With the kit that we are working on, there will not be much turbo lag. Right now at the boost levels that we are at(5psi), the power band is pretty smooth. The problem that you run into with this car and a roots style supercharger is the amount of heat they produce. On a car with normal to low compression it does not pose a big issue. On the other hand a car like the IS F with 11.8/1 compression we are going to have problems with the heat soak, which will cause detonation on a high compression engine like the one in the IS F. Now you can after cool a roots blower, but again after any amount of abuse it will start to create a lot of heat. So in my opinion an intercooled turbo system is the best forced induction option for this car. Plus a turbo is MUCH more efficient then a supercharger
Now will the FI/C work on a supercharger system? Yes it will work perfect for a supercharged car just as well as it would on a turbo car! If you are really interested in doing a supercharger on the car we would be more than happy to do it, but you need to know the risks and weigh them! I have a great idea for a blower that i would use, if any one really wants to try it!