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. 

On 6/26/2021 at 5:29 PM, LorenS said:

I would think that setting the Low PSI Timing Reduct to 5⁰ vs. 2⁰ should more than make up for starting the timing table at 15⁰ vs. 13⁰. That's what it is for, right, to retard timing to spool the turbo?

That’s the way I understand it to work, but with the scaling set to 50% I’m only going to see 2.5 degrees of that total 5 degrees correct? 
I did make the changes suggested by Silverwolf2691 and the truck seems much happier. Still waiting for the boost elbow to arrive, and I haven’t pulled a trailer with it yet but I will this weekend. 
 

2 hours ago, Nathan S said:

but with the scaling set to 50% I’m only going to see 2.5 degrees of that total 5 degrees correct?

That's the way I've seen it described, but I also found an early post Nick wrote where it was described as being the full 5 degrees, but at half the max RPM (which makes the most sense to me, but I'm not a programmer).

Half of the timing but maxes out at 50% Throttle.

 

For example, low psi is 5*, scaling is 50%. When you accelerate, you will pull 2.5* of timing max by 50% throttle. 

I haven’t driven the truck on the highway but it is much more responsive in town those changes. Thanks for the tips and the clarification on how the scaling works. 

To the best of my understanding:

 

Max load offset is your "tip in" timing pull while moving. When you transfer from cruise state to performance state, you need a timing pull to help spool the turbo up.

 

Low psi timing reduct is your acceleration timing pull to help spool the turbo from a stop. Uses TPS and boost to calculate the pull. Also only used in the 0-10 psi range.

 

nothing like a 10 page dig for that lol. 

 

Slightly off topic but I think that those two settings are the biggest wall to anyone who is just starting out with the quad. That and the verbiage used to describe the settings.

 

@Me78569, I know you haven't worked with the quad for a while, and adding info buttons to the app is a major restructure, but what about just changing the names of the settings? (the white text you click on to open the field to enter your numbers) I have a couple ideas for changes but not for everything.. Unless it was intentional to get people to slow down and actually look at/into what they are changing... 

Not my arena anymore.   I don't have insight into that stuff.  I would ask @Quadzilla Power and @dieselautopower to consider adding info buttons to each item.

3 minutes ago, Me78569 said:

Not my arena anymore.   I don't have insight into that stuff.  I would ask @Quadzilla Power and @dieselautopower to consider adding info buttons to each item.

 

not adding info buttons but changing the names from say:

 

TPS pump maximum to Wiretap maximum TPS/max throttle

TPS pump minimum to Wiretap minimum TPS/min throttle

Minimum pump tap fueling percentage to off idle wiretap

pump low boost scale psi to wiretap boost minimum/boost low limit

(not attached to the phrases, open to suggestions)

 

Just saying make it a bit more user intuitive as to what you are adjusting.

 

Also, to be clear, I wasn't asking if you specifically could do it, just if it was easier than doing a program redo like you mentioned in the thread I linked above. I don't know programing, so I don't know what simple to ask for but is actually program breaking or start from scratch paths there are.   

The Json reference file needs to be updated on the iquad app download.  This would require a new update file to work.   not a huge deal from what I remember techinically speaking.   Customer support wise though it is a pretty big change.

13 hours ago, Me78569 said:

The Json reference file needs to be updated on the iquad app download.  This would require a new update file to work.   not a huge deal from what I remember techinically speaking.   Customer support wise though it is a pretty big change.

It would be a very easy change to make. However, we have a customer base, and documentation, that is  familiar and accustomed to the current jargon. Adding descriptions to each variable is doable, but would be a large app update.  We will definitely look into it and see what we can do! 

Well I got the boost elbow put in this morning. I bottomed the screw out so the wastegate is essentially blocked. I ran the truck up a hill we use for bench marking in the area, about a 6% grade that’s about two miles long. The egt in 5th gear was 1300+ with the truck empty. Just accelerating in  4th gear to get back up to speed between 1500 and 2200 rpm the egt got to 1100. I’m gonna put the other turbo on and see what it does. 
 

When I had the intake tube off to put the boost elbow in, I noticed the compressor spins much easier one direction than the other. The blades should slap the air similar to a pump, correct? Spinning in this direction it would stop before a full rotation. It would spin about 2.5 rotations the other direction. 
 

Edit: 

Got the turbos swapped out this afternoon. There is a definite rub in the stealth 64 with it on the bench. There are a couple of spots you can actually hear the metal to metal contact and feel either the compressor or turbine rubbing. I am gonna talk to calibrated power again before I pull it apart to see what it is. 
 

Egt up the same hill with the same tune, just stock turbo with a wicked wheel and a banks quick spool housing was 1050 egt up the same hill as earlier today. 

Be aware just changing the timing curve just a little bit you might gain more on the Stealth 64 turbo. Bigger turbos typically need a bit more retard to get them spun up this is why the small HX35 (with mods) did better on EGT's. More you advance timing the harder it is to spool a larger turbo. When you retard the timing a bit your are blowing more fire out the exhaust port to aid in spooling the turbine. 

2 hours ago, Mopar1973Man said:

Be aware just changing the timing curve just a little bit you might gain more on the Stealth 64 turbo. 

Thank you. I will keep that in mind for when the turbo is either repaired or if I go the compound route. I need to talk to calibrated power before I make a decision on what the next setup will be. I feel like the mechanical problems with the turbo are what was causing the majority of the issues. The rubbing issue will only get worse as the turbo gets hotter, then making it contact those places in the housing 100,000 times a minute while it’s as spooled as it could get probably causes a lot of drag on the rotating elements. 

20 hours ago, Nathan S said:

The rubbing issue will only get worse

 

Out of balanced. If it truly balanced it would never make contact no matter how fast it was spun. Compressor wheel make sure its clean and dirt is riding on the compressor wheel. If its making contact it because it out of balance even little bit.

Do you think the out of balance condition would still cause the rub even with the shaft vertical on the bench and basically no centrifugal force on the shaft? It feels more like it’s out of round to me, just because the rub isn’t consistent all the way around the housing.