Holsets and Possible High Boost Issues?

[TSimage]

The title says it all.

I ask this because 'we' (and by 'we' I mean 'we' as in those interested in seeing the Holsets succeed) have a chance to get one of our beloved Holsets in the hands of a big named tuner first hand. And by a 'big name tuner' I'm pretty much referring to the top dog in the entire 4G community right now. Lucas English.

He's new to the Holsets but admits he has wanted to play with one and is definitely excited to have the opportunity to do so. Lucas, unlike many of the other big name tuners isn't tied down to a turbo company so I don't worry about any sort of bias or negative feelings towards tuning this setup. I was worried at first because my car had one of his favorite turbos the FP3065 on it that he was excited to tune but then I flipped the script on him and am throwing him something completely foreign with an HX40 billet 7 blade with the T3 .70 BEP housing.



My setup is as follows-


Built 2.3l with an 8500-9000rpm redline
Race port/built head
FP4 cams
HX40 billet 7 blade
T3 .70 BEP housing
ERL or similar exhaust manifold
44mm WG
Custom full 3" exhaust
Hallman MBC
Magnus V3 intake manifold
90mm Q45 TB
4" thick Buschur FMIC w/ 3" piping
50mm TiAL BOV
EcmLink V3
S/D
MSD DIS-2 ignition
Twin Aero Stealth 340s
1850cc injectors
Fuelab SS/E85 filter and AFPR
-8an in / -6an return
Auto
4500rpm Stall
Nitrous 75hp wet shot (spool)
E85 for street
E98 for track



Basically it is what I have researched over the years and determined to be the absolute most efficient setup for the HX40. Capable of spooling it the fastest and using every drop of its power band with hopefully no fall off.

There is one area that I have yet to verify, one that Lucas and myself need to know heading into this tuning session and that is related to maximum boost levels. I have seen multiple occurrences of high boost i.e. 40PSI+ failures related to Holsets and specifically the HX40, on various platforms at that.



2 Things I need from those of you who have raveled in the world of high boost Holsets-


1) Is there truly an issue with Holsets and high boost or are all of these occurrences accounted for as owner negligence or freak accidents? (I know the most recent case the owner suggested that oiling issues were to blame)

2) With that in mind, what boost levels should I be looking to max this turbo out at safely?



This thread is open for all to hopefully use it for their own research in the future but its being heavily moderated and I ask that it stay civil and technical. This isn't a bash thread, it isn't a "My turbo is better than yours.." 'Garretts rule" or any sort of debate thread. If you haven't any experience with Holsets at high boost levels, please refrain from cluttering the thread.

Thanks in advance guys. Hopefully we can get to the bottom of this and use it as a means to get Holsets more widely accepted. Last thing we want is to put this in a big name tuners hand and have it blow up as soon as he turns up the wick.

To combat that Justin (jusmx141) will be the only handler of this turbo besides myself. His experience with them is above and beyond. It will be rebuilt by him and verified by him as a stout unit. I will be using his installation and oiling advice as well which as of now will be a -4an feed off of the OFH with a -12AN return line. I'll let him decided if it will need to be further restricted due to me using the -12an opposed to the -10an or if suggested I can move back to a -10an and a restricted -4an like Dave runs.

 

[bastarddsm]

What are you asking about? high boost reliability, or high boost performance?
On diesel pull truck shit we run hx40's into the mid 40's on a 5.9l turning 3500 with no problem.

On the HX60's we see 60-70psi at 2500 and it falls to 55 by 5000. The cummins guys that run the bad ass aftermarket billet wheel, go thru about 3 turbo's a year. Out oem holset billet wheel turbo lasted the equivlent of about 3 season with no problems.


That hx40 you best be looking for 40psi. Realistically you should treat it like a gt4086. If you can even get one. The compressor is about the size of a gt3586's, but the turbine is huge, about the size of a gt40. Lucas is no dummy, he should know whats going on with it on the dyno. I hope somthing good comes out of this, I see you talk all the time, but I can't say I have ever seen any sort time or power figure come from your stuff.

