The old debate of superchargers vs. turbochargers has once again showed up, and unfortunately information was posted in another vendor section and we do not post in other vendors sections. So we figured it would be best to just get a common thread going on in a public place again, where anyone can post up what they feel.
There is this comparison that was written awhile ago between turbos and superchargers - Dave @ DDM Works Supercharger and Turbo Info
Even with that being said, some people seem to still think that one form of supercharging (yes a turbo is a form of supercharger) is better than another for everyone, this is simply not the case. The term "better" is a relative term and that being said, will mean different things to different people. All forms of supercharging have their pros and cons, anyone that will tell you otherwise is either highly misinformed or purposely misleading others.
Here are some quotes from another thread -
Turbocharging's extensively more adaptable and adjustable range of power levels offers the enthusiast many options, from upgrading to higher power levels later, to using the infinitely variable nature of turbocharging's boost levels to adapt power flow on the fly. With turbocharging, we can build a complete curve of power levels available on the same vehicle, whereas supercharging is limited to one fixed, pre-set power level which requires mechanical changes to alter.
In a turbocharged machine, we can not only enjoy multiple boost/power levels at the flick of a dash switch, we can also automate them to automatically reduce power at lower speeds so as to enhance traction in the quite traction-limited environment of the Slingshot. We can therefore completely manage power to suit available traciton, whcih improves with vehicle speed. Our history of world records and championships in such disciplines has empowered us greatly to authoritatively manage this aspect on Slingshot. Supercharging offers no such capability.
Further to the versatility of tubocharging, the Precision turbo we use is effective all the way out to 520 engine HP. Should one ever need to exceed that, numerous other Precision models exist that will bolt-in and go."
Once of the cool things you can do with turbochargers is offer adjustable boost levels with the addition of a electronic boost controller. We have yet to see anyone really make use of this on the Slingshot effectively. In fact with a good electronic boost controller, we have setup different turbocharged engines to have 3 different boost levels that are instantly switchable, which is a neat option. The reason this can be done is that the air flow of the turbocharger is not directly linked to engine RPM, so therefore you can adjust boost levels by controlling the wastegate and create a setup like that. The belt driven supercharger is just hooked directly to the engine and boost is linked directly to engine RPM, so with a belt driven supercharger, you simply adjust the boost level on the fly with your accelerator pedal. As to which way is more "versatile" would depend on the driver and what they like.
A gear depended boost controller is also a neat option and In the past, maybe having gear dependent boost settings could have been an advantage, but the Slingshot is not an old vehicle and like most modern cars has a very good traction control system. The traction control monitors rear tire slip and adjusts the throttle to maximize acceleration. With a turbocharger, anytime the factory traction control engages, it closes the throttle blades, which then slows the turbo charger and when the traction control dis-engages, the throttle opens back up and the turbocharger has to spool back up. This can create an issue in getting the turbocharger to maximize acceleration in the Slingshot with the factory traction control. The belt driven supercharger simply reacts just like a larger engine and the traction control on the Slingshot handles it much easier.
Big turbos can make a ton of power, but having a turbo that is capable of making 520HP at the engine really does not mean the system can make that much or that it is really the best setup for a particular need. You could bolt on a turbocharger capable of 2000HP onto your engine, but to think there would be no compromises doing that would be foolish. Every choice has compromises that you make and going with a larger turbo than the power you are planning to use has compromises also. If your plan is to make 350HP at the engine, using a compressor that is capable of 520HP means the compressor is larger in diameter than needed, which means it weighs more, is more mass to accelerate, which increases the time it takes for the turbo to respond. Also, if you have that same turbo on a restrictive turbine A/R (like the Alpha kit did), you will never be able to achieve that peak flow of the 520HP by the compressor because the exhaust will not be able to flow that much air out of the engine. Other parts in the system like the intercooler, exhaust manifold and exhaust will also affect the peak potential power of the system, the 520HP compressor is just a small part in that system. We looked and could not find the actual compressor map for the precision turbo being used in these kits, the air flow of 520HP by the compressor is typically going to be at a very specific boost pressure and compressor speed range. It would be interesting to see that compressor map to see if the flow rate of 520HP is even in an area that is even achievable on the 2.4L and what the compressor efficiency is in that range.