[slowSwede]

Hello,

What are the drawbacks and bright sides of having 2 turbos?
What are the drawbacks and bright sides of having 1 turbo?

Cheers!

[joec500]

Originally Posted by slowSwede

Hello,

What are the drawbacks and bright sides of having 2 turbos?
What are the drawbacks and bright sides of having 1 turbo?

Cheers!

depends on the application....size of turbo, size of motor, purpose of motor (top speed vs quick spool/acceleration), # of cylinders....list goes on. Kind of like asking if two testicles are better than one.....Apparently one is better when it comes to winning bicycle races hmmmm in that case, two are usually better than one, it's good to have backups

[slowSwede]

Well, I like having two testicles...and really don't want to settle for one ;-)

Anyhow, seems like a lot of people like the idea with one turbo and I don't understand why, unless it's for cost savings when upgrading your turbo(s).

[Tee212]

Im just hear to talk about scrotums..subscribed.

[AltecBX]

I say two. But again, depends on the application...

[Jonny550]

Originally Posted by TrackRat

There is no engine performance benefit to one over the other per se. A single turbo is easier to package, has lower weight and cost, etc. Dual turbos are convenient for I-6, V-6 or V-8 etc. cylinder engine packaging purchases.

and v10's and v12's their convenient for all engines take the sl600 or veryron both are v12's ( two v12's for the veyrons) twin turbo.

[JoshM813]

The Veyron's engine is 2 Audi Twin Turbo V8 engines put together in "W" configuration. Not "2 V12s" as you said. So it's a W16 Quad Turbo.

IMHO I believe TT is better but not always possible. So single at times is better and can make more power but not through out the rpm range like TT can

[GreenPlease]

Anyhow, seems like a lot of people like the idea with one turbo and I don't understand why, unless it's for cost savings when upgrading your turbo(s).

Bingo. Much cheaper to upgrade one turbo. Also, packaging restrictions prevent us from using two larger snails on the N54. The best we can do with the TT setup is upgraded CHRAs.


In theory, one snail should be more efficient than two. For the same volume of air, it should be possible to have less total mass on the turbine and compressor wheels of a single turbo than on a comparable twin turbo setup.

The primary advantage to having a twin turbo setup is that you can have shorter exhaust mains and thus reduce enthalpy loss.

[Mr. 5]

I think it all comes down to lag and power.
The bigger the turbo the bigger the lag and the bigger the power.
The smaller the turbo, the smaller the lag but the smaller the power.
Put 2 turbos togehter with different sizes, you have just increased the power and decreased the lag.

[Mr. 5]

Originally Posted by TrackRat

There are all kinds of turbo designs and configurations. Variable geometry turbos have no lag and flow big air. (Think current Porsche models). There are several styles. Dual scroll turbos can be lag free and flow big air. Dual turbos can be lag free and flow big air. Sequential turbos can be lag free and flow big air. (Think Porsche 959). If properly engineered they can all deliver excellent results. It' not an either or deal now days.

Understand, but when we are talking about an aftermarket single turbo, I kind of doubt that anythign would be lag free.
I guess we'll see though soon.

[bdkevoIX]

Originally Posted by TrackRat

There are all kinds of turbo designs and configurations. Variable geometry turbos have no lag and flow big air. (Think current Porsche models). There are several styles. Dual scroll turbos can be lag free and flow big air. Dual turbos can be lag free and flow big air. Sequential turbos can be lag free and flow big air. (Think Porsche 959). If properly engineered they can all deliver excellent results. It' not an either or deal now days.

No such thing as no lag.
And the main advantage of the twin scroll set up is in its much improved transient response over open scroll. Yes, the lag is reduced also, but the difference in response is night and day.

[slowSwede]

I'm guessing twin turbo should have advantages, since BMW actually did put that in the N54. If there were no gains in that approach they probably would have gone the easy route from day 1, ST.

[StatenEye]

Originally Posted by joec500

depends on the application....size of turbo, size of motor, purpose of motor (top speed vs quick spool/acceleration), # of cylinders....list goes on. Kind of like asking if two testicles are better than one.....Apparently one is better when it comes to winning bicycle races hmmmm in that case, two are usually better than one, it's good to have backups

hahhahaha

[bdkevoIX]

Originally Posted by TrackRat

Really? OK, thanks for telling me since I've done advanced turbo engine development for the past 20 years on turbos you've never seen or won't see for five more years.

