Laggy 65mm Turbo

Wildeman101

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Feb 8, 2022
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I have an LBZ that I am struggling to get clean, decent driveability with. It has a 65mm wold fab turbo on it. Does anyone have any experience with this specific turbo? I've checked for boost leaks and don't have any, is it possible to have an exhaust leak that I can't hear? I haven't looked too thoroughly, but haven't seen any soot marks pointing towards an exhaust leak and definitely haven't heard any screeching. I've tried tuning the vanes all over the place and no matter what, the spool up is still smokier than I would like and is way slower than stock. I have 60 over injectors, but I'm not sure how to utilize them to help with turbo lag without just making it even smokier than it already is. I would really appreciate some help determining if it is a problem with tuning, or if it's possible that there is something wrong with the turbo? Or is it not possible with a bigger turbo to have similar spool up to stock and still being clean (1.2+ lambda/17.5:1+ AFR).

I thought maybe with the bigger injectors that I would want to lower the fuel pressure to have a longer injection pulse for the same amount of fuel and that maybe that would help with spoolup, but maybe my thinking with that is backwards because it hasn't seemed to help. I'm hoping to still have a truck with decent throttle response and ability to tow, but right now I haven't had either. EGT's have been too high and throttle response from a stop is terrible. If you don't mind taking a look, I've attached a zip file containing my most recent tune and datalog. This turbo doesn't seem to flow very much air at lower rpms and I'm thinking it may be too big for what I need and that I should just go back to a stock lbz turbo. Obviously I'd like to have the extra power potential as well, but really miss the drivability that I had before.

Another note that I feel is pretty telling that there is an issue, if I command 100% vpos on decel and downshifting, I will only see maybe 6-7 pounds of back pressure and 1 pound of boost. I thought it wasn't uncommon to see 5+ pounds of boost??

Is it possible that there is an issue with the turbo? It was brand new and have been having issues right from the get go. Could the compressor cover be over-machined for the compressor?

This has been driving me nuts and I haven't been able to enjoy my truck for like a year. Any advice would be greatly appreciated!
 

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Dozerboy

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First of all a 65mm turbo will have a little more lag then your stocker pretty much no matter what. Did you do a 65mm for more power or was the stocker needing replaced? Do you have a built trans? Did you install the injectors and turbo at the sametime or had you had the bigger injectors with the stock turbo? Do you have a stock CP3?

My guess is tuning is your main issue. I would really suggest you buying GOOD quality tunes. Since it seems you are getting a bit frustrated which is understandable. Good tuning isnt easy to do. You can do it yourself, but you need to do a lot more research into what you are doing and a lot more testing and logging. Searching thing like better spool, fuel pressure, and timing will get you started. You where thinking wrong about fuel pressure and you have probably made thing worse with the vane table. The vanes are not magic they really have a limited % they work well at and produce the right amount of boost and a given rpm and fuel quantity.
 

08lmm72mm

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May 13, 2019
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What do you have for a torque converter ? I feel like alot of issues people have when upgrading to a bigger turbo is they don't change or get a loose enough torque converter and that's myself included .

Stock to 64mm - 2000-2200rpm stall
65mm - 2200-2300 stall
68mm vgt 2300-2500 stall
72mm vgt 2500-2700rpm stall

I run a Limitless 1078 and it's an awesome converter with a 2300rpm stall, but I really should have something like a georend K or J . If only they were cheap to change out 😅

Should make a sticky for proper converter recommendations when the turbo gets upgraded, would save some aggravation for when the truck doesn't perform as expected.
 
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Matrix

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Can you post your stock file as well and a more detailed parts list please.
 

TheBac

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Mismatched turbo, mismatched injectors, mismatched tuning, mismatched converter. They are all playing a part in this. Everything has to work together.
 
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Bdsankey

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Can you post your stock file as well and a more detailed parts list please.

I don't see how posting his stock file will solve anything. You were given a warning by James about tuning, I would heed that warning.



First of all a 65mm turbo will have a little more lag then your stocker pretty much no matter what. Did you do a 65mm for more power or was the stocker needing replaced? Do you have a built trans? Did you install the injectors and turbo at the sametime or had you had the bigger injectors with the stock turbo? Do you have a stock CP3?