Anyway, there are several guys running the holsets hard on a dsm with no problems. Do your ####ing homework, and make sure you got good pressure at the turbo. Don't leave it to johnnnyjackoff said you need an restrictor and now your shits broke. Put a gauge on the inlet of the turbo, run it hard when hot, and make sure you got the pressure it wants.

I personally ran my HX35 to 35+psi, ( never got a clean pass) and the thrust bearing died. I ran it really really really hard, I live in the country at my car see's 8500 in the first 4 gears every corner I turn every day. I'm not sure if it was lack of lube, something else. The turbo had 20psi at idle, and 70psi at 8000, so unless it had some debris plug the thrust bearing passage, I have no idea what happened. I couldn't find anything wrong with it though other than a smoked thrust bearing.

 

[richard33]

Im sure you are referring to me about the recent failures at high boost. I destroyed a brand new 6 blade hx40 on the dyno running 45lbs or so. I brought it in to a diesel re builder who said it got hot from lack of oil. This past Wednesday I was trying to run it all out and put down some good numbers. I ran the max boost in every gear I could which was about 30lbs in 2nd and 40lbs in 3rd and 4th with no problems. I did port my oil filter housing and go to a bigger restrictor though. KrustyDSM was running his hx40 at high boost for a while with no problems other than a blown motor .

I run about 30-35lbs on the street cause anything higher it will spin even in 3rd and 4th on my QTPs. Just put it on there and see what it can do. Im sure Lucas English is gonna know more than almost anyone who is gonna even post in this thread giving advice so you're probably good to go.

BTW- hows the race car doing?

 

[TSimage]

What are you asking about? high boost reliability, or high boost performance?
On diesel pull truck shit we run hx40's into the mid 40's on a 5.9l turning 3500 with no problem.

On the HX60's we see 60-70psi at 2500 and it falls to 55 by 5000. The cummins guys that run the bad ass aftermarket billet wheel, go thru about 3 turbo's a year. Out oem holset billet wheel turbo lasted the equivlent of about 3 season with no problems.


That hx40 you best be looking for 40psi. Realistically you should treat it like a gt4086. If you can even get one. The compressor is about the size of a gt3586's, but the turbine is huge, about the size of a gt40. Lucas is no dummy, he should know whats going on with it on the dyno. I hope somthing good comes out of this, I see you talk all the time, but I can't say I have ever seen any sort time or power figure come from your stuff.

Anyway, there are several guys running the holsets hard on a dsm with no problems. Do your ####ing homework, and make sure you got good pressure at the turbo. Don't leave it to johnnnyjackoff said you need an restrictor and now your shits broke. Put a gauge on the inlet of the turbo, run it hard when hot, and make sure you got the pressure it wants.

I personally ran my HX35 to 35+psi, ( never got a clean pass) and the thrust bearing died. I ran it really really really hard, I live in the country at my car see's 8500 in the first 4 gears every corner I turn every day. I'm not sure if it was lack of lube, something else. The turbo had 20psi at idle, and 70psi at 8000, so unless it had some debris plug the thrust bearing passage, I have no idea what happened. I couldn't find anything wrong with it though other than a smoked thrust bearing.

I talk a lot because I do a lot. I'm not like most DSMers that struggle with one car. I always have multiple builds all of which I build for their purpose and then they go. I have a 2.3 Whippled lightning on spray I am building along with a 56 F100 I am dropping a Lightning swap in and a couple other projects. I like many others such as Jake Montgomery, Shep, Kevin originally tune on the streets. I've never had purpose to dyno anything and in all honesty this car wouldn't be getting dyno'd if I tuned it myself but the opportunity knocks, so be it. On top of that, I don't half ass anything and when I build a car I build it to the point it can't be improved, doing that takes time, I could toss together the setups most have quite uneventfully but I'll be damned if I do something that's been done already. Where's the fun in that? I've always been about the journey and always will be. I'm an Architectural Engineer by trade. I find the joy in planning, build, detail and execution. I let the petty Mechanical engineers worry about packing numbers.

