loxxrider

There's merit to what you say. Here's BMW's stance on break-in for more than just the engine https://www.bmw.com/en/automotive-li...ar.html#pwjt-4

That said, there's too much vagueness in Porsche's blanket statement of "keep it under 4k RPM for 1800 miles" for me to take it too seriously. Right or wrong, this is the impression it gives off (to me). Now a break-in procedure which is more like this, would make much more sense to me and I'd respect that much more closely. Perhaps that's a misguided sentiment, but this is much more in line with my understanding of mechanical systems.




Another interesting point... here's a Porsche dealer who suggests that the break-in procedure in the owner's manual is too conservative. Interesting, right?


And one last point that I found interesting... the owner's manual of the 991 GT2 and GT3/GT3RS gives different advice for the turbocharged vs. N/A engines. This is probably a function of the tolerances used in each engine and the fact that the rings in each of them are subjected to completely different conditions. This at least indicates to me that there is some rhyme or reason behind Porsche's recommendation to keep it below 4k RPM until 1800 miles.




None of this evidence proves or disproves my own assertion that Porsche's recommendation is too conservative. Therefore, I choose to mostly respect their recommendation... but the occasional slip-up may occur, and I'm not going to sweat over it

dudeoverthere

take it from someone who decends 3,000' every day in his 911 and spends pleny of time driving in the rockies. there is plenty of engine braking on these cars.

that said, i followed break-in by driving mountain roads. decent pulls to 4k when warm, lots of engine braking etc. couple oopsies to 6k since the car wants to go there. so far a solid engine that sees redline regulary.

excited to see the OPs results.

VarTheVar

There was an interesting conversation on The Smoking Tire Podcast between Betim from BBI and Matt Farah. Matt has a Deman Motorsports stroker engine in his Boxster and they started talking about how the break-in procedure from Deman was very long and involved like the factory one. And Betim said they just send it on the dyno and break the engine in immediately and look at the oil samples afterwards.

I am fully convinced that there is not a single production engine on the planet that requires hundred or thousands of miles to break in and in fact people do more damage than good if they baby their engines maybe a bit too much. People often have the mindset during break-in that they are supposed to baby the engine before they are allowed to exercise it. But in fact the opposite is true. You have to exercise your engine before it's safe to baby it.

VarTheVar

I don't have to take it from you. I have a 992. There is absolutely no engine braking under normal driving conditions. When you're going downhill the car actually adjusts it for you but if you're driving on a flat surface there's practically no deceleration

Fishah

100% agree. Maybe the guy is referring to a car in automatic mode? Leave the car in gear though and it will absolutely engine brake. So much of my break in process was running the car up to 4-5k in 2nd gear and then letting the engine slow itself back down.
​​

VarTheVar

Mine is a 7MT so maybe it's tuned differently than the automatic?? Not sure

notfastenough

Mike818, Hopefully I haven't insinuated that I would hold Porsche unconditionally responsible and file a warranty claim if something unfortunate happened! As a matter of fact, I would "half" welcome the chance to tear it down myself to see exactly where failures occurred. (Although there's probably proprietary fine print that would not allow me to ship a very wounded new car back to the U.S. under Porsche's European Delivery program.) As for Porsche crawling all over social media... there are no secrets with an ECU. They know exactly what we do with our cars without the assistance of SM.

As far as break-in for the rest of the systems? I'll challenge you on that. Aside from the engine and transmission, break-in can be accomplished easily in the first 50 miles. Racecars enjoy no such luxury as "break-in" on most components. BTW: I would agree with the voices here that babying an engine or manual transmission can be detrimental in the long term.

Fishah

Racecars also have their parts refreshed/replaced much more frequently.

silversurfer6

There are 2 sides on this and of course it is your car:

1) Follow the break in procedure so if something happens you have the warranty. You can probably do the break in miles in 3 days around Europe?

2) If you really do not care about the value of the $180k car and you can ship the car "damaged" to the US then go for it!

P.S 1) is more sensible but when is it sensible when we are talking about $200k+ cars

pal

I simply followed what was in the manual. Vary rpm and keep it under 4000’ish rpm for 1850 miles. Then I did an oil and filter change, bled the brakes, installed a set of track pads, and did 2 track days And those were a glorious 2 days learning the car.

loxxrider

My 7MT also feels like there's no engine braking to speak of. In fact, it sounds like its not going into complete overrun fuel cut. It burbles on decel (even in sport plus mode) which is your indication that overrun fuel cut isn't in play. I find this fairly irritating actually, and hope that a tune can address it.

VarTheVar

If I ever get a tune, this is one of the things I want addressed. I really like that there's no engine braking when I'm driving on the freeway as it makes for a nice driving experience. But when I switch it into sport mode I want it to have aggressive engine braking. Mostly in the hopes of getting more rotation on corner entry and getting a more pronounced mid corner adjustment when lifting off the throttle. 911s are supposed to be driven with the pedals but all the modern ones have transitioned to be driven with the steering wheel and it is pretty lame

Mike818

Perhaps the turbochargers themselves have a break in and the reduced RPM is to keep the shaft speed down. Like I said, I think you really have to keep every system in the car in mind when thinking about these recommendations.

That could be true about ECU black boxes, but if you did find yourself in a court room with Porsche I think the Lawyers would refer to those social media posts as "bad facts".
As was stated, race cars break all the time, and take an entire crew of people to keep them operational. Their reliability is measured in races and seasons, not decades and hundreds of thousands of miles.

loxxrider

Let me state first that I enjoy this discussion, and am genuinely interested in the debate. My intention is only to find and discuss the facts and to have a good discussion. I don't want to argue for the sake of arguing or for the sake of being right (or wrong ). So take my commentary with that in mind.

Having installed many a brand new turbocharger over the years, I can tell you that this is not a thing. You crank the engine with the plugs out just to establish oil flow and pressure at the turbo. Then it's ***** to the wall for the turbo as soon as its up to operating temperature. No turbo manufacturer recommends a break-in period in my experience. I hate to sound rude, but I think you're grasping at straws here and possibly out of your depth debating with people who have decades of experience and formal education on these topics. That being said, if you have actual evidence to cite (even if it's anecdotal), then I'd be very open minded about it and really interested to dig in further.

Mike818

I was just speculating, I don't have any facts to try and argue that point with, and I don't want to invest any energy looking for some. I've got a couple of decades of experience with turbocharged Mitsubishis so I am no stranger to turbo's myself. That certainly doesn't qualify me to speak authoritatively about turbocharger engineering / mechanics. I think the level / criteria of quality control engineering that goes into aftermarket turbos is likely not the same as an OEM shipping cars.