chickenwafer wrote:Eh, you guys just don't get it so I won't waste time trying to explain it anymore LOL. If you guys did your own tuning you would understand....
You don't NEED two different maps....adjusting boost, I can see the advantage of that (I do with an EBC) but you don't need two different maps unless you are running different fuels, which would have to pull over and re-fuel anyways so switching on the fly is pointless....
I already tried explaining but it's a bit like trying to eat a steak with a straw at this point
For most people, I would say you are 100% correct. That's exactly why you tune for load, so that if at 4250rpm if your motor is seeing XXX G/S of air from your MAF instead of whatever value it was seeing whenever it was tuned, your ECU will know the correct fueling algorithm to send the proper amount of fuel. Even tuned for only one preset boost level, as seasons/weather change, your motor is constantly seeing a different amount of air injested. Don't believe me? Log your vehicle's peak WOT GS from your MAF in both 100 degree weather and log again in 15 degree weather, fairly substantial difference. That's why we tune, so that the ECU knows how to respond when we introduce higher/lower loads while driving.
Although for someone like OCD, I can completely understand why he would want separate "maps"/boost settings, mostly just for the boost control aspect. Although you're right, he could just as easily just tune for his peak pressure, and turn down the boost without any negative repercussions. It could be argued that if he wanted to make more power at a lower boost level, he could add more timing, however, that would kind of defeat the point of turning the boost down wouldn't it? Haha. His fuel trims though should be fairly similar if they were tuned correctly, if anything, maybe a tad bit richer.
For someone like myself though, unless I wanted to switch back to 91 octane, having two maps is pointless. I can see OCD's point about detuning the car because he doesn't want his wife getting into trouble/beating on the car ect. Someone like me? My wife doesn't want anything to do with my car LOL!! I don't let anyone else drive it, and almost never take my car to a place where there is valet available haha.
Wanting to detune your car because someone else you don't trust to drive it responsibly/safely I can understand. That makes sense. Wanting to be able to switch maps because you're running a different/multiple fuel sources, I completely understand. If you have a 91 octane map and a 104 octane map, obviously the 104 octane map is going to likely be more aggressive, and will likely result in motor damage on 91 octane, it makes sense to have a separate map for fuel changes. Hell, it even makes sense if you're running meth injection in case you run out, or don't want to use it on the street but still want to drive WOT occasionally (maybe it's a PITA for you to come by, I don't know? lol).
However, wanting to drive around on a "detuned" map for "fuel economy" is retarded in my opinion. Want to know the secret of good fuel economy? Keep your car in CLOSED LOOP/partial throttle. Seriously, there it is folks. Don't know when your ECU is in closed loop? Buy a boost gauge and keep the needle below 0 haha. On top of that, buy a WBO2 gauge, and when it starts going richer than 14.7:1 (+/- 0.5 on average), there's your indicator, you're giving it too much throttle/introducing too much air into the motor, and your ECU is compensating by adding additional fuel/switching into Open Loop programming (read: much richer/more fuel used).
To anyone who is only planning to run 91 octane, and doesn't let anyone else drive their car, for the most part, the ability to change maps on the fly is pointless. Let me break this down:
-Car A is tuned for 10psi peak boost.
-Car B is tuned for 20psi peak boost.
^^^Both are identical in every way except the peak boost settings. Which one do you think gets better gas mileage under CLOSED LOOP driving (very light acceleration, cruising on the freeway, idling ect)? If you chose Car A, you're dead wrong, as they would both get identical fuel economy under closed loop as the ECU would simply try and target 14.7:1 AFR's. Although yes, under WOT/Open loop, Car A would be moving less air, and therefore require less fuel, giving it better fuel economy. As I said before though, the point is, if you want better gas mileage while driving around town, stop driving at WOT. Technically, you could also play with your OL/CL delays, to slow them down in order to try and make up for your lack of pedal control, but I wouldn't recommend that on a turbo car.... it's a recipe for detonation IMO. Want your car to last a long time? Don't beat the shit out of it. Seriously, it's that easy.
If you're at a light and you want to race Ricky Ricer in his Prelude (no comment lol), unless you're running a secondary fuel source (i.e. meth injection or have a fuel cell full of C16 ect) that you want to engage, there should be no reason to change maps on the fly. Like I mentioned above, fuel economy maps are pointless if you just learn to stay out of boost. If you're the type of person that "can't control yourself", and have to go WOT every chance you get regardless of the situation.... IMO, you don't need a secondary map, what you need is to learn a little bit of discipline and restraint. Don't blame the tool, blame the user.
Just my $.02
In other words, if you're worried about fuel economy, stop going WOT.
Nothing is more reliable or consistent IMO. Most tuners worth their salt will tell you the same thing... the only downside is you may lose out on some added "safety" features your ECU may have programmed in to save your motor, but usually a motor will cut fuel prior to cutting boost, so even those are debatable.
