Twin Turbo and Shortys

[SSambumbia]

Since the TT's (Granatelli and Hellion) attach to the stock manifold, can it be attached to shorty headers?
Probably no a whole lot of gain hp wise but there is something about tune length manifolds that I have always liked.

[Z_Rocks]

Originally Posted by SSambumbia

Since the TT's (Granatelli and Hellion) attach to the stock manifold, can it be attached to shorty headers?
Probably no a whole lot of gain hp wise but there is something about tune length manifolds that I have always liked.

I read something very interesting this weekend regarding how Hyundai is going to be adding a new 2.0T to it's line. This turbo design is very similar to the design Porsche and BMW use as twin scroll turbo which has two gas inlets into the turbo to get better result in low and high end.
However, the interesting part is that they see by having individual outlet from each cylinder merging to the turbo provides a much better air intake to each cylinder at different phases than if they had used the traditional exhaust manifold. Since at certain phase the pressure of one exhaust can prevent the other cylinders (when the intake & outtake valves are overlapping, meaning being opened). Once they had separate exhaust runners, they saw the engine breaths better and gets a better air/fuel mixture than running to rich.
The article explains it better. Here is a good read:
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TWIN-SCROLL TURBOCHARGER AND GDI TECHNOLOGY

Twin-scroll turbocharger designs have two exhaust gas inlets divided by split walls inside the turbine housing, with both gas passages controlled by a waste-gate. A twin-scroll turbo recovers even more energy from the exhaust than a single-scroll turbocharger thanks to a divided manifold. The twin-scroll design separates the cylinders whose exhaust gas pulses interfere with each other resulting in improved pressure distribution in the exhaust ports and a more efficient delivery of exhaust gas energy to the turbocharger's turbine.

For example, at the start of the intake stroke of cylinder one, and when both the intake and exhaust valves of cylinder one are open (valve overlap period), cylinder three already starts its exhaust stroke with the exhaust valve open. If the exhaust passages of cylinder one and three were connected, the exhaust gas pulse from cylinder three would increase the back pressure of cylinder one. This would reduce the induction of the fresh air and increase the amount of hot residual gases inside the cylinder. However, with the twin-scroll turbocharger setup, this interference is minimized.

The result of this superior scavenging effect from a twin-scroll design leads to better pressure distribution in the exhaust ports and a more efficient delivery of exhaust gas energy to the turbocharger's turbine. This in turn allows greater valve overlap, resulting in an improved quality and quantity of the air charge entering each cylinder. In fact, with more valve overlap, the scavenging effect of the exhaust flow can literally draw more air in on the intake side. At the same time, drawing out the last of the low-pressure exhaust gases help pack each cylinder with a denser and purer air charge. Maximum boost from the turbocharger is 17.4 psi.

The twin-scroll turbocharger design has several other advantages over traditional, single-scroll turbocharging systems, including:

* Improved combustion efficiency
* Low engine-speed efficiency
* Kinetic exhaust gas energy is not wasted or trapped
* Cooler cylinder temperatures
* Lower exhaust temperatures
* Leaner air/fuel ratio


* Better pressure distribution in the exhaust ports and more efficient delivery of exhaust gas energy to the turbocharger's turbine

Essentially, Sonata's twin-scroll turbo directs even more air into the engine while a compressor increases the pressure entering the cylinder. This allows the air entering the cylinder to be even more densely packed for higher compression and better performance, contributing to a more-efficient burn and fuel efficiency.

Two key features of Hyundai's twin-scroll turbocharger setup are:

* The stainless steel exhaust manifold and the twin-scroll turbine housing are cast in a patent pending one-piece design
* The waste-gate for the turbocharger uses a motor-driven electrical controller instead of being mechanically controlled

Thanks to the integrated stainless-steel turbine housing with the exhaust manifold, not only is the weight and cost of the casting dramatically reduced, the durability of the turbine housing is also improved.

By adapting the motor-driven electrical waste-gate, the boost pressure is precisely controlled. The back pressure is reduced when turbo boost is not necessary by opening the waste-gate, which improves fuel efficiency. In addition, during cold starts, the waste-gate remains open which results in faster catalyst light-off for reduced exhaust emissions.

A GDI fuel delivery system contributes to improved fuel efficiency and lower emissions. This shorter, more direct path of fuel delivery allows for greater control of the fuel mixture at the optimum moment, thus improving efficiency. The fuel is injected by a camshaft-driven, high pressure pump that operates at pressures up to 2175 psi. Direct injection also utilizes a higher-than-normal 9.5:1 compression ratio while achieving a remarkable 137 horsepower-per-liter. The piston heads are "dished" to increase combustion efficiency in the cylinder.

