As someone who pushes.. some power, and is pretty close friends with those who do, I couldn't disagree more. There's more to a car's health than just 'making a difference' in HP.
With high IATs on a stock motor, the car starts to pull timing aggressively. Heat soak is absolutely something that...
Without more information, this isn't helpful. There are a lot (Yes, a lot, this time, Justin), of 700hp stock block motors. Could have been a 'friday rod' or something in the tune, mechanical failure, or something else that caused a premature failure.
I mean-- sorta yes.
Japanese Domestic Market means the car is built for.. well.. the Japanese Domestic Market. Originally sold in Japan as a street-legal car there.
I mean, he's wrong. Literally wrong. You can check to see how the oil is holding up, if there are shavings, if there are impurities.. always. Why wait to 30,000 to see if there's a problem if you can know right now?
Intake manifold should 100% be number 1 for cooling. I've yet to see any data that says the heat exchanger upgrades do anything to improve cooling performance.
If you want an engine build, you only really have a few options.
1. BMB - Billy Mason
2. Norris - p2uned
3. Titan
There are others, these are the three I shopped.
All three build solid engines. They all use different parts, I'm going with Billy. It's a little more expensive for the build...
Regardless of why this part failed, either OPs failt, a manufacturing defect, or -whatever-, the man is without a car.
I believe the best thing to do at this point is to go to an independent BMW shop with an alignment rack, and pay ~$500 to fix this, and move on.
Oh you.
I mean, HP numbers on their own aren't interesting. You're not faster if you can't get the power to the ground. There's more involved than purely HP. Also, HP numbers are generally relative, especially when the big fast bois are making more power.