I've done plenty (years) of Holset research and my other Talon has an HX52 on it that saw sub 40psi before I had the new motor and manifolds built. The problem with the HX40 is the multiple failures I have seen with a couple local guys as well as a few of my Diesel buddies. In the Diesel world they don't run HX40s at high boost because according to them its not IF it'll break but WHEN. On the flip side DSMs are different and there is only 1 or 2 people running Holsets of any kind above 40psi currently regardless although I still value input from guys like Dave and those who have big powered 600+ Holsets that are obviously pushing these bad boys to the tilt even with out maxing the turbos out (beyond their more restrictive turbine housings in some instances)

The rest of the stuff you said is no brainer... I know the specs of the HX40 and regardless of that conglomeration of a '4086' you described it as the HX40s I have ran behave unlike either turbo. No one doubted Lucas ability to 'figure out' a turbo, we're beyond that but foreign/uncharted territory is still on a learning curve adn I am trying to reduce that dramatically to get the most amount of time efficiently devoted solely to the tune. As I said, I just want to know about what those who have pushed the envelope believe is the safest max boost that should be ran through this turbo.

 

[ckrell]

A few years back the MFG's took most of the zinc and phosphorous out of our off the shelf oils (It was messing with the catilatic converters). With out a fair amount of these goodies things with extreme pressure, heat and speed will be at risk. Some offroad uses only and racing oils still have the desirable amounts of zinc and phosphorous. Another zinc and phosphorous alternative is a Comp cam product called ''engine break-in oil additive" its about $15. Synthetics may help cover this oiling problem but i don't know. However I belive this is a VERY VERY important additive to get back into our big boost high RPM engines

 

[TSimage]

Im sure you are referring to me about the recent failures at high boost. I destroyed a brand new 6 blade hx40 on the dyno running 45lbs or so. I brought it in to a diesel re builder who said it got hot from lack of oil. This past Wednesday I was trying to run it all out and put down some good numbers. I ran the max boost in every gear I could which was about 30lbs in 2nd and 40lbs in 3rd and 4th with no problems. I did port my oil filter housing and go to a bigger restrictor though. KrustyDSM was running his hx40 at high boost for a while with no problems other than a blown motor .

I run about 30-35lbs on the street cause anything higher it will spin even in 3rd and 4th on my QTPs. Just put it on there and see what it can do. Im sure Lucas English is gonna know more than almost anyone who is gonna even post in this thread giving advice so you're probably good to go.

BTW- hows the race car doing?

Thanks for the info. I have definitely been keeping an eye on your thread for sure and yes you were the one I made mention of in the OP. At the end of the day I'm not worried about if Lucas can tune the turbo, I'm positive he can tune the turbo. The car is setup to hopefully make this an easy ordeal but regardless of that he can't go tuning an relatively unknown turbo (to himself and those around him) without knowing its peak limitations. We are obviously looking to max this bad boy out on the 2.3 and E98 however we wanna do so within reason and definitely not beyond a point where there are any issues. If this bad boy can easily take what ever we throw at it then I can simply give Lucas the green light to keep playing with the boost until it is efficiently making optimal power through out the power band.

This is something he himself has asked me in discussion. I'm not simply asking out of sole curiosity but it was something he asked to be verified.

As far as the other 'race car' which is nothing more than an over built street car Its making for a great shelf.. But seriously I did a change up on the motor build and picked up some custom high compression pistons and some monster Crane cams. The Forward Facing manifold/intercooler set has been designed but the fabricator is waiting on me to ship everything out to him to get it completed but as with most things, no rush... I've been too busy with my trucks to care but had to pick up a new DSM to have something to put around in while the ruck is down and now I already have my hands full. There's nothin I can do until the motor gets half filled and the turbo/intercooler come back... If I have too many issues with the safety people that motor/turbo setup might winde up in the caged Black shell until everything comes together.

