Twincharging a turbo car

obi_waynne

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I've been reading up on twincharging and it would appear that a fairly modern upgrade option for a turbo engine is to add a supercharger.

There are a few configurations to choose from but it does make sense when you think about it. It's a good way to overcome lag in turbos.

Does anyone have any information about twincharging, the pros & cons, best setup and tech info about the problems encountered. Does one put the supercharger and turbo inlets inline and which should go first?

Surely a supercharger pre the turbo will help the turbo to spool up more quickly as it catches the charged air stream. Why do VW do it the other way round with the turbo coming first (or do they I might have misread it)?

(I've just added this article http://www.torquecars.com/tuning/twincharging.php on twincharging for reference, thanks for the updates and tips guys.)
 
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The setups are inline, in parallel or switched all seem to have advantages and disadvantages though and I'm still trying to get my head around them all.

I think even the parallel ones have a bypass system. I was worried about the restriction a supercharger will place on the turbo inlet if it shares the same line.

There is also a big problem with air temps but that's nothing a good intercooler should be able to sort out.
 
This is something that is fairly common in the Cobalt world. You see, they made supercharged cobalts, then they made turbo cobalts. Basically the same, for the most part, so lots of parts swap over. twincharging is pretty easy.

First you need your parts. You can use a fair sized turbo, (One that is optimized for 3.0 to 4.0 liters works really well for a 2.0L cobalt SS) look up what size would work for yours.

Then a roots style blower. Roots blowers don't create boost inside the blower, they create massive amounts of flow. The compression happens inside the intake manifold as there is not enough space for the sheer amount of air being rammed in all at once.

a huge intercooler will do you wonders, as the supercharger will super-heat the already hot air charge.

You can use a big turbo, because (As I understand it) The supercharger boost will make the turbo spool faster.

so the easy way to say it is:

supercharger boosts into engine
huge amount of exhaust gas flows into big turbo, spooling it
turbo boosts into supercharger
supercharger takes more air from turbo than engine would alone=more flow
Giant intercooler cools charge so engine doesn't go pop.
you go really fast.

Another good idea is to put an air-to-air intercooler between turbo and supercharger, and an air-to-water intercooler between supercharger and intake manifold. That's what the cobalt guys do.

Cobalt SS Supercharged (SC)= 205 brake hp from factory.

Cobalt SS/SC after twincharge(turbo, intercooler, associated piping, 1,000cc injectors, "tune"(remap)= over 450 wheel hp.
 
So a screw supercharger is best if you want to install a twin charge setup in your engine?
 
Screw type would still work, you just need a positive displacement supercharger.

This is called staged charging or compound charging., you can have as many "stages" as you like so 3 or 4 turbos are possible if used in series, you can use superchargers or turbo chargers

the reason for doing this is that if you need loads of boost and not a lot of air flow like in diesel engines (due to lack of revs) and small petrol engines. No turbo will flow 30 lbs/min at 40 psi, so you use 2 to make it up and keep both of the turbos or supercharger and turbo operating efficiently, you have the smaller of the 2 making loads of boost pressure and the bigger being able to flow the total volume of air not just half, it needs to flow all of it.

Simples really...
 
Screw type would still work, you just need a positive displacement supercharger.

This is called staged charging or compound charging., you can have as many "stages" as you like so 3 or 4 turbos are possible if used in series, you can use superchargers or turbo chargers

the reason for doing this is that if you need loads of boost and not a lot of air flow like in diesel engines (due to lack of revs) and small petrol engines. No turbo will flow 30 lbs/min at 40 psi, so you use 2 to make it up and keep both of the turbos or supercharger and turbo operating efficiently, you have the smaller of the 2 making loads of boost pressure and the bigger being able to flow the total volume of air not just half, it needs to flow all of it.
Simples really...

Excellent sum up, I always strugle to explain it to people.
 
It is hard to explain in a way because people "so the small one cuts out then" no, "so doesn't that create a restriction?" no because it will compress what ever incoming air it has....

