Single turbo, twin turbo?

[dkstz]

Hello, I've watched an episode of Initial D those days and there was two RX-7 racing, one was a single turbine and the other had two turbines. I understand something about it but not too much.
Anyone can explain in details the differences between those "types"?

In the anime they said that a single turbo should be more unstable when turning. y? And "under the hood", what the difference?
Thank you!

 

[The359]

Turbine is a type of engine usually used in a helicopter. Not the same as a turbo.

And, um...two turbos are usually more powerful then one turbo.

 

[Takumi Fujiwara]

Wrong and wrong.

Turbine is a commonly used term for the turbo itself, especially in Japan.

Twin turbos are generally setup for response, not power. Topspeed and drag cars usually use large single turbos.

 

[Purple Platypus]

Well, with one big turbo, you get plenty of turbo lag where the engine is not revving high enough to keep the turbo spooled. With twin turbo setups, there is a small turbo and a big one. The small turbo keeps boost up when the engine isn't revving high, and the big turbo kicks in to increase boost when the engine gets around to the higher rev's. So...basically, the small turbo is covering for the big one's lag time.

As for instability in a corner, there shouldn't be that big of a difference between the two setups. The only difference I could see is in power delivery. With a single large turbo, the power will jump when the rev's get up and the boost goes up. A twin turbo setup lowers this effect. So, if you're turning and accelerating, the twin turbo setup could deliver smoother power. However, I don't think that this would be that much of an influence on the car's stability.

As far as faster goes, the twin turbo is not always faster. If the single turbo is really, really big, it's going to provide more boost, hp, and speed than the twin turbo.

Well, I hope that stuff's right. I'm just kinda relaying material I've picked up here and there

 

[Evo7GTA]

He's right, the turbos on standard twin turbo cars usually run sequentially.

One spins up at a low rpm and the other at a high rpm. That's why people who modify twin turbo engines usually run one big turbo, to free up weight and power. (the twin turbos share the power whereas one big turbo can use all the power itself)

Plus I'm guessing engine mapping would be easier to do with one turbocharger.

The twin turbo would probably be faster out of the corners but the single turbo would be alot faster on the straights.

 

[The359]

Wrong and wrong.

Turbine is a commonly used term for the turbo itself, especially in Japan.

Turbine:

Turbo:

Big difference. If the Japanese are calling it a turbine, they're wrong.

 

[pimp racer]

Can someone say supercharger?

 

[Taurine]

Turbine:

Turbo:

Big difference. If the Japanese are calling it a turbine, they're wrong.

A turbo is a form of turbine, but when people see 'turbine' they think jet turbine. That's where the confusion lies.

 

[Ev0]

A turbo is a form of turbine, but when people see 'turbine' they think jet turbine. That's where the confusion lies.

True. The working part of a turbo is the turbine, so the name is completely correct. It's like calling a turbojet engine a turbofan, becuase the fan is a major part of the engine.

And the only reason I could see a single turbo being more unstable during turning (you sure you didn't mean tuning) is if it is one absolutely massive turbo mounted on a side of the engine bay, promoting asymmetrical weight distribution.

 

[Taurine]

And the only reason I could see a single turbo being more unstable during turning (you sure you didn't mean tuning) is if it is one absolutely massive turbo mounted on a side of the engine bay, promoting asymmetrical weight distribution.

With twins you'll be able to power through and out of the corner, whereas with a big single you'll get halfway through the corner, floor it and by the time you get off the apex the boost hits you and your facing the other way.

If you were an amatuer of course, if you're used to the sudden surge from the single turbo then you'll be just as fast as twins through a corner.

 

[McLaren'sAngel]

Hiya! Meow! (='.'=)

Interesting topics and reply! hmmm I can't seem to make up my own judgement on which is better to have in a car. A single turbo setup or a twin turbo? Wouldnt the twin turbo just go flying past the single turbo because of the smaller turbo kicking in and THEN to have the second one spool and go far? But then the single LARGE turbo set up will build boost and then go ROCKETING up the speed limit! Which one would be better for freeway runs? Twin or Single?

 

[Emohawk]

Freeway runs = onramp drag racing? That'd be twin turbo.
If you're alredy at freeway speed, a big single would be better.

