993James993

A recent post on the 993 forum asked about keeping the revs above 4K once the car reaches operating temp:

https://rennlist.com/forums/993-forum/380296-keeping-the-revs-up.html

The original poster, Terry McLeod, asks if there is technical data to support this.

I thought it would be informative to ask the same question here.

Is it a good idea to maintain high revs after your 911 reaches operating temp?

Thanks in advance!

Jim

Jay H

You'll get a billion different responses to your question. Some will state that they rev their cars to near redline for most shifts. Others will claim that their car doesn't see many high revs all that often.

I use my 911 for a lot of daily driving chores and typically shift in the 2000 to 3500 rpm range. Much more than that and I'm climbing over the rear bumper on the car in front of me. If I'm driving very hard on back roads, I'm keeping the revs way up for most of the time. Coming back from the grocery store with my kids and you'll see me puttering around 1800 to 2200 rpms. Driving around town at 5000 rpms can get tiresome all the time...

So, it really depends on how you use your car. I would assume most people will agree that you should take these cars to red line on a regular basis (I try at least once a week to run her hard to 6k or so on a few shifts if I've been dawdling a lot).

Murphy said it well on the 993 thread. More rev's = more friction = more wear and tear.

DARISC

I'd say that's nuts.

It's simple; as applies to any manually shifted car, 1. don't lug it and 2. don't over rev it. You should be EASILY able to tell when you're doing the former if you have any feel at all for infernal combustion engines and manual transmissions.

As for the latter, the redline on the tach is there for your guidance - go beyond it at your own risk.

How you drive it in between those two extremes is up to you - the engine really doesn't care.

By the way, you'll do more damage lugging the engine than you will by over revving it (within reason). Lottsa drivers over rev on occasion (no real harm done if not TOO high).

There is really no excuse for EVER lugging an engine.

Like Jay, in my daily driving the engine spends it's time between 2 & 4krpm when putting around town, with occasional runs to the redline when traffic allows and the spirit moves me.

The general consensus, and my personal experience, is that these engines don't take well to putting around, lugging or not. They seem to run best and longest if driven vigorously.

Jay H

I agree with this statement. Lugging an engine will do quite a bit of harm if done on a regular basis...

Daniel Dudley

The early four cylinder, four cam engines with roller bearings used to have quite a bit of trouble with lugging. 911 engines are pretty tough, and lugging isn't really an issue. You can feel lugging- it's pretty pronounced.

kick7ca

lol Kinda off topic but I gotta tell this story...
I drove 8 hrs this weekend to look at a car, original owner, we go for a test drive and he drives first...from the moment he pulled out of his driveway until he let me drive this guy lugged the engine in every flipping gear! He shifted at less than 2! Pulled away from a dead stop in 2nd! Plus every shift was an aggessive power shift. Ghad! Then I realized this car has been recieving this treatment for 20 years!

Mike Murphy

Proves how durable these engines are at any RPM.

Mike Murphy

Someone took me for a ride in their Testarossa once and never shifted at anything higher than 3,000. All discussion about reliability aside, I think it's a shame to drive a car like that...like that.

GothingNC

I always shift above 3000 RPM when driving any car with a manual gear box unless the driving surface is slick.

John.

Alan Herod

I had one of those roller bearing four cams and I still have some factory pubs with the dire warnings and all. That said, I have been driving air cooled 911s for years. I now have a 993 engine in the SC and occasionally start in second. The ratio in first is simply too low. It is one less shift with the 915 box.

Consider that there is a huge difference between lugging and running at 2500-3500 rpm. At the same speed (MPH) your pistons travel twice as far using a lower gear then a higher gear at half the rpm. You can't escape that you are putting more wear on the engine.

Peter Zimmermann

Shift points and steady-speed driving are two very different things. Revving the car to about 4-4.5K before shifting is a good thing, because the next higher gear will be in the lower end of the torque/power band of most 911 engines, which you can use for acceleration or comfortable motoring. Lugging never becomes an issue. SC and later cars don't even mind loafing along at 2600 rpm, but if/when this is done the driver should anticipate situations around him and if quick acceleration is needed a downshift can be made. Driving any 911 around town at a steady 4-5K revs is nuts, and completely unnecessary; 993s have gobs of torque and higher revs at steady speed will do nothing more than drown out the radio and give your passenger a headache.

DARISC

Glad someone finally stated the obvious .

Also, for those not clear on what "lugging" is, it's not strictly rpm dependant at all. It's possible to lug an engine at 2500 rpm as well as at low rpms - it's all dependant on the gear and the load on the engine. You can idle along at 750 rpm in 3rd gear on a flat road without lugging - step on the gas to accelerate and you will immediately lug the engine.

I feel kinda' silly expounding as if profoundly about some of this stuff, as it should seemingly be intuitive, based on tactile & aural feedback, to anyone even remotely sensitive to machinery.

Geez, I hope I'm not sounding condescending - just been raised on manual trannies and I never even think about some of these things anymore. So, my apologies to those who've mainly driven automatics and are learning the nature of manual trannies and the decisions that one has to make while operating them (decisions that automatics make, well...automatically ).

Cheers,

David

Oh! Yeah, what Pete says (I said "nuts" also)! (I was typing the above when he posted).