60lb fuel injectors because I will be installing the new Super 75 Turbo soon! Sounds like the posts all agree the MAF is best suited with upgrades!
Boost out.
Boost out.
