Twins vs single.

[SSpeeDEMONSS]

what size are your chargers now?

Garrett

 

[6.0dirtworker]

S366/74 .70 open or .90 dual volute. And a s475/96/1.32. I'm not positive but I think I can downsize to a 1.10, I'm not sure if my turbine wheel will allow it. Also have a 62/65/.70 sitting in the shop too that's dying to be spun

 

[SSpeeDEMONSS]

why dont you just upgrade to something in the 80-88mm range for your primary?

Garrett

 

[6.0dirtworker]

I can up the 75 to an 83. I didnt know if a s510ish charger would net me a solid gain over the compounds. If it's minimal I would rather just do two big chargers.

 

[windrunner408]

I have a question that I just came up with and since this is a singe vs. twin turbo thread, i thought I might ask it since a few things seem to make more sense now after following it.

Lets say I want to run a 62mm, batmowheeled, non-VGT turbo with stock sticks. I install the turbo, tune the truck, and go rockin. The truck behaves however it behaves, i.e. drives fine. Maybe has a little more lag than the stock turbo.

Now what would the truck act like if I added say a batmowheeled s475 to the mix?? I am inclined to think that the only thing that would really happen (besides having my bank account go below zero) is that I could possibly produce more boost??

I understand that I would have WAY more air than fuel available but would the truck in theory anyways really bogg down?? It seems to me, that in a compound setup all the exhaust from the motor goes to the high pressure turbo first (which is what is necessary to spool the high pressure turbo) and whatever energy is left over goes to the low pressure turbo. I would be interested in seeing how you guys think this would work.

 

[6.0dirtworker]

S5 would be fuggin crammed next to the 75 tho.

 

[Dzchey21]

I have a question that I just came up with and since this is a singe vs. twin turbo thread, i thought I might ask it since a few things seem to make more sense now after following it.

Lets say I want to run a 62mm, batmowheeled, non-VGT turbo with stock sticks. I install the turbo, tune the truck, and go rockin. The truck behaves however it behaves, i.e. drives fine. Maybe has a little more lag than the stock turbo.

Now what would the truck act like if I added say a batmowheeled s475 to the mix?? I am inclined to think that the only thing that would really happen (besides having my bank account go below zero) is that I could possibly produce more boost??

I understand that I would have WAY more air than fuel available but would the truck in theory anyways really bogg down?? It seems to me, that in a compound setup all the exhaust from the motor goes to the high pressure turbo first (which is what is necessary to spool the high pressure turbo) and whatever energy is left over goes to the low pressure turbo. I would be interested in seeing how you guys think this would work.

Turbos spool faster with no restrictions on the backside of the turbine wheel. Adding another turbo adds a restriction and causes slightly slower spool than what you previously had as a single ... how much depends on the size of the turbine on the big turbo

 

[6.0dirtworker]

I have a question that I just came up with and since this is a singe vs. twin turbo thread, i thought I might ask it since a few things seem to make more sense now after following it.

Lets say I want to run a 62mm, batmowheeled, non-VGT turbo with stock sticks. I install the turbo, tune the truck, and go rockin. The truck behaves however it behaves, i.e. drives fine. Maybe has a little more lag than the stock turbo.

Now what would the truck act like if I added say a batmowheeled s475 to the mix?? I am inclined to think that the only thing that would really happen (besides having my bank account go below zero) is that I could possibly produce more boost??

I understand that I would have WAY more air than fuel available but would the truck in theory anyways really bogg down?? It seems to me, that in a compound setup all the exhaust from the motor goes to the high pressure turbo first (which is what is necessary to spool the high pressure turbo) and whatever energy is left over goes to the low pressure turbo. I would be interested in seeing how you guys think this would work.

It's all in how you have your gate tuned. Otherwise it should drive the same as a single.

 

[windrunner408]

Ok makes sense I guess. thanks.

 

[smokinstroker]

The high press charger is spooling that low pressure charger. The excess energy i.e. wastegated exhaust from the high pressure is also directed to help spool the low pressure.

