Redline
04-17-2013, 11:32 AM
#1
Three Wheelin'
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Redline
Forgive my ignorance. I come to well of knowledge here in Racing/DE.
I've read numerous posts in various forums, discussing redlining Porsches.
I own a 997.1 and do realize Porsches are high performance machines, not to be driven like minivans and econoboxes. I'm not into racing, but in my teens and twenties I was (rally and ice racing).
Examining my own car ('06 C4S Cabrio) I know that peak hp (355 hp) arrives at 6600 rpm, and peak torque (295 ft. lb.)) arrives at 4600 rpm. Examining hp and torque curves (info from Porsche - again, for my car) reveals that neither hp nor torque plateau once arriving at peak output - they both drop off.
My question is this - what benefit(s) are derived from redlining?
I've read numerous posts in various forums, discussing redlining Porsches.
I own a 997.1 and do realize Porsches are high performance machines, not to be driven like minivans and econoboxes. I'm not into racing, but in my teens and twenties I was (rally and ice racing).
Examining my own car ('06 C4S Cabrio) I know that peak hp (355 hp) arrives at 6600 rpm, and peak torque (295 ft. lb.)) arrives at 4600 rpm. Examining hp and torque curves (info from Porsche - again, for my car) reveals that neither hp nor torque plateau once arriving at peak output - they both drop off.
My question is this - what benefit(s) are derived from redlining?
04-17-2013, 12:01 PM
#4
Race Car
AFAIK, only more time accelerating in the corner.
and avoiding the the drop in power when you do eventually shift.
-you have a rev-limiter, but nothing to save you on the wrong gear down shift. aka money shift.
and avoiding the the drop in power when you do eventually shift.
-you have a rev-limiter, but nothing to save you on the wrong gear down shift. aka money shift.
04-17-2013, 12:56 PM
#5
Rennlist Member
Sometimes it makes sense to upshift at or near redline in order to avoid any sort of dramatic drop off of power due to gearing. Sometimes it makes sense to upshift sooner to stabilize the chassis and/or suspension.
So IMO it is situational.
So IMO it is situational.
04-17-2013, 01:10 PM
#6
Drifting
This.
If you plot out the torque at the wheels (through the gearbox) you will find that acceleration is always higher in the lower gear. Even when the power is coming down after the peak, the thrust is still higher because you lose leverage when you hit the next gear.
Obviously there are situations where you don't want to downshift, or when you want to short shift, but those would be when you aren't trying to put maximum torque to the pavement or would lose more time shifting twice than you gain.
If you plot out the torque at the wheels (through the gearbox) you will find that acceleration is always higher in the lower gear. Even when the power is coming down after the peak, the thrust is still higher because you lose leverage when you hit the next gear.
Obviously there are situations where you don't want to downshift, or when you want to short shift, but those would be when you aren't trying to put maximum torque to the pavement or would lose more time shifting twice than you gain.
04-17-2013, 01:16 PM
#7
Rennlist Member
This.
If you plot out the torque at the wheels (through the gearbox) you will find that acceleration is always higher in the lower gear. Even when the power is coming down after the peak, the thrust is still higher because you lose leverage when you hit the next gear.
Obviously there are situations where you don't want to downshift, or when you want to short shift, but those would be when you aren't trying to put maximum torque to the pavement or would lose more time shifting twice than you gain.
If you plot out the torque at the wheels (through the gearbox) you will find that acceleration is always higher in the lower gear. Even when the power is coming down after the peak, the thrust is still higher because you lose leverage when you hit the next gear.
Obviously there are situations where you don't want to downshift, or when you want to short shift, but those would be when you aren't trying to put maximum torque to the pavement or would lose more time shifting twice than you gain.
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04-17-2013, 01:23 PM
#8
Drifting
04-17-2013, 01:23 PM
#9
Nordschleife Master
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Ref. Kibort, et al, (2010). If you had ever actually raced a car, you would know this to be patently false. It is entirely dependent on little squiggles and lines on charts, the strength of argument and the will one might have to debate countless logical statements to the contrary.
Obfuscation helps also.
Obfuscation helps also.
04-17-2013, 07:29 PM
#12
The Penguin King
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