[TTI George]

Originally Posted by SSambumbia

Since the TT's (Granatelli and Hellion) attach to the stock manifold, can it be attached to shorty headers?
Probably no a whole lot of gain hp wise but there is something about tune length manifolds that I have always liked.

Headers will feed the turbocharger as well if not a little better that the stock manifold and could easily be added to almost all of the turbo systems offered. Do yourself a favor, if you decide to go that route be sure there stainless. The turbo system will generate exhaust back press almost equalizing boost pressure. Mild steel won't last very long.

[Heliwrench]

Faster boost can't hurt

[radz28]

Will there be a concern with the shorties being of sufficient strength to hold those turbos' over time? I mean, with the weight of the turbos', unless it's offset with some additional bracing, won't there be potential for the headers to deform, or leak, or the welds crack? With seeing so many turbo' builds, on street cars, using manifolds, I'd just be cautious and make sure you have additional support Otherwise, I can't see the harm.

[SonnyakaPig]

Originally Posted by Z_Rocks

I read something very interesting this weekend regarding how Hyundai is going to be adding a new 2.0T to it's line. This turbo design is very similar to the design Porsche and BMW use as twin scroll turbo which has two gas inlets into the turbo to get better result in low and high end.
However, the interesting part is that they see by having individual outlet from each cylinder merging to the turbo provides a much better air intake to each cylinder at different phases than if they had used the traditional exhaust manifold. Since at certain phase the pressure of one exhaust can prevent the other cylinders (when the intake & outtake valves are overlapping, meaning being opened). Once they had separate exhaust runners, they saw the engine breaths better and gets a better air/fuel mixture than running to rich.
The article explains it better. Here is a good read:

Thanks for sharing. That was a real good read. Sounds like that 2.0L, turbo engine is pretty advanced. And they are making good power.

I really think Hyundai is improving and at a relatively fast rate.

Regarding this thread, it would seem that the more exhuast that a manifold can flow the better. But, of course, radz brought up a good point. So it would be good to find out if weight could even possibly be an issue for shorties.

[yonson]

The biggest issue with using a tubular header over the log manifold is that over time the heat will crack the tubular headers much quicker/easier than with the manifolds. Also as you add more boost the back pressure increases and this will happen much quicker, on a street car with a smallish size turbo and a typical exhaust system it's not hard to see 40 psi of back pressure when running 14 - 16 psi of boost.

We put a turbo on my Lightning and used a set of tubular headers and after about a year or so at 15 - 16 PSI (once or twice I ran 20 - 24) they had cracked in a couple locations and needed to be repaired.

[SonnyakaPig]

Originally Posted by yonson

The biggest issue with using a tubular header over the log manifold is that over time the heat will crack the tubular headers much quicker/easier than with the manifolds. Also as you add more boost the back pressure increases and this will happen much quicker, on a street car with a smallish size turbo and a typical exhaust system it's not hard to see 40 psi of back pressure when running 14 - 16 psi of boost.

We put a turbo on my Lightning and used a set of tubular headers and after about a year or so at 15 - 16 PSI (once or twice I ran 20 - 24) they had cracked in a couple locations and needed to be repaired.

That's very good information. Important consideration.

[Slowhawk]

I would keep the stock manifolds since they are stronger.Doubt you would gain 1hp from switching.

For a long time alot of builders have used stock "cast" manifolds because they hold heat(good for turbo spool) and strength. We have a few LS based vehicles that run stock manifolds and push north of 800hp/800tq and have been doing so for years.

[PoleCat2SSRS2010]

What about thicker/heavier wall materials for the tubes? I understand that steel fatigues faster than s/s but if a stronger tube was used then wouldn't there be a better life expectancy?
Aren't there industries (ex: HVAC, petro-chem) that use extra-heavy steel pipe wall thickness solutions for the very same reasons of heat and fatigue and pressure and service life.

[SSambumbia]

I have been looking at the JBA S/S shortys with the titanium ceramic coating. They claim to be thick walled. Would be ideal if they where 1 7/8" primaries, but they are
1 3/4". I don't expect a whole lot in hp gain, but overall efficiency of the system and a bit quicker spool-up if I decide to go with the bigger turbos option. I wouldn't add a BAP fuel solution no matter what hp range I am in, for the same reason.

[yonson]

Unless you are going to be using 500+ cubes a 1 3/4" primary is more than enough, we have made well over 2000 HP with 1 3/4's... Bottom line on a street car with elevated boost it is HIGHLY recommended to use cast manifolds they will flow more than enough and will live a lot longer, thus the reason the Hellion and GMS kits use them...