BiTurbo Vs. Twin-Turbo?

[omni]

Alright, I hope I don't get flamed by this... I am new to Audi's (long time VW owner) and definetally new to the turbo arena.

So... can someone please explain to me biturbo vs. twin-turbo?

what exactly makes them different?
pros and cons of both?

thank you very much in advance.

[S4 in_lowplaces]

I'm not sure if i am totaly correct on this but bi turbo means one turbod hit on the low end of the rpm band and the other hits on the higher end of the rpm band. Thats all i know. There a few other guys here that will elaberate i bit more on this. Twin turbo i am guessing hit at the same rpm band and are pushing double the air through the cars system than one turbo

[krew53]

Bi turbo is the same as twin turbo.... Bi meaning two

[tonggi]

bi-turbo means both turbos hit at certain RPM at the same time.

While twin turbo= one turbohits at a certain RPM/speed then the second one hits after a certain rpm/speed


I think tahts right because someone corrected me once.

[omni]

see... this is the problem, everyone says something different :/

[10SecS4]

In this instance, they are one in the same. There is no difference between bi-turbo and twin-turbo when referring to the S4's turbo configuration. Bi-turbo is simply Audi's own jargon for it.

However, there are two different kinds of twin turbo setups: one is the bi-turbo (or twin-turbo) found in the S4 which has two exact same sized turbos spooling simultaneously. The other twin-turbo configuration is what's commonly referred to as "sequential" twin turbos. In a "sequential" setup, there are two turbos, but one is bigger than the other. This is typically to help with lag - one smaller turbo will spool up almost immediately and then the bigger turbo will "take over" once a certain RPM is achieved. This is what's used in the latest generation Supra TTs, RX7s, etc. Hope that helps.

[10SecS4]

I'm not sure if i am totaly correct on this but bi turbo means one turbod hit on the low end of the rpm band and the other hits on the higher end of the rpm band. Thats all i know. There a few other guys here that will elaberate i bit more on this. Twin turbo i am guessing hit at the same rpm band and are pushing double the air through the cars system than one turbo

Sorry dude, but this is incorrect. Bi-turbo refers to the Audi's twin-turbo setup of two same sized turbos. What you're referring to with the one big/one small turbo reference is a sequential twin-turbo setup. We do NOT have that in our Audis - both of our turbos are the same size and run simultaneously.

[jlaw]

Twin-turbo and Bi-turbo both mean the same thing... two turbos. It's just semantics.

Parallel and sequential turbocharging are the proper terms to refer to the two main ways that twin-turbo setups can be run.

e: f;b!

[omni]

In this instance, they are one in the same. There is no difference between bi-turbo and twin-turbo when referring to the S4's turbo configuration. Bi-turbo is simply Audi's own jargon for it.

Thank you! that's the answer I was looking for.

I understand sequential turbo setups and what not. But I just knew I kept hearing 'biturbo' and then looking at diagrams and pictures thinking... it's the same thing as twin-turbo?! but didn't want to sound like an ignorant asshat if it was infact different :)

[S4 in_lowplaces]

Sorry dude, but this is incorrect. Bi-turbo refers to the Audi's twin-turbo setup of two same sized turbos. What you're referring to with the one big/one small turbo reference is a sequential twin-turbo setup. We do NOT have that in our Audis - both of our turbos are the same size and run simultaneously.

Thanks for correcting me marc. Someone told me this a while back before i even got into turbo cars, so i based it off what he said. Now i get to go back to him and tell him he's wrong haha, How well would the S4 do with a sequential twin turbo setup? Has this even ever been done?

[Tifosi]

In this instance, they are one in the same. There is no difference between bi-turbo and twin-turbo when referring to the S4's turbo configuration. Bi-turbo is simply Audi's own jargon for it.

Listen to this man, he knows what he is talking about on the Bi vs. Twin and the differences between sequential vs. true Bi/Twin setup.

I will also like to add this: Maserati used the same terminology for their famous Bi-Turbos back in the 80's. I think it is more European (Bi-Turbo) vs. US and Japanese (Twin-Turbo).

[10SecS4]

Thanks for correcting me marc. Someone told me this a while back before i even got into turbo cars, so i based it off what he said. Now i get to go back to him and tell him he's wrong haha, How well would the S4 do with a sequential twin turbo setup? Has this even ever been done?

