AFM question
08-11-12, 04:11 PM
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AFM question
is the AFM in the se a 0-5v set up? lindsey racing has AFM to MAF upgrade for the 944 and say it will swap to any car with a 0-5v AFM. does anyone know of anybody doing a MAF conversion?
08-11-12, 10:33 PM
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Some people have tried making their own MAF adapter, but I am not aware of any success.
There really isn't much point in a MAF adapter though. The weak point in the stock RX-7 system is the ancient 1980's non-programmable non-OBD2 computer, not the AFM. Therefore, even if you spend a lot of time and money to replace the AFM with a MAF, it is still feeding information to an outdated computer that is running your engine. The AFM isn't all that much of a restriction and will work for 400hp, but those who have race cars that need as little restriction as possible will use a standalone EMS in Alpha-N mode rather than a MAF sensor. Those who want a lot of power on a street car, drift car, or drag car will usually have a turbocharged engine, and therefore will tend to want a standalone EMS running in speed-density mode with no AFM or MAF at all. I don't know of anybody who really wants a MAF sensor, but if they do, then they are better off using a regular MAF with a standalone EMS rather than using an adapter to try to make it work with the crummy old stock computer.
There really isn't much point in a MAF adapter though. The weak point in the stock RX-7 system is the ancient 1980's non-programmable non-OBD2 computer, not the AFM. Therefore, even if you spend a lot of time and money to replace the AFM with a MAF, it is still feeding information to an outdated computer that is running your engine. The AFM isn't all that much of a restriction and will work for 400hp, but those who have race cars that need as little restriction as possible will use a standalone EMS in Alpha-N mode rather than a MAF sensor. Those who want a lot of power on a street car, drift car, or drag car will usually have a turbocharged engine, and therefore will tend to want a standalone EMS running in speed-density mode with no AFM or MAF at all. I don't know of anybody who really wants a MAF sensor, but if they do, then they are better off using a regular MAF with a standalone EMS rather than using an adapter to try to make it work with the crummy old stock computer.
08-12-12, 01:57 AM
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yeah that makes sense, there are def alot of flaws with early fuel injection, i had an 83 volvo 240 turbo with bosch mechanical fuel injection that was a nightmare. anyway, is there a decently priced stand alone ems? i hear that you can get more power with a carb but i really hate to do that, thats very nascar. no offense to anyone who does that but i dont want to take a technological step backwards. anyway im not looking for 600hp, id really like 200 to 300 reliable hp, i was thinking of a renesis swap with the 6 speed but i dont have the cash and i have a fresh rebuild so im gonna work with what i got for the moment.
08-12-12, 11:29 AM
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Oh, you just wanted more horsepower? Yeah, don't bother with a MAF conversion.
I assume that you have a non-turbo engine?
The easiest and cheapest way to get reliable 200hp is to swap in a turbocharged RX-7 engine of the same series (86-88 = Series 4, 89-92 = Series 5). Above that range, the best bang for the buck would include fuel system upgrades (injectors, pressure regulator, and pump), BNR turbo, piggyback fuel control system, performance clutch, upgraded radiator, and aftermarket exhaust system. However, at this point you would need professional tuning in order to keep the engine reliable. This could take your car all the way up to 400hp with the stock computer and AFM, and still maintain an acceptable amount of reliability. Above 400hp these cars begin to get expensive and time-consuming.
If you want to keep your non-turbo engine, then all you really need is a nice exhaust system. The Racing Beat exhaust systems are very good if you do not want to have a custom system built. You can do other things to make your car faster, such as installing special 6-port sleeves, light flywheel, short shifter, and port the engine. However, if you want more than 200hp on a street car, then I would recommend simply saving your money for a turbo conversion. Anyway, here is an archived thread about how to make a beefy non-turbo engine:
https://www.rx7club.com/2nd-gen-arch...dations-31410/
Carburetors only make more hp if the tuner is oblivious to modern fuel injection technology. Haltech and Microtech make budget standalone EMS products that are popular for RX-7s, or you can make your own Megasquirt. However, if you have a mostly-stock non-turbo 13B engine, these products will not significantly raise the peak hp, although they will significantly help expand the power band and increase the fuel economy when tuned by a professional. If not tuned by a professional, then they may blow up your engine.
Platinum Sprint RE ECU
Microtech EFI
MegaSquirt - Electronic Fuel Injection Computer by Bowling and Grippo ©2010
I assume that you have a non-turbo engine?
The easiest and cheapest way to get reliable 200hp is to swap in a turbocharged RX-7 engine of the same series (86-88 = Series 4, 89-92 = Series 5). Above that range, the best bang for the buck would include fuel system upgrades (injectors, pressure regulator, and pump), BNR turbo, piggyback fuel control system, performance clutch, upgraded radiator, and aftermarket exhaust system. However, at this point you would need professional tuning in order to keep the engine reliable. This could take your car all the way up to 400hp with the stock computer and AFM, and still maintain an acceptable amount of reliability. Above 400hp these cars begin to get expensive and time-consuming.
If you want to keep your non-turbo engine, then all you really need is a nice exhaust system. The Racing Beat exhaust systems are very good if you do not want to have a custom system built. You can do other things to make your car faster, such as installing special 6-port sleeves, light flywheel, short shifter, and port the engine. However, if you want more than 200hp on a street car, then I would recommend simply saving your money for a turbo conversion. Anyway, here is an archived thread about how to make a beefy non-turbo engine:
https://www.rx7club.com/2nd-gen-arch...dations-31410/
Carburetors only make more hp if the tuner is oblivious to modern fuel injection technology. Haltech and Microtech make budget standalone EMS products that are popular for RX-7s, or you can make your own Megasquirt. However, if you have a mostly-stock non-turbo 13B engine, these products will not significantly raise the peak hp, although they will significantly help expand the power band and increase the fuel economy when tuned by a professional. If not tuned by a professional, then they may blow up your engine.
Platinum Sprint RE ECU
Microtech EFI
MegaSquirt - Electronic Fuel Injection Computer by Bowling and Grippo ©2010
08-12-12, 02:59 PM
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ok, i was asking about that cuz they have good results on the 944 turbo, (mine has been sitting on the side of the house in pieces for the better part of 2 years) with the cost of porsche parts and the cost of rotary stuff im seriously considering swaping in either a turbo2 motor or maybe a built 20b and make that my 400-600hp monster (all registerd for the street but not really a street car, beauty of a no emissions testing county) so for the fb i dont really need anything crazy, i mean the car dont weigh a whole lot so it really dont need a hell of alot of power to be fast, i think with some serious suspension work, coilovers, maybe with some ambition an irs swap. and maybe a 6 speed swap (for that extra gear on the highway. its gonna be a daily) would really be more benificial then gobs of power. i did look at haltech's website but everything was for s4 or s5, will an s4 ecu work on a gsl-se? would an 84-85 13b be an s3?
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