So last week I installed a set of 7x10 injectors.  I am thoroughly impressed with them but they make me nervous with my stock HY35.  I'm traveling for work right now and happened on a good deal on an HX35 off another 01.  I scooped it up because of the price.  No shaft play and looks pretty good.  From what I've read this should be a direct swap for the HY.  Is there anything else I may need?  I'm planning on hauling my fifth wheel back home Friday and may try to install in the hotel parking deck.  I'm sure they will love that!  The HX should have lower EGT's than the HY correct?

 

Thanks!

6 minutes ago, dave110 said:

Sorry if I missed something here. We went from rebuilding to drilling and milling. I can do those things easy enough. What is the improvement in drilling the hole to 7/8 and milling the divider? Is this just a standard HX 35 or is it a hybrid or being used for twins or something?

 

This is a standard HX35.  While apart for rebuild I am doing machine work per DAP's advice.  Opening the hole and milling the divider allows the flow to the wastegate from all 6 cylinders instead of just the front three.  Results in lower EGT's.

20 hours ago, Manimalmother said:

Results in lower EGT's.

But that should only be affected on high PSI when wastegate is set to open? Am I thinking correctly. 

My wastegate isn't even hooked up it's always closed, I rely more on tuning and defuel settings as backup. I can see where milling divider may help in better spooling, unless it has nothing to do with that.

2 minutes ago, Dieselfuture said:

But that should only be affected on high PSI when wastegate is set to open? Am I thinking correctly. 

My wastegate isn't even hooked up it's always closed, I rely more on tuning and defuel settings as backup. I can see where milling divider may help in better spooling, unless it has nothing to do with that.

 

I'm just doing what DAP said to since I have a mill.  Lol

I'd like to hear @dieselautopower's explanation. I'd hate to miss out on a free performance upgrade 

On 3/27/2019 at 3:07 PM, Dieselfuture said:

But that should only be affected on high PSI when wastegate is set to open?

Correct,  It will help top end power.  Low end spool up will be slightly inhibited as you will lose some of the pulsing of the twin volute.

 

Reducing back pressure is important.  1.2psi back pressure or lower  to 1.0psi Boost otherwise you are leaving HPon the table.

 

Running a waste gate or getting a larger turbine wheel or housing will reduce back pressure.  You add more exhaust gasses/ from fuel/ boost/ higher RPM and it gets constricted.

 

The stock hx35 is about 58mm exducer on the turbine (25.4mm = 1")   =2.3"  figure you have a 7mm shaft, + hub (lets say 2x 3mm=6mm)  and a number of blades on the shaft.  So with bad math we get to about 45mm with blades in the way.  So thats about 1.8" with blades.  Enter the wastegated housing... 17mm to 22mm are common sizes,  S300 turbos usually have 2 of them. 

 

So with the wrong size turbine/wastegate/ turbine housing its common to have over boost (less efficient), over speed of the compressor wheel (reduced life from centripetal forces on the wheel = deformation, oiling problems, less efficient, more wear),  and restriction to the flow of the exhaust).  Its about flow in and out of the engine (boost does help). Think of a water hose.  Low pressure... high flow.  Kink the hose and you get 40-60psi.... and no flow.    There is a sweet spot and a good place to start is 1.2back pressure to 1.0psi boost.

 

No one would recommend ditching a 3" or 4" exhaust and putting a 2" exhaust on just to overspeed the turbo, make it less efficient and wear out your turbo faster to create greater pumping losses in HP and a pressureized engine/box).  But that is what blosking off the wastegate can do for you if you do not know your boost /drive pressure ratio.

 

Who has measured their back pressure/ drive pressure and lowered their boost to bring back pressure to a more beneficial #?  Please post your experience.

 

Manimalmother,

 

Looks like you did a nice job.  The more you pull out of that center divider the more the sides can equalize pressure and gate from both sides, but the more it disrupts the pulsing and therefore the spooling of the turbine.  If more power is your goal do aggressive machining  as pictured.  If you want a small reduction in drive pressure/ with less reduction in spool go milder.

 

 

 

Again the machine work looks great.

I have everything to monitor drive pressure, but then decided ignorance is bliss and never followed through. 

 

If it gets any more serious than how it currently sits, it’s going to get a 73mm turbine on the s300 and then I’ll be fine. 

Edited March 31, 20196 yr by trreed

Turbo is back together and going on right now!

On and running.  No test drive yet.

We'll test drive was an absolute failure.  Half a mile from the house I heard something let go.  The noise it made sounded like a boot getting blown off.  I shut it down and pulled over.  First thing I saw was the large snap ring holding the compressor housing on had let go.  Then I pulled the bhaf off and saw the damage to the wheel.  Not sure what happened first, but she's toast.

Send it back for repair... Makes me wanna cry. Just as good as me feeding a turbo a hose clamp.

It was probably caused by whatever dummy rebuilt it.

1 minute ago, Mopar1973Man said:

Send it back for repair... Makes me wanna cry. Just as good as me feeding a turbo a hose clamp.

 

Got the turbo back off and it appears that I didn't have the snap ring fully seated.  Shaft spins perfectly fine.  Coincidentally, here's a screenshot of where I was when it let go 

 

 

20 minutes ago, Manimalmother said:

Got the turbo back off and it appears that I didn't have the snap ring fully seated.  Shaft spins perfectly fine.  Coincidentally, here's a screenshot of where I was when it let go 

 

 

Did happen to come down TURKEY creek road first? 

Man I hate that for you. This head gasket replacement weighs heavy on my mind of what I might miss. Hope to crank it tomorrow.

47 minutes ago, dripley said:

This head gasket replacement weighs heavy on my mind of what I might miss. Hope to crank it tomorrow.

 

I've got faith in you @dripley . You've got a 100k jump on me and keeping it together. As long as there is no extra parts I'm not going to worry.

 

Anyone happen to have an hx35 compressor wheel laying around?

1 hour ago, Manimalmother said:

Anyone happen to have an hx35 compressor wheel laying around?

 

https://www.amazon.com/Holset-HE341-Blade-Compressor-Wheel/dp/B01BUK4AR2

3 hours ago, Mopar1973Man said:

 

https://www.amazon.com/Holset-HE341-Blade-Compressor-Wheel/dp/B01BUK4AR2

Bought it.  Thanks

Sorry to hear about your turbo.

 

Unfortunately I do not think the he341 will work.... iirc its 58mm and your hx35 is 54mm or 56mm.  

 

 

Heck, you'd be better off with my HX35/40 (60/60/12).

HE341 should work, it's the HE351 that's 58mm. 

Edited April 8, 20196 yr by trreed

he351 is 60mm, same as hxsuper40