MAF swap
07-22-2013, 11:54 AM
#7
Junior Member
Join Date: Dec 2006
Posts: 191
Total Cats: 8
If my research is correct the RX7 swap is because the AFM has the same response curve as the miata's AFM, and since it's larger, it sucks less. I wouldn't think you could just drop a random MAF in and expect the OE ECU to be able to use it. Especially since the AFM's run 5-0v vs. 0-5v of the normal MAF sensor.
In a turbo miata, I wouldn't look twice at anything other than Speed Density, but riddle me this, why does MAF suck for a non turbo motor? And if it sucks so much why does basically every manufacturer use it?
For the record, I'm running SD on mine, but considering MAF if/when I go to individual throttles and big cams.
In a turbo miata, I wouldn't look twice at anything other than Speed Density, but riddle me this, why does MAF suck for a non turbo motor? And if it sucks so much why does basically every manufacturer use it?
For the record, I'm running SD on mine, but considering MAF if/when I go to individual throttles and big cams.
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07-22-2013, 11:57 AM
#8
Senior Member
Join Date: May 2011
Location: Pennsylvania
Posts: 1,112
Total Cats: 35
If my research is correct the RX7 swap is because the AFM has the same response curve as the miata's AFM, and since it's larger, it sucks less.
In a turbo miata, I wouldn't look twice at anything other than Speed Density, but riddle me this, why does MAF suck for a non turbo motor? And if it sucks so much why does basically every manufacturer use it?
In a turbo miata, I wouldn't look twice at anything other than Speed Density, but riddle me this, why does MAF suck for a non turbo motor? And if it sucks so much why does basically every manufacturer use it?
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07-22-2013, 12:05 PM
#9
Junior Member
Join Date: Dec 2006
Posts: 191
Total Cats: 8
every manufacturer USED to use them frequenly...... not seen so much now. and if they DO have them, its usually the heated wire style MAF, rather than the "flapper box" style AFM. I havent seen a flapper box style in a while.... I also do NOT claim to have seen the engine compartment of every car ever either... so maybe some still DO use them. IDK. haha
I'm pretty sure most still do. The only ones I could find that DON'T are the new ecoboost and the Hemi. Dodge does have a history of using speed density.
Agreed on the AFM/flapper boxes. They're LONG gone. But MS and most to all aftermarket ECUs will run a hot wire MAF.
I know MT's groupthink is that MAF's are bad and SD is the only way to go, but I'm just not convinced this is 100% for 100% of miatas.
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07-22-2013, 12:08 PM
#10
Senior Member
Join Date: May 2011
Location: Pennsylvania
Posts: 1,112
Total Cats: 35
If my research is correct the RX7 swap is because the AFM has the same response curve as the miata's AFM, and since it's larger, it sucks less. I wouldn't think you could just drop a random MAF in and expect the OE ECU to be able to use it. Especially since the AFM's run 5-0v vs. 0-5v of the normal MAF sensor.
In a turbo miata, I wouldn't look twice at anything other than Speed Density, but riddle me this, why does MAF suck for a non turbo motor? And if it sucks so much why does basically every manufacturer use it?
For the record, I'm running SD on mine, but considering MAF if/when I go to individual throttles and big cams.
In a turbo miata, I wouldn't look twice at anything other than Speed Density, but riddle me this, why does MAF suck for a non turbo motor? And if it sucks so much why does basically every manufacturer use it?
For the record, I'm running SD on mine, but considering MAF if/when I go to individual throttles and big cams.
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07-22-2013, 12:22 PM
#14
Junior Member
Join Date: Dec 2006
Posts: 191
Total Cats: 8
I guess that's what I/we/you get for having a MUCH better signal to noise ratio vs. CR or m.net. The occasional oddball like me, ski_lover and hingstonwm shows up.
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07-22-2013, 03:12 PM
#15
Hot wire MAFs are awesome. I love hot wire MAFs. The effort to reward ratio for putting a good GM maf into a car that didnt have one is too high for me. It lets me have marginally more accurate fueling and spark but requires extra wiring and more time devoted to dialing in transient fueling, and none of the affordable tuning options support transient spark which is kind of important to have in a maf car.
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07-22-2013, 09:28 PM
#16
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Thread Starter
Join Date: Jul 2013
Posts: 31
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From what Ive read their is a little to gain on the top end with a larger MAF over the stock on my 97 as the flow of the stock is limited due to the size. The MAF is a hot wire as is the ford version. This car is a track toy and spends most of its time 4k-7k rpm so anything I can do to help the top end is a good thing. I am not afraid to experiment so if their is any merit to the idea at all I will give it a shot. One day Ill probably just swap a v6 in it but till then Ill experiment and have fun doing it. If it wasn't fun I would find something different to do. Im not a purest and love the thought of cheap grassroots upgrades.
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07-23-2013, 08:13 AM
#18
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Join Date: Dec 2006
Posts: 191
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From what Ive read their is a little to gain on the top end with a larger MAF over the stock on my 97 as the flow of the stock is limited due to the size. The MAF is a hot wire as is the ford version. This car is a track toy and spends most of its time 4k-7k rpm so anything I can do to help the top end is a good thing. I am not afraid to experiment so if their is any merit to the idea at all I will give it a shot. One day Ill probably just swap a v6 in it but till then Ill experiment and have fun doing it. If it wasn't fun I would find something different to do. Im not a purest and love the thought of cheap grassroots upgrades.
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