 

[richard33]

I think a good round number for the peak boost is 40. At least for me anything over that and it will cut the life of the turbo down a lot. Even running 40lbs probably isnt going to last very long honestly. Im on my 3rd hx40 this month unfortunately so if you dont have the oiling figured out, they go very quick if you try to push them.

 

[JusMX141]

I personally ran my HX35 to 35+psi, ( never got a clean pass) and the thrust bearing died. I ran it really really really hard, I live in the country at my car see's 8500 in the first 4 gears every corner I turn every day. I'm not sure if it was lack of lube, something else. The turbo had 20psi at idle, and 70psi at 8000, so unless it had some debris plug the thrust bearing passage, I have no idea what happened. I couldn't find anything wrong with it though other than a smoked thrust bearing.

Oil contamination or too low of a ZDDP level in your oil. A Holset's thrust system is literally the most durable that I've seen on any journal bearing turbo available today.

If it's straight-up wear, the washer will make an even cut in the thrust plate. This can come from high boost levels using oil that does not contain enough zinc. If the thrust plate and washer were both grooved like an old record, it's from oil contamination.

 

[TSimage]

Oil contamination or too low of a ZDDP level in your oil. A Holset's thrust system is literally the most durable that I've seen on any journal bearing turbo available today.

If it's straight-up wear, the washer will make an even cut in the thrust plate. This can come from high boost levels using oil that does not contain enough zinc. If the thrust plate and washer were both grooved like an old record, it's from oil contamination.

With all that aside then what are your recommendations? That's the point of this thread to kind of put the issue to bed or at least identify it so that no one else has to go through 3 turbos in a month .

Lucas wont push the turbo farther than I tell him to be I've yet to conclude what that magic number is or if it is a matter of having everything absolutely perfect and thus being able to max this badboy out for all that its got.

 

[bastarddsm]

Oil contamination or too low of a ZDDP level in your oil. A Holset's thrust system is literally the most durable that I've seen on any journal bearing turbo available today.

If it's straight-up wear, the washer will make an even cut in the thrust plate. This can come from high boost levels using oil that does not contain enough zinc. If the thrust plate and washer were both grooved like an old record, it's from oil contamination.

I was running 20W50 VR1, and its changed often. I had just put a set of bushings in it, as it was loose when I got it. They were supposed to be OEM, I got them from Gillets Diesel. It was wore pretty good into the the thrust bearing. I'd certainly think a 5.9 at 30psi moves a lot more air than our engines, shouldn't that load the thrust bearing a lot more? I ran it in the 35psi range while doing tuning and at the track. I probably had about 50 passes on it, and it was fine. I got home from the track fixed a few issues and turned the boost back to 25, and within 200mi, it was gone. Anyway, I picked up solid hy35 today for $125 so I'm putting that on with a turbonetics mani.

I talk a lot because I do a lot. I'm not like most DSMers that struggle with one car.
I've done plenty (years) of Holset research and my other Talon has an HX52 on it that saw sub 40psi before I had the new motor and manifolds built. The problem with the HX40 is the multiple failures I have seen with a couple local guys as well as a few of my Diesel buddies. In the Diesel world they don't run HX40s at high boost because according to them its not IF it'll break but WHEN.

Well hopefully we actually see some results out of this. I wish you were doing this with a full prepped race car with a hx35, and get some numbers that shut up the 16g/68hta crowd.

I don't know what your diesel buddies are doing but around here the stock diesel class is being dominated by HX40 and HX35/40 hybrid 5.9's with big p pumps. The only ones that are breaking are guys with aftermarket wheels in them. Same with the HX60 guys in the 3.0 class. The cummins trucks run a 20-23cm hot side and fancy aftermarket billet wheel, and the break shafts about twice a year. We run an off the shelf HX60 in a 32cm housing on a duramax and have run two classes all season, along with 35 dyno runs with no issues. Supposedly the high shaft speeds the cummins guys are seeing, are straightening the blades on the compressor and locking it up, and it twists the turbine off.

