[Z06] HP, Torque and Shift Points
Thread Starter
Drifting
Joined: May 2000
Posts: 1,797
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From: Thompson Falls MT
HP, Torque and Shift Points
A few of us got into a discussion on drag racing and the Z06. One person theorized that you should shift the Z06 when dragging prior to redline since once you pass the peak power point (which went undefined as to HP or torque) you're running out of steam and need the next gear to get back into the power zone. The other side of the argument is that by staying in the lower gear past the peak point you are still making more power (and thus acceleration) by using the lower gearing than you are losing by being past the peak power point.
For the Z06 specific should you drag race by shifting at redline or shift earlier? Don't worry about losing the 1/10th second by shifting...we're talking about shift points along the way.
Can you determine by formula the point at which it makes sense to shift? What's the formula for power to the ground, including the effect of gearing?
TIA
For the Z06 specific should you drag race by shifting at redline or shift earlier? Don't worry about losing the 1/10th second by shifting...we're talking about shift points along the way.
Can you determine by formula the point at which it makes sense to shift? What's the formula for power to the ground, including the effect of gearing?
TIA
Drifting
Joined: Aug 2000
Posts: 1,698
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From: Chapin SC
Cruise-In II Veteran
Cruise-In III Veteran
On a stock Z06 it's always best to shift as close to the limiter as possible (without hitting it). I use a DragSim software program that recommends shift points and in most cases it calls for redline shifts for the best ETs. In my case it calls for 7000+ shifts on motor only runs and closer to 6000 on the bottle because of the significant torque loss beyond 6500.
Pro
Joined: Apr 2000
Posts: 608
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From: Gilbert, AZ
The "right" way to do it is complicated. You need to graph hp versus mph in each gear. Then, when the graphs for two gears intersect, that is the shift point, you basically put yourself in the gear that has the highest hp at any given mph. Technically, if you have a wierd gearbox with unevenly spaced gears (like a really tall overdrive) you might need to shift at different rpms in each gear. The difference between this method and shifting just shy of redline in most cars is really small since engineers take this into account when spec'ing engines and matching them to transmissions, so it's probably not worth the dyno time to figure this out, but that's the "right" way to determine shift points.
Mike
Mike
