When running the hack, how much % can you go UP? I mean right now I'm at -33% at 3000 and 4000rpms (the more I add the more torque I kept getting down low by adding fuel). I know if I add 1-2 more % I could get even better torque down there.

My question is with 440cc's and the afc hack whats the HIGHEST and LOWEST in negative %'s one can go before tripping a code?

 

from all the post I have read, i thought -35% was enough for a cel....guess it's at -33% now...


[Modified by CzanSOHC, 9:21 PM 9/29/2002]

 

Damnit, you saying -33% has already pushed the barrier? I mean have a CEL 24-7 but not a map code, stupid baro code which I don't care about but thats been there since I did the afc hack period, but doesn't affect performance in anyway.

I wanna add more fuel down low poop on that.... need more feedback

 

 

The trim you can use before throwing a CEL depends on how much boost you are running. It has nothing to do with the injectors. I figured it out at one point, exactly, but it escapes me. basically, the MAP normally shows 2.8v, or so, at atmospheric. If you go much higher than that for more than a split second, you will get a CEL. SO, the sensor, itself, tops out at 5v at around 14psi. Therefore you have 2.2v to go from 0-14psi (because it is a 1bar MAP sensor)... if you did a trim of -45%, you can run higher boost than a fuel trim of -30% because that is the percentage of the voltage you are taking out and is stopping you from throwing a code. I think that if you run at -50% to -45% trim you should be able to get the whole 14psi. (though you're pushing the limit of the sensor at that point.)

 

Basically, the LESS fuel you trim out (higher -trim%) the more boost you can run and you will be less likely to throw a CEL. the LESS fuel you take out, the more likely, all depending on boost. how much boost are you running? 8psi? your MAP is putting out around 4v, then...I think...so, I think that the LEAST amount of fuel you could run is -30% trim before you throw a CEL, but if you run more fuel trim you will never throw a MAP CEL. yeah. I was going to write an equation, but it's late and I fucked it up, my bad.

 

eric, i'm using -33% across the rpm, but i'm only able to boost at 7 psi... I could probably bump it up to 8 but sometimes it creeps and spikes to like 9. Thats when it throws a cel. So when i keep it at 7, that gives me some room to spike to 8

 

Basically what your saying is the more boost you run the less fuel you can give.. well damned if thats a flaw in this hack setup.... why would you wanna run more boost and have to keep taking away fuel in order not to throw a CEL is beyound me. I don't know about most people but I sure as hell like to be around 12.0-12.3 a/f ratio in boost, no more and no less....