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+--- Thread: Holset Turbo Maximum Specs... (/showthread.php?tid=471)
Holset Turbo Maximum Specs... - Rawze - 05-27-2016
I found a video by Cummins that actually mentions the Maximum specs of a Holset VGT.
Max RPM: 150,000 RPM.
Max EGT: 760-C (1400 F).
Max Cold Side Temp: 200-C (392-F).
These settings can be found inside the ECM parameters as well.
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RE: Holset Turbo Maximum Specs... - Mrkentee - 05-27-2016
That 1400F egt is probably airstream temp, right? What comparison can be made between that and heat sink when the probe is on the outside?
Along with that-when the fan comes on and brings that temp down,is it real, or is it just fooling the probe & gauge?
RE: Holset Turbo Maximum Specs... - Unilevers - 05-27-2016
1350F for 5 min or 1150 sustained - right from the holeset engineering department.
i have personally run a 551 vgt at 175k and it held, for a month.
RE: Holset Turbo Maximum Specs... - Mrkentee - 05-27-2016
"i have personally run a 551 vgt at 175k and it held, for a month"
????
RE: Holset Turbo Maximum Specs... - Unilevers - 05-27-2016
(05-27-2016 )Mrkentee Wrote: "i have personally run a 551 vgt at 175k and it held, for a month"
????
got to push one to the extreme limit to see what it would do. it had peak speeds of 175k multiple times over that month. the vgt stuck from heat, the turbo still worked fine bearing wise.
RE: Holset Turbo Maximum Specs... - trucklogger2 - 05-27-2016
Someone was telling me if the turbo doesn't turn white after a while of use, it probably is not getting that hot and not abused. Has anyone seen a white discoloured turbo like this? Is there any truth to it?
RE: Holset Turbo Maximum Specs... - Mrkentee - 05-27-2016
(05-27-2016 )Unilevers Wrote:(05-27-2016 )Mrkentee Wrote: "i have personally run a 551 vgt at 175k and it held, for a month"
????
got to push one to the extreme limit to see what it would do. it had peak speeds of 175k multiple times over that month. the vgt stuck from heat, the turbo still worked fine bearing wise.
Yeah. I missed that. That's cool!!
RE: Holset Turbo Maximum Specs... - Unilevers - 05-27-2016
(05-27-2016 )trucklogger2 Wrote: Someone was telling me if the turbo doesn't turn white after a while of use, it probably is not getting that hot and not abused. Has anyone seen a white discoloured turbo like this? Is there any truth to it?
this is true, they get a light blue/white tint to them when they are getting hot.
RE: Holset Turbo Maximum Specs... - Rawze - 05-28-2016
(05-27-2016 )Mrkentee Wrote: That 1400F egt is probably airstream temp, right? What comparison can be made between that and heat sink when the probe is on the outside?
Along with that-when the fan comes on and brings that temp down,is it real, or is it just fooling the probe & gauge?
1400 is max spike, -- It can withstand 1350 for 3 - 5 minutes,... and that translated to a casing temperature of roughly 1050 degrees F (outside the turbo).
Having the EGT probe mounted to the outside of the manifold is NOT going to give someone an actual EGT reading. That is not the point of putting in on the outside, but only monitoring the 'Heat Soak" instead.
A "Heat Soak" gauge in the dash is meant to be used a fuel savings device. It does not matter that it reads lower than the actual EGT's. It is a tool that gives the driver an average temp reading while climbing hills, and pulling heavy freight that can be used for using better driving habits, and therefore saving them fuel.
I.E.> It is the exhaust manifold casing/metal temperature that the driver uses to maintain and keep down, find better ways to climb hills and such. The less average heat buildup (less heat soak) to do the same amount of work = the more fuel savings. It does not really matter that it reads incorrectly vs. the actual EGT's, but that it reads something relevant to the work being done. It becomes more of a gauge that tells someone "How hard am I working that engine" more-so than anything else... and that can be very useful.
If your fan kicks on and drops the "heat-soak"/manifold temp readings then also, YES, that is real, and it is NOT fooling any kind of sensor. Good Air-flow around the outside of the turbo will also help keep its temperatures in check and allow it to absorb/withstand more internal heat over time.