Last fall I “upgraded” the stock hx35 on my truck to a Calibrated Power Stealth 64 Hx35. This turbo is the same basic frame as a stock hx35 so I can still use my Jacobs exhaust brake. Calibrated power makes their own 11 blade billet compressor, compressor cover. They also make their own turbine wheel which is larger to match the larger compressor wheel, and use a 9cm turbine housing. I think this tight turbine housing is what is causing my issues. I have been battling egt problems with the truck since I put the turbo on. I’ve upgraded injectors after finding posts discussing the effects of too small of an injector with out enough fuel causing high egts. I have updated the old Edge JWA to a Quadzilla to be able to custom tune and have spent the last 6 months trying to get the egt back to where it was with the stock turbo and 75 horsepower injectors. 
 

Accelerating on the highway, at less than half throttle I can see 1350 on the egt pretty easily, with the truck empty. I sometimes carry my rzr side by side on the back of the truck on the flatbed, and with it on the truck, pulling a relatively large grade in northwest Colorado I struggled to keep the temps below 1300. With the old setup I would barely break 1200 with my 10,000 pound fifth wheel on the same grade. You could say I’m less that impressed with the turbo. 
 

I have been all over the truck searching for boost leaks, change every seal, gasket and o ring that could be causing a boost leak. I really feel that the increased compressor flow with the tighter exhaust housing is what is causing my problems. Does anyone know if I could buy a stock housing and have a company bore the housing out to accept the larger turbine? I’ve talked with Calibrated power about this and they told me they do not offer any other housing for this application. 

I believe the tight housing and bigger injectors are a large part of your problem. That turbo will spool quick but not so good at the top end. I am by far not the expert on this but am sure some others will be along pretty soon. The quad can help but that is even further out of my area of smartness. Be patient, the smarter ones will be along.

3 hours ago, Nathan S said:

Accelerating on the highway, at less than half throttle I can see 1350 on the egt pretty easily, with the truck empty

 

What are the engine rpm's and which gear are you in when you see the 1350°?

 

3 hours ago, Nathan S said:

I sometimes carry my rzr side by side on the back of the truck on the flatbed, and with it on the truck, pulling a relatively large grade in northwest Colorado I struggled to keep the temps below 1300.

 

What are the engine rpm's and which gear are you in when you see the 1300°?

 

3 hours ago, Nathan S said:

With the old setup I would barely break 1200 with my 10,000 pound fifth wheel on the same grade. 

 

What are the engine rpm's and which gear are you in when you see the 1200°?

 

Is your transmission a 5 speed or a six speed?  Is the gear vendor in direct drive or overdrive for the above condtions?

 

- John

Edited June 23, 20213 yr by Tractorman

The 1350 was in 4th gear, just as I was going to shift to 5th around 2300 rpm. Pulling the grade with the rzr on the back was 4th gear, overdrive off 2200 rpm. My transmission is a 5 speed, that’s why I went with the gear vendors. It helps to bridge the gap between 3rd and 4th. With the overdrive engaged in 4th gear, the ratio is so close to 5th direct that it’s unnoticeable, but the transmission runs 50 degrees cooler while towing the camper. 
 

I am constantly watching the pyrometer while driving, loaded or not. I did order a couple of gaskets to put the stock turbo back on and see what the truck acts like with the larger injectors and quadzilla. 

Edited June 23, 20213 yr by Nathan S

I can't believe they recommended a 9cm housing, sounds like they don't know what they're doing or didn't quite understand what you were trying to achieve.

I had my turbo built by a North American turbo, which looks like the business is closed now for whatever reason. 62/67/12 hx35/40 platform. It was a good improvement from the hx35. My next setup maybe twins 

Is there a possibility of having a 12 cm housing machined to fit the larger turbine wheel? 

12 hours ago, Nathan S said:

I really feel that the increased compressor flow with the tighter exhaust housing is what is causing my problems.

 

I think you are correct.

 

5 hours ago, Nathan S said:

I did order a couple of gaskets to put the stock turbo back on and see what the truck acts like with the larger injectors and quadzilla. 