My guess is tuning is your main issue. I would really suggest you buying GOOD quality tunes. Since it seems you are getting a bit frustrated which is understandable. Good tuning isnt easy to do. You can do it yourself, but you need to do a lot more research into what you are doing and a lot more testing and logging. Searching thing like better spool, fuel pressure, and timing will get you started. You where thinking wrong about fuel pressure and you have probably made thing worse with the vane table. The vanes are not magic they really have a limited % they work well at and produce the right amount of boost and a given rpm and fuel quantity.
What do you have for a torque converter ? I feel like alot of issues people have when upgrading to a bigger turbo is they don't change or get a loose enough torque converter and that's myself included .

Stock to 64mm - 2000-2200rpm stall
65mm - 2200-2300 stall
68mm vgt 2300-2500 stall
72mm vgt 2500-2700rpm stall

I run a Limitless 1078 and it's an awesome converter with a 2300rpm stall, but I really should have something like a georend K or J . If only they were cheap to change out 😅

Should make a sticky for proper converter recommendations when the turbo gets upgraded, would save some aggravation for when the truck doesn't perform as expected.
Mismatched turbo, mismatched injectors, mismatched tuning, mismatched converter. They are all playing a part in this. Everything has to work together.


^Both of these are spot on. I think the largest factor here is the tuning itself but there are parts that are not well explained. Running 60% injectors and a 65mm turbo is not a bad combo but what trans/converter?
 
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Wildeman101

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Trans/converter: I am still on a stock tranny and converter. Not looking to make big power until upgrading later on.

Tunes: I have run tunes from a couple other tuners on this turbo and both seem to have the same struggles as I have had. Went through multiple sets of revisions with both. That's why I decided to try and tune on my own to have the ability to test and try all sorts of different vane positions to see what responds the best.

Parts list:
Sb intake
3 inch down pipe
5 inch straight pipe with flow through muffler
60 over flux injectors
65mm wold fab turbo
PPE Up Pipes
Airdog 165
Fuel rail plug

It seems like a pretty mild setup and I don't believe it is mismatched, just night be missing a proper TC. I imagine the right TC would help with spoolup, but not my low boost and mileage issues. I feel like the turbo may have mismatched turbine to compressor or too much clearance causing it to not run properly, but I still think it may have to do with my tuning and want to give that as good of a chance as possible before taking an L on this turbo and buying another.

It seemed like my stock turbo was going out and I got a good deal on this one brand new so I went for it. It has been a pain. It will really get moving once the turbo has lit, but cruising and trying to get moving, the egts are high and my main complaint is low mileage (can you blame me with these gas prices?). Towed a 10k trailer and only got a miserable 8mpg at 70 mph... No big hills or anything. I would think it would be possible to get at least 12, maybe even 14. I am on 33s, but know with good tuning these can run efficiently.

Elevation may be hurting some, but I would think this bigger turbo would still be able to flow air? I'm at 4700 feet.
 

gmduramax

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Trans/converter: I am still on a stock tranny and converter. Not looking to make big power until upgrading later on.

Tunes: I have run tunes from a couple other tuners on this turbo and both seem to have the same struggles as I have had. Went through multiple sets of revisions with both. That's why I decided to try and tune on my own to have the ability to test and try all sorts of different vane positions to see what responds the best.

Parts list:
Sb intake
3 inch down pipe
5 inch straight pipe with flow through muffler
60 over flux injectors
65mm wold fab turbo
PPE Up Pipes
Airdog 165
Fuel rail plug

It seems like a pretty mild setup and I don't believe it is mismatched, just night be missing a proper TC. I imagine the right TC would help with spoolup, but not my low boost and mileage issues. I feel like the turbo may have mismatched turbine to compressor or too much clearance causing it to not run properly, but I still think it may have to do with my tuning and want to give that as good of a chance as possible before taking an L on this turbo and buying another.

It seemed like my stock turbo was going out and I got a good deal on this one brand new so I went for it. It has been a pain. It will really get moving once the turbo has lit, but cruising and trying to get moving, the egts are high and my main complaint is low mileage (can you blame me with these gas prices?). Towed a 10k trailer and only got a miserable 8mpg at 70 mph... No big hills or anything. I would think it would be possible to get at least 12, maybe even 14. I am on 33s, but know with good tuning these can run efficiently.

Elevation may be hurting some, but I would think this bigger turbo would still be able to flow air? I'm at 4700 feet.

