I went back and took a look at the compressor map for best 50/55 wheel.

At 1000 ft of elevation ( a good average I suppose ) the pressure will be close to 14.3

The map shows the compressor making .75kg/sec or 100 pounds per minute at 29 pounds of boost.
It drops to .70kg/sec at 40 pounds of boost
It drops to .65kg/sec at 44 pounds of boost
It drops to .55kg/sec at 47 pounds of boost
It drops to .50kg/sec at 50 pounds of boost

After 50 pounds of boost it is off the Holset Map and probably overspeeding a bit. Off course from the numbers above you are delivering less mass of air as the boost pressure increases.

BTW, the HX50 will max out at 1300CFM @ 60 degrees ambient temp with one caveat: Euro designed and built turbos like the Holset generally map their turbos at 85 degrees not 60 like we do.

Don~

 

[quote author=Jetpilot link=board=7;threadid=13676;start=0#129139 date=1050609243]<br>I know of a shop in Northern Indianna that has an engine dyno and a 24v motor.<br>[/quote]<br><br>I think this would be a great idea. Is Indiana on the way to Virginia from Sask?<br><br>Rod

 

Rod, I would be willing to test the B-1 against my PDR40 at Clairmont. I am already on the dyno list and we could drive around to compare spool up on a mid hp truck. Let me know if you want to compare them, I will bring the tools and suds. Tim

 

[quote author=Push Rod link=board=7;threadid=13676;start=15#129327 date=1050647192]<br>[quote author=Jetpilot link=board=7;threadid=13676;start=0#129139 date=1050609243]<br>I know of a shop in Northern Indianna that has an engine dyno and a 24v motor.<br>[/quote]<br><br>I think this would be a great idea. Is Indiana on the way to Virginia from Sask?<br><br>Rod<br>[/quote]<br><br> :<br><br>Look on a map Sheepy...IT can be done.<br>Where in Indiana?

 

[quote author=Scotty link=board=7;threadid=13676;start=15#129410 date=1050677572]<br>Look on a map Sheepy...IT can be done.<br>Where in Indiana?<br>[/quote]<br><br>Hmmmm, maybe go do a couple burnouts in the TST parking lot too? <br><br>Rod

 

[quote author=Timinva link=board=7;threadid=13676;start=15#129364 date=1050669279]<br>Rod, I would be willing to test the B-1 against my PDR40 at Clairmont.<br>[/quote]<br><br>This would be interesting as well, however we'd want to externally waste the B1, which would require extensive mods to your exhaust manifold. We may be able to get ahold of a manifold though....<br><br>Rod

 

Rod,

I am not opposed to you using an external wastegate but I am surprised. The B-1 is not available for purchase this way and we were talking about how much more it flows as well as its efficiency so why not test it in the configuration that a consumer purchases it? I have said for awhile now that the B-1 should be limited to 40-45 lbs, looks like you are coming to the same conclusion about heat and overspeed.

As far the dyno shop it is located in Syracuse Indianna just south of South Bend. The shop will be able to check exact flow of the chargers so the flow question would be laid to rest. I will supply the injectors if you will supply a fueling box. I might even be able to wrangle up a PDR-40 to make it a 3 way trial.

Doug

 

Rod, I am probably gonna get a ATS pulse manifold this month so we could cut my stock one if need be. What do you normally wastegate a B-1 at? My Pdr 40 is around 41 psi. Tim

 

[quote author=Don M link=board=7;threadid=13676;start=15#129306 date=1050638508]<br>I went back and took a look at the compressor map for best 50/55 wheel.<br><br>At 1000 ft of elevation ( a good average I suppose ) the pressure will be close to 14.3<br><br>The map shows the compressor making .75kg/sec or 100 pounds per minute at 29 pounds of boost. <br>It drops to .70kg/sec at 40 pounds of boost<br>It drops to .65kg/sec at 44 pounds of boost<br>It drops to .55kg/sec at 47 pounds of boost<br>It drops to .50kg/sec at 50 pounds of boost<br><br>After 50 pounds of boost it is off the Holset Map and probably overspeeding a bit. Off course from the numbers above you are delivering less mass of air as the boost pressure increases.<br><br>BTW, the HX50 will max out at 1300CFM @ 60 degrees ambient temp with one caveat: Euro designed and built turbos like the Holset generally map their turbos at 85 degrees not 60 like we do.<br><br>Don~<br><br>[/quote]<br><br>Your info of the mass flow rate is correct except that it is a little misleading to the average &quot;Joe&quot;. If I didn't know any better, I would never bother to take the HX50 over 29psi, heck it flows more at 29psi (0.75kg/s) than 50psi (0.50kg/s). Which is incorrect. Also you must take into considereation of how much air the engine is taking in. The 5.9 at 2000 RPM takes in quite a bit less air than a Sig. 600 at 2000 RPM. All these factors would change the mass flow rate of the wheel. But you are correct in saying that as the boost increases over 29psi on the HX50 the efficency of the wheel decreases. <br><br><br>If Holset does their testing at an ambient temperature of 85° and Garrett does their testing at 60°, than all the numbers that Holset produces are low, not high. If you bring down the temperature of the air going into the charger than the mass flow will increase.<br><br><br>Don, if you have the HX50 compressor map right there, tell me what the RPM of the wheel is and the outer diameter of the wheel. And I'll tell you if its over speeding.