 

I think it will perform much better at the higher rpm's.

 

- John

2 hours ago, Nathan S said:

Is there a possibility of having a 12 cm housing machined to fit the larger turbine wheel? 

Yes, I used North American turbo but seems like they are out of business now 

Maybe someone else can machine a housing for you.

I will do some research on turbo builders and see what I can find. I really don’t want to give up the exhaust brake that mounts to the turbo. Thank you for your help. 

Your going to have to give up that turbo mounted exhaust brake to give more options. Im in the same boat. I need a different turbo but selections that allow that exhaust brake is very small.

I talked with Lenny at Diesel Auto Power about it and he suggested trying an external waste gate between the turbo and the manifold. Does anyone have any experience with running an external waste gate? I saw that DPS makes an exhaust manifold with a waste gate flange built in and I’m sure stainless diesel does as well. Thanks again guys. 

Dang it, we are all newbies. Where are that smart ones @Mopar1973Man

2 hours ago, Nathan S said:

Does anyone have any experience with running an external waste gate?

None here... I've only used a HX35W and HX35/40 Hybrid... 

 

2 minutes ago, dripley said:

Dang it, we are all newbies. Where are that smart ones @Mopar1973Man

Ummm... I'm not very smart about turbos... I know its got a spinny thingy that spins really fast and makes all kinds of weird high pitch noises. Just need a better hamster...

 

 

9 minutes ago, Mopar1973Man said:

Ummm... I'm not very smart about turbos... I know its got a spinny thingy that spins really fast and makes all kinds of weird high pitch noises. Just need a better hamster..

Or a bigger hose clamp. @JAG1 can help.

This is the turbine wheel and housing I’m running on my hybrid with my turbo mounted exhaust break. 
https://www.ebay.com/itm/124046401103

What boost are you seeing? The wastegate setting (35psi) they put on is barely over what a factory hx35 can do.. the 64 mm comperessor should be pushing 45+ with 7x010s and a quad.. the wastgate isn't letting the compressor actually get into its stride and provide enough air

 

 The 9cm^2 housing while not ideal, shouldnt have a problem with an rzr..

 

The other thing is the 11 blade compressor is a higher pressure design. As best I understand compressor design from digging around forums all over, the stacked/staggered blade like a factory hx35 (6+6) is a mix of high volume/high pressure. All the same height (11 blades) cant "grab" as much air as the other design. But if i remember correctly, it is able to maintain a higher pressure. Turbos like the 5 blade mafia turbos (5+5) can move a lot more air because they are more "open" (bigger area between the blades). But they cant maintain as high of boost as easy. 

 

This is My understanding of a mix of forum posts, please take with a grain of salt. Even my understanding is likely flawed. 

Max boost pressure I can see is 25psi. It stops dead at 25psi and will not climb higher. I’ve thought of adjusting the waste gate to see if it was opening early and contributing to the problem by not allowing the turbo to spool properly. The 11 blade compressor is very different sounding from the wicked wheel 2 and factory hx35 compressor, it’s difficult to describe but it just sounds like a giant vacuum cleaner under the hood. 
 

The day with the rzr on the truck was when I knew it was time to make a change. We are getting in to the best camping season here and worrying about how the truck is going to do is the last thing I want to have on my mind. 

Yeeeaaahh.. you should be seeing a lot more boost. 25psi is stock HX35 range. Before spending money try clamping off the wastegate line. Then get an adjustable boost elbow or similar. 

 

25 PSI is to low.  MY truck has a stock HX35 with a cheap manual boost controller and it produces 30 PSI.   

I’ve got an adjustable boost elbow on the way, I’ll try that before taking it off the truck. Tomorrow I can try crimping the line off to see if that makes any difference. When I was checking for boost leaks I made sure to watch the actuator for the waste gate and couldn’t see it move with 25 psi on the piping. 

Heck even back with my Edge Comp and +75 HP injectors on a HX35W turbo I was seeing 35 to 38 PSI.