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HX-40

because unlike the ATT some chinese turbos are not made very well compared to their american cousins there trying to imitate and carnage happens.
 
That's a possibility with any part you install Chinese or amer. these days.

If you're that worried you could weld in a debri scree in the intake system.

The quest will continue and there will be those who will take one small step for safetys sake and those that will take the leap for all out experimintation and find the ragged edge.

God bless the fools who go where no fool has gone before!!!
 
On ebay there are a couple different knockoffs with actual different specs. A larger turbine trim, the difference between its exducer and inducer, is typically good as the actual outer diameter decreases. When the turbine itself is just large outer diameter (inducer) it gets less efficient, but a small one with large fin area is good. So if the exducer on the turbine is smaller but the trim is the same or more then it would be a better fit for the 6.5. I'm not sure on the compressor wheel, but since it was mentioned shafts were breaking on them, I would pick one with a smaller outer diameter (exducer on compressor), like 76mm max if turbine is 76mm, with a max inducer of 62mm.

I believe the GMX turbine exducer is 54mm and the inducer is 62mm. And the Holset HX40 turbine is large like 76mm inducer and 64mm exducer with 71 trim, and another that is 70mm and 60mm with a trim of 73, which would be more approriate for the 6.5 most likely. And the knockoffs could have whatever.

I dont know how they get the "trim" value but its that area of the fins between 62 and 54, so in that 8mm span. With a wider span I would expect the trim to be higher, but thats not the case on the Holset turbines. I need to read up a lot more on turbo tech to understand it more, but I gather you dont want really big turbine or really big compressor. The housings matter too, an HX40 with the large turbine wheel and 16cm housing might seem real laggy, but get the smaller turbine wheel and 12cm housing and it will spool quick.

Not all HX-40s are created equal pretty much.
 
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Wouldn't the bigger turbine flow more exhaust ? For that price it is worth experimenting with. I also thought of trying the HY35 , like the early common rail Cummins. There is a super 40 that the Cummins guys use that is supposed to be pretty sweet ,and uses a high flow 6 blade compressor,china ones are 8 Genuine holsets have 8,7 or 6.
 
If you flow more exhaust it means it wont build boost as fast and maybe not enough because boost is built from a pressure differential across the turbine. For a normal 6.5 performance person that wants less than 20psi boost it may not be efficient, because it would take a lot of fuel to make the drive pressure if it flowed too well.
 
Ferm is right, ON the 8.3l CTD they lag like hell even with the AFC turned up. I know I have one and it is a dog off the line and is inconsistent in throttle response and yes, I replaced the O ring in the AFC. Most Cummins guys chuck the Holsets which is why they are available so cheap used on ebay. I'd look at a Banks or a Garret. FWIW I think The GMx Turbo works very well for the 6.5TD. It just needs WMI or an ATA. Same problem Cat had with the 3208T. Snappy engine that could easily produce ALOT of power but could also melt it real quick. I always find it Similar in flaw to the 6.5TD. It seems to share same issues. Heads cracking, HG's High egts,and when it's done, it's done.
 
The GMx is a good turbo, unless you like having boost of 20+ psi. And I run that every day, which just isnt as strong and you can feel and hear the engine working harder to do it on the GMx turbo compared to one that is more efficient in that boost area. So if you are only after good performance and not holy crap this thing is strong perfomance the GMx is good.

That can actually be provem in math and real world, how much more parasitic the GMx is of engine power to provide boost pressure, while also transferring more heat to the air.

Seeing the specs on the 8.3L turbos they would have to be laggy, with 16cm2 housings that have 76mm diameter turbines and 88mm diameter compressor wheels. Thats why we should look for the ones with smaller turbines and compressors. And the "quick spool" mod is using an HX35 14cm2 housing instead of the 16cm2 one, to provide more backpressure capability faster.
 
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