I was not assuming the catalytic converter was clogged.
I realize it wasn't your statement, but the logic given earlier for getting from running on E85 to having clogged cats strikes me as probably incorrect.
I wasn't saying it was gospel, I was merely stating it's a
possibility and I've seen it happen on a couple forced induction applications, both supercharged and turbocharged.
Using both pump and E85.
To answer a few other of your questions you asked myself earlier in thread:
Knock itself isn't what kills a turbo. It's the logic in what the ECU does when it retards timing. If you're at WOT and you get a 4º or a 5º timing reduction at full power enrichment, there's a decent amount of unburnt(cool) fuel going out the back. If it can kill a catalyst, it can kill a turbo.
Can is the keyword here, not will,
can.
You can't see how a turbo would fail if there was suddenly a restriction in place that would cause it to work harder in order for it to spin?
If it was an externally wastegated turbo setup it would only exhibit power loss, but since the wastegate dumps into the rest of the exhaust like everything else, the turbo never gets to spin without doing a ton of extra work.
Using the clogged cat example, yes it would build boost faster, which means the ECU would see it's target airload, open the wastegate sooner, but that exhaust is still dumping to an over restricted system that doesn't have enough volume to do it's job anymore.
Yes, overall you would be lessening the amount of air the engine and take in and move out by putting such a restriction in the exhaust, and yes there would be less air moving past the turbine because of this. If the car moves under it's own power and only making say 100hp, that's still about 10 lbs/min +/- a lb or two that's being moved with no place for it to go when it's done being used.
In supercharged cars it usually kills the exhaust valves because that's the next thing working backwards from the cat(terminator cobras that are running cats that are 1/2 milers or highway stars). In turbocharged cars, usually the turbo becomes the martyr in clogged cat situations, especially in internally gated turbos.
If you
still can't see how a low d/p across any turbine due to restriction can lead to shaft failure, think that the amount of force being applied hasn't changed, and the energy has to go somewhere.
No need to throw a bunch of shade over the internet because someone throws some ideas out there based off of their own personal experiences.