The sequential twin turbo setup is only typically used in factory applications where the manufacturer is aiming for good low end response and minimal lag. Most people who upgrade their sequential turbos go with a single turbo because the sequential turbos are generally viewed as a restriction to making big power.

It's not something you'd want to hack your car up installing, as the electronics to control it would be a nightmare. Also, there is already little to no lag with the K03 or K04 turbos we have in our cars, so there would be no need for a sequential setup.

[10SecS4]

Listen to this man, he knows what he is talking about on the Bi vs. Twin and the differences between sequential vs. true Bi/Twin setup.

I will also like to add this: Maserati used the same terminology for their famous Bi-Turbos back in the 80's. I think it is more European (Bi-Turbo) vs. US and Japanese (Twin-Turbo).

Yeah, I think you're right. Audi did probably rip that term off from Maserati!

[Cole]

The sequential twin turbo setup .

There has been a lot of good information in this thread. However, This use of the terms bothers me. A sequential set up is NOT "twin" turbos. It is two turbos. But they are not "twins" They are different.

[10SecS4]

Technically, you are correct. But Toyota and other auto manufacturers still refer to sequential turbo setups as "twin turbos."

[Cole]

Do they? Or does everyone just kind of adopt a "twin turbo" phase due to lack of understanding?

[AB18]

We need more threads like this, great info in here.

[AB18]

What cars are out out today with sequential setups?

[omni]

What cars are out out today with sequential setups?

I believe one of the new(er) Porsches has a sequential turbo setup (?)

[batmannie]

i think benz uses the term bi-turbo as well.

[SoFresh]

ok... so heres another question... is it possible to run a "Quad-turbo" setup... meaning 2 sets of sequential twin-turbos... in replacement of the Bi-turbo setup? dont flame, just thought this would be interesting....

[AB18]

Im sure its physically possible to do, but why? You would need a large engine bay to even think about trying it, just think of all the hardware/piping that would go into it.

[flips4]

i read in car and driver that the new porches are running electronic fin turbos, so virtually no lag at any rpm, like disels.
but then again who wants to mess around with electronics--- ohh thats right our audis are a computer / wiring nightmare. gotta love um

id like to see the new porche electronic fin turbos in an audi setup. it would be cool

[omni]

I think the saying goes:

"with enough time and enough money, anything is possible..."

[turbo kraut]

The sequential twin turbo setup is only typically used in factory applications where the manufacturer is aiming for good low end response and minimal lag. Most people who upgrade their sequential turbos go with a single turbo because the sequential turbos are generally viewed as a restriction to making big power.

It's not something you'd want to hack your car up installing, as the electronics to control it would be a nightmare. Also, there is already little to no lag with the K03 or K04 turbos we have in our cars, so there would be no need for a sequential setup.

you hit it on the head

i don't know of too many people, not to say there is not any that run 2 bigger turbos

most just dump both factory and go to one, enormous turbo

there was a guy that was running over 1100 hp in his supra, and he just had a garrett turbo i do believe

[turbo kraut]

wait, i got a question, and i know money can do anything, which i have none of, but could you do a biturbo ap on an a4 1.8 motor?

or the real question is has someone done it?

[10SecS4]

Do they? Or does everyone just kind of adopt a "twin turbo" phase due to lack of understanding?

No, the manufacturers started it. Here is an example of a cutaway taken from a Toyota Supra Twin Turbo sales brochure:



I reckon the manufacturers did it to try to show superiority over the older models that they were replacing. Remember, the earlier generation turbocharged 300ZXs, Supras, etc. were all single turbo.

[10SecS4]

wait, i got a question, and i know money can do anything, which i have none of, but could you do a biturbo ap on an a4 1.8 motor?

or the real question is has someone done it?

With enough money, sure, why not. You'd have to make mini-headers coming off of the exhaust manifold. It would be really dumb and really expensive to get it running right, but sure, it could be done.

[Cole]

Now I wonder where the line gets blured at the factory level. Think it was some marketing guy that thought "Squential twin" sounded cooler?

