school me on twin turbos....
#12
06-21-2009, 12:29 AM
yes you are correct we run compounds on these.. never really thought about it that way.
#13
06-21-2009, 01:13 AM
Sean
#14
06-22-2009, 10:32 AM
Diesel Bomber
With that much weight, I would definitely look at twins.
Skip the HX35 and hybrid unless you want no more than 500HP. Expect crazy drive pressure with anything bigger than a 150HP injector.
I would run a 62/65 13ss or 14 over a S400. That will provide plenty of air for up to the maximum available fueling for a VP truck. The next step would be a 62/71, but you are going to add lag and not much else.
A S480 is really a waste on a VP truck. They just don't have enough fuel to make the most out of it. And if you were going that route, you would want a 64/71 over the S480.
Dave
Skip the HX35 and hybrid unless you want no more than 500HP. Expect crazy drive pressure with anything bigger than a 150HP injector.
I would run a 62/65 13ss or 14 over a S400. That will provide plenty of air for up to the maximum available fueling for a VP truck. The next step would be a 62/71, but you are going to add lag and not much else.
A S480 is really a waste on a VP truck. They just don't have enough fuel to make the most out of it. And if you were going that route, you would want a 64/71 over the S480.
Dave
#16
06-22-2009, 12:25 PM
Dave is talking about running anything larger than a 150 if you use an hx35 as your secondary(top turbo). Essentially the drive pressure or exhaust manifold pressure would be very high. Ideally you want to maintain as close to a 1:1 ratio as possible between drive pressure and boost pressure.
One of the draw backs to high drive pressure, is that it will increase turbine speed, and make it hard to keep you top turbo in its compressor map, without a lot of wastegate. High drive pressure also limits efficiency and increases reversions.
Sean
One of the draw backs to high drive pressure, is that it will increase turbine speed, and make it hard to keep you top turbo in its compressor map, without a lot of wastegate. High drive pressure also limits efficiency and increases reversions.
Sean
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scarecrow (06-22-2009)
#17
06-22-2009, 01:19 PM
Diesel Bomber
Compounds are two turbochargers of different sizes running in series with each other...one turbocharger compressor side feeds the other.
Twins are two turbochargers of the same size feeding the engine in parallel...usually seen on V engines, one per bank.
Twins are two turbochargers of the same size feeding the engine in parallel...usually seen on V engines, one per bank.
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biged681985 (06-22-2009),
scarecrow (06-22-2009)
#18
06-22-2009, 01:48 PM
#19
06-22-2009, 06:53 PM
I'm fairly ignorant about these combos myself, so I ask you this Dave. I'm goin for about the same goals with my truck. Why do you say no bigger than a 150? Would 150s be streetable and towable with one of the setups you suggested and how bad would MPGs suffer? Also, if you wanted to get to 500+ RWHP is it possible to get there and not suffer too much on MPGs as long as you keep your foot out of it?
The HX35 is just done at around 550HP, you can easily get there with a 150 injector. In fact, my truck would not make any more power no matter how big of a stick I used. So, without an external gate, power will be limited. Not to mention there is only so much efficiency available in the HX35 with the compressor/ turbine package.
Even with a hybrid, you are only going to a HX40 wheel. While that wheel will support more airflow, it does nothing for the turbine side and that is the choke in this equation. That said, the HX35 and hybrid will spool fast and cool 500HP pretty easy. With the box turned down, you can tow a ton of weight. And water temps will be an issue far before EGTs are.
As far as economy, I got my best mileage with the Dodgezilla with a modded 14cm housing over S400 setup and 150HP injector. I could crack 24MPG on a regular basis (Summer fuel) at speeds up to 70MPH. Of course this is on the highway, cruise on, Juice on 1x1. AS a comparison for the same HP level, with the Smarty I got 20MPG and horrible cruise surge and the Adrenaline I got 22MPG. I make the same drive a lot.
My towing mileage is best with the Juice.
But with the setup listed above, and 150HP sticks I would see a high of 545HP. As smaller stick could be used, but many of the 100Hp sticks will struggle to meet 500HP and usually the spray pattern and raw flow is not optimized for our setup. So, power and economy suffers.
It's important to decide now what you want to end up with. Otherwise you'll be spending your money many times to get to where you want to end up. I am working on some new parts that will address some of this in our own compound sets, but there's still some issues I want to see handled better.
Dave
---AutoMerged DoublePost---
Dave is talking about running anything larger than a 150 if you use an hx35 as your secondary(top turbo). Essentially the drive pressure or exhaust manifold pressure would be very high. Ideally you want to maintain as close to a 1:1 ratio as possible between drive pressure and boost pressure.
One of the draw backs to high drive pressure, is that it will increase turbine speed, and make it hard to keep you top turbo in its compressor map, without a lot of wastegate. High drive pressure also limits efficiency and increases reversions.
Sean
One of the draw backs to high drive pressure, is that it will increase turbine speed, and make it hard to keep you top turbo in its compressor map, without a lot of wastegate. High drive pressure also limits efficiency and increases reversions.
Sean
I would recommend anyone that wants 500+ and a HX35 type setup to look at a non wastegated housing and an external gate. It works much better and helps with drive pressures a bit. But there's no way of getting around that small housing.
Dave
Last edited by Fishin2Deep4U; 06-22-2009 at 06:53 PM. Reason: Automerged Doublepost
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AF1CUMMINS (06-23-2009)
#20
06-26-2009, 09:26 AM
Diesel Fan