 

[quote author=Jetpilot link=board=7;threadid=13676;start=15#129459 date=1050683978]<br>I am not opposed to you using an external wastegate but I am surprised. The B-1 is not available for purchase this way and we were talking about how much more it flows as well as its efficiency so why not test it in the configuration that a consumer purchases it?[/quote]<br><br>Actually, Doug, this is the reason for doing this test with an external waste. The B1s have been available for a couple months now with an external waste, and there has never been an arguement that the B1 will be more efficient, and probably produce more HP with it.<br><br>Up to this point, any dyno tests or seat of the pants tests with B1s vs another turbo has seen the 'other' turbo wasted inside its map. The B1, on the other hand, has often been driven to rediculous boost levels that no 'charger of its size could possibly hope to be efficient at. So the tests have not been apples to apples, and no proper airflow comparisons could possibly have been made. It may have even been possible that the B1 would have generated even more power if the fueling levels had been turned when it was on the truck.<br><br>This is all I'm simply trying to illustrate. For all I know, when the two turbos are put side to side in a fair test, with each turbo/wastegate combo tuned, the 50 may very well make more power with lower EGTs (especially with the new wheels. Thanks for those numbers Christian. Much appreciated.). I'm currently trying to get my schedule wrapped around Indiana. As much as I want to see something like this happen, I do have a business to run and customers to service. If Indiana doesn't fit in, then we'll definitely do it at another time. I think the numbers will be very useful.<br><br>Rod

 

[quote author=Timinva link=board=7;threadid=13676;start=15#129463 date=1050684476]<br>Rod, I am probably gonna get a ATS pulse manifold this month so we could cut my stock one if need be. What do you normally wastegate a B-1 at? My Pdr 40 is around 41 psi. Tim<br>[/quote]<br><br>We're still playing with these numbers, but to do a proper job, each truck has to be individually tuned. Anyone can simply strap on 500 HP with #2, but to get the 'good' numbers requires many, many moons of tuning. The 40s have a fair bit of testing behind them, so we've got a good starting point. The B1s haven't been wasted out all that long, so we end up starting from scratch on each truck. By the time Virginia rolls around, we'll have a better idea.<br><br>Rod

 

I think we are on the same page here Christian. The &quot;caveat&quot; I posted was to show the HX50 will make more CFM at 60 degrees than it will at 85. Giving the thumbs up to the Euro designed wheels when comparing them to the American wheels. This being said the HX50 moves plenty of air for the 5.9 at reasonable boost levels.<br><br>Compressor overspeed is a relative term for the most part. You can run turbos off the map if you can deal with the heat generated by doing so i.e..intercoolers, water, etc. As long as the overspeed does not grenade stuff. For the most part my luck and others has been mixed with Holset turbos. I have seen the 50/55 exploded many times with just 50PSI. I cant count the number that have died an untimely death from under 50 psi. The compressor wheels have had casting flaws from the factory on two that I know of. Two of them have also had a bad friction weld from the factory. Something that in a stock application with lower boost numbers may never uncover, but once we go anywhere near 50 pounds of boost they have begun to come apart on just plain old number 2. On the other hand, I know of one dead B-1 from the use of nitrous and massive overspeed. <br><br>Of course as you cool the intake charge down the CFM demand goes up and if you are off the map and out of the largest part of the CFM delivery the wheel has, it can be a double edged sword. Overall boost can be misleading anyway. Residual pressure in the manifold is not what makes HP. It is the overall air density of the air charge. Yes, as boost or pressure increases so does air density, but the higher boost or pressure will also heat and the hotter the air the lower the air density. <br><br>Air being a fluid will always fill the cylinders with the same volume. The only thing you change is the density or weight of the fluid. It still fills the same space or void. Higher density equals more weight. Hot air weighs less than cold air but still occupies the same area. <br><br>An easier way to explain would be that a cubic foot of lead and cubic foot of steel occupy the same area or space, but the density of the lead is higher. If we take air and compress it to a few atmospheres the density goes up. Compressed air is not linear to density hence the need for highly efficient compressor wheels and intercoolers to get back some of what is lost during compression. <br><br>Holset and others maps are very confidential. <br><br>Jet,<br><br>I think the B-1 has been sold now with a divorced external wastegate for sometime. We have had one on order for the test truck for a month or so. <br><br>Kurt,<br><br>Where is the wastgate? <br><br>Don~<br><br><br><br><br><br><br>

 

Don you are corrrect that the be all, end all is air density. Although pressures do play an important roll in scavaging, this has more to do with charger setup than anything. Also you must take into consideration intercooler efficiency and pressure drop. I'm sure everybody would be surprised at the pressure drop across the Dodge intercooler at 50psi plus (This should actually be a flow rate not a pressure, as pressure does not indicate flow).<br><br>I thought you were reading the flow rates for the 50 off of a map??? It should also have wheel diameter and RPM on the map as well. I'm sure that wheel speed is not that secretive, and heck if I had a 50 here I could get the wheel diameter. <br><br>Every turbo manufacturer has there own over speed limit. For standard Garrett production models I think its around 1800 fps (I maybe wrong).

 

Cool Man, Yeah the map is secretive. Sorry. Heck I aint got one of you ask me most days <br><br>We measured a 15 pound drop on the stock intercooler at 85 psi with X amount of CFM. So, you are correct the stock intercoooler is a choke point with too much boost and CFM.<br><br>Don~

 

We used to call the intercooler a &quot;Headgasket saver&quot;. In some ways its kinda good that its so bad. :P<br><br>Seriously though, up at high flow volumes, this drop across the intercooler makes it impossible to get a good delta P across the engine. The pumping losses just keep adding up.