I was just wondering about this, Has anyone tried adding some unleaded race gas (103 octane) and swapping out a smaller pulley that adds 1-3 more pounds of boost? Would this be a safe bet with a "stock" supercharger set up. i.e no standalone or injectors or vafc. Coming from a turbo car, I was able to bump boost up signifigantly with race gas and was wondering if this was possible with the s2k.

 

The problem is these kits out of the box run to lean. Adding high octane and increasing the boost will not correct but only intensify the problem.

 

jeez, how about with just a vafc, or do you have to get bigger injectors before you even think about upping boost?

 

It is my belief that a VAFC can "remove" fuel, but it has a tough time "adding" fuel, making it a poor choice to correct a lean condition.

 

Let's say you swap to a 9psi pulley, and still use the Vortech 10:1 FMU. The fuel pressure in the rail at max boost will be 9X10+55=145psi.
Considering stock fuel injector spray pattern starts getting iffy over 70psi I don't think this is the greatest idea.

A stock Vortech kit runs 125psi of fuel pressure at max boost. Most of them run a bit lean stock. (13-13.5:1 AF ratio) If you want to up the boost, you will need to upgrade to sme other engine management that can add fuel.

A VAFC can add fuel indirectly by modifying the MAP sensor input to the PCM. You can not give the PCM a MAP sensor signal that is in boost, the PCM doesn't understand a boost pressure. This is why you can't add fuel with a VAFC on a FI car.

AEM ems, or a Greddy emanage are the 2 options most go with. The Greddy is still a piggyback controller, and doesn't give you the tuning ability of the AEM.

 

Gotcha, Thanks for the great info.