school me on twin turbos....
 

some of you may remember a post i put up a little bit ago asking about turbos. well i have not yet bought one. i am now thinking about twins but i do not know anything about them or how they work. the truck they would go one is the 1 in my sig. plans changed for me and i sold some toys so the only thing i will be towing is a 30ft toyhauler and my john deere tractors...over all i would like to produce 500+ hp and 1000+ tq. also i want the truck to run 12s in the 1/4. ofcoarse more hp and fast then 12 will be ok...:U: .....

I would say a 35/40 and HTB3 or S475 combo or 62/71 and HTB3 or s475. You could also run a 64/71 but for the power your lookign for you dont need it. Stay away from an S480 I think its going to be way to big for your needs. Honestly you dont really need twins a 62 or 64 single should be fine.

I dont see injectors in your sig. What do you plan to run?

not sure i was gonna wait until i figured out what i was doing for a turbo...

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

I really like the he351 over 3b I've been running. Great tow setup with the 200 horse injectors and adrenaline on 2nd setting. I'm going to make another set with a s400 for the other truck to see if it's any better than the 3b. Twins are the only way to go if you tow alot.

I am getting ready to add the s400 to the bottom of mine and the 200hp injectors. a buddy had the same thing in his before ppump and a lot more injector he loved it and it ran clean.

Similar to my Vulcan setup. Cleans up everything I can throw at it.

Dave

this sucks i really have no clue what i wanna do......:argh::argh::argh:

That sounds about like the next set I'm going to build myself. 62/14 over an s475. But I need o-rings and head work first, and more money. I love my little towing twins, and they clear up the small sticks well with great spool up and low egt's, but I think a bigger set and more stick would be a lot of fun.

You will definitely want twins for towing, the biggest part is going to be determining which sticks you are going to want to run and building your set from there. Pairing turbos properly takes a bit of research to do, but there are some decent proven combos out there that will work well for what you are looking to do. I honestly think that with the proper exhaust flow, you could get an hx35 or 35/40 hybrid to be comfortable in the 550hp range and still be able to turn the box down and tow. I intend to see just what mine are capable of with some 200's in the near future when I finally get my truck back together.
Sean

the HX35 35/40 is one at just under 550HP. Drive pressures are crazy!

If I were building another set for me, I would skip the wastegated housing and go with an external gate. Cost will be about the same, more plumbing, but it will work MUCH better!

Dave

Twin turbochargers on an inline six engine are for the most part a waste of time, money, and energy.

Compound turbochargers, on the other hand....that's the ticket.



Smart ass comment #44....

Cheers,

Dan

lol yes you are correct we run compounds on these.. never really thought about it that way.

Yep, I run an external gate with a full size adapter to it, no a necked down piece of pipe squeezed into a 3/4" adapter. That just seems like it wouldn't flow well.
Sean

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?

whats the difference between compound and twin ????

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

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.

i want twins so bad

The 150 is a great all around size.

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

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Drive pressures are always going to be an issue with a charger that small on top and any kind of fuel. Even though the EGTs are controllable, the drive pressures ct like an engine brake and when it's done. it's done.

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

Possibly an s300 over s400? Not positive on this but I know there is a guy running a stock 3rd gen turbo over an s400 on hisvp truck and it's doing him a prettygoodjob.... And is pretty darncheap to build

The stock 3rd gen over S400 is a decent setup. However, it does have some serious drive pressure issues if you exceed 50 PSI. I helped a few buddies try to use the stock turbos and both ended up going to a S300 to fix the drive pressure issues.

So, it might be cheap, but if you are going to make up to 500 or more HP, skip it and go to a S300/ S400 Setup.

Dave