MilosB

Great work.
Sadly mistakes happen...

Ps, CNC is most often just a time saver. And allows for more intricate 3D shapes, but for all the rest, not better than a manual at all..

Brettus

iTrader: (2)

Great work getting the 1/2" studs to fit .
It seems like quite an overkill given what the engine is capable of though.

motodenta



MilosB

Unless you are i metric system...

ciprianrx8

Rebuild kind of done. Have to sort some small oil leaks here and there(trans reverse switch and turbo oil return) and then it's back to tuning for more boost mid-range now that I know the keg can take it.



Dry compr. test to be sure all seals are in place.

Ditched internal wgt actuator entirely, wrapped everything in heat insulating tape and covered the turbine hot side.

TeamRX8

iTrader: (25)

interesting, that last photo
.

TeamRX8

iTrader: (25)

referring back to the past wastegate size discussion, still say a 50mm is the way to go

from the latest release of the Garrett wastegates, initial lift flow comparison between their 40/45/50mm sizes

ciprianrx8

Mine is a 44mm. Plenty big to run as little as 30kpa, plenty spring options to go up to 120kpa of boost. No changes there, just clean & inspect & refit.

ciprianrx8

Put the engine back in, back to the usual stuff. Won't be compression testing too soon but it hot starts well enough not to ponder on that.

What I am doing nowadays is try to prevent whatever it is that cracked my front iron. It could either be:
1) sustained high torque and no knock, no preignition. I kind of believe this reason the most because it really held up quite a long time and during harsh driving. Excepting trackday duty, this engine saw about 20 boosted pulls to redline every fuel tank, for about 50 tanks' worth.
2) consistent light knock that the ecu didn't care about. Possible. Can't verify.
3) EMAP-induced knock or preignition that fatigued the metal until it gave way. EMAP was huge once, and still is high.

Leaving the past be, this time I'm assuming that EMAP is more reasonable and that there's something I can do to the ecu to pull timing(and torque with it) when/if it knocks. To that scope I've played with this table:
Top is stock, bottom is what I currently run and still tune.


This should be a knock threshold in the range of 0-255 where the ecu will start to pull timing - presumably by "knock retard base (B)" and then up to "knock retard max". The trouble is entering Z values that won't just hammer the timing back needlessly. So far I've tried thresholds in the 45-50 area and that has shown consistent timing retard across both NA and boosted operation. Then again these tables might just set a floor reading of the knock sensor below which the readings are totally ignored. Knock control strategy is still widely unknown - along with fueling and timing "safe mode" of which I know even less.
Fancy seeing that the factory setup cuts and all KR past 5000 RPM. I've always set that higher than redline though.