Durty Deere winning Yorkville pulls - YouTube I setup the bosch ms15.1 ecu on this truck and helped tune it. Its the highest power single 3.0 turbo duramax, and the second highest power 3.0 turbo diesel. It's the HX60 I mentioned. We run 125psi oil pressure to the turbo.

I think a good round number for the peak boost is 40. At least for me anything over that and it will cut the life of the turbo down a lot. Even running 40lbs probably isnt going to last very long honestly. Im on my 3rd hx40 this month unfortunately so if you dont have the oiling figured out, they go very quick if you try to push them.

How much oil pressure are you running it at? Maybe the secret is more oil pressure.

 

[TSimage]

Ok.. So is the common consensus to simply tackle the oiling issues and then allow Lucas to turn up the wick as he sees fit? Or is 40psi the magic number?

 

[bastarddsm]

Personally, I'd give it as much oil as possible, and make sure you have a good drain. After that, let it eat. Talondave is not having any reliability issues, so I'd have to say its not fully a turbo issue. Its, an improper installation issue.

Like I said, you cannot believe the abuse we put our HX 60 thru. Can you imagine surging down from about 150lbs+/min @60psi? You should hear the bark is has, its ####ing awesome. We run these turbo's sooooo far off the map its unbelievable. I've heard reports of 250krpm shaft speed. Do the math on a 6.6l at 60psi and 5000rpm, its in the 200lbs/min area, on a turbo probably rated for choke at 100. We see 2000+*f egts, 80-90psi drive, 75psi peak boost. They live because the turbo has it's own separate oil circuit. It drains right into a dry sump tank, and is scavenged by the pump, and fed at 125psi+ back to the turbo with a -8 line, no restrictor.

 

[richard33]

Im not sure what the oil pressure was when they were blowing. I wasnt logging oil pressure at the time. I had a .73 restrictor or somewhere around there with no balance shafts so i figured it would be ok since I used the same setup on my hx35 with no problems. Now I ported the oil filter housing and have a .100 restrictor off the oil filter housing instead of having the restrictor on the turbo and so far it seems to be working better. Peak oil pressure is 80-85lbs after the restrictor which I am happy with.

I was running 20W50 VR1, and its changed often. I had just put a set of bushings in it, as it was loose when I got it. They were supposed to be OEM, I got them from Gillets Diesel. It was wore pretty good into the the thrust bearing. I'd certainly think a 5.9 at 30psi moves a lot more air than our engines, shouldn't that load the thrust bearing a lot more? I ran it in the 35psi range while doing tuning and at the track. I probably had about 50 passes on it, and it was fine. I got home from the track fixed a few issues and turned the boost back to 25, and within 200mi, it was gone. Anyway, I picked up solid hy35 today for $125 so I'm putting that on with a turbonetics mani.


Well hopefully we actually see some results out of this. I wish you were doing this with a full prepped race car with a hx35, and get some numbers that shut up the 16g/68hta crowd.

I don't know what your diesel buddies are doing but around here the stock diesel class is being dominated by HX40 and HX35/40 hybrid 5.9's with big p pumps. The only ones that are breaking are guys with aftermarket wheels in them. Same with the HX60 guys in the 3.0 class. The cummins trucks run a 20-23cm hot side and fancy aftermarket billet wheel, and the break shafts about twice a year. We run an off the shelf HX60 in a 32cm housing on a duramax and have run two classes all season, along with 35 dyno runs with no issues. Supposedly the high shaft speeds the cummins guys are seeing, are straightening the blades on the compressor and locking it up, and it twists the turbine off.

Durty Deere winning Yorkville pulls - YouTube I setup the bosch ms15.1 ecu on this truck and helped tune it. Its the highest power single 3.0 turbo duramax, and the second highest power 3.0 turbo diesel. It's the HX60 I mentioned. We run 125psi oil pressure to the turbo.




