Techsalvager

Does anyone know here how to make the secondary afr table useable?
Say I wanted to have map switching on to switch to the secondary afr table because I'm running higher octane fuel.
ms2extra 3.2.1

Braineack

iTrader: (62)

use table switching.

Why would the AFR targets change by the fuel octane?

Techsalvager

I did use table switching but the 2nd afr table doesn't show itself as an option, it is still greyed out.

meant different fuel.

richyvrlimited

iTrader: (1)

But unless you recalibrated your O2 sensor too it'd still read correctly.

As in the AFR is calculated from lambda, so a displayed 14.7:1 when burning petrol (gasolene) which is lambda of 1, will also display 14.7:1 when at lambda and burning pure meth.

So from the user point of view the AFR you're looking at in your tuning software will never change, but the engine will be seeing much different levels of fuel/air.

I'm finding it very hard to explain, but Joe Perez put it very sussinctly in one of his posts.

Braineack

iTrader: (62)

You have to turn the second table on within the AFR settings. Then I'm not even sure AFR targets is a tableswitching option, it's been a while.

I think two timing tables for different octane gas makes more sense, and old and tired msI can handle that simple request.

Techsalvager

I'm aware of this

Reverant

iTrader: (10)

AFR table switching is not an option on the MS2. The second table is there if you want to run different AFRs on the two banks of a V engine (ie a V8), using two different wideband sensors.

richyvrlimited

iTrader: (1)

So what are you trying to achieve then?

Techsalvager

Another fuel map to make use for table switching

Braineack

iTrader: (62)

I still dunno why fueling requirements would change, and why not timing?

Ben

iTrader: (33)

If you're switching between types of fuel, say pump 93 and E85, your fuel (and timing) requirements will change radically. I'm not sure why a simple table switch isn't good enough for the OP though.

Techsalvager

Because the VE table is useless in MAF mode

wolfram

I know this is an old thread, but i too am looking for a way to utilize the second AFR table for pump gas (as opposed to my standard e85 maps). I am currently running e85 on the normal fuel and spark maps, and have table switching enabled for those two (fuel and spark) when i have to put regular pump gas in. The hardware switch i have setup is working great, but i live in Denver and the temps here will vary by 40-50deg and i want to run EGO to make sure i'm close when the temp drops and rises. Is there a way to have this AFR map change with the others? Or even hook up an additional hardware switch to enable it? I'd also like to have my EBC map change as well, as i am running an additional 4-5lbs when running e85. Am i asking too much, or can my MSPNP2 handle that?

triple88a

iTrader: (2)

You will have large problems switching from e85 to gasoline and back on the fly. For example say you're running e85 and u fill up gasoline. For the first 20 miles you'll be stuck somewhere in between where one map is too rich, the other is too lean. Also unless you run until your tank is dry you will be 4-5 % off each switch and it will be either 1 point lean or 1 point rich. If you're looking to switch between e85 on the fly you need a flex fuel sensor. Also when switching from each fuel your afr targets will be way off, same with the cranking maps, same with the enrichments.

wolfram

Only thing that i dont like about the the flex sensor is the vanilla adjustments for adding percentages to fuel and timing. I just got off the dyno and had both fuel and spark tuned for both 91 and e85, so i'd like to use the "tunned" maps instead of just adding 4% timing, and 50% fuel. Plus it doesnt seem linear for cruising compared to boost. For example, at/around cruise i am only adding 15-20% fuel, but at 15psi its almost double. The correct curve doesnt seem linear, but maybe i am wrong, or there is a way to smooth that within the flex fuel settings. I realize the issue of non-pure e85 and non-pure pump gas, but again i mainly am running e85 and the off chance i am putting 91 in the car, my maps are safe to run with a little e85 in the tank, and the tables should be very conservative. However, when going back to e85 and having a gallon or so if 91 still in the tank, i know my tables are at that point going to be a bit too aggressive for the mixture of "diluted" e85. Which i can hold off the pedal for that time period. So what are my options for boost switching and AFR switching for the MSPNP2. I know the MS3 code can run it, but i dont think i can flash my MSPNP2 to a version of the 3 code.

wolfram

So after thinking about it, if i keep my AFR's relative to the lambda value, would it be at least close, by keeping my AFR's on gas settings (14.7) and letting the MS delineate rich/lean based on its voltage reading for both 91 and e85? When i thought about it, the 0-5v readings are linear where 2.5v is stoich (whether its 14.7 or 9.9), and it adjusts up and down, rich and lean, based on low or high voltage. Would this be accurate enough to run openloop/EGO for cruising (below boost)?

triple88a

iTrader: (2)

You want to be in the 16ns with e85 in cruise. That is one of the big issues when running e85, the targets are way off.