types of air metering

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hoshy
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Post Sun Jun 19, 2005 6:46 pm

Ok, so there's AFM, MAF, and MAP. MAP is best for high boost? MAF is a good conversion for throttle response ? restrictionless is best ?

As far as I can tell, at least on my m40, AFM is pretty crap. but are there any disadvantages of the other types of metering or restrictionless? Can you run restrictionless if you're running boost?

My plan was to go Unichip, MAF and 5/6psi but I just wanna get opinions and discussion on otherways.

Cheers dudes :) :cool:
E46 M3 CSL but dreaming of another E30.
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hoshy
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Post Sun Jun 19, 2005 6:47 pm

Ohh, forgot to ask. In a restrictionless setup what sensors do you map on? I can't figure that out!
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Ant
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Post Sun Jun 19, 2005 8:12 pm

MAF
MAP
AFM
variable TPS
02 sensor as closed loop+ accel
K jet type mech

Which is best ?

Speed density provides the most accurate load info, and is cheapest :lol:
Alpha N is the least restrictive but hard to setup and only really used in conjuction with TB's

lets use MSq as an example.

map load via MAP
map accel via TPS
map enrichments via IAT/coolant temp

if using a wideband 02 that can be set with look up maps to ensure a perfecto Stoich mix @ idle, 13:1 AFR for snap accel via TPS rate of opening and corresponding MAP drop ( N/A setup)
the you get into variables like time and PWM/duty cycles of injectors

none of the above is fixed, you can use many other sensor including two extra IAT sensors , one pre IC one post to measure the IC efficiency and again alter maps to compensate.

you can also use dual tables for all sensor inputs if you really wanna go to town.

best system is the one with the most load sites you can map too.

Unichip uses 8x8 tables for fuel and ingnition I believe ?
MSq uses 12x12 for fuelling , all the setpoints are variable so if you had a chronic flatspot etc you could move three locations into a 1k rpm band to improve the situation

do what I did dude, get info on all, realise the potential of all and then spend the :bling:
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M5pilot
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Post Sun Jun 19, 2005 8:28 pm

They all have their benefits and disadvantages.

Mapping without MAF/AFM takes alot of time and skill to get it 100% right. Its very hard to get it to drive as smoothly as a car with an AFM.
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hoshy
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Post Sun Jun 19, 2005 9:21 pm

Hmm, I can see there's alot more reading gonna have to be done here. Any links on differing systems would be cool.

I'd also like to know how the different setups would affect torque, bhp, fuel economy - i.e which is the most efficient.

Ant. phew that was a tough read but I think I understand what you say. I hadn't considered using IAT and I like the idea of knowing the IC efficiency. Have you posted up anywhere the real gory inside boring geek details of what you're doing with yours? I'd like to have a nose if it's not trade secret ;-)

Didn't quite follow this Ant :

"Speed density provides the most accurate load info, and is cheapest :lol:
Alpha N is the least restrictive but hard to setup and only really used in conjuction with TB's "

I had some more questions too but my house mate just came and started talking crap to me (Karma :) ) so I'm off to google efi systems
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Andy335Touring
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Post Sun Jun 19, 2005 10:16 pm

hoshy wrote: so I'm off to google efi systems
Try this :thumb:

http://emeraldm3d.com/ems.htm
Ant
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Post Mon Jun 20, 2005 12:36 am

Good call !

Dave is THE man , excellent info on that site :cool:
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hoshy
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Post Mon Jun 20, 2005 2:04 am

cheers. that's cool, now I need more!!! :)
E46 M3 CSL but dreaming of another E30.