I really want an SC on my HE, but probably won't for reliability issues. I'm going to keep weight down by avoiding bumpers if possible, AL BudBuilt skids instead of steel, paying attention to tire weight and limiting size and tread to only what I really, really need. Eventually I may supercharge, but only when it reaches toy status. At that point I'll probably build a motor intended for boost.
Is there a 101 version of an explanation why the 200 series supercharger would need a tune and the 80 didn't?
There could be all kinds of specific reasons but it boils down to can the stock components measure the increased air, including pressure versus vacuum (depending on AFM, MAF or speed density may or may not be capable), do the fuel and ignition tables in the ECU have data to fuel the amount of additional air, do the stock pump and injectors have the capacity, etc. This is anecdotal but it also seems like earlier FI systems had more capacity and flexibility in them, maybe because they were less precise and needed more margin for error? Taking this "less flexible in current vehicles" even further I know that VW and Audi (for example my 2018 VW R), and likely others, no longer directly measure everything via sensors (closed loop) but instead build all the programming/data tables and then rely on fewer sensors. Sort of like eliminating TPMS sensors and using rotational speed of the individual wheels (using the ABS sensors?) to indirectly determine low tire pressure as opposed to measuring tire pressure directly. Cost savings. There's very little flexibility in a system like this because it doesn't have as much feedback/compensation capability, and it is much more complex to backwards engineer/tune.
And finally how much do you care about a perfect tune as opposed to one that will simply not blow up but may do things like decrease life due to over fueling a bit and gas washing the oil off the cylinder walls under certain conditions. And don't trust a standard O2 to tell you this - they are not intended for tuning as they can't measure high and load load well (where you need to be further away from 14.7). You need a wideband.
On my 2FE (bored over 2F with cam, porting, exhaust, bored TB, matched/balanced intake, etc.) conventional wisdom was to decrease the spring tension in the AFM to compensate for the additional air and get the right A/F ratio. I ran a wideband Innovate O2 tied into my in dash PC (wrote the code to display A/F ratio in the front end software that did music, maps, etc) and found that it ran pig rich under load when doing this.
I eventually swapped for a Split Second programmable MAF to replace the factory AFM so that I could program the output voltage to the stock ECU to get the right A/F ratio for the increased displacement from the stock fuel tables. Which way back when the 3FE was designed in the mid '80s had the data in the ECU and enough capacity in the stock hardware to handle the increase (and more, from what I observed).
