I have been trying to decide for months now what to go with, turbo or supercharger, I just don't know. I have a 04 Civic SIR and just don't know what will work best. Hints, tips, suggestions tell me what you think.

 

Depends on how you want your power delivery. Generally speaking a supercharger won't put out as much power as a turbocharger because of the parasitic loss it takes to run it. But a supercharger provides a nice flat torque band all over the rev range.

Turbos usually produce the most power but also produce a lot of heat, and generally the powerband doesn't receive an increase in performance till 3000RPM or so.

This can change depending on setup though. A small turbo will spool fast but make less power. A centrigual supercharger will make tons of horsepower but needs to spin high into the rev range before it makes power.

Personally I prefer turbos.

 

Turbos don't produce any more heat than the supercharger. If anything, the supercharger blows hotter air into the engine than any intercooled turbo setup. That is of course if we are talking blower type superchargers. Centrifugal superchargers will be like turbos, except you get some parasitic power loss thrown in there with the lag. They usually don't peak until very late in the powerband, so it is can produce high peak numbers but it is not very effective in creating a smooth powerband.

 

The problem I am having is a very erratic torque curve. It go up steady then just before my VTEC kicks in at 5900 rpm it drops quite a bit then jumps up when the VTEC kicks in. at around 3500 rpm I have quite a loss and I can actually feel it and I don't like it.