Spyder said:
I recently read in a major auto mag that turbos actually take a bit more power to run due to the restriction of the turbine in the exhaust path and (depending on set up) twists that the exhaust tubing makes to get to it. That was sited as a large contributor to lag as well. As far as power per pound of boost, with my KB, I make 376rwhp/385rwtq from just 7.5 psi on 93 octane premium pump gas. The stress can be argued two ways. Amount of boost and tune. Both are major factors. But, the tune is really the key to making any kind of power, whether it's a KB or a turbo (or anything for that matter). Blowing head gaskets will happen if you don't get it tuned right and it detonates (boy do I know that!!! lol!!). The tune is really the key to unlocking safe, detonation free power. Tune, tune, tune, I can't say it enough.
Here's another reason I vote KB: I'm cruising down the highway in overdrive at 55mph (about 1750 prm w/3.55's). I need to pass a car. I just crack the throttle a little bit, dial up a couple pounds of boost and away I go. No downshifting to get into the power band that begins at 2500 to 3500 rpm and builds from there. My positive displacement KB literally has a power band from 1500 to 5700 rpm. That means (nearly) full boost is available dependant on throttle position, not rpm. Do I make more power as rpm increases? Sure, more airflow through the engine. But the power is available down low where most of my driving/passing/etc. is done. For my puposes, the power is more usable.
Now, I'll play devil's advocate. Some of the fastest cars I have ever seen are single and twin turbos. And I think that a lot of the negative association with the turbo is from a lack of good, stable aftermarket kits. A lot of early turbo kits forced the user to fabricate, cut, and bend to get it to work. And then it was a tuning nightmare. (Don't worry about that with a KB!). More recently, the turbo is catching on now that there are some better kits out.
Matt, the question is, what do you want from your car?
