Hey guys, This is probably going to be a dumb ass question. (history first) I've boosted my zed from 6 psi, to 12psi.(it has an electronic boost controller and the previous owner reset the controller, which is the reason for 6psi). I've boosted it to check for any problems, nothing serious seems to be showing itself. Finally the question, Part A, when i accelerate the car at 12psi, from a set of lights through 1st, 2nd and I think 3rd gear the injectors seem to reach 99% flow? Is this normal? if not, what could be causing it? The air/fuel will dip as far as 8:1. Is this rich or lean? Part B On the highway, 3rd 4th and 5th, same psi It only reaches 70% injector flow? Can I have some enlightenment? Figures provided from the nissan/Apexi multichecker.
It is possible to max out stock injectors at 12psi, would expect larger than stock turbos plus some good exhaust and intake mods though. 8:1 is very rich, even 10:1 is pretty rich, is the ecu chipped or tuned? Does the car have atmo blow off valves and is the richness just happening when changing gears? For your highway figure, are you reaching the same revs as in low gears?
The turbos have been re-cored, not sure if hiflowed etc. Not sure about the ecu, looks like a factory ecu. Standard bovs plumbed back, can go down to 8:1 at full boost full revs(7krpms) it looses traction in this scenario, not on the highway of course. Doing the same rev scale on the highway aswell in 3Rd 4Th, not in 5Th though, way over the speed limit by the time ive hit 5Th. The exhuast is just a 2.5 cat back,,nothing exciting, with a pod filter and factory intake. Will be running a selin dual maf setup soon. Anyone in Brisbane can come drive the car with me and tell me if it feels normal or somethings amiss?
Actually that's a good question. Some widebands (innovate) display 8:1 (from memory) when it detects an error. When I had an LC-1 I had it programmed to display 22:1 when detecting errors.
The stock O2 sensors are not wideband, all they do is tell the computer how close you are to stoic to maintain closed loop while cruising and idling. They are absolutely meaningless for anything else. The 8:1 you are seeing is therefore meaningless also.
You would have to agree though, if the car was leaning out to dangerous levels, it wouldnt be telling me it was an 8:1 ratio. As accurate or not it is, it has to be a general indication of whats actually going on, particularly when the ecu relies on this information to run the engine? Under light boost general driving it goes from 16 - 12 ratio. More to the actual question, its saying my injectors are pretty much maxed out, what are my option's? Should i run a bigger fuel pump? A nistune? Clean the injectors? Etc etc.
The absolute first thing you should do when modifying a turbo car is install a wideband O2 sensor. The narrowband sensors only operate on a very limited range. As said above depending on other mods 12psi can max out the factory injectors. If you're seeing 100% duty cycle at 12psi you need to drop it back to 11psi, etc. Next mod is then injectors and Nistune (or aftermarket ECU).