Really? I don't care if you're the head engineer of the BW or garrett. You can't completely eliminate lag.

[prelude2perfect]

Single Turbo FTW if you're going big. Its more efficient to run one large turbo off all 6 cylinders if you want real big power. That's why most all twin turbo supra owners switch to single

[bdkevoIX]

Originally Posted by TrackRat

Rediculous comments in this thread... posing as knowledge.

Agreed...if you're referring to the twin turbo comment.

[prelude2perfect]

Originally Posted by TrackRat

Rediculous comments in this thread... posing as knowledge.

Umm, confusing coming from someone who just stated a single twin scroll is more effective.

So how bout if you're gonna knock down what I said you back it up with some of your "knowledge"

[bdkevoIX]

Originally Posted by prelude2perfect

Umm, confusing coming from someone who just stated a single twin scroll is more effective.

So how bout if you're gonna knock down what I said you back it up with some of your "knowledge"

You said that supra owners switch to large single because it's more efficient than twin turbo set up. You made it sound like single turbo is more efficient than any twin turbo set up out there, which is not necessarily true.

Large single turbo is more efficient than STOCK twins mainly because of higher compressor efficiency and reduced turbine backpressure.

Aftermarket twin turbos can also make big power due to this reason.

Most supra owners go to big single because of its simplicity and reduced cost, not because single is superior to twin turbo set up.

The opposite can be said in other applications where twin turbo set up is favored over the single such as large displacement V motors.

[JoshM813]

Originally Posted by TrackRat

Close but not exactly...

The Veyron is based on two VW W8 engines (with a 90 degree included angle vs. the normal 72 degree), put together to make a W16. They are hand built at VW's Salzgitter engine plant. The engine is HUGE and takes up the entire rear of the vehicle with the quad turbos to make a paltry 1001 HP and four Bazillion lbs. of torque at 200 rpm. Yes VW did in fact make a W8 engine for the Passat.

[url]


As far as TT vs. single you can get the exact same performance from either setup if properly engineered. Been there, done that for advanced prototype car maker turbo engine development.

Old for a reply but had to because I know I'm right...thanks for providing a link that does not bck up your statement...all it saidis that it was talking about "W" shaped engine

eg: W8 engine= 2 VR4 engines at a 72 degree angle.

Now you may have been right about VW producing the engine but VW and Audi are in the same boat. The reason the W8 is called that is because it is 2 V4s(VR4) so V+V=VV or W...but you are saying the Veyron uses 2 W8s so if my math is correct...

(V+V)x2=(V+V)+(V+V)=W+W=WW= Zigzag

[JoshM813]

Originally Posted by TrackRat

Really? OK, thanks for telling me since I've done advanced turbo engine development for the past 20 years on turbos you've never seen or won't see for five more years.

Also if you want to get technical...there is really no such thing as a lag free turbo...you maybe able to get it to spool up unnoticably to person but there will always be lag as exhaust gases have to spin the turbine...if you want argue even further...superchargers aren't lag free either it still takes time before cranking the engine before the pulley starts turning...but then again it's all perceived to be lag free...but it isn't.

Now people might go against me on this but it's true...nothing is instanteneous that involves more than 1 moving part and even with one moving part it has to be inflexible. Now if you want to start getting into really instantaneous then we can get into quantum mechanics but I won't go there.

Sorry everyone just woke up and in a bit of an argumentative mood today.

[prelude2perfect]

Originally Posted by bdkevoIX

You said that supra owners switch to large single because it's more efficient than twin turbo set up. You made it sound like single turbo is more efficient than any twin turbo set up out there, which is not necessarily true.

Large single turbo is more efficient than STOCK twins mainly because of higher compressor efficiency and reduced turbine backpressure.

Aftermarket twin turbos can also make big power due to this reason.

Most supra owners go to big single because of its simplicity and reduced cost, not because single is superior to twin turbo set up.

The opposite can be said in other applications where twin turbo set up is favored over the single such as large displacement V motors.

Yes but the N54 is not a large displacement V motor and that is why my comparison with the Supra. If you are going big on a small motor like this than single would be the way to go. And no, most Supra owners go single because you can make better power off one. That's a known fact in the Supra community.

[lyndon_h]

simply put, 2 is almost always better than 1. But single turbos are often preferred for price and space considerations. If you could have a engine that was truly bulletproof and had the room, 2 turbos would be advantageous.