Great work.
Question: The wastegate looks like an MVS, is a single 38mm wastegate enough to keep boost pressures low and stable or is this a higher boost application? I've been teetering on a MVR or a 60mm because I want to run 3-8psi depending on the gear I'm in...
It's an MVR. Wastegate priority placement is of utmost importance when trying to maintain low boost levels. Bear in mind, you can only ~double the gate spring unless you start dealing with pressurizing the top of the gate with a compressed source.
An update on this car; in the 3rd pull of the day, well in advance of any timing optimization, and still leaning the base tune out from 10.5:1 AFR or so, the rear bank went kaput at just over 7psi.
The culprit......an overly loose timing belt. With over 5degrees of mechanical crank rotation before belt tension on either side, the front and rear banks were not able to maintain proper mechanical timing, and as such had an advanced timing condition on the rear bank, with a retarded condition on the front. All three rear pistons suffered broken ringlands.
The customer was obviously disappointed as he had a long trek back home with an empty trailer, but we struck a deal on an LF600 Engine build to be done quickly and cost effectively.
Lesson of the week for all parties involved...make sure the car is 100% tip-top shape before forced induction, regardless of the maintenance history. FYI, the timing belt job was shoddy at best with loose and missing bolts, gaskets, and obviously an overly loose belt.
It'll be June 1st or so before we are ready to go again with this project, I'll update then.
