Good creative thinking, but unfortunately not correct.

The (OBD0 anyway) Honda ECU triggers open loop when TPS is above 4.0 volts or when there is a rapid enough change in MAP volts from change in manifold pressure. Monitoring O2 volts I see a smooth transition from close loop switching to full rich open loop when I increase my TPS from 15% to 20% - I have a very small turbo and it spools at highway speeds from minor throttle angle changes.

I'm also sure that it is ignition related and not closed loop to open loop transition (on top of the fact I don't have said problem after fixing my ignition maps ) from experimentation with ECU settings. I've severely richened my ECU's fuel maps (direct alteration of the ECU program, not AFC adjustment) for experientation purposes and even when in closed loop you dwell on the extreme rich mixture between closed loop correction pulses - it is very noticeable compared to a stock fuel map.

 

I should have datalogs to back this supposition up in a week or two. I just have to fab the TTL<-->RS-232 cable to interface my ECU to my PC, get an AC/DC inverter, and get off my lazy @ss and stuff my PC in the CVRX.

Anyone with an el cheapo laptop? /me sighs.

 

no problems with the vafc wercs great .. but sold it today and im replace it with the greddy emanage... any of you running this and what can you tell me

 

i almost got the eManage, but i'll be running the hack setup instead. Dyno tune in March!

 

By 'chip', do you mean a generic 'performance' NA ECU chip, like the "Mugen", "JUN", XS, Top Fuel, etc. Like running that AND the AFC hack? Since most of those chips adjust fuel/ignition, as well as play with open loop, I thought that's what you were referring to (since someone above said he has a Top Fuel chip and the AFC hack and has no bucking problem).

Or do you mean "chip" as in ditching the AFC "hack" altogether and adding one of the Filetofit style "hack chips"?

Also, is it possible to use both the filtofit hack chip and the AFC? I know what the basic hack idea do, and you would not use the AFC for the major MAP voltage adjustment. The 'main' hack adjustment would come from the hack chip in the ECU (which of course also allows boost timing retard). But you lose adjustability with the static ECU chip; many people have found that there's no one best value for the hack %, and you have to "tweak" the % at idle or at certain spots. So what you would do is have the AFC at or about 0%, but you can adjust it a few more % here or there as need be (without having to burn a whole new hack chip with the different values).

I think this would give the best of both worlds - proper fueling for 450cc injectors, no bucking from the AFC, boost retard, as well as all of the normal features the AFC provides (adjutment on the fly, VTEC control, data recording, digital readouts for boost pressure/sensor checks/rpms etc. Basically this would be as close to the ultimate ghetto Hondata as you can get.

But first we would obviously have to see if it would work. It's possible the MAP values would be so screwed up by the time it ran through the AFC and ECU hack chip that it may cause more problems than it solves.

What do you think?

- Slater

 

Can someone explain the VAFC hack to me???

 

i thought bucking problem only occurs in OBD0 ecu since it requires 2 o2 sensor, 1 for cyl 1/4 and the other for cyl 2/3. in my experience, when i did my swap, i had the two wire backward and the car was bucking really bad at part throttle. after i switch the wires it ran perfect, but then one of the o2 sensor went bad so i ran both o2 wires from ecu to one good o2 sensor and it started to buck again but not as bad as when i had the two wires backward ( all this was before boost). after i was boosted, i only used one o2 sensor because there's no sence using 2 o2 sensor in the same place. i just hooked both wire into one sensor and it bucked like before. i then bought a turbo chip on ebay, i dont have any specs on it reguarding fuel and ignition, i just know that it's made for pr3 ecu and design for 8psi of boost. i'm using that chip now with my vafc hack and the car bucks a little but not as bad as the oem chip, i just try not to let off the gas as much as possible. i also think that the chip eliminate close loop because i dont see the a/f meter bouncing back and forth during idle or crusing speed.

 

You purchased pirated Hondata code.