Put a stock turbo back on it. Cool you got a good deal on a 65mm turbo, that’s causing all your problems. Maybe even your Flux injectors. There’s nothing we can do to help you.
 
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Bdsankey

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Trans/converter: I am still on a stock tranny and converter. Not looking to make big power until upgrading later on.

Tunes: I have run tunes from a couple other tuners on this turbo and both seem to have the same struggles as I have had. Went through multiple sets of revisions with both. That's why I decided to try and tune on my own to have the ability to test and try all sorts of different vane positions to see what responds the best.

Parts list:
Sb intake
3 inch down pipe
5 inch straight pipe with flow through muffler
60 over flux injectors
65mm wold fab turbo
PPE Up Pipes
Airdog 165
Fuel rail plug

It seems like a pretty mild setup and I don't believe it is mismatched, just night be missing a proper TC. I imagine the right TC would help with spoolup, but not my low boost and mileage issues. I feel like the turbo may have mismatched turbine to compressor or too much clearance causing it to not run properly, but I still think it may have to do with my tuning and want to give that as good of a chance as possible before taking an L on this turbo and buying another.

It seemed like my stock turbo was going out and I got a good deal on this one brand new so I went for it. It has been a pain. It will really get moving once the turbo has lit, but cruising and trying to get moving, the egts are high and my main complaint is low mileage (can you blame me with these gas prices?). Towed a 10k trailer and only got a miserable 8mpg at 70 mph... No big hills or anything. I would think it would be possible to get at least 12, maybe even 14. I am on 33s, but know with good tuning these can run efficiently.

Elevation may be hurting some, but I would think this bigger turbo would still be able to flow air? I'm at 4700 feet.


I highlighted things I think that, in my opinion, are certainly NOT helping your issue.

1) Stock trans/converter are definitely the #2 factor here. A drop in turbo that is larger than stock GREATLY benefits from a looser converter.
2) Wold Fab is pretty local to me and I refuse to use their turbos. Tom and I have a fundamental disagreement that I will never get past. A friend of mine (who I will leave nameless) used to build turbos there and some of their practices are not at all acceptable (at least while he worked there).
3) Depending what make/manufacturer of turbine it could be part of the issue but I don't think that's a smoking gun.
4) I think this (your tuning) is the absolute biggest factor, especially at elevation.
5) Elevation isn't helping you one bit, as elevation increases any turbo becomes laggier and makes less overall HP.
 

08lmm72mm

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What's your calculated fuel rate at idle and up to temp and balance rates of injectors? Have you pressure tested the system for boost leaks? Is the rad really dirty not allowing the intercooler to get airflow?

I had similar symptoms once, turned out to be a shitty vane position solenoid . Truck was laggy as shit. Have you ever changed it and if you do go with OEM, the knock offs are junk.

I suspect the turbo is the culprit, can't polish a turd. That or vane position solenoid.
 
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Bdsankey

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What's your calculated fuel rate at idle and up to temp and balance rates of injectors? Have you pressure tested the system for boost leaks? Is the rad really dirty not allowing the intercooler to get airflow?

I had similar symptoms once, turned out to be a shitty vane position solenoid . Truck was laggy as shit. Have you ever changed it and if you do go with OEM, the knock offs are junk.

I suspect the turbo is the culprit, can't polish a turd. That or vane position solenoid.
Last I knew Tom was using cheaper solenoids/sensors. That was last fall, I don't know if anything has changed since then.
 
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OleBlackyLBZ

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May 22, 2020
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Trans/converter: I am still on a stock tranny and converter. Not looking to make big power until upgrading later on.

Tunes: I have run tunes from a couple other tuners on this turbo and both seem to have the same struggles as I have had. Went through multiple sets of revisions with both. That's why I decided to try and tune on my own to have the ability to test and try all sorts of different vane positions to see what responds the best.

Parts list:
Sb intake
3 inch down pipe
5 inch straight pipe with flow through muffler
60 over flux injectors
65mm wold fab turbo
PPE Up Pipes
Airdog 165
Fuel rail plug

It seems like a pretty mild setup and I don't believe it is mismatched, just night be missing a proper TC. I imagine the right TC would help with spoolup, but not my low boost and mileage issues. I feel like the turbo may have mismatched turbine to compressor or too much clearance causing it to not run properly, but I still think it may have to do with my tuning and want to give that as good of a chance as possible before taking an L on this turbo and buying another.

