After warm-up, is there such a thing as an ideal RPM?

[H.G.P.]

This is a 69 911 E. After proper warm-up I still do not know the ideal proper RPM.

1. For instance, say I'm driving on a normal highway interstate that posts 65 mph. Where would I keep the gear and RPMs.

2. Also, at certain RPMs does the transmission work harder?

Thank you.

[bigchillcar]

not sure where the peak of the power band is for a '69 e model, but it's around 4k in my 2.7. not sure either if you have a 4 or 5 speed tranny in your car, but i'd think the highest gear for cruising is appropriate at 65 mph, unless you're in traffic and anticipate passing, changing lanes, etc. in that case, stick with the next highest gear until you're in a position to simply cruise and assuming the temperature of the car isn't prohibiting an overly high rpm. you definitely don't want to operate around town in lower gears that don't allow at least about 3k rpms...these motors actually need the higher rpm's to keep air moving over the heads for more efficient cooling and also so as not to 'overload' the tranny by making too high of a gear work with too few rpms..hope this helps.
ryan

[svandamme]

1
depends on what you want, fun , or low fuel consumption

you want fun , then pick the gear that will facilitate the best accelleration

you want fuel consumption to be low , then pick the highest gear you can without lagging the engine

2
redline is definately better on the tranny than idling

[RoninLB]

Originally posted by bigchillcar
.
you definitely don't want to operate around town in lower gears that don't allow at least about 3k rpms...

ditto for top gear

[H.G.P.]

Originally posted by svandamme



2
redline is definately better on the tranny than idling

A. What exactly is "redline" anyway? I did a search and found no definition. It can't be the redline on the tach can it? I mean 7 grand cruising ??

B. How is this easier on the transmission too?

[dd74]

I don't know if 7,000 RPMs is exactly cruising - I'd call it racing.

[Miguel Antonett]

Keep that engine over 3K rpm, and every chance you have floor it to blow and clean the conbustion chamber, valves , intake & exhaust.

[RoninLB]

Originally posted by H.G.P.

This is a 69 911 E. After proper warm-up I still do not know the ideal proper RPM.

do all your shifting between 3-4k rpm and keep top gear cruising above 3.2k rpm and your engine will love you.

[svandamme]

Originally posted by H.G.P.


B. How is this easier on the transmission too?

sar·casm ( P ) Pronunciation Key (särkzm)
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2. A form of wit that is marked by the use of sarcastic language and is intended to make its victim the butt of contempt or ridicule.
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[jstobo]

Peak HP on a 69E is at 6500 RPM. Rev limiter kicks in at 7120 RPM if you have the stock rev limiting rotor installed. The 69E manual says do not go below 1500 RPM in any gear except first. So after first gear anywhere between 1500 and 6500 is where you want to be. As a practical matter the torgue on the 2L engines does not really appear until you are above 3000 RPM. I try to keep my RPMs above 3000 in every gear with fun excursions to redline as I shift up. Of course I probably get the worst gas mileage but winding the short strok Porsche engines to redline is a lot of fun. Of course you are probably exceeding the speed limit after second gear(65MPH) but so what. Shift when you want and most importantly have fun.