Twin Turbo vs Bi-Turbo

[anonymous-user]

There is currently a Mercedes SL65 AMG parked outside my work (very nice it is too)

However on the side it states that it is a 6.3 Bi Turbo

Is this different from a twin turbo or just a new name for twin turbos?

[Mastodon2]

Ginger / strawberry blonde - two different names for the same thing.

[Section 8]

Hardly a new term.The old Audi s4 2.7 was bi turbo. Even stated it on the engine cover IIRC.

[daveco]

Okay I was wrong, confusing my sequential and non sequential up

Edited by daveco on Tuesday 12th October 11:48

[Marf]

Bi/Twin does not infer sequential or twin turbo. Look at Japanese cars, RX7 and Supra, both "twin" turbo, but are in fact sequential. 300zx, skyline, both "twin turbo", but not sequential.

BiTurbo tends to be seen on european cars, Twin turbo seems to be a Japanese thing.

[Pannywagon]

Twin turbo engines have two identical turbos which work together and do half the work each.

Bi-Turbos have a small low inertia turbo for low rpm and a large one for higher rpm. My last car was a bi-turbo diesel and the first turbo came in at 1200rpm and the second at about 2000rpm. Obviously slightly different to a big petrol bi-turbo, but the surge from almost at tickover was very nice indeed.

ETA: Just before I get slated by the bi-turbo diesels don't exist brigade. This was my last car:

Peugeot 607 2.2 HDi (Twin-Turbo)

Edited by Pannywagon on Tuesday 12th October 11:53

[Mr Roper]

daveco said:

I could be wrong...

Twin turbo-two turbos of the same size
Bi-turbo-one smaller turbo spools first and the second spools higher up in the rev range.

.

Edited by daveco on Tuesday 12th October 11:44

The BMW D3 ALPINA BI TURBO works on this basis

[Marf]

Pannywagon said:

Twin turbo engines have two identical turbos which work together and do half the work each.

So why are both the RX7 and Supra "Twin turbo" and sequential?

As I stated above, bi/twin as a model designation infers nothing about the operation of said turbos, merely that the car has 2 turbos!

[Pannywagon]

Marf said:

Pannywagon said:

Twin turbo engines have two identical turbos which work together and do half the work each.

So why are both the RX7 and Supra "Twin turbo" and sequential?

As I stated above, bi/twin as a model designation infers nothing about the operation of said turbos, merely that the car has 2 turbos!

Don't know, but bi-turbo in my experience is sequential.

[Arese]

Pannywagon said:

Twin turbo engines have two identical turbos which work together and do half the work each.

Bi-Turbos have a small low inertia turbo for low rpm and a large one for higher rpm. My last car was a bi-turbo diesel and the first turbo came in at 1200rpm and the second at about 2000rpm. Obviously slightly different to a big petrol bi-turbo, but the surge from almost at tickover was very nice indeed.

ETA: Just before I get slated by the bi-turbo diesels don't exist brigade. This was my last car:

Peugeot 607 2.2 HDi (Twin-Turbo)

The 1.9 that GM/Fiat share can also be twin-turbo'd. I think so far only Saab have used it this way though.

Edited by Arese on Tuesday 12th October 12:53

[Pannywagon]

doogz said:

Pannywagon said:

Marf said:

Pannywagon said:

Twin turbo engines have two identical turbos which work together and do half the work each.

So why are both the RX7 and Supra "Twin turbo" and sequential?

As I stated above, bi/twin as a model designation infers nothing about the operation of said turbos, merely that the car has 2 turbos!

Don't know, but bi-turbo in my experience is sequential.

Audi S4.

There was an older S4 that had a bi-turbo? What was your point?

[Meoricin]

Pannywagon said:

Twin turbo engines have two identical turbos which work together and do half the work each.

Bi-Turbos have a small low inertia turbo for low rpm and a large one for higher rpm. My last car was a bi-turbo diesel and the first turbo came in at 1200rpm and the second at about 2000rpm. Obviously slightly different to a big petrol bi-turbo, but the surge from almost at tickover was very nice indeed.

ETA: Just before I get slated by the bi-turbo diesels don't exist brigade. This was my last car:

Peugeot 607 2.2 HDi (Twin-Turbo)

Edited by Pannywagon on Tuesday 12th October 11:53

You realise that your link describes your 'Bi-turbo' car as a 'Twin-Turbo'?

[Big Rod]

Marf said:

Pannywagon said:

Twin turbo engines have two identical turbos which work together and do half the work each.

So why are both the RX7 and Supra "Twin turbo" and sequential?

As I stated above, bi/twin as a model designation infers nothing about the operation of said turbos, merely that the car has 2 turbos!

Cars like the Supra and Lotus Carlton are straight six engines so will have the exhaust ports all on the one side of the block and al the induction ports on the pother side so plumbing in a sequential system will be relatively easy and by and large preferable. I would imagine the same could be said for the rotary power plant regards exhaust etc.

The 300zx, (like mine), and cars like Mitsubishi 3000 GTO are vee configuration engines so have the exhausts at either side of the engine so have a turbine serving each bank. Plumbing in a sequential system wouldn't be impossible, but it would be very complicated and no doubt expensive.

Edited by Big Rod on Tuesday 12th October 12:05

[RicksAlfas]

Surely "Bi" just means two.
Doesn't matter if they are sequential or not.
Many V-engines will use a setup with one turbo on each bank like the Merc the OP mentions, or indeed the Maserati Biturbo!

Edited by RicksAlfas on Tuesday 12th October 12:14

[GravelBen]

Its just a name, nothing more.

My sequential twin turbos operate in parallel at high revs

[BriC175]

Pannywagon said:

Twin turbo engines have two identical turbos which work together and do half the work each.

Bi-Turbos have a small low inertia turbo for low rpm and a large one for higher rpm. My last car was a bi-turbo diesel and the first turbo came in at 1200rpm and the second at about 2000rpm. Obviously slightly different to a big petrol bi-turbo, but the surge from almost at tickover was very nice indeed.

ETA: Just before I get slated by the bi-turbo diesels don't exist brigade. This was my last car:

Peugeot 607 2.2 HDi (Twin-Turbo)

Edited by Pannywagon on Tuesday 12th October 11:53

Where did you get that information from? Bi and Twin are just two words for the same thing, and as far as I can see, it just depends on which way the manufacturer wants to tell their customers that the car has two turbo's.

[Mr_Yogi]

RicksAlfas said:

Surely "Bi" just means two.
Doesn't matter if they are sequential or not.
Many V-engines will use this setup with one turbo on each bank like he Merc the OP mentions, or indeed the Maserati Biturbo!

+1

There are many people making assumptions based on the cars they know of.

If you are told a cow has four legs, and you see an animal with four legs you can't assume it's a cow.

There are a number of older bi-turbo cars that I'm sure don't have sequential turbos, such as the 1980/90 Maserati biturbos.

Surely bi/ twin purely identifies the number of turbos and not their configuration.

[BriC175]

Mr_Yogi said:

If you are told a cow has four legs, and you see an animal with four legs you can't assume it's a cow.

Hit the nail on the head.

[RJDM3]

For example the Gumpert Apollo is a Bi-Turbo car, but they are not a sequential setup. Bi-Tubo/Twin turbo is the same thing.

[Sicob]

A Bi turbo takes it up the gary. Predictable.