Yeah, the kit was budget for sure. Found the receipt - $2500 all in for DP, Manifold, Turbo, and gaskets. Builder originally rated the kit as Turbo - Good, Downpipe - Acceptable, Manifold - not great but street car ok. I'll bring up your concern but I think he has already gone through it. It had an etch that caused an exhaust leak that he fly cut on a CNC. The other thought was gasket bits may have been the issue. Seems like the pressure would have blown them away rather than through, but not outside the realm of reality.

 

Unless a recent phenomenon - and short of driving Miss Daisy - the bridge in the manifold would be fairly effed I'd expect with an excessive EGT over 25k miles.

Did find similar wheel damage on supposedly chinese sourced garrett copies several years ago, but put that down to a known FOD incident. Must have been a nice woof, woof at idle with that exhaust leak! We usually blow them (and resurface the flange) every few events....never had a gasket go through the hot section.

 

Agree - light load lean is still relatively low EGT. What I said mostly applies to close-to-full throttle running, like in a racecar in a race or in a loooong pull up a mountain.

 

Interesting - seems like you make a good point on the bridge. Hell, the manifold was the "weakest link" pointed out when it was new. Wouldn't EGTs high enough to do this to the wheel eat through the mediocre manifold first or as well? Genuinely curious about that.

The overall answer might be that yes the EGTs were too high.. for a knockoff hot side wheel.

Also, wasn't this around the time Garrett was offering the massively discounted CHRA exchange program? Without going all tinfoil hat, I wonder if the two events were related. Perhaps the issue was a bit bigger overall or the knockoffs weren't just knockoffs but an issue in sourcing/manufacturing.

I'm ashamed to admit it, but I never noticed the exhaust leak! Sounded fine at idle. I think it was tight enough to only be notable under load but I attributed the sound to an atmosphere-dumped wastegate which always sounded like chaos.

 

I suppose the turbine blade section is thinner further downstream, what I've found at least, the bridge drops, distorts and erodes at high temp, way earlier and at a lot fewer miles than what you've done. That one appears fairly sharp edged and crisp.

Would have thought with that amount of gasket blown, it would be a bit smoky at light off too. With the typical rotary exhaust note though, often when I think it's going to be perfectly ok, a smoke test will disabuse me of that notion! Short of welding these twin scrolI things to the manifold, the use of the hi temp Fuchs sealant, that one infamous guru here and elsewhere recommended in days past, seems to work fairly satisfactorily.

 

like this!