i was talking to an rx-7 guy here in florida, he told me the best way to get maximum hp for a 1986 n/a is to turn it into a carburated car, taking out the fuel injected system. is this safe and true. also how big of a difference is it in power.

 

that guy that told you that needs to be slaped. There is no way your going to get more power by puting a carb on ur rx.

 

well he told me that is what they do when they race them. well that same guy is rebuliding me engine. hope he knows what he is doing

 

A carb does have its benefits.

 

like?

 

simplicity

 

Yeah, right...What's simpler, tuning a carb by turning a bunch of screws, replacing jets, and adjusting pressure, or simply pressing a few buttons on your fuel injection computer (S-AFC or the like).

To the original poster: stick with the EFI system, and tell your friend he/she doesn't know a damn about what he/she is talking about.

 

Simplifly the engine and get a carb. No more shitty Mazda ECU, and no band-aids like the S-AFC.

 

one good thing is u can get more air flow, and get the plugs just as u want. Yes to keep it at peak u have to change jets with temp change ect.. But a set of webs im sure can flow more air and fuel then a stock fuel system the airflow meter on the stock system is small

 

you can get more power.....obviosly w/ a well tuned carb you are going to net more power, because a) most carbs flow better than the stock efi system and b) you get rid of the afm! So yes carbs have their benefit, but I speak from experience when I say that if you dont know the carb system your getting inside out, dont get it. The efi is way more user friendly and will compensate for changes in atmospheric pressure, airflow (mods) and other **** that you have to tune the carb for. So I would say there is no way in hell I would put a carb on my car....so you shouldnt either unless you really know what your doing.

 

There is no such thing as a "well tuned carb". Carbs are sensitive to temperature, barametric pressure and voodo. Therefore, tuning a carb in one circumstance will completely negate the tuning in another circumstance. The EFI system easily compensates for this via it's sensors.

As for simplicity, it is very easy to simplify the EFI 13B. Loose all the emissions stuff, and suddenly the system becomes very simple, consisting of only the ECU, wiring harness, two fuel rails, injectors and sensors (AFM, temp, O2, intake air, TPS). VERY simple and reliable. Also a lot cheaper to modify the EFI system then convert to carb, wich would require changing out the intake manifold, ignition system, fuel pump, etc.

All things being equal (and pay attention to that!) you will make more power with a properly tuned EFI system then with a properly tuned carb. Period.

Also, the AFM is not a significant restriction until you get some very high power levels. I really wish people would stop spreading the myth about the AFM being the be all and end all of restrictions.

And are you SURE that a carb will flow more then the EFI intake? Even if it does, it is very easy to port out the EFI intake to match. Remember that there is NO WAY to get rid of the restriction in a carb (venturi) as it is a design requirement. The EFI intake can be as wide open as you want.

 

Your right about everything aaron, except when you said that with properly tuning, the efi will make more power. If the carb is properly tuned Im pretty damn sure it will make more power. Its just tougher to tune. Why do many racers use carbs if its itrue that the stock system is more capable of making power?

 

People keep repeating this myth, but have no idea what they're talking about. What kind of carb are you referring to? A small one that's choked and jetted to maintain a good spread of torque but strangles the top end as a result, or a huge one that flows lots of air but runs like a dog down low because of it's size? Power is about airflow, not fuel delivery. If you find a carb that can outflow the stock EFI system, it'll make more peak power. If you can't, it won't. Period. Usually because the rules say you have to.