AFAIK; twin = 0 -to> fastish
single = fast -to> really fast

Twin turbo setups traditionally come in 2 flavours:
Paralell: both turbos operate at once. I think this is mainly used in V and Boxer engines so that there's one turbo per cylinder bank. Seems to me just a big single would be better, but I guess there's some reason behind this I don't get
Sequential: Already explained; one first, then both.

There's something new on the BMW 535d, also. 'variable sequential twin turbo'
Normal twin turbo setups have 2 turbos the same size, one spools up first, then the second one engages and they both run together to produce maximum boost.
The variable sequential twin turbo setup uses two turbos of different sizes. A small one and a big one. At first the small one operates alone, not producing very much turbo lag. At midrange, some exhaust gasses are diverted to the larger turbo (because the small one has already reached it's maximum boost level). When theres enough exaust gasses flowing, the big turbo operates entirely by itself.
Small turbo for quick throttle response, big turbo for big power (the 535d makes something like 400 lb/ft). It's great!
I'm pretty sure it was developed by BorgWarner (not BMW), so there's potential for this system to make it to the aftermarket eventually. BMW uses it to pretty much eliminate turbo lag, but if you're willing to accept a little it could make some pretty impressive numbers potentially.
(<fingers crossed for a 2JZ kit)

 

[PublicSecrecy]

Wrong and wrong.

Turbine is a commonly used term for the turbo itself, especially in Japan.

Twin turbos are generally setup for response, not power. Topspeed and drag cars usually use large single turbos.

The Bugatti EB110SS uses FOUR IHI Turbos. And something like 6 catalytic converters too...i unno i guess Bugatti is enviro-friendly or something.

I'm pretty sure it was developed by BorgWarner (not BMW), so there's potential for this system to make it to the aftermarket eventually. BMW uses it to pretty much eliminate turbo lag, but if you're willing to accept a little it could make some pretty impressive numbers potentially.
(<fingers crossed for a 2JZ kit)

Doesn't the supra (the twin turbo of course) have 2 turbos the same size? I saw an engine layout and they looked exactly the same. Anyone know why this is, or just some weird anomoly stock cars sometimes exhibit?

 

[Taurine]

The Supra has the variable sequential system described above.

 

[JNasty4G63]

Too many different setups to list, so I'll just do some basics.....

Sequential turbos
Not really twins, because they aren't the same size. Good for response. Smaller turbo has very quick spool. Then, by the time its running out of steam, the larger turbo is full bore. Good for all around power. Almost always used on inline engines. The Supra and RX7 were like this.

Twin on V Engines
Because you only have half of the cylinders to spool each turbo, they tend to be smallish, limiting max power. But, that makes for good response. Sequential setups on a V engine would be silly and fairly useless considering the complexity of piping needed to work.

Twin on inline
Same with the V engine, you only have half the engine for spooling each. That is why you see soooo many Supras and RX7s with big single turbos. Much easier to spool a big turbo with all the engine spooling it.

But, there are occasions where you'll see big twins put on cars. The twin HKS GT3037S is a great setup for Supras. That turbo, just for reference, will make close to 550hp on a 4G63. But, when you combine two of them on a built 2JZ in a Supra, you have magic. Easilly over 1000hp. They spool very fast because of the ball bearings used, but make big power because of the size.

Turbos are all about flow. If the engine you have has enough flow to spool a bigger turbo, go for it. If not, you'll be wasting your time. Like, if you tried putting a T88 on a DSM. It would spool up at like 6000rpm, if at all. Just pointless. But, too small a turbo, and you'll be running out of turbo and not making as much power as you could. The stock T25 in a 2G DSM is a good example of this. Makes great power very low in the revs. But, it gets maxed out at like 250hp. Its just too small. Its a big balancing act this turbo thing.

Hilg

 

[Taurine]

Is a T51R too big for a little 4G63?

http://www.performancecar.co.nz/download_files/docile.jpg

 

[JNasty4G63]

Is a T51R too big for a little 4G63?

Nope, not for a drag car like that. And, neither is a SCM61 on a street car!!!