How much oil pressure are you running it at? Maybe the secret is more oil pressure.

 

[JusMX141]

With all that aside then what are your recommendations? That's the point of this thread to kind of put the issue to bed or at least identify it so that no one else has to go through 3 turbos in a month .

If you go through that many turbos in a month, obviously it's not the fault of the turbo- something is horribly wrong with your oiling whether it be excessive/too little pressure, or inability to drain.

This topic has been discussed over and over and over again about various turbo brands and to this day, the ONLY turbos I've seen fail for no reason at all when oiled as directed by the manufacturer are PTE journal bearing turbos. One customer even had a 6152's turbine shaft break the very first time the turbo was boosted, only on wastegate pressure....the turbine wasn't even dirty with soot yet. Obviously some type of quality control issue there.

There is more oiling information available about Holsets than any other brand....download the service manual and see for yourself:

www.cummins.com/turbos - Service Repair Manuals

Play by the rules and be rewarded with the same longevity as the turbo would see on it's OEM application.

To this date I've only personally witnessed one HX40 turbine failure, and it was on an E85 car that was tuned to very lean AFR's....to the point where EGT's were likely well in excess of the danger zone. The shaft started to bend, but never broke completely off. At that point it's no surprise the shaft would become weak from heat. That's not bad when compared to a handful of PTE shaft failures (one the very first time the turbo was boosted), a SBR G60, and a pile of broken shafts on GT Concepts Evo III turbos.

I'd certainly think a 5.9 at 30psi moves a lot more air than our engines, shouldn't that load the thrust bearing a lot more?

Thrust load at 30psi is the same no matter what engine it's on. Actually, I don't believe the factory boost level is quite that high on a Dodge truck, but then again I serviced a HE351CW that was being used a 48psi on a customer's truck and the turbo had zero thrust wear.

Im not sure what the oil pressure was when they were blowing. I wasnt logging oil pressure at the time. I had a .73 restrictor or somewhere around there with no balance shafts so i figured it would be ok since I used the same setup on my hx35 with no problems. Now I ported the oil filter housing and have a .100 restrictor off the oil filter housing instead of having the restrictor on the turbo and so far it seems to be working better. Peak oil pressure is 80-85lbs after the restrictor which I am happy with.

.073" is far too small for 40psi of boost unless you're at 150+psi before the restrictor. I'm glad you got the oiling situation figured out- the HX40 on Dave's car currently has a restrictor that I drilled to 7/64" (.109") to be the exact same spec as a -3AN fitting's I.D. So far it's working great, and we haven't had an oil issue in two seasons running 37-38psi of boost using Brad Penn 15W40 Racing Oil, even with a TopLine oil pump failure.

 

[bastarddsm]

zero[/U] thrust wear.

So your implying that the thrust load on the turbo is completely independent of the flow rate? I don't believe that for a second. I think it would be safe to assume a 5.9 @30psi and 3000rpm moves more air than a 2.0 @30psi and 7000rpm, even with the 5.9's shitty head. I don't think 30 is out of the range of a stockish truck. One of my close friends had a slightly turned up pump (i know I did it) on a early big h1c truck and it would hit 30psi in second and 3rd gears, but fell to 25.

 

[richard33]

If you go through that many turbos in a month, obviously it's not the fault of the turbo- something is horribly wrong with your oiling whether it be excessive/too little pressure, or inability to drain.

This topic has been discussed over and over and over again about various turbo brands and to this day, the ONLY turbos I've seen fail for no reason at all when oiled as directed by the manufacturer are PTE journal bearing turbos. One customer even had a 6152's turbine shaft break the very first time the turbo was boosted, only on wastegate pressure....the turbine wasn't even dirty with soot yet. Obviously some type of quality control issue there.

There is more oiling information available about Holsets than any other brand....download the service manual and see for yourself:

www.cummins.com/turbos - Service Repair Manuals

Play by the rules and be rewarded with the same longevity as the turbo would see on it's OEM application.

