Turbo V`s Bi-turbo

np · Unread post by np » 05 Apr 2005, 02:17

Whilst i know all about the workings of Turbos & Superchargers,what does Bi-turbo mean[?][:I]
Like the new Noble M14 "Bi-turbo V6"
Can anyone explain please.
Thanks [:I][:)]

lighteninguk · Unread post by **lighteninguk** » 05 Apr 2005, 02:32

two turbos?
theres some car in development at the mo (cant remeber who's designing it) thats got 4 of them...... more power any one?

np · Unread post by np » 05 Apr 2005, 02:36

2 turbos would just be "Twin turbo`d".
The new Bugatti Veyron has 4 turbo`s.Its also got 8ltrs,W16(more or less a V16),1001 BHP!250 mph.

VisaGTi16v · Unread post by **VisaGTi16v** » 05 Apr 2005, 03:12

The noble also has a 3 litre mondeo engine if you didnt know however vastly more tuned

The ill fate Bugatti EB110 was a quad turbo. I remember once seeing an old american car, late 50's cadallac type thing with a V8 and 1 turbo per cylinder..yes 8! imagine the turbo lag!

Homer · Unread post by **Homer** » 05 Apr 2005, 04:34

I thought they used more turbos to reduce turbo lag?
i.e.
one large turbo - takes a long time to spin up - lots of turbo lag.
several small turbos - spin up very quickly - very little turbo lag.
In answer to the original question. Bi-turbo means two turbo chargers, usually one per bank of cylinders on a V engine.

Kowalski · Unread post by **Kowalski** » 05 Apr 2005, 04:37

Bi-turbo and twin-turbo largely mean the same thing.
"biturbo
The “bi” comes from Latin and means “two”. The “biturbo” designation in connection with Audi V engines signifies that two turbocharger have been installed, one for each bank of cylinders. The driver benefits from increased torque at the low end, more power at the upper end and improved engine response. Audi uses these advantages in the Audi RS 4, for example as well as in its competition cars (the Audi R8). "
See http://www.audi.com/audi/com/en1/glossary/biturbo.html

oilyspanner · Unread post by **oilyspanner** » 05 Apr 2005, 14:45

I remember seeing a large Suzuki drag bike using a Bi-turbo setup, in that case it had one large and one small turbo the idea was that tha smaller on spun up quickly to provide boost at lower rpms and to avoid turbo lag while the larger one got going. I imagine that on a Vee configured engine there would be one turbo per bank of cylinders to make manifolding simpler.
Stewart

p20 · Unread post by **p20** » 05 Apr 2005, 17:07

BMW are using sequentail turbos on their new 535d engine. Its actually the 530d engine but with twin turbos. The smaller kicks in early to reduce lag, whilst the big one spins up.272bhp and 413llbft from a 3ltr diesel!! Only manages mid 30's mpg though.

yangreen · Unread post by **yangreen** » 05 Apr 2005, 23:06

The Noble is a beast! You wouldn't know it was a Mondeo engine when 60 flashes up in less than four seconds! Makes a cracking noisem, especially the "squelch" when you change gear.

VisaGTi16v · Unread post by **VisaGTi16v** » 06 Apr 2005, 00:30

p20: Yep unlike psa/jaguar, their 2.7V6 twin turbo diesel has 1 turbo per bank and so suffers from more lag. Far better to have a small one then a larger one later on

np · Unread post by np » 06 Apr 2005, 03:22

Looks like i stand corrected lighteninguk,sorry[:I][:)].So Bi-turbo is 2 turbo`s on V engines,but maybe a smaller one on one side,& a larger one on the other bank?
I remember the Escort Cosworth being fitted with the smaller T25 turbo to reduce lag.
Topgear/Clarkson rate the Nobel.If only i could have one![:D][}:)]

Kowalski · Unread post by **Kowalski** » 06 Apr 2005, 15:02

When you've got two different sized turbos and a V engine you have to connect both turbos to both banks of a V engine to benefit from the big turbos boost. The BMW 535 is a straight six, so there is no bank problem. There are lots of variants of twin turbo set ups. Some are in series (sequential), others in parallel. I think the 3.0 Saab V6 turbo diesel only uses the turbo on one of the banks of cylinders.
My Dad had a Lancia Thema which had a system to overcome turbo lag. What it did was to initially blow some of the boost into the turbo's turbine i.e. bypassing the engine to get the turbo up to speed, the manual called this an overboost device. The Thema was the sort of turbo car where there was no power initially then it all came in all of a sudden and you had to grip the steering wheel very tightly and take your foot off the accelarator quick to avoid running into the car in front.