Using the stock turbo & s400 or k-31 for twins

No divider, open throat. And it has a 60mm compressor not 62. I would try adjusting the wastegate on the K31, it will ultimately determine/control total flow and HP potential.
 
Adjust the K31 so it's wastegate does not open and see what boost peaks out at. You need to be able to build 30 or so psi with that primary, 27 probably at it's peak efficiency but not at it's peak flow potential.

And to clarify, the HE351 has an open throat nondivided housing so it wastegates all 6 cylinders when the wastegate opens. This is a good thing.
 
Big Blue24 said:
Adjust the K31 so it's wastegate does not open and see what boost peaks out at. You need to be able to build 30 or so psi with that primary, 27 probably at it's peak efficiency but not at it's peak flow potential.

And to clarify, the HE351 has an open throat nondivided housing so it wastegates all 6 cylinders when the wastegate opens. This is a good thing.
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I have a g-42 as a primary. I was told that 25-29 ( least to max) is where the primary should be set. If I close offf the g-42 and see how much it makes what will that tell me. I did just the opposite with the stock charger. The gate locked open netted 27 psi on the primary.
 
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osci said:
I have a g-42 as a primary. I was told that 25-29 ( least to max) is where the primary should be set. If I close offf the g-42 and see how much it makes what will that tell me. I did just the opposite with the stock charger. The gate locked open netted 27 psi on the primary.
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When you check the boost ratio between the top and bottom turbos you need to do it with a 2nd boost gauge in the cold piping (between the 2 turbos). Locking open the top WG isn't going to give you the true ratio. You need to monitor boost from the top turbo and total boost simultaneously and then tune the top WG so the ratio is as close to 50/50 as possible.
 
JustinR said:
When you check the boost ratio between the top and bottom turbos you need to do it with a 2nd boost gauge in the cold piping (between the 2 turbos). Locking open the top WG isn't going to give you the true ratio. You need to monitor boost from the top turbo and total boost simultaneously and then tune the top WG so the ratio is as close to 50/50 as possible.
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Right, I use 2-3 boost guages. I run 1 off the cold pipe(primary) 1 off my attitude, and 1 off my inatake- overall. It is set to a close 50-50. If i'm making 27 off the bottom 33 is from the top- right with a total of 60. But no matter what i do adjusting the sec wastegate makes no chage on psi, drive pressure or egts.
 
osci said:
Right, I use 2-3 boost guages. I run 1 off the cold pipe(primary) 1 off my attitude, and 1 off my inatake- overall. It is set to a close 50-50. If i'm making 27 off the bottom 33 is from the top- right with a total of 60. But no matter what i do adjusting the sec wastegate makes no chage on psi, drive pressure or egts.
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I'm no twins expert by any means, but that doesn't make sense to me. You should definitely see a difference in secondary boost, max boost, and EGT's when adjusting the secondary's WG. It sounds like something is up with that WG. How are you adjusting the stocker's WG? Are you using Nathan's manual WG controller?
 
JustinR said:
I'm no twins expert by any means, but that doesn't make sense to me. You should definitely see a difference in secondary boost, max boost, and EGT's when adjusting the secondary's WG. It sounds like something is up with that WG. How are you adjusting the stocker's WG? Are you using Nathan's manual WG controller?
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Why do you assume it's Nathans wastegate? And yes it is, thats the only way since the stocker is elect.
 
osci said:
Why do you assume it's Nathans wastegate? And yes it is, thats the only way since the stocker is elect.
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That's why I asked if it was his.

Mine uses the same lever and spring controller and it works well. You can definitely see a difference in boost ratio, max boost, and EGT's when adjusting it just a few threads.

Something must be up with one of the WG's or maybe you have a boost/drive pressure leak somewhere?

I wouldn't be too concerned with low dyno numbers unless you're running right next to other similar trucks that do better. Some Mustang dyno's can be really stingy. Mine did around 405hp on a Mustang and then 2 weeks later (with the same exact mods) it did 550hp on a Dynocom. IMO a dragstrip will tell you much more than a dyno.
 
JustinR said:
That's why I asked if it was his.

Mine uses the same lever and spring controller and it works well. You can definitely see a difference in boost ratio, max boost, and EGT's when adjusting it just a few threads.

Something must be up with one of the WG's or maybe you have a boost/drive pressure leak somewhere?

