Throttle Body Coolant Bypass - The throttle body coolant bypass kit is often sold as a magical kit that adds up to 5 horsepower. The kit retails for $20 but contains only three components, an inline hose coupler and two hose clamps. The components of this kit can easily be purchased for under $5 at any local hardware store. The theory behind this modification is somewhat sound but it deserves some explanation. From the factory GM routed a small portion of coolant through a passage in the throttle body for the sole purpose of keeping that throttle body from icing. Apparently in extremely cold weather this is a real problem, but the temperature has to be extremely cold, such as well below zero. GM engineers were probably not considering the car that the engine was going in when this feature was designed. Although the Corvette does much better in the snow than most people give it credit for, it is not usually considered a winter vehicle. For temperatures so low that icing could actually become a problem, the cars equipped with the LT1 engine will probably be parked anyway. The original design intent is sound, but it is not really needed in most cases. For any person living in the continental United States it is a safe bet that the coolant can be bypassed around the throttle body without causing any harm. The question then has to be asked, why bypass it? The coolant flowing through the throttle body can heat the incoming air charge somewhat which can possibly cause a decrease in performance. The benefit of this modification has never been quantified in the form of a proven horsepower gain. The real benefit of this modification is that it allows for easier maintained of the car. With the throttle body coolant circuit bypassed the intake and throttle body can be removed as a unit without having to drain the coolant from the engine, or if necessary the throttle body can easily be removed from the intake, again with out spilling any coolant. This modification takes about 5 minutes to perform and has no ill effects unless the car is routinely driven in sub zero temperatures. I list this modification in this section because the performance benefit is not as great as the convenience benefit, and it can be done much cheaper than the "kit" costs.