[turbo kraut]

No, the manufacturers started it. Here is an example of a cutaway taken from a Toyota Supra Twin Turbo sales brochure:



I reckon the manufacturers did it to try to show superiority over the older models that they were replacing. Remember, the earlier generation turbocharged 300ZXs, Supras, etc. were all single turbo.

i want one of those

but a nice one is still more than my nice audi
and it would not be as practical as my audi

[Cole]

ok... so heres another question... is it possible to run a "Quad-turbo" ....

Quad-Turbo W16

[S4 in_lowplaces]

Ok Since where on the subject, i have seen this in car shows and i have only seen trucks with this set up and no cars. Turbocharger and supercharger. I am guessing one is using the other to spin the turbine fastest correct. I know this is possible because i have seen it first hand but are there really any gains to doing somthing like this?

[PiggieSmalls]

In this instance, they are one in the same. There is no difference between bi-turbo and twin-turbo when referring to the S4's turbo configuration. Bi-turbo is simply Audi's own jargon for it.

However, there are two different kinds of twin turbo setups: one is the bi-turbo (or twin-turbo) found in the S4 which has two exact same sized turbos spooling simultaneously. The other twin-turbo configuration is what's commonly referred to as "sequential" twin turbos. In a "sequential" setup, there are two turbos, but one is bigger than the other. This is typically to help with lag - one smaller turbo will spool up almost immediately and then the bigger turbo will "take over" once a certain RPM is achieved. This is what's used in the latest generation Supra TTs, RX7s, etc. Hope that helps.

Wow, I'm actually agreeing with BBDS about something. Hell must be freezing somewhere.

[PiggieSmalls]

There has been a lot of good information in this thread. However, This use of the terms bothers me. A sequential set up is NOT "twin" turbos. It is two turbos. But they are not "twins" They are different.

Touche.

[Shomegrown]

There has been a lot of good information in this thread. However, This use of the terms bothers me. A sequential set up is NOT "twin" turbos. It is two turbos. But they are not "twins" They are different.

The Toyota Supra used two identical turbos plumbed sequentially.

To finally answer the thread, our cars are called "biturbo" because this is "twin turbo" in German. Nothing more. Biturbo can be any engine with two turbochargers.

[PiggieSmalls]

The Toyota Supra used two identical turbos plumbed sequentially.

To finally answer the thread, our cars are called "biturbo" because this is "twin turbo" in German. Nothing more. Biturbo can be any engine with two turbochargers.

Go away. You're not wanted here.

[Kievskiy]

if you are thinking this way then Supercharged-Turbocharged engine is the way for you my friend, supercharger kicks on low and turbo/turbos on higher rpm's, kinda like new scirocco from VW......

ok... so heres another question... is it possible to run a "Quad-turbo" setup... meaning 2 sets of sequential twin-turbos... in replacement of the Bi-turbo setup? dont flame, just thought this would be interesting....

[Kievskiy]

it makes sence, turbo for each 4 cyl.......

Quad-Turbo W16

[Tifosi]

ok... so heres another question... is it possible to run a "Quad-turbo" setup... meaning 2 sets of sequential twin-turbos... in replacement of the Bi-turbo setup? dont flame, just thought this would be interesting....

Yes, but these are usually non-factory setup as in all aftermarkets. For example, Koneig Ferrari Testarossa: 12 cylinder, Quad-Turbo charger (Non-sequential, I believe). You must remember, in order to have more than one turbo, the engine must produce enough exhaust volume to spin the turbines. Thus in order to run 4 turbos, you will probably need a 12 cylinder engine to do so. Unless you have a 5.0 liter 4 cylinder engine....*L*

[Tifosi]

IIRC, the reason for the sequential turbo setup is to minimize the turbo lag affect. This is when turbo technology was still in its infancy. With all the techological advance, it is possible to creat a smaller, lighter turbo that spins at an extremly high rpm with the help of well made synthetic oil: As much as we all cry about the KO3s, they are an impressive set of hardware in their own right. Audi chose KO3s because they are more compact, can fit into tight places, and minimize turbo lag along with the electronic throttle to a minimal. A stock S4 has a similar power delivery to a small block V8 engine and in 1999, this was not easy to do.

Anyway, the newest thing now is the BMW's variable displacement turbos in their diesel engine which is basically a set of turbines within another set of turbines, sort of speak that is. All these changes in turbo technology makes sequential turbos obselet, at least until something else better comes along that is.