Holset Turbo Question

[zerodsm96]

So I was talking to the owner of my local machine shop today, and I was discussing Holset turbos with him. He was mentioning how diesel turbos do not work under vacuum. So when you use one on a gas engine, if you back off quickly and create a large vacuum on the system it will blow smoke and eventually ruin the oil seals in the turbo. I'm just curious if anyone has had this problem. I have been doing my build around a Holset HX35 setup and this is pretty discouraging. He said you could replace the oil seals with a different kind in a rebuild and be just fine but it would require that. I'm just looking for feedback. Thanks in advance.

 

[JusMX141]

Never heard of this in my life.

There are no "upgraded" seals available for Holset turbos because, unlike Garrett turbos, a Holset generally doesn't have any trouble with oil burning when given the proper incoming oil pressure.


What type of "vacuum" is this 'tard talking about....in the manifold or the crankcase? Turbocharged gasoline and diesel engines both generate crankcase pressure, and on any gasoline engine there is no vacuum seen in the charge piping itself....only in the intake manifold which is after the throttle plate.

Actually, the majority of upgraded turbos available for our cars were intended for use on diesel engines including most of the T3/T4 hybrids. I can't see where what he's saying has any significant role in turbocharger life.

 

[zerodsm96]

If it seems I'm having a hard time explaining it, its because I had no clue what he was talking about. Its like he was saying after a hard pull and you just let off quickly and maybe downshift right after the pull, and that would create some type of vacuum, I assume, on the intake side. I couldn't finish my conversation with him because I had to leave for work. This guy is usually knows his stuff from what I've seen but I'm questioning this. Then again when I was asking about o-ringing my block, he was suprised. He did give me the reaction of "Wow, never thought of that, great idea." I thought o-ringing was an old school thing???? Haha

And thanks for making me feel not quite so newbish.

 

[JusMX141]

Its like he was saying after a hard pull and you just let off quickly and maybe downshift right after the pull, and that would create some type of vacuum, I assume, on the intake side.

....hence the reason gasoline cars have blow off valves / compressor bypass valves on the charge piping and diesels do not.


Bottom line- guys have been installing Holsets on DSMs since 2004 when Bullseye Power made the turbine housings available; I've never once heard of different seals being used.

The only application that requires a different seal to be used are carbureted gasoline applications (depending on the placement of the charge piping on the intake) that need a carbon seal on the compressor side to prevent the vacuum from drawing oil through the compressor seal. Carbon compressor seals haven't been used since the mid-80's; perhaps this dude's about twenty years off on his gasoline turbocharging knowledge?