I have no experience with DFI. As far as how it works, well if you keep the 1 bar map you can only adjust the timing up to 0psi. Any boost above that will use the last reading I believe (the 0psi because the map sensor is maxxed out). Now, people just use timing retards like MSD, Accel, etc. where they are setup to retard the timng per lb of boost the system sees. This works fine, but doesnt give you that fine adjustability. With a 2 bar and rescaling the tables you would be able to make individual timing inputs while on the dyno and adjust it more accurately. This is my understanding how it works and this will be the way I go. I do have an accel ignition system along with the Accel 375 timing retard for sale if interested.

 

I'm going to make the assumption the stock map sensor is actually 1.75 bar like most other speeddensity cars.

The real solution to this problem (and I assume the guy who has the 'real' 2bar boost bin did this) would be to extend the tables beyond 100kpa. Thats what us honda boys did for their boost code (FYI I was into Hondas for a long time and this year got into Fbodys/GM). We just added 5 more columns and expanded the MAP scalars to include positive (aka boost) scalability. If anyone here is familier with the inner workings of the GM rom's, would it possible to just change the column values. IE cut vacuum resolution and change some to beyond 100kpa? Then you could keep the stock 1bar mapsensor, unless of course you wanted to go beyond 10-11psi (where a 1.75bar MAP begins to lose resolution).

I own a 93, so obviously I have a lot more vested interest in speed density operations. Also after owning and tuning turbocharged hondas for many years, tuning speed density is like second nature to me.

I already do the cut injector in half & VE tables trick...

So anyway... if anyone here knows if the column values can be changed, let me know

 

Yes the guy that did it, if he did it, he did extend the tables to 190kpa with the same resolution. He also extended the maf limitation.

he is one of the hptuners owners.

 

How was this done alittle more info

 

Very interesting thread..... chiming in to get a subscribe to this thread.

 

How should i know...

I don't have it.

He even deleted the thread on corvette forum, which i think i have it print or something.

 

I sent tunercat a couple questions about his software. I'm trying to figure out if TC reads the map scalars from the rom, or if TC just 'assumes' Column 1 = 20kpa, Column 2 = 25kpa, etc. If it is infact reading the scalars, thats promising and will make hacking this rom a lot easier.

If I get anything figured out, you can bet I'll post the rom/results free of charge for all on here.. I'm all about ECU freeware.

 

Highlander - how'd the pro-M maf work? I know the stang guys have been using them with great success, how'd your progress work?

I'd be incredible to get the lt1 ecu to read boost and eliminate the MAF issue. Dang... There's also the idea of using the SyTy ECU and piggy-backing it with the stocker, but I dont really like that idea. Easier with one ECU and get it done.

 

I thought about the SyTy ECU, but it all comes back to just hacking the stock code. An ECU is just like any computer, it only does what you tell it to.... must figure out how to tell my stock ECU to do my bidding

 

THe pRO-M maf has its own converter and tuner. I can post pics if you like.

 

The PCM has the increment and the ammount of columns (size of table) and has a starting value, IIRC.

They deleted the posts from KEN from digital corvettes, but i think i have that page saved up somewhere

 

Sorry to bring it back. Did anybody find anything.