So I jump on the 55 from 19th in Newport Beach yesterday and this Suby Legacy and I stretch a leg. I run it up to about 5.5k rpm for like 2 min. Plenty fast for the both of us as I wasn't going to go any faster and he seemed content as well. Here's the question. What's a safe cruising rpm? If I find a place to finally top out my car where should I put the mental limit of 'don't go any faster than this' ?

So, what are you driving? I assume 914, but 4 or 6?

4's don't do well above 5k as there is no torque left, and above 5500 is taking the engine's life into your hands.

Assuming it is not a rebuild, the engine is potentially 40 years old with maybe a top redo at some point.

You must have been at about 125 at 5500. Right to jail, no plea, just bail and an impound/confiscation!

Woohoo!

I have had mine up to 100, but at my age, I don't want a $2.4K ticket. Obvious displays of speed and you lose your car. Forever, from what I hear. I have heard stories from people that are reliable, but I am not sure if it is first offense or not.

Good luck!

John
avidfanjpl

My stock-ish 2.0L is happy cruising between 3200 and 3500 for extended times.

Have been cruising a lot the past 2 weekends, have put almost 2000 miles on the odometer and find 3200 to 4200 seems to be the sweet zone, short bursts up to the 5000 area seemed okay. Just got home this afternoon from a PCA Acadia region tour and during lunch one of the 911 guys who is also a mechanic was in the car behind me, he said my engine sounded real good, and I had no trouble keeping up with the pack so I would suggest the same would be true for your car.

Ian Stott
Moncton
Canada

Stock D-jet 2.0L 73-74 - 3-4k all day 4th or 5th, otherwise in bursts as needed or wanted - there's a little red area on your tach's right arch which is "RNE" - "rpm never exceed" at about 5600!

If you can't trust yourself to stay under redline, then put in a rev limiting dizzy rotor!

... & if you open it up like that on the 55, 5, 22, etc. - invest in a good radar/laser detector & watch the mirrors!

4500 rpms all day long if you don't get caught by the police...If the rotating parts are balanced 6000 rpms in short bursts is fine but there isn't much hp in a stock engine there.

When on a long trip, I set the cruse control at 3000 RPM that is 70 ish on the

speedo. (Yes, I installed Cruse on my 914 ). Tire size comes in play here , but i am

not smart enought to figure that out. But I feel the looks I get from the cop is " Cool

Car". Dave

I like to stay under 4000 rpms. engien seems happy at that, low stress, = long life, good mpg. small tires dont help me any, at 70 mph I am at near 3500 rpm (15 inch 195 50 tires)

yesterday we took 10jreen to the concouse at Dana pt. its 730pm and were petting lamas in capistrano when I remember that the race car has no headlights, oops. 4500 all the way back to san diego. stock-ish 2056 D-jet. heads were cracked 6 years ago(and 100+ AX) when i put them on. rev limit set to 5500

it really depends on the build quality and eng config

oil temp 190, cht 300-320

Thanks for all the input. <4k will be my mental limit.

125 at 5500 sounds about right and ya I'm flirting with disaster both mechanical and legal at that speed. I think I'll find a track if I want to take it up there again.

You don't want to cruise under ~2500 - 3000 for long periods. Cooling fan speed is tied to engine RPM, so keep that fun spinnin' to keep that air flowing to cool engine.

Is that the same for a 911 2.2 L 6?

I dunno, why don't you loan me your GT and let me test it for you!

I'm sure there is a "target" minimum or that 2.2L 6. Gotta keep feeding air to these air-cooled (or oil-cooled) engines! Don't wanna lug them at low RPMs.

Maybe the Cap'n will chime in. I'm sure he knows the best RPM for every possible 6 displacement within 5 revs!

Come on down to Oklahoma and I will give you a ride and maybe let you drive!?
You are probably right. The cap'n probably does know. I normally don't cruise with it below 3 K anyway cuz I drive it like I stole it.