To this date I've only personally witnessed one HX40 turbine failure, and it was on an E85 car that was tuned to very lean AFR's....to the point where EGT's were likely well in excess of the danger zone. The shaft started to bend, but never broke completely off. At that point it's no surprise the shaft would become weak from heat. That's not bad when compared to a handful of PTE shaft failures (one the very first time the turbo was boosted), a SBR G60, and a pile of broken shafts on GT Concepts Evo III turbos.


Thrust load at 30psi is the same no matter what engine it's on. Actually, I don't believe the factory boost level is quite that high on a Dodge truck, but then again I serviced a HE351CW that was being used a 48psi on a customer's truck and the turbo had zero thrust wear.


.073" is far too small for 40psi of boost unless you're at 150+psi before the restrictor. I'm glad you got the oiling situation figured out- the HX40 on Dave's car currently has a restrictor that I drilled to 7/64" (.109") to be the exact same spec as a -3AN fitting's I.D. So far it's working great, and we haven't had an oil issue in two seasons running 37-38psi of boost using Brad Penn 15W40 Racing Oil, even with a TopLine oil pump failure.

haha ya I figured it out the hard way though for sure. Now I check the shaft play after every pull im so worried about it

 

[DSMTyson]

Another thing most people don't seem to know, is that when you rebuild a holset turbo you are supposed to get the rotating assembly LINE BALANCED. Don't believe me? Call Holset and ask.

I had a friend that got his holset hx40 rebuilt and he didn't know if it was ok just to use component balanced parts as he is planning on running 40+psi and didn't want to make a simple #### up. He called holset to find out and they told him to get it line balanced.

 

[bastarddsm]

Another thing most people don't seem to know, is that when you rebuild a holset turbo you are supposed to get the rotating assembly LINE BALANCED. Don't believe me? Call Holset and ask.

I had a friend that got his holset hx40 rebuilt and he didn't know if it was ok just to use component balanced parts as he is planning on running 40+psi and didn't want to make a simple #### up. He called holset to find out and they told him to get it line balanced.

How balanced do you think they are after a few runs? Carbon buildup doesn't weight anything? Air doesn't abrade the wheels?

 

[turboglenn]

Just buy my DBB pte6776, rated at 750, known to push 900 at it's limit and loves to be run at up to 49psi, it's way more than i can ever use and i need something smaller, then you don't have to worry about holsets blowing at over 40

j/k but really, it's a great turbo for high boost unles your set on a holset (i want an hx-35 myself )

 

[JusMX141]

So your implying that the thrust load on the turbo is completely independent of the flow rate? I don't believe that for a second. I think it would be safe to assume a 5.9 @30psi and 3000rpm moves more air than a 2.0 @30psi and 7000rpm, even with the 5.9's shitty head.

I don't know what you're getting at....I can't picture how compressor flow will vary by engine size. Surely the turbine flow is going to differ, but I can't imagine that the HX35 compressor would be making a pile more airflow on a diesel when our 2.0's are pushing the compressor well beyond the map in certain situations. The compressor wheel is the main source of the thrust load since the compressor itself is doing all the work.

I'm sticking with believing the thrust loads are the nearly identical at the same boost level(s). Shaft overspeeding could do it being that you're making the thrust system work at boost and airflow levels beyond what it's designed.

I don't think 30 is out of the range of a stockish truck. One of my close friends had a slightly turned up pump (i know I did it) on a early big h1c truck and it would hit 30psi in second and 3rd gears, but fell to 25.

Early Big H1C = non-wastegated, so they were designed with a much larger turbine housing to keep the boost level under control....most likely why boost pressure dropped as the RPM's climbed and load levels dropped.

I don't think a standard wastegated HX35 truck would ever be allowed to exceed 30psi, but I don't know at what point they have the gate open on those trucks either. I know it's around a 20psi actuator, but Holset preloads the hell out of it from the factory.

 

[bastarddsm]

I don't know what you're getting at....I can't picture how compressor flow will vary by engine size.


