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HX40II Turbo Install

I think there is a trade off. Holsets are know for fast spooling, possibly because they use a larger radius housing and the way their blades are designed. Mitsubishi may be using small radius housing because they are cramming them in tighter spaces, and may need more blades to spool, or the blades arent as wide.

I do not see how a 12-blade fan would be more efficient than a 10-blade in general. The purpose of the 10-blade on the Holset is to achieve better flow. But depending on the design a 10-blade could have just as much surface area as another manufacturers 12-blade. And the pitch on the 12-blade could be less so that it doesnt slow the air as much. Comparing a Holset 12-blade to a Holset 10-blade, the 10-blade will alow more unrestricted flow.

Since I was originally comparing the Holset H1C to the Holset HX40, I thought it was a reasonable explanation how the smaller housing could be running similar drive pressure values.
 
buddy said:
Fewer blades has less surface area to catch the air on its way out. There is more space between each blade, less obstruction. Comparing Turbonators H1C to the HX40 its one reason it will be able to have similar backpressure values even though the HX40 has a smaller housing.

Blade design also has an effect, to where some 12-blade turbines might flow as well or better than the Holset 10-blade design, depending on their pitch, surface area and size.
Click to expand...

Exactly, Buddy, because the surface area of the ten blades may very well be equal or greater than that of the twelve blade and of an entirely different design. Then take into consideration factors such as blade shape and pitch and suddenly we are comparing apples to oranges to bananas to grapes. One has to look no further than to electric radiator fan designs to see the various configurations of say, a 15" diameter fan, when it comes to number of blades, pitch, shape, rpm, etc., etc. and yet several different manufacturers will all offer them as say, 2500 CFM fans. Look at the various impellers available for standard configuration turbos that radically alter their flow characteristics, the Bat-Mo-Wheel impeller being one of them. One simple change totally alters the performance of the turbo.
 
I think a general rule could be said that fewer blades will cause less restriction. With the fan analogy, our early 6.5s had the 6-blade, which doesnt have enough blades or surface area to pull in enough air for most people. So they get the 9-blade. Its the opposite on the turbo though, if you want to flow more you dont want your blades catching as much air.

Its just a general rule though, because of those things already mentioned about actual blade surface area and pitch. I have the benefit of seeing the GM8, HX40WII, ATT and HE351ve in my garage.

The larger inducer/exducer 10-blade turbine is one of the big reasons I belive the HX40WII is superior to an HX35, not just the slightly larger housing. It is aslo why its more of a universal, works with anything kind of turbo. Its not the biggest and best flowing, thats for sure, but it does alright, while also having the low end, off the line advantage.

Here are some pictures to illustrate some things

Can you believe GM decided to push our 6.5 liters through this peanut of a turbo, and some still contend its the best match
P1010593.jpgP1010595.jpg

This 3rd pic shows why you need a special elbow for the HX40WII, the back sits further back from the T3 mounting flange, and the radius is larger so the wheel is closer to the engine (further from the T3 mount).
P1010596.jpg

The compressor side of the HX40WII lines up with the stock manifold pretty well, because from the T3 mount to the housing outlet it is about the same height as the GM turbo. The regular/larger HX40 and ATT are about the same height, about an inch taller.
TurboExhaustSizes-labels.jpg

The compressor on the ATT looks real good for flowing, one of the reasons you get some better MPG on the interstate at low boost. I don't know why Holset paired that behemoth of a turbo HE351ve with the compably small wheels, it makes it less worth using IMHO.
TurboSizingCompressor-Labeled.jpgTurboSizingTurbine-Labeled.jpg
 
buddy said:
There isnt one, which helps it flow a bit better, smoother housing to create less turbulence.
Click to expand...

Ahh Ha so its like the Banks setup for 6.2's that GM also used just prior to the 6.5's turbos. The boost is controlled by the turbo running out of input and up its efficiency curve. Not intending to dis it in any way, just that its the same approach.
 
L98TPI said:
Ahh Ha so its like the Banks setup for 6.2's that GM also used just prior to the 6.5's turbos. The boost is controlled by the turbo running out of input and up its efficiency curve. Not intending to dis it in any way, just that its the same approach.
Click to expand...

Actually the banks was a tdo 6 housing if I am correct, it had much different wheel configurations. Not really a comparison except for being non wastegated. Yes non wastegated turbo Boost is NOT controlled by exhaust cfm, it is controlled by exhaust heat.
 
Looks like mine will be in tomorrow, so hopefully I can get it installed this weekend.

RDM, or others who have installed this. Did you cut down the compressor outlet or just grind off the ring? Also, did you need to cut down the intake any?

I also got the 2.5 to 2.25 reducer that RDM sells.
 
I should have asked, "Did you grind off the Vband" rather than the ring, but I think you knew what I was talking about. And, I think I found the answer as this topic was just discussed over at the 'place today, but would still like to get someone's input on it.
 
Just gcut that v band flange right where it starts. You will have to cut the upper manifold an inch or two or so im not really sure cause i had cut mine previously from another turbo. I just used a sawzall on it but i removed the intake side of the turbo first so no shavings make it in the turbo. then jjust smooth any burs with the right grit sand paper or aluminum oxide.

Good luck with the install! You will love this turbo!!
 
You can adjust the boost level that the wastegate pops at on the one it comes with, from like 15-30psi, I believe Bruce explained it earlier in the thread.
 
buddy said:
You can adjust the boost level that the wastegate pops at on the one it comes with, from like 15-30psi, I believe Bruce explained it earlier in the thread.
Click to expand...
He did. The can you have sets the low end of the boost. So the one that comes on the HX40 is a 20 psi so you can adjust it from 20 up till the turbo stalls out or runs out of heat or something goes boom. :hihi:
 
Slim Shady said:
Actually the banks was a tdo 6 housing if I am correct, it had much different wheel configurations. Not really a comparison except for being non wastegated. Yes non wastegated turbo Boost is NOT controlled by exhaust cfm, it is controlled by exhaust heat.
Click to expand...

The 6.2 Banks turbo was a T04B turbo which was non-wastegated. The 6.9 and 7.3 IDI banks kits used both the T04B early on, and later the TE06H wastegated turbo.
 
L98TPI said:
Here is the cheap and easy fix to the HX40's waste gate being set to 20 psi out of the box. There are units with various length rods also, just match it up.
This one is set at 10 psi. Add a remote boost control valve and you can turn it up from there from the cockpit. Tada :hihi:
http://www.ebay.com/itm/T3-T4-Turbo-1-Pt-Wastegate-Actuator-90D-4-L-Rod-/160765654994
Click to expand...

I recently picked up a Holset HX35W (off an 01 Cummins) and am collecting parts to install this on my 94 K2500.

If my memory is working right the guy I got this from said that it was set to 30 PSI boost (may have been 20). With this and subsequent posts between you and buddy I'm questioning being able to re-adjust the wastegate down in PSI.

Do you know if it is possible to re-adjust the stock can on this HX35? Or, will I need to go with something like this ebay replacement can?

Don
 
They way i understand it is the spring inside is set for 20psi and can not be lowered, I adjusted mine just 3 turns away from the end and that did nothing to lower the boost. If anything it can be adjusted higher then 20psi.

I like the idea of using a 10psi can or pot or whatever u want to call it, then plumb in an adjustable boost controller like one that was previously posted on this thread. Then boost can start out at 10psi and go up from there just by adjusting the the controller from in cab.

Am I on the right track here?
 
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