This low pressure pushes more cfm I.e. flows more air

Like nick said, when setup correctly you should run the same as a single with more airflow

 

[6.0dirtworker]

Turbos spool faster with no restrictions on the backside of the turbine wheel. Adding another turbo adds a restriction and causes slightly slower spool than what you previously had as a single ... how much depends on the size of the turbine on the big turbo

Didn't know that. So a bigger wheel creates more of a restriction since it's heavier to turn than a small wheel?

 

[nvme_63]

I have a question that I just came up with and since this is a singe vs. twin turbo thread, i thought I might ask it since a few things seem to make more sense now after following it.

Lets say I want to run a 62mm, batmowheeled, non-VGT turbo with stock sticks. I install the turbo, tune the truck, and go rockin. The truck behaves however it behaves, i.e. drives fine. Maybe has a little more lag than the stock turbo.

Now what would the truck act like if I added say a batmowheeled s475 to the mix?? I am inclined to think that the only thing that would really happen (besides having my bank account go below zero) is that I could possibly produce more boost??

I understand that I would have WAY more air than fuel available but would the truck in theory anyways really bogg down?? It seems to me, that in a compound setup all the exhaust from the motor goes to the high pressure turbo first (which is what is necessary to spool the high pressure turbo) and whatever energy is left over goes to the low pressure turbo. I would be interested in seeing how you guys think this would work.

i think if you went with a .70 housing on the high pressure, and a tight housing on the big turbo you would have enough heat to make that work. Again this is my opinion not necessarily fact. With a hot tune from Eric i think it is very possible, probably a great towing setup. Once again this is all my opinion.

 

[Dzchey21]

Didn't know that. So a bigger wheel creates more of a restriction since it's heavier to turn than a small wheel?

No a bigger exhaust wheel will be less restrictive Hince the slower spooling ... of the big turbo but it will actually help spool the small turbo... which in turn usually helps spool the big turbo faster. Since as a single most trucks stand no chance to.spool a s510 ... ever but like on my truck the big turbo can make 15psi at 1800 rpm... because the small turbo is already making 20

 

[windrunner408]

Well it definitely wouldnt be permanent that is for sure. I mean who drops the coin for a compound setup to use stock injectors?? Really?? I was merely asking from a theoretical stand point to figure out if it would be more laggy, less laggy, or the same amount of lag as if I had just put the single turbo on. It makes sense that it would be more laggy due to restrictions I guess but just wasnt sure and really wanted to better understand the principles of operation.

 

[Dzchey21]

Well it definitely wouldnt be permanent that is for sure. I mean who drops the coin for a compound setup to use stock injectors?? Really?? I was merely asking from a theoretical stand point to figure out if it would be more laggy, less laggy, or the same amount of lag as if I had just put the single turbo on. It makes sense that it would be more laggy due to restrictions I guess but just wasnt sure and really wanted to better understand the principles of operation.

In a situation like u speak I would use a stock turbo and an s475

 

[windrunner408]

In a situation like u speak I would use a stock turbo and an s475

Really?? I didnt think we could use a VGT for a high pressure turbo.

 

[nvme_63]

In a situation like u speak I would use a stock turbo and an s475

stock vgt wont hold up to it. Way too small of a shaft to handle the thrust placed on the cold side.

 

[Dzchey21]

stock vgt wont hold up to it. Way too small of a shaft to handle the thrust placed on the cold side.

Says who? If anything compounds would help since the pressure ratio of the stock turbo would go down so would the load on the charged

 

[nvme_63]

Says who? If anything compounds would help since the pressure ratio of the stock turbo would go down so would the load on the charged

If you say so, ask Shawn about it, he tried way back in the day if i remember correctly.

 

[Dzchey21]

If you say so, ask Shawn about it, he tried way back in the day if i remember correctly.

I did. He said it works awesome just doesn't last long when you spray nitrous at it...