Wow..just wow...

For someone who sounds like you know what you are talking about, you really don't know a thing.

 

Shops clip the 71 wheel too. I was talking to a local turbo shop yesterday and when I said drive pressure he said clip the turbine I'd think the larger low pressure turbine would help my drive pressure, but am unsure how a clipped 71 wheel would act when compared to my current 65mm

 

i found this on another site...

"The older S300 turbos utilized a 64mm 11 blade pinwheel which often causes surging issues when coupled with a 64 or 66mm compressor wheel. The only way to previously eliviate this was to clip the pinwheel, but this process lowers the efficiency of the turbo. The newer versions of the S300 turbos offer a 71mm 10 blade pinwheel which offers much greater efficiency when coupled with larger compressor wheels. The new pinwheel also greatly reduces the turbos tendancy to surge under load, so future buyers of the S300 line of turbochargers, make an informed decision."

 

Most people dont really care how a Turbo looks on paper, just how it performs. Get advice from people who have used them just like we do with everything else (injectors, intakes, modules,chips, etc.) I agree a trubo may not be Efficient up to 550 horsepower (egt wise) but it will lay that down on the ground, therefore its good "up to 550 horsepower"

 

Interesting...........care to qualify that statement so the rest of us understand what you mean? An ad hominem attack without any explanation is rather unfair.

Just the observations of a newby to the mysteries of high performance Cummins engines.

 

Philosophically, I adhere to anti-ad hominem interaction.



Now - 'bout time for this subject to come up again!
Diesel HIGH-performance is still relatively new, with a steep learning curve... witness the weekly bombshells of who did how much how fast for how long with so little.

Most of our "technology" to increase performance was borrowed from the industrial/commercial sector (like the GMC Roots-style blowers were adapted from OTR rigs to gassers back in the day), and much of it is still in use; however, the operating range/envelope of an industrial turbodiesel is quite different than that of a personal vehicle application.

The vast, concomitant amount of engine operating envelope parameter variables increases the order of system complexity by several magnitudes, from a data processing point of view. Obviously AirWerks (along, no doubt, with the other major manufacturers) has at least one, but who among the turbodiesel shops has a computational fluid dynamics facility equal to the task?

Far easier (and cheaper ) to run empirical tests on existing hardware than to theoretically design your own SuperTurbo.

Lastly, of course, one must follow the money.
With "high-performance" turbos, it's strikingly similiar to a commodities market (such as gasoline), where the numbers (maps, etc.) aren't particularly useful as a selling point, since they all must follow the same laws of Physics.
Instead, marketing is much more effective when espousing "runs cooler" "spools faster" "best HP" or whatever...

No one can predict with accuracy how much power a turbo will make on YOUR engine, unless it was already tested on an identical mill. Engines are a bit like fingerprints, especially when they are modified!

Now, there's are a bunch of great products on the market right now, and it's amazing to see how well the aftermarket has responded to the demands of the Muscle Truck boom!

However, I firmly believe there is plenty of room left for innovation, R&D, ingenuity and pure serendipity for the high-perf diesel turbocharger.

 

Probably not. A quick search would prove that!

 

Top is a factory wheel bottom is a clippped wheel bad pic I know but you can see that there pretty close to the same , most HIPO turbos come with clipped turbine wheels machined already so theres no need to take it any farther

 

I suspect it would lose efficiency and spoolup would worsen.

Clipping is a band-aid, imo. It seems like clipping is so ingrained in turbo shop mentality that it's almost dogmatic now.

Take my opinion with a grain of salt. After all, I'm the ignorant guy who bought those overpriced Don M injectors

 

I am familiar with your posts, and I will stand by my statement.

 

Mr. Hohn does not question any results with the Mach whiz bang injectors, and has no interest in knowing what parts actually make an injector pop.

However, when it comes to turbos, he thinks all the dyno results are running an extreme correction to make them look as good as possible, and is very skeptical. Regardless of how many good reviews have been posted.

Wanting to know the compressor map on a specific turbo is exactly the same type of information as knowing hole size, spray pattern , and pop off pressure of an injector.

He previously claimed that "Picking injectors isn't like picking a turbo at all. And the business angle is different too", that is a very dumb comment.

I will agree that turbo design and injector design are different, however, both are key points in having a well running truck.

I just find it very biased that he demands compressor maps, and full explanations of everything turbo related, but blindly follows whatever he is told on injectors.

 

Hohn asked for compressor maps. He didn't ask for how a turbo shop might do some "trick" machining to some whiz bang turbo housing. I think that's the difference.

 

I was gonna say the same thing. There is no comperable item to a turbo map for injectors. There is however the guy that make them being very helpful to the prospective custome with questions as he tries to decide what to get.

IIRC Don makes his from scratch, not the same as modifying a S300 and claiming you have the greatest turbo ever.

 

But they are Based off of a 24 valve injector just as the turbos are based off of an s300

 

Last I remember, Don is using Bosch bodies, since they are the strongest ones available.

Like a billet engine block though, it's the machining/assembly that really makes the difference!