mooty

it's the driver who needs breaking in. the car is ready to go full tilt as soon is it gets off assembly line.

TraqGear

I did the proper break and hey, I've only needed 2 RMS's!

mooty

see, what did i tell you.
i babied the RS for 500 miles it needed one RMS, now i use the rev limiter as my shift indicator, RMS is doing just peechee.

my 996GT3 were on track as soon as they come off the showroom floor, none of them needed RMS.

Steven_H

What is RMS?

mooty

rear main seal leaking problem
some 997GT3 and RS have experienced it.
talking to porsche factory tech in germany, the confirmed that if you drive it there's no prob. most cars with RMS are rarely driven.

sjgreco

The service manager at my dealer said after 1,000 miles you can start to run over 4,200 RPM's, but don't exceed 7,500. I can't remember for sure, but I think the owners manual for my 996 GT3 also said break-in was a 1,000 miles. Can anyone confirm. The 997 and 996 have fairly similiar motors.

TraqGear

Yeah, I know John...but I'm kindof OCD when it comes to doing stuff like breaking in cars, preparing for DE's, etc. It would be funny to someone that could look at my revs....4k revs all the way to 2000 miles, then 8k at 2001 miles! Good news is, I'm in line for the new RMS that P just put out, so hopefully the end of the problems.

sjgreco

The following information was taken from the 996 GT3 owners manual. Looks like the break in for 997 GT3's increased to 2,000 miles for some reason.


Break in hints for the first
1,000 miles/l,600 kilometers
The following tips will be helpful in obtaining optimum
performance from your new Porsche.
Despite the most modern, high-precision manufacturing
methods, it cannot be completely avoided
that the moving parts have to wear in with each
other. This wearing-in occurs mainly in the first
1,000 milesj1,600 km.
Therefore:
I> Preferably take longer trips.
I> Avoid frequent cold starts with short-distance
driving whenever possible.
I> Avoid full throttle starts and abrupt stops.
I> Do not exceed maximum engine speed of
4,200 rpm (revolutions per minute).
I> Do not run a cold engine at high rpm either in
Neutral or in gear.
I> Do not let the engine labor, especially when
driving uphill. Shift to the next lower gear in
time (use the most favorable rpm range).
I> Never lug the engine in high gear at low
speeds. This rule applies at all times, not just
during the break-in period.
Controls, Instruments
I> Do not participate in motor racing events,
sports driving schools, etc. during the first
1,000 milesj1,600 kilometers.
There may be a slight stiffness in the steering,
gear-shifting or other controls during the break-in
period.

SpeedGeek

Why is this the only instruction that includes "This rule applies at all times, not just during the break-in period"? What about "Do not run a cold engine at high rpm either in Neutral or in gear"?

Mike Murphy

The following is taken from the January 2008 edition of the Tech Q&A section of Porsche Panorama:

Q: The rebuild is complete and I'm ready to re-install the engine. Can you suggest protocol for engine break-in?

A: (Mayo) ...I don't use any special break-in oil...as soon as the engine starts, I keep it at 2,000 RPM and hold it there for 5 minutes...once everything is buttoned up, I go drive it, accelerating reasonably hard from 2,000 to about 5,000 rpm repeatedly. After that about 20 times the rings are mostly seated...I give the car to the customer and tell him to drive it as hard as he'd like, but to avoid long periods of constant rpm for 1,000 or so miles...After 500, but certainly 1,000 miles, I consider it broken in...

Mike Murphy

Note that because Porsche already runs these engine at the factory, there is no need to do the first few steps. It seems that we should be running these engines pretty hard from the start.

Kolbjorn S

I have a ROW car, and in my RS manual (print date 7/07) it says on page 15:

"The wearing-in occurs mainly in the first 3,000 km. During the first 3,000 km you should:
- preferably take longer trips
- Avoid frequent cold starts with short-distance driving whenever possible.
- Not participate in motor racing events, sports driving school or similar.
- Avoid high engine speeds, especially when the engine is cold. "

No more mention about it as far as I can find.

dmundy

Alright I have a silly question. How much do people really think piston rings wear after the first few hundred revolutions? I have never seen much sense in an extended break in period but I'm happy to listen.

fc-racer

I don't think the break-in period is really about the engines anymore, but more about everything else around it. During break-in periods on various cars, I've had gearboxes loosen up significantly, discovered the shipping bump rubbers still left on the shaft of shock absorbers and have had a radiator cap stay stuck shut. All three of those may have caused damage had I been redlining the car up a mountain road.

It's only a few thousand km, I don't know why it's such a difficult thing to keep the revs reasonable and to keep the load varied. I broke my car in < one week as I drove it everywhere and took a short road trip. It was actually some of the best driving as I had time to appreciate the nuances of the car as I grew accustomed to it.

dmundy

It's not that it's a big deal, it's that I can't see how it makes much difference. So far (admittedly on race engines) I have had better luck with running motors as hard as I can once they are in cars. I do one pace lap and that's about it. I just don't see how the rings care much past the first few hundred revolutions. Which took place before you got the car.

There is no question that random other stuff can be found during early ownership of a car.

I confess I am still getting accustomed to the radiator cap on 911's.