"Is it like twin turbos?" no because twin implys theres 2 the same when here you don't have that.

and thanks for your seal of approval Clay...

also it should be noted that both turbos should be able to operate independantly of each other, for example the small turbo should still mkae useable power up to where you want to make peak power, rather than the boost dropping off at the top then it will hamper the large turbo also as the "plot" on the compressor map will move to somewhere else usually where you don't want it.
 
Thanks for the input Claymore, it was much appreciated, hopefully it will put people on the right track.
 
It is hard to explain in a way because people "so the small one cuts out then" no, "so doesn't that create a restriction?" no because it will compress what ever incoming air it has....

"Is it like twin turbos?" no because twin implys theres 2 the same when here you don't have that.

and thanks for your seal of approval Clay...

also it should be noted that both turbos should be able to operate independantly of each other, for example the small turbo should still mkae useable power up to where you want to make peak power, rather than the boost dropping off at the top then it will hamper the large turbo also as the "plot" on the compressor map will move to somewhere else usually where you don't want it.

To help.

twin charging is running a supercharger and a turbo charger on the same engine. This is what this thread is about

twin turbo is 2 turbos on one engine with no supercharger.( these can be sequential or together but as claymore said that isnt what this thread is about
 
Hi Wayne have you found any further info on the twincharging?
I'm interested in the different ways people plumb their systems , as you asked early in the thread ,supercharger before or after.
People say the turbo before makes it a compound charg system, True but i see no sense in that it would just make more heat.
I would think supercharger first both makes the extra exhaust gass and also blows the right way to help spool a bigger turbo. The only problem i see us when the turbo takes over the supercharger.
I see mostly good in this though. with a roots , if it's not creating pressure it dosen't use so much power.
So if we put a tube on the intake between super and turbo so it can suck when in vacuum and put a filter on it problem solved.
Of course all this is just thought so might be flawed inactual use, so that is why i'm on the forum to ask people that have physicly done this and i can avoid any mistakes already made.
looking forward to any info.
 
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If you are thinking of twin charging an MX5, then watch this forum, the Supercharged MX5 engined Triumph Herald will soon be gaining a turbo.
 
Common sense seems to dictate supercharger before the turbo, the sc is more restrictive and the turbo flows better at high RPM so can take over. Placing the Turbo first you will hit a wall when the flow rate of the supercharger is reached and the turbo is wanting to push out more air.
 
Common sense seems to dictate supercharger before the turbo, the sc is more restrictive and the turbo flows better at high RPM so can take over. Placing the Turbo first you will hit a wall when the flow rate of the supercharger is reached and the turbo is wanting to push out more air.
Completely wrong Waynne, the SC will compress whatever it has going into it, it will never cause a restriction.(as long as it's a roots type SC)
 
But do you need the compound charging?
To my understanding from air compressors compound is more about reaching a greater pressure than the compression from 1 allows.
We have the ability to reach the pressure and flow necessary with the turbo alone.
The supercharger will boost engine capacity so as to spool the big turbo as if it were twice the capacity (If say boosting to 1 bar for example)
I have not built a twincharge engine yet so i'm just speculating.
Glad to get info from someone that has actually done it .
 
One of the benefits of compound chargin, it you can run the turbo at much lower boost which means a lot les heat. Also boost controle and plumbing is a lot simpler.
 
Have you seen it done SC 1st?
What problems do you forsee?
I have a mate with a suprcharged sr20,He has the throttle plate after the supercharger and a big blow off between the sc and throttle.I thought stupid at 1st but he runs overspeed and a big intercooler. He claims much better throttle responce. I have only been in after the mod so i can't say if it is right .But it does make me think there is more than 1 way to kill a cat.
Just trying to gather as much info as possible before i decide on the setup.
 
I would think that having the sc first would choke the turbo unless you have a very complicated bypass system. I used to run the Throttle body after the SC with a big dump valve, but couldn't get the car to run cleanly at part throttle as the ecu would always see load and overfuel massively
 
My theory is to have a 3inch branch on the pipe between the turbo and sc. To have a simple valve to allow suction through the pipe but seal under pressure , with a pod filter.
I would think this would servre 2 purposes, to allow the turbo to suck through when it needs more than the sc is putting out and drop the outlet pressure of the sc to zero, so the pumping loss of the sc can be minimised reducung heat and wear on the sc. From my info the sc produces more heat to compress the same volume and pressure of air than turbo's, so there should be efficiancy gain there.
I would realy like to hear from anyone that has tried the sc first , even if it just proves all my thoughts wrong.
 
