Well I am finally back at it. I fabbed up the braided -6 AN lines to the fuel rails last night and clearanced the PS UCA for the 3" downpipe so that I can better fit the plug wire boots. I also figured out how I am going to hang the downpipes off the engine (this way the only support isn't the turbo exhaust housings) and where the other v-bands are going to go. Unfortunately there is going to be a lot of work involved when I want to service the spark plugs, as pretty much everything is going to have to come off to get to them. I've got the next 4 days of to work on this thing... other than racing the Buick on Sunday.
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If anyone is reading this I am going to bounce a theory out there and see if it sticks:
Tricking the ECM to run on E85 without changing the chip calibrations.
How you ask? By using the simulated narrow band (NB) output of my MTX-L WB02 sensor. The cool thing about this WB02 is you can set stoich to whatever you want via the provided software and the MTX-L will output the NB voltage in the factory favoured 0-1V range. So, if I set the MTX-L for E85 (stoich 9.76:1), during closed-loop operation the ECM will see it as Gas stoich (14.7:1) and attempt to maintain that target air fuel ratio (TAF) because of the output NB voltage still being in the correct scale.
Now, there is a catch as I see it... the stock gas rated injectors, in this case 28pph, will have to be upgraded due to the increased fuel demands of E85. This difference between the two fuels, as a rule of thumb, is 1.47; so the new injectors will have to be around 42pph to deliver the appropriate fuel flow to meet what is being demanded by the ECM to maintain stoich (via the programmed VE table).
And then there is the fun part: WOT. Where (as I understand it) the ECM will switch over to open-loop and then pays little attention to the NB signal for fuel correction. This is where we can tune with rising rate fuel pressure and supplementary fuel systems (ie. propane or methanol injection) to ensure that the TAF is achieved. Here datalogs for RPM, KR, timing and AFR will have to be made to ensure that the engine doesn't go lean; or go boom.
I am using a '91 Camaro Speed Density set up which means no MAF correction to worry about either. This thread sort of confirms my theory:
http://www.delcohacking.net/forums/viewtopic.php?f=7&t=1248#p13623 Finally, I am going to start looking for an appropriate aftermarket DFI setup to use. However, I am still very much in favour of keeping the factory EFI system due to its knock sensing ability.
