GT2554R Record??? leads to a run of the mill EFR build
#202
TheCarPassionChannel
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*C5 Z06, and I know. I had planned this day (the 300hp attempt part, not the blown engine) ever since I pulled the trigger on the 2860R a couple months ago, Corvette guy just happened to challenge me at the perfect time so it lined up. It was fun while it lasted and I knew the risk, time to start over!
#205
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As an aside, overboost protection won't cause a total loss in oil pressure. The oil pump is still spinning at ~6000rpm regardless of whether the injectors are on or not. You will lose some pressure briefly, but that's just because the bearings aren't as heavily loaded as they were a split-second beforehand. IOW, hitting overboost didn't break the rod, but ~300whp on a stock bottom end did
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#206
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As an aside, overboost protection won't cause a total loss in oil pressure. The oil pump is still spinning at ~6000rpm regardless of whether the injectors are on or not. You will lose some pressure briefly, but that's just because the bearings aren't as heavily loaded as they were a split-second beforehand. IOW, hitting overboost didn't break the rod, but ~300whp on a stock bottom end did ![Party Kitty](https://www.miataturbo.net/images/smilies/birthday[1].gif)
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#209
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nothing wrong except that's it's missing out on a bucket full of mid-range and no extra top end (especially once you bolt up a square top) -- out of the box.
If youre going to do a motor swap, do it right.
If youre going to do a motor swap, do it right.
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It really does make a huge, huge difference between 3000 and 4000rpm. I've posted charts comparing them before, since I had the same 2871R setup on a BP4W and a BP6D head. Especially with larger turbos, the difference is dramatic.
#216
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Just odd that it's been putting down roughly 240wtq for a year, and it was only making 230-235 all day, and after a very abrupt OBP limit it was game over. But it's anyone's guess really. I'm interested to see what the other 3 rods look like.
#219
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AIUI, most rods fail in tension (that's where they're weakest), usually at high-RPM with vacuum in the intake manifold (maximum tensile load), and it's not unusual for something that weakens a rod to result in it a seemingly random failure days or weeks later.
FWIW, my stock motor had arrow-striaght rods when I took it apart, with 50K boosted miles on it, much of those at 250-260 rwtq.
--Ian
#220
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Where did you have the redline set? Did you rev it higher when upping the boost? Ever miss a shift and hit 2nd instead of 4th?
AIUI, most rods fail in tension (that's where they're weakest), usually at high-RPM with vacuum in the intake manifold (maximum tensile load), and it's not unusual for something that weakens a rod to result in it a seemingly random failure days or weeks later.
FWIW, my stock motor had arrow-striaght rods when I took it apart, with 50K boosted miles on it, much of those at 250-260 rwtq.
--Ian
AIUI, most rods fail in tension (that's where they're weakest), usually at high-RPM with vacuum in the intake manifold (maximum tensile load), and it's not unusual for something that weakens a rod to result in it a seemingly random failure days or weeks later.
FWIW, my stock motor had arrow-striaght rods when I took it apart, with 50K boosted miles on it, much of those at 250-260 rwtq.
--Ian