Been looking at eventually running a compound system in my old diesel... :) Seems reletivly easy. As there is no throttle, is the forced air constantly running and making boost from both the SC and turbo?
 
As long as you sort the fueling.
With no extra fuel , no extra power, but put too much in , and the EGT goes too high and does damage.
If doing a diesel, it's good to fit an EGT guage just to keep an eye on temps.
Not a bad thing on highly boosted petrol engines either.
 
As long as you sort the fueling.
With no extra fuel , no extra power, but put too much in , and the EGT goes too high and does damage.
If doing a diesel, it's good to fit an EGT guage just to keep an eye on temps.
Not a bad thing on highly boosted petrol engines either.


Meth injection or water to air coolers would help? So... Turbo, then SC then cooler, then back to the inlet? Is that correct?
 
Anyone got pictures or links to the lancia s4 twin charged engine?.
I don't seem to be able to find info on the charge system plumbing. I can find pics of the engine but it's too hard to see what's going on. On some sites they talked about having trouble syncronising the setup, then going on to say when they got it right it was awesome.
 
Thought this may be of use. Please post drawings of different factory systems you have found.
Supercharger + Turbo: Volkswagen Twincharger
Everybody knows mechanical superchargers are good for low end output but short of efficiency at high rev, while exhaust turbochargers works strongly at high rev but reluctantly at low rev. For decades engineers dreamed of combining supercharger and turbocharger together. This was tried once in history – the 1985 Lancia Delta S4 rally car. The car was successful in motorracing, but the technology never extended to production.

In 2005, Volkswagen finally introduced a production unit to its Golf 1.4 TSI. Called "Twincharger" system, it is actually developed by supercharger maker Eaton. It connects a supercharger and a turbocharger in series.

At low rev, the supercharger provides most of the boost pressure. The pressure it built up also speeds up the turbocharger so that the latter can run into operating range more quickly.

At 1500 rpm, both chargers contribute about the same boost pressure, with a total of 2.5 bar. (If the turbocharger work alone, it can only provide 1.3 bar at the same rev.)

Then the turbocharger – which is optimized for high-rev power – started taking the lead. The higher the rev, the less efficient the Root-type supercharger becomes (due to its extra friction). Therefore a by-pass valve depressurize the supercharger gradually.

By 3500 rpm, the turbocharger can contribute all the boost pressure, thus the supercharger can be disconnected by an electromagnetic clutch to prevent from eating energy.


In the 1.4-litre Golf, the Twincharger system produces 170 horsepower and 177 lbft of torque. That's equivalent to a 2.3-litre normally aspirated engine but it consumes 20% less fuel.


Advantage: All road performance
Disadvantage: Complicated
Who use it ? Volkswagen Golf GT 1.4TSI


http://www.autozine.org/technical_school/engine/tech_engine_3.htm
Sorry the drawing didn't come through , but it's about 2/3 down the page on this attachment.

This explains the system on youtube:
http://www.youtube.com/watch?v=20qqavckWdw&list=LP6wpOzR0_2jE&index=1&feature=plcp
 
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Anyone got pictures or links to the lancia s4 twin charged engine?...
Read A. Graham Hill's book "Forced Induction Performance Tuning". There are pictures, specs and a good description on the Lancia Delta S4 system. This book is full of good knowledge about forced induction.
 
Hi guys. New to the site but lotta info here. I've got a '99 Honda Civic Si with a Jackson Racing SC installed. Running 5-7lbs boost right now. Considering twincharging. Seems like a great option to drastically increase my performance. Looking to install an LHT intercooler to keep SC temps down and a water/meth kit to further decrease temps and increase octane allowing me to get more power on 93 octane. It's a 1.6L engine and I know I have to size the turbo as if its a bigger engine, any idea what size to run?
 
Greetings Nevyn04 and a Warm Welcome to our TorqueCars Forum my Friend! Good to have you along with us :)

Hopefully someone will be along in a while who can help you more directly! :)
 

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