Ive been looking at the editable tables in $58rr_v14.xdf and noticed some SA tables that say "premium fuel". How does the ECM determine if there is premium fuel in the tank? Is this through the knock test at startup? Does it actually even try to evaluate the fuel quality of did someone just label it premium fuel?

I also noticed a lack of any highway mode. Is it there just not uncovered? could I incorporate it from another mask?

I am about to make some changes to the tune on my newly aquired 1993 Typhoon. Its running lean on the top end (high 13.xx AF ratio at WOT) and it drives at a perfect 14.7 at cruise with a very light load. I would like it to be more like 15:1 or so for better mileage. 15-16mpg sucks in a small V6 SUV. The mileage is pretty much the same on the highway or in town.

 

Ok $58 is some what different from $8D. No highway mode that I know of, no real injector constant (Closest Thing $58 has is Base Pulse Constant -vs- Desired EGR (F28) at address 040E). $58 Premium Fuel detection algorithms don't work too well... do they even at all...

For $58, you need to know this formula inside and out for your fueling. It is in the P4 Document.
BPW = BPC * MAPP * T' * A/F' * VE * F33C * BLM * DFCO * DE * CLT * F77

I would read these pages.

Ty1295 made these nice posts at syty.net
Fuel Tuning 101
SyTy/SGT - Forums - FUEL Tuning 101

Boost Tuning 101
SyTy/SGT - Forums - BOOST Tuning 101

Code 58 Table Desciptions (The XDF on the front page of NWSTP has all the notes from this page in the description of each table) Also shows the difference between 2 bar and 3 bar tables.
$58 Table Descriptions

Also read the P4 Doc. It goes into more detail on how all the formulas work and what tables it uses.
P4 Doc in HTML (Read the Fuel Control Section)
P4 Doc

P4 Doc if you prefer it in a PDF
http://www.nwstp.com/chips/P4_docs/Turbo_P4_Doc.pdf

Basically $58 you run out of VE values in the Base VE -vs- RPM & MAP (F29)table (address 0422) (responsible for the fueling) at 100kpa (0 PSI) and you need to use the table Base Boost Multiplier -vs- Map (F77) (address 06D0) to handle fuel when going into boost. The short of it, it will take the last cell you are in in F29 table and multiply it by the value in this table to get more fuel.

Those links I gave you will give you a better description of the tables and how they all work in $58.

 

There was a guy who used the EGR function as a "highway mode" I have my *.bin prepared to test it this year. Seach and you will find the info, I made the post


/N.

 

Thanks for the great info.

I will search for that EGR/highway thing too. I hope to increase my mileage to at least 18mpg. I dont think that would be pushing it too hard. Please keep me posted on the results of your highway mode project.

 

The EGR function as a "highway mode" you have to be very careful when using. You can damage your Catalytic Converter when using it since it run on the lean side and can make your EGT run high. There is a post somewhere on www.syty.net about it and I think I linked it in gta324 posts. Just know you might want to put a EGT gauge on your Ty before trying this. I took the T3-22 psi setting of the Ultimate chip I have and tuned it some more. I am routinely getting 17 MPG with that bin without having to run the EGR as Highway mode and that is in traffic no less.

Good tune with more timing should get you some more MPG you are looking for.

 

Yeah I plan to start soon. I was just looking through the xdf to get familiarized with it. My Ty is totally stock. Ive just tuned it up and it is too lean at WOT for sure, with knock too. Ive got to look into my fuel pump next.
My pressure leaks down fast- like in three seconds its zero- so I know the check valve isnt working. It runs fine when not under much boost, and all the plugs looked the same so I have no indications of a stuck/leaking injector.

I just figured while I am tuning I would address the MPG too. I am not planning to go to far leaning it out. I figure low 15:1's should do it. Again, Im not asking for much of an increase- just some. I wont go the EGR/highway mode until I get it tuned normally. Theyre rated 16-19mph so I think a little more MPG is possible with it running optimally as it is.