It seemed like my stock turbo was going out and I got a good deal on this one brand new so I went for it. It has been a pain. It will really get moving once the turbo has lit, but cruising and trying to get moving, the egts are high and my main complaint is low mileage (can you blame me with these gas prices?). Towed a 10k trailer and only got a miserable 8mpg at 70 mph... No big hills or anything. I would think it would be possible to get at least 12, maybe even 14. I am on 33s, but know with good tuning these can run efficiently.

Elevation may be hurting some, but I would think this bigger turbo would still be able to flow air? I'm at 4700 feet.
I tow with a danville 65mm and have 33's as well, It's a nice all-around turbo but you have to tow differently with it than a stocker to get it to perform. If you lug it around at 16-1700 rpm's it won't make enough boost to pull well, high egt's, crappy fuel mileage etc. Basically putting a larger turbo on moves the torque/efficiency curve on up in the rpms, so if you want that engine to perform now you'll have to drive it accordingly! I never run 6th unless I'm empty, my truck in 5th at 65-70mph and 1900-2K rpms is happy, egt's usually around 1100 and mileage 11-12ish with 10Klbs unless I'm towing something very non-aerodynamic and/or bucking a strong headwind. I agree I would want to rule out a potential tuning issue by using professional tunes or at least having someone look over the ones your using, but you will still have to drive the truck differently with that bigger turbo no matter the tuning. As far as 13-14mpg towing, that is probably possible with a stock turbo but 11-12 is more realistic with a 65 imo.
 
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Wildeman101

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I'm using my stock solenoid and position sensor and they seem to work fine. The turbo follows commanded vpos no problem, it just doesn't seem to matter what I command, it is always low on boost. Really interested in Danville 65 stg2 but would love to have more data about it before dropping more cash. Anyone with that turbo willing to share a Datalog of how it responds? Or a video of the CTS showing maf/rpm/vpos/iat also your elevation or baro pressure. From data I've found, the 68stg2r would spool better (flow more air at same rpm) than this wold fab charger. I have to assume the 65 would be even better.
 

Bdsankey

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I'm using my stock solenoid and position sensor and they seem to work fine. The turbo follows commanded vpos no problem, it just doesn't seem to matter what I command, it is always low on boost. Really interested in Danville 65 stg2 but would love to have more data about it before dropping more cash. Anyone with that turbo willing to share a Datalog of how it responds? Or a video of the CTS showing maf/rpm/vpos/iat also your elevation or baro pressure. From data I've found, the 68stg2r would spool better (flow more air at same rpm) than this wold fab charger. I have to assume the 65 would be even better.

Bigger turbos require matching ECM/TCM files as they simply DO NOT flow anywhere near the same airflow as a stock charger down low due to the sizing/mass/airflow characteristics of the larger compressors and turbines.


A 68 Stage 2R is not at all a great towing charger, I had ~15k miles towing on my 68 stage 2r and was not a fan. Does that make it a bad turbo? Hell no, it was great at everything else but not at all ideal for towing. I'm also extremely picky which doesn't help.


If your goals are towing with over stock HP either run a very small drop in (63-65mm) or S400/stock compounds. Bigger single turbos at elevation and towing are a recipe for a poor experience, especially with an inexperienced tuner. If you're dead set on tuning it yourself you'd be best suited with a stock charger and learning that. If you're going to stay down the larger charger path and tune it yourself go right ahead but you have to expect people are going to stop responding to your posts with the same info over and over again. It's like the boy who cried wolf, sooner or later the community isn't going to actually are when you have a problem as your question has been answered multiple times.
 
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Chevy1925

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At the end of the day, you are on a stock converter. every turbo you drop in there besides stock is going to be a bitch to tune and not run like it should. that wold turbo is your issue, both in size and who's it is.

you arent going to get the answer you want to hear.
 

08lmm72mm

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I wouldn't worry one bit about running a Danville. Mark knows what he's doing and there is many of us who are more than satisfied with his turbos.

I'm usually skeptical about any part or company that has the word "world" in it, usually is cheap junk .
 
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Bdsankey

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I wouldn't worry one bit about running a Danville. Mark knows what he's doing and there is many of us who are more than satisfied with his turbos.

I'm usually skeptical about any part or company that has the word "world" in it, usually is cheap junk .
They are "Wold Fab" after the owner's last name (Tom Wold).