I wouldn't be too concerned with low dyno numbers unless you're running right next to other similar trucks that do better. Some Mustang dyno's can be really stingy. Mine did around 405hp on a Mustang and then 2 weeks later (with the same exact mods) it did 550hp on a Dynocom. IMO a dragstrip will tell you much more than a dyno.
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I just don't know what's up with the lever, there is no making headway with it. I have checked for boost/drive leaks and found none.
 
osci said:
I have a g-42 as a primary. I was told that 25-29 ( least to max) is where the primary should be set. If I close offf the g-42 and see how much it makes what will that tell me. I did just the opposite with the stock charger. The gate locked open netted 27 psi on the primary.
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That doesn't really tell you anything. The primary will react much differently with the secondary feeding the engine. Like JustinR said they boost in the cold pipe when everything is up and running is more informative.

When is the top wastegate opening/whats it set at? What are the pressures like at that instant?
 
dual k20s said:
That doesn't really tell you anything. The primary will react much differently with the secondary feeding the engine. Like JustinR said they boost in the cold pipe when everything is up and running is more informative.

I do not think that a g-42 is wastegated is it? This would mean the top wastegate is the only thing to play with, When is the top wastegate opening? What are the pressures like at that instant?
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I'm taking my reading from reading from the cold pipe and also horn. The gt-42 is wastegated at 27 psi. I can't tell at all if and when the sec gate opens, no drop in pressure....
 
JustinR said:
That's why I asked if it was his.

Mine uses the same lever and spring controller and it works well. You can definitely see a difference in boost ratio, max boost, and EGT's when adjusting it just a few threads.

Something must be up with one of the WG's or maybe you have a boost/drive pressure leak somewhere?

I wouldn't be too concerned with low dyno numbers unless you're running right next to other similar trucks that do better. Some Mustang dyno's can be really stingy. Mine did around 405hp on a Mustang and then 2 weeks later (with the same exact mods) it did 550hp on a Dynocom. IMO a dragstrip will tell you much more than a dyno.
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I have tried to help Scott out with this a bit. He has run multiple boost gauges and even switched them around to ensure accuracy.

In the cold pipe he will see 27-28 psi depending on loading. The top charger gate is just too small IMO. He could run the bottom harder, but he still needs to get the exhaust past the top turbo. He tried wiring the top gate open to check overall drive pressures. Even with the gate open, he had high drive. He tried another top turbo that was looser with a modded gate as well. Drive pressures were in line, but would not spool fast enough. He is compounding a little over a 2:1 ratio, so everything should be well withing the fat parts of the maps. I told him we can change the ratios a bit, but the drive pressure will not allow less than that ratio on top. Changing the spring/ bolt controller thingy results in a change of spooling time, but not overall boost or drive pressures.

Regarding HP, he has run along side other trucks on DynoJets and Mustangs. He is always a good bit lower than similar fueled trucks.

I think the solution with the stock top charger may be a large external. How big, I dunno. Was thinking something close to 50mm for around 600HP. But I do not know how big to go without going too big. The other option is to modify the stock gate and see what happens. Also, building an arm to accept the factory wastegate actuator with a ball and spring controller.

The thing spools like crazy. But Scott pulls some pretty good weight and lives in a very hilly area where speeds are limited to 30 or so mph. Add a tight auto and it just makes things worse. He needs his fast spool. So, I would like to see a solution that does not require reinventing the wheel or putting on a slower spooling charger.

I am really impressed with the fast spool. Fit and finish was pretty good. The only things I would have liked to see would have been a bottom turbo support included and a better top gate control. But other than that, I would love to have that kinda of spool. And I think flat land towing has been good for Scott. It's when he hits some steep terrain and hits higher levels of boost that he sees higher temps. Hopefully, it's as easy as making a bigger hole in the housing and making up a new flapper.

Dave
 
dual k20s said:
When is the top wastegate opening/whats it set at? What are the pressures like at that instant?
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No way to check cracking pressure in the conventional sense. Since the controller is a bolt and spring, there is no where to hook up air. And since it's a spring with no boost pushing against it, the load increases on the spring trying to push the gate closed the further it's open.

This thing hit's 27 on the bottom FAST. He's at 55psi when mine is still making 30 psi. But the bottom never exceeds 28. The gate is working on the primary.

But as stated in my last post, if the gate on the top turbo is left wide open, he could still easily pass 60 psi boost and continue to climb as he turns the box up. Just too much exhaust for the wastegate to handle.

Dave
 
osci said:
justin r, what chargers are you running. The stocker?
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Stocker over an S400.

There's quite a few people out there running 600+hp with that setup, so I'm not sure the stock WG design or Nathan's controller are really your problem.
 
JustinR said:
Stocker over an S400.

There's quite a few people out there running 600+hp with that setup, so I'm not sure the stock WG design or Nathan's controller are really your problem.
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What else could be the problem and where should i be looking.
 
What boost are you running and what are the drive pressures?
 
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