Twincharger: ever seen one on our cars?

[Dubstep Shep]

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Nah, we never heard of it....

http://www.s197forum.com/forum/showthread.php?t=49583&highlight=Compound+boost


http://www.s197forum.com/forum/showthread.php?t=74321&highlight=Compound+boost

http://www.s197forum.com/forum/showthread.php?t=84151&highlight=Compound+boost

http://www.s197forum.com/forum/showthread.php?t=65335&highlight=Compound+boost

Thanks for the clarification. The titles are a bit deceiving.

Interestingly enough though, I didn't get a single result when I searched "twincharger"

This is something Ive researched a bit, and it is definitely nothing new. I found some pics of this being done that were on black and white film

Heres how it breaks down.
With a setup like this you get the advantage of having higher manifold pressures than the pressures found inside the turbo manifolds, due to the supercharger. So, just like with a normal supercharger setup, you get a lot of scavenging effect which helps make power and reduce heat by clearing the cylinder. This means more timing and/or more boost.
Also, the supercharger helps the turbo(s) spool easier, so you can run a higher A/R turbine housing, which make more power without sacrificing spool.

All together, if you have a supercharger running at low speed (wherever its most efficient), and the turbos on top of that making most of your boost, you can make lots of power with a nicely shaped powerband.

Its a cool idea and it does work well, but its also expensive and complex. As much as I like it, Im not sure Id ever do it, Im a road racer and I dont think I could ever justify the added weight up front.

EDIT:
Also, modern turbos have almost zero lag. Lag is different than being below boost threshold.

Exactly. Each cancels the disadvantages of the other, to an extent.

Without mincing technical terms, it takes turbos time to build up to their boost level, and by concept of the technology, that is unavoidable, though it's been minimized in many circumstances.

The way I see it you have all the power of a supercharger down low, that most turbo setups just don't produce, you reduce parasitic draw, and you get the power up high in rpms that turbos are known for.

Stuff's just expensive hahahaha.

 

[Greg Hazlett]

You are partially correct; the PD blowers will help down low, centri's are similar to the turbo's as in they need rpm's to build boost.

 

[Thekid760]

Diesel's have been using compound boost for a very long time.

Generally the super is used at lower boost pressures, then bypassed as pressures increase and it becomes a restriction.

A compound turbo setup however doesn't bypass, all the air from the primary (big or low pressure) gets compounded in the secondary then it enters the intercooler then engine.

the smaller turbo gets up and spooling fast then the big one provides the airflow. The HP potential of the engine is determined by the airflow of the primary.

General rule of thumb sizing is 1.5-2:1 for primary to secondary ratio.

 

[drive_55_not]

Thanks for the clarification. The titles are a bit deceiving.

Interestingly enough though, I didn't get a single result when I searched "twincharger"



Exactly. Each cancels the disadvantages of the other, to an extent.

Without mincing technical terms, it takes turbos time to build up to their boost level, and by concept of the technology, that is unavoidable, though it's been minimized in many circumstances.

The way I see it you have all the power of a supercharger down low, that most turbo setups just don't produce, you reduce parasitic draw, and you get the power up high in rpms that turbos are known for.

Stuff's just expensive hahahaha.

Hennessey
The compound boost does look cool but a Hennessey built twin-turbo feeding a supercharger Ford GT and it ran 230 on the Texas Mile.


They yanked the supercharger and picked up 30+mph by removing the SC restriction.

Granted that maybe an extreme example but it does show the SC will be a bottle neck at extreme power levels, If you wanna cure turbo lag, spray it.



.

 

[Dubstep Shep]

Hennessey
The compound boost does look cool but a Hennessey built twin-turbo feeding a supercharger Ford GT and it ran 230 on the Texas Mile.


They yanked the supercharger and picked up 30+mph by removing the SC restriction.

Granted that maybe an extreme example but it does show the SC will be a bottle neck at extreme power levels, If you wanna cure turbo lag, spray it.



.

Really it depends on the rpm you're running the supercharger at. If it's geared to run low rpms then it won't cause much resistance, but it also won't produce as much boost. It's a trade off, just like how a larger turbo makes more boost but takes longer to get there than a smaller turbo.

