Quote:
Originally Posted by ZM2
Thanks johnung
It is confusing. For instance, in the MultiMap Stage 2+ notes that you posted above, why does it have the note that adding more E85 than an E30 mix will not result in more power b/c the OEM fuel pump can't flow enough, when the MultiMap requires an upgraded HPFP?!
What's also confusing to me is if MultiMap Stage 2+ map only contains the Stg 2+ E30 map and the Racegas map, how do I instead set the car up to go between the Stg 2+ E30 map and the Stg 2 93 map, in case I'm somewhere where there's no E85 or Racegas around?
An then of course is the other ultimate question is if you run E40, E50, E60, E85, etc., vs E30, is the map actually providing more boost/timing based on the ethanol sensor? Seems like that's the whole point of this effort, but I haven't seen logs confirming that.
I believe I remember detroitm2 messing with all this before going Ecutek, but I'm not sure.
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Lots of good discussion here i will just add a few things. AFAIK, you can't mix stages on the multimap, right? So you cant do a stage 2 tune in one slot and a stage 2+ tune in another slot. That means even if you have the flexfuel sensor to adjust for varying ethanol on the fly, you will always be on the same stage. Whether or not this means the boost target remains the same i want to see in the logs. I am very curious to see if the tune scales boost with E% or just timing and fueling.
Quote:
Originally Posted by johnung
Yeah, I don't know why more guys don't upgrade their TMAP sensors to 3.5bar to avoid any issues with boost spikes above what the 2.5bar TMAP can handle.
Someone I was reading reminded that bar is a fluid measurement that can vary depending on ambient conditions. I vaguely remember this from HS Physics. So when you hear guys quote that a tune's boost target is Xpsi and the 2.5bar TMAP is Ypsi, it's not always that cut and dry.
When you are playing around with tunes that aren't just very basic it doesn't hurt to upgrade the inexpensive TMAP sensor in the charge pipe so you aren't anywhere near its limit. Just take that variable out of the equation.
I also upgraded the TMAP on the intake manifold because I couldn't think of a good reason not to. And it's a configuration choice right in BootMod3.
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To expand a little bit on what you were getting at, the thing is that the MAP sensor are
absolute pressure sensors, meaning they measure total pressure: atmospheric + pressure in your CP. The DME reports this in the log as
gauge pressure, which basically subtracts out atmospheric pressure so its just reporting your boost or vacuum. So the boost pressure at which a 2.5bar MAP sensor maxes out depends on your atmospheric pressure. Unless you have exceptionally low DA your probably not going to have a atmospheric pressure above 1.01 bar or about 14.7 psi, but there are lots of cases when you have lower than that when at altitude. So in reality the max boost the 2.5bar can read is about 1.5bar, but it's always a function of your atmospheric pressure.