HAZ-Matt

On stock rubber only if you are on a surface that is close to what they modeled when they calibrated the system, so maybe "it depends." I recall seeing some people claim that on the ZR1 they gained several tenths of 60 ft at the drag strip translated into ET savings, but I do not recall ever seeing that dramatic of mph increase. Most people complain that indeed the system may not be too great as implemented by GM, but then again most are comparing to Euro exotics.

In any event you can gain more mph with more traction. On stock tires with LC on or off someone has to reduce power so you don't just make a smoke show. LC or no LC should show mph improvement simply switching to the drag radial because you have more average power (more power in the earlier gears). That is where your mph gain can come from. This is also dependent on the design of the LC system. If it was never tested with more grip from stickier tires and stickier surface, then it may exhibit unusual behavior when you use it at the strip (which is why GM had drag radials with them at Milan... PTM5 with LC is supposed to work on a VHT surface with DR's).

Above there was a comment about the clutch, and indeed you still have control of the clutch on an LC car with a real manual, but the expert driver has to manipulate that with LC on or off so in theory the difference there should be moot, but clearly the difference between an amateur and an expert manipulating the clutch can be drastic. Cars with computer controlled clutches do not have this limitation.

The alternative theory about LC is that its primary function is not necessarily traction, but modulating revs as the clutch is engaged, which in turn would limit bogging or excessive wheelspin.

I am curious about the 0.5s difference claim on the ZL1 for LC. I haven't really seen any numbers either way on that car and would like to see where they are coming from. In theory, Camaro should have superior LC relative to the Corvette as PTM5/LC in that car is made for drag racing. The other interesting bit is that the GM telemetry when they tested LC for Corvette showed quite a limited difference in launch times between it and their expert drivers, but I would have to review the actual numbers (I know the owners are saying at drag strips it hops too much in the ZR1).