Oh, I know that
But I was just using that as an example, because below 4k rpm and not at full throttle the ECU tries to keep the AFR at 14.7
AFC-SplitSecond PSC1 Map Library
- Thread starter lcruz64
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Oh, I know that
But I was just using that as an example, because below 4k rpm and not at full throttle the ECU tries to keep the AFR at 14.7We've established that by now
What we haven't established is the fact that the supermap doesn't make sense based on those values. If a lower number means less fuel, then how can a value of 9.9@2psi@3000rpm add fuel, which is the case of the supermap? As soon as the pressure hits 2psi below 4k rpm the AFR jumps down to ~12s from the stock ~14.7.Hey guys im new to this site and i been looking for help but theres none to be found. Please anyone with a map that can help me. I live in florida (Naples) This are my mods. GT 28rs boosting 10psi, Vibrant exhaust with deleted cat, SS A/F 1, SRI, Walbro fuel pump, Perrin FMI, hks BOV. Please help me guys.
slo03.5msp
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- 03.5 yellow msp
Does anyone know how to set up the afc to tune vaccum as well?
It's because the AFC is kicking the car into open loop as soon as it sees over 1 psi of boost. Without the AFC the stock ECU kicks into open loop around 4000 RPM I believe. From what I understand when the car is in open loop it is just dumping fuel without any sort of feedback loop like while in closed loop. The AFC tricks the ECU into going into open loop because it is easier to tune the car in open loop (no feedback from the ECU) than in closed loop. The stock ECU has pre-set fuel MAPs for open loop probably throughout the RPM range. The 9.9 supermap setting is actually leaning out the stock ECU's open loop map for 3000 RPM based upon the the pressure it is seeing (I'm not sure if the stock ECU uses a MAP sensor anywhere). Yes, stock is ~14.7 at 3000 RPM because it is still in closed loop mode and therefore basing the fuel map off of the readings from the MAS and primary O2 sensor but in open loop the AFRs at 3000 RPM are probably much, much richer. You can check this by getting high in the RPM band without going into boost - around 4000 RPM or so the AFRs will dip really, really rich.We've established that by now
Is this making any sense? I kind of feel like I'm rambling on a little.
The AFC has a built-in voltage clamp which works like a FCD in certain situations. I have been running 10 psi for a while now but still fuel cut occasionally at very high RPM (not the limiter but more around 6500 RPM) on cooler days and I have also hit fuel cut due to "MAS voltage too high" because of my relocated MAS (and some other issues). I know come people were fuel cutting around 12 psi and I figured that would be because of the injectors so I would say that isn't your problem. Where does it hit? Could be a dirty MAS. Dirty injector?
Your theory makes sense and is probably correct. However, the open loop pre-set AFRs are ~15 anywhere from 2k-3.8k RPM at which point it drops to ~9 anywhere from 4k-5.2k at which point it jumps to ~11. This was dyno and wideband tested on my car, but i'm sure it's the same for every untuned msp. Which brings us back to the same dilema
According to Split Second, a value lower than 10 should technically lean the AFR out which is the opposite of what's happening @ 2psi @ 3k rpm.That's good to know - I do not know the stock ECU's open loop fuel Maps. What you say makes sense but that's all I've got. I know the AFC does some weird things with these cars. Unfortunately I didn't have anything to datalog the AFRs on my P5 before the AFC and I don't reall remember them (although an old, pre-AFC dyno confirms what you've said). The only other thing I can say is that I didn't think the ECU would kick into open loop before ~4000 RPM (could be 3800 like you say) at any throttle position. For instance, I know it will go into open loop independent of throttle position above 4000 RPM (I forget the exact number my car does it).Your theory makes sense and is probably correct. However, the open loop pre-set AFRs are ~15 anywhere from 2k-3.8k RPM at which point it drops to ~9 anywhere from 4k-5.2k at which point it jumps to ~11. This was dyno and wideband tested on my car, but i'm sure it's the same for every untuned msp. Which brings us back to the same dilema
I hit fuel cut at 5500rpm almost every time when I'm boosting 10psi. I've alo relocated my MAF, so I guess that may be the problem. I'm going to put it back into the stock location to see if the problem still persists.
As you probably know, I was using the MSP as an example. The P5 has a different open lool fuel map. I'm probably going to try using the AFC as an additional fuel injector controller with two extra injectors running a P5 ECU since the stock injectors are maxing out at 10psi for me.
Well actually I do have a MSP ECU
now whether it's flashed or not is a different story. What you're describing sounds a lot like how Kooldino recommends using the MPi. I've thought about doing something like that as well but the timing of the P5/LX/DX/ES ECUs scares me a little. I've been running 10 psi for a while now and I contribute that to the more conservative timing with the MSP ECU. Either way, definitely let us know how that works as that would solve a lot of problems with maxxing out the MAS on relocated setups. The only thing I fear with that setup is that even the P5 ECU maps go really lean up top.The different number correspond to the boost pressure in which the AFC kicks the ECU into open loop. The AFC works by tricking the ECU to believing it is in open loop where it is much easier to tune (no feedback loops controlling air/fuel ratios). By using the "over pressure" option you are telling the AFC exactly at which pressure you want this to happen. So set at 1 psi means that as soon as the AFC's MAP sensor sees 1 psi of pressure it will kick the car into open loop and start to manipulate the air/fuel map based on what is tuned into the AFC. A value of 7 means the AFC won't take over until it sees 7 psi of boost. Alternatively you can also enter negative numbers to tune out of boost (theoretically you should be able to set it at like -20 and then tune the entire RPM range similar to manner of a complete standalone).
