Holsets and Possible High Boost Issues?

[-red97rum-]

You're over-restricting for running boost above 30psi. That restrictor in the link is .075"; you'll want to drill that to around 7/64" (.109") to keep from killing your HX40....or run no restrictor at all if you're sure the oil pressure is below 72psi at all times, as Kurt has said above.

Well too late for that. I was out doing some tuning last night and had the car feeling really good. HX40 boosting around 37-38psi, just dialing in my AFR and starting to throw some timing at it. After a hand full of pulls.. Clink, Zing!! No boost. I can move the compressor wheel every which way. I think the shaft may have snapped.

I took the restrictor off to measure it and you're right Justin, it's .075-.076. I was going by what was listed in the ebay auction as .04. So I kept the restrictor in place and proceeded to beat on the turbo. My car routinely makes upwards of 100psi of oil pressure at high rpm. If I can get away with rebuilding this turbo cheap enough (doubtful) I'm definitely going to borrow by buddy Clint's (turboawdfanatic) oil pressure measuring rig. Lesson learned here, don't assume anything when it comes to oiling your holset.

Sorry TSimage, didn't mean to clog up your thread with my shit.

 

[bastarddsm]

Man whats going on with these HX40's. What are you doing to make them last justin?

Redrum, can you post or email me some really good pictures of what ever broke on your hx40.

The HX60 guys with the newest aftermarket billet wheel are breaking shafts a couple times a year, and yet the bearings are still perfect, infact most times, they clean up the compressor housing, and put a new turbine and compressor wheel it and go back to pulling. They speculate that its the really thin blades straightening out and grabbing the compressor housing locking up the turbo, and then it twists the shaft off.

So in your case, if the shaft broke, I can't imagine that it was the direct result of insufficient oiling. I just wonder if lack of oil kill the thrust bearing and the compressor grabbed the housing and locked it up like above. When the hx60's do it, its just like a light switch, all is good then boom, game over.

 

[JusMX141]

Man whats going on with these HX40's. What are you doing to make them last justin?

Oiling them according to Holset's specs while taking actual engine oil pressure into consideration instead of just throwing darts at a board.

Keep in mind it's much cheaper and easier to rebuild a turbo with blown seals from over-oiling than it is to replace a turbo with a broken shaft from too little oil.

 

[-red97rum-]

Redrum, can you post or email me some really good pictures of what ever broke on your hx40.

When the hx60's do it, its just like a light switch, all is good then boom, game over.

Sure, I'll get you some pictures. I'm going to try and get it off the car and apart this weekend.

That's exactly what happened, car was pulling great and boom, nada..

 

[Killa_dsm]

Keep in mind it's much cheaper and easier to rebuild a turbo with blown seals from over-oiling than it is to replace a turbo with a broken shaft from too little oil.

Never thought of it that way. I guess I should change out my .078 restrictor since I plan on upping the boost next season on my h1e. Its been doing fine at 30psi with that size restrictor but as you guys stated, its probably safer to run a larger restrictor... Or I should stop being lazy and actually check oil pressure at the turbo.

 

[JusMX141]

The H1 turbos also have a smaller oiling hole in the thrust plate, so this will cause less parasitic drain on the available oil in the cartridge- leaving more oil available for the journal bearings.

I'd still punch that restrictor out to around a 7/64" hole (which happens to be the same size as a -3AN line's I.D.) just to be on the safe side if you aren't able to check pressure.