If I have a good tune for a s/c and then remove or lose my s/c belt, will the fuel tuning be way off or will the PCM & MAF adjust the fuel so I don't run rich? Isn't most s/c charger tuning done in the PE tables once the MAF has maxed out?

 

Are you running an FMU and an external timing control?

 

No FMU. Using 60 lb. injectors and an MSD Digital 6 with no external timing box.

 

WOT is usually compensated for that way (if you're using the MAF anyway), but you need to ask your tuner how they set it up to be sure.

You may or may not run a little rich everywhere though since the supercharger puts some load on the engine even at idle, which needs to be compensated for in fueling. However, there should be a different fueling value at the lower load, so who knows. Like I said before, talk to your tuner about it to be sure.

 

How is the PCM compensating for boost? Are you running a 2bar MAP? If there's something (in the PCM or an FMU/retard box) that adjusts fuel + spark based on boost level, you could probably switch back and forth between SC/NA. Of course, if the blower is still in place with the belt removed, it will be a restriction in the airflow.

 

There is not much difference in the tunes other than the timing and PE tables at WOT. Superchargers require a much lower A/F ratio at WOT. Also the timing is retarded in the 95 and 100KPA MAP area for superchargers. I take the belt off and run my ram air on long highway trips with my supercharger tune but I don't go WOT. No problems as long as your running MAF and closed loop.