I don't think a standard wastegated HX35 truck would ever be allowed to exceed 30psi

Think about that statement for just a bit. Then go back to the very basic math that me use to size a turbo for a particular engine.

airflow in lb/min = (displacement*rpm*PR*.07*ve)/3456

From that you can see that at a given rpm, pr, and ve if the displacement increases the airflow MUST increase. Further more, if your up against the choke limit for airflow, and you increase the rpm or displacement, the PR must fall!

Anyway, onto my 5.9 moving more air:

1. 4g63 with peak power at 7k, running 30psi (~3;1 pr) and it has a good head so it has 100%ve
it moves 51lb/min

2. 5.9 cummins turning it 3000rpm, at 30psi again, and it has a shitty head so we'll say 80%ve
it moves 65lb/min!

Obviously the 5.9 should be compressor limited on a hx35, so its boost would fall off.

Anyway. I think that the thrust loading is probably based on lots of things. There's no way its not dependent on mass flow. I bet that the turbine has a huge part in the thrust loading. Not saying which direction it is in, but its there.

I wonder if the turbo companies know? I'd imagine they do. Should be pretty easy to measure.

I suppose I need to pick up some books on turbine design and see how it all works.

 

[Morphius]

Interesting discussion. So, Lucas is going to run one on his car, or tune your car? (Edit, so reread the initial post, I thought maybe you were eluding to Lucus trying to run one himself, but not the case)

As for what a stock truck runs, if I can find a tapped boss, I'll put a gauge on mine and find out (03 w/HE341). I do know it's durable as I've hit 252,000 miles on mine.

 

[-red97rum-]

I was running 33-35psi of boost on the HX35 for months and months. I used to check shaft play pretty regularly and it always felt mint. Now for the past 4 or so months I've been spraying the car with a 75 shot and the boost would spike to 42psi and taper back to 36ish.

Last Friday I installed my HX40 and pulled my HX35. When pulling the HX35 I noticed there is a significant amount of in-out shaft play indicating serious thrust bearing wear. I've been running a 0.04" (This one) oil feed restrictor and a full -12 return since day one.

I haven't had time to start cranking up the boost and tuning my HX40 yet.. but I currently have the same restrictor in place and now I'm thinking of pulling it off before I start running 35+psi of boost with it.

 

[bastarddsm]

oh man 0.04" is waaaay to small. You really need to put a gauge on it at the turbo. It needs to have 60-80psi at full load/high rpm/ect. Tune your restrictor to make it have that pressure.

Additionally, no matter what restrictor you have, the gauge pressure at the turbo is the "end all" "all telling" indicator of the volume and pressure of oil going into the turbo. The turbo has its own "restrictors" in the internal oil passages, thus at a given inlet pressure, the volume of oil flowing through it is the same for a given pressure, regardless of where and what the oil is coming from. If your engine has high oil pressure you'll need a smaller resrictor, and if your engine has lower oil pressure you'll need a larger, or no restrictor.

Theoretical Examples:
Engine 1 has balancer shafts, and 200k mi. it also only has 60psi oil pressure at the filter housing. Feed your turbo from the housing with a -4 line unrestricted, your gauge at the turbo will read 60psi. It something like 1l/min of oil flow through it.

Engine 2 is a fresh rebuild with no balance shafts and a not ported ofh, it shows 120psi at the ofh. Feed this turbo with a -4 line and a 0.078" restrictor at the ofh. The gauge shows 60psi the turbo, thus it flows about 1l/min of oil through it.

This isn't that hard, the holset literature clearly states what its oil feed requirements are. 40-72psi under load, and at least 20 at idle. On a cold start up, 88psi is permissible for a short while.

 

[JusMX141]

You're over-restricting for running boost above 30psi. That restrictor in the link is .075"; you'll want to drill that to around 7/64" (.109") to keep from killing your HX40....or run no restrictor at all if you're sure the oil pressure is below 72psi at all times, as Kurt has said above.