 

[RocketcarX]

Hennessey
The compound boost does look cool but a Hennessey built twin-turbo feeding a supercharger Ford GT and it ran 230 on the Texas Mile.


They yanked the supercharger and picked up 30+mph by removing the SC restriction.

Granted that maybe an extreme example but it does show the SC will be a bottle neck at extreme power levels, If you wanna cure turbo lag, spray it.



.

This.

 

[07TGGT]

You didn't get results because no on says "twin charger."

 

[Full_Tilt]

twin charged is the most common name for this setup
its been done on mazdas, hondas, vws, minis, all sorts of shit

 

[psfracer]

I always thought it was called "compound boost"

 

[Greg Hazlett]

I always thought it was called "compound boost"

This, end thread.

 

[stkjock]

I always thought it was called "compound boost"

It is on real motors.

 

[Full_Tilt]

It is compound boost, but so is this:

and this:

The first time I heard this particular setup called "Twincharged" was about 10 years about on miata.net

but there are plenty of other people using the vernacular

 

[Department Of Boost]

Hennessey
The compound boost does look cool but a Hennessey built twin-turbo feeding a supercharger Ford GT and it ran 230 on the Texas Mile.


They yanked the supercharger and picked up 30+mph by removing the SC restriction.

Granted that maybe an extreme example but it does show the SC will be a bottle neck at extreme power levels, If you wanna cure turbo lag, spray it.

Do you know what kind of PD blower it was? Roots improved blowers work a lot better than twin screw blowers in compound boost setups. The roots improved blower is a far smaller restriction.

That said I agree. If maximum HP is the goal and turbo lag is not an issue (race car) twins will perform better than a compound boost setup. But compound boost is a pretty cool combo for a street car where you want power everywhere. Expensive, heavy and complicated, but pretty cool.

 

[Department Of Boost]

It is compound boost, but so is this:

and this:

The first time I heard this particular setup called "Twincharged" was about 10 years about on miata.net

but there are plenty of other people using the vernacular

Using those pictures as an example it looks to me like ricers call them “twinchargers” and real cars get compound boost.

 

[Dubstep Shep]

I always thought it was called "compound boost"

My understanding is that compound boost is merely when you have two stages of compression.

In comparison, a twincharger is a supercharger and a turbocharger.

 

[07TGGT]

My understanding is that compound boost is merely when you have two stages of compression.

In comparison, a twincharger is a supercharger and a turbocharger.

 

[Department Of Boost]

I’ve never seen a setup where a supercharger and a turbocharger were pressurizing a common “plenum” or intake. I’m not even sure how well that would work…..or wouldn’t. I have only ever seen where a turbocharger feeds a supercharger, which is compound boost.

By your definition a twin turbo would be a “twincharger”, and no one calls them that.

 

[Rasmus]

My understanding is that compound boost is merely when you have two stages of compression.

In comparison, a twincharger is a supercharger and a turbocharger.

'Twin charged' has also been used for two superchargers feeding the same plenum.

It doesn't have anything to do with it having to be two different types of forced induction.

Even Hellion, the maker of the twin turbo kit that feeds into the stock blower, calls it 'compound boost', and not 'twin charged'

 

[Dubstep Shep]

'Twin charged' has also been used for two superchargers feeding the same plenum.

It doesn't have anything to do with it having to be two different types of forced induction.

Even Hellion, the maker of the twin turbo kit that feeds into the stock blower, calls it 'compound boost', and not 'twin charged'

From Wikipedia:

"Twincharger refers to a compound forced induction system used on some piston-type internal combustion engines. It is a combination of an exhaust-driven turbocharger and an engine-driven supercharger, each mitigating the weaknesses of the other."

So twincharging is a system that produces compound boost by using a turbo and a supercharger.

 

[Department Of Boost]

Even Hellion, the maker of the twin turbo kit that feeds into the stock blower, calls it 'compound boost', and not 'twin charged'

Wouldn't that be "Triple Charged"? LOL!