At what RPM do you shift?
06-17-2007, 01:34 PM
#46
Rennlist Member
in most folks book, easy driving should be shifting at a min of 3000rpm. luggin around in the next gear at 1500rpm sounds painful for the engine for me. also, there has been some speculation that low rpms increase the chance (or is the reason for ) cam pitting.
certainly there are cases for shifting at higher rpm as the max fuel economy doesnt actually happen at the lowest possible rpm. That happens at the engine speed that creates the most efficient burn.
mk
certainly there are cases for shifting at higher rpm as the max fuel economy doesnt actually happen at the lowest possible rpm. That happens at the engine speed that creates the most efficient burn.
mk
Originally Posted by Normy
"Cheap, fast, reliable. You can never have more than two of these"
The closest you can get is probably a 928, but that line above still implies. Man- you folks really rev your motors higher than I do! In the heat of battle, I occasionally hit the rev limiter, but only once in a while. Normal driving? I shift at around 2200 rpm, which is just high enough to prevent the tach from dropping below 1500 rpm [Porsche's stated mimimum] in the next gear. I don't overboost the engine either: low RPM's = low throttle. Basically, my point is that the harder you drive your car, the sooner it wears out.
Going to the grocery store, I usually don't accelerate any faster than the people around me in minvans and Corollas.
The closest you can get is probably a 928, but that line above still implies. Man- you folks really rev your motors higher than I do! In the heat of battle, I occasionally hit the rev limiter, but only once in a while. Normal driving? I shift at around 2200 rpm, which is just high enough to prevent the tach from dropping below 1500 rpm [Porsche's stated mimimum] in the next gear. I don't overboost the engine either: low RPM's = low throttle. Basically, my point is that the harder you drive your car, the sooner it wears out.
Going to the grocery store, I usually don't accelerate any faster than the people around me in minvans and Corollas.
06-17-2007, 10:56 PM
#47
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Join Date: Feb 2002
Location: Ft. Lauderdale FLORIDA
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Originally Posted by mark kibort
in most folks book, easy driving should be shifting at a min of 3000rpm. luggin around in the next gear at 1500rpm sounds painful for the engine for me. also, there has been some speculation that low rpms increase the chance (or is the reason for ) cam pitting.
certainly there are cases for shifting at higher rpm as the max fuel economy doesnt actually happen at the lowest possible rpm. That happens at the engine speed that creates the most efficient burn.
mk
certainly there are cases for shifting at higher rpm as the max fuel economy doesnt actually happen at the lowest possible rpm. That happens at the engine speed that creates the most efficient burn.
mk
Mark, my car is a daily driver. That means that I run it to full power and max rpm occasionally, but it doesn't see max rpm at maximum manifold pressure for long periods on a regular basis. I don't know how it would take to racing- there is no Hobbs meter on this car, and I think I am about the 3rd or 4th owner.
Well, I put the pedal to the metal the other night, after a can of
Seafoam went through my engine, and I had no problem achieving twice the maximum legal speed on a Florida highway. For about a mile. I accidently bounced off the rev limiter, the one that John Speake set for me at 6500 rpm, so I let off and coasted to the exit.
Normally, however, I shift at 2200 rpm and in the neighborhoods around here I just idle around at less than 2500 rpm. Most of the time I'm down around 1500 or so- the beauty of the V8 engine.
I really believe that a properly maintained 928 will not mind this sort of low use. A good hard run now and then works miracles, but I don't think that pre-S4's like mine really need "Italian tune-ups"
N!