My Talon

Hilg

 

[Taurine]

Very nice 👍 DOCILE (car in picture above) is hoping to break the 4Cyl 4wd record of 8.76 held in the USA. His fastest run before his rebuild was 9.59 and thats without the front half tube section and new turbo setup. He's only been out once or twice but is already doing 164mph trap speeds with poor launches .

 

[PublicSecrecy]

I really honestly don't mean to shoot anyone down here, but that didn't help at all lol. I already knew that, i was just asking if the Supra's turbos were the same size or not lol. The engine cutaway i have shows that the turbos are exactly the same size.

 

[Taurine]

I already knew that, i was just asking if the Supra's turbos were the same size or not lol. The engine cutaway i have shows that the turbos are exactly the same size.

Well then why did you feel the need to ask?

 

[PublicSecrecy]

Well then why did you feel the need to ask?

cuz ppl keep saying one's bigger, one's smaller!

 

[dkstz]

Thanks for all the answers! I've learned alot now...
Just to clear up:
They were running in a very bumpy road, the black RX was a single-turbo, the yellow had two. The black knew the road very well, the yellow don't and it was hard to control. Then the black had to release the accel for a second beacuse of a bump. The driver of the yellow RX realized:

Then in the next corner he came from the inside and just touched the back of the black RX, makin it lose control/line for just a second, but without spinning, having to release the accel.

Then they got side-by-side and he said:

In the next corner the yellow RX passed the black.

 

[TS1AWD]

Nope, not for a drag car like that. And, neither is a SCM61 on a street car!!!


My Talon

Hilg

That better not still be the 7-bolt in there!
I can't believe you are running low 11's with an air meter still!! Time to ditch that.

 

[retsmah]

A turbo is a form of turbine.

Sort of... a turbine takes energy out of a moving fluid or gas and puts it into the rotation of a shaft. A turbocharger isn't just a turbine, it's a turbine and compressor connected together.

 

[Azuremen]

Here is how I Think about these kinda things.

Single Massive Turbo - Drag racing and top speed
Twin Turbo - Racing where response is needed.

The twin turbo setup provided a larger powerband, and allows for power at lower RPMs. Single turbo setups on drag cars (which is where the twin system is normally pulled in favor on 1 turbo) are designed for high RPM output, and not for any reasonable range of response. ADditionally, the sequential twin system reduces lag by having one spool up sooner.

Asymetry created by a single massive turbo would not cause enough issues to modify handling much. It just comes down to engine response.

 

[McLaren'sAngel]

Hiya! Meow! (='.'=)

Thanks for answering my question guys! 👍 It is just that I am curious about Supras! I really love them! You see, I have several videos of a supra running onthe freeway against another car. I read that one of them was using a BIG single Turbo while another is a Twin Turbo. There is just to many debates going in my heads wondering which would be better. Sometimes it gets me to think that its better to buy the non-turbo supra than the twin turbo(2JZ-GTE) Just put a big turbo in the nonturbo and WALLAH! Save buncha money! But in that case, I heard that the non-turbo engine isnt as strong as the 2JZ-GTE...so things are a bit over spolling around

Although we see turbos usually placed in 4 and 6 cylinder engine, how come we dont see V12s being put with a turbo? I can at least assume that the person buying an Enzo wouldnt care much for how fast it goes I guess, so they just leave the car stock. V12 cars are also RARE compared to less 4,6,8 cylindered cars so companies would think its a waste to make a turbo for a V12 when they are so scarrce on the street Have anyone ever seen a V12 with turbo before?

 

[I6-4-eva]

Thanks for all the answers! I've learned alot now...
Just to clear up:
They were running in a very bumpy road, the black RX was a single-turbo, the yellow had two. The black knew the road very well, the yellow don't and it was hard to control. Then the black had to release the accel for a second beacuse of a bump. The driver of the yellow RX realized:

Then in the next corner he came from the inside and just touched the back of the black RX, makin it lose control/line for just a second, but without spinning, having to release the accel.

Then they got side-by-side and he said:

In the next corner the yellow RX passed the black.

which episode is that? I havent watched Initial D in a while.

 

[I6-4-eva]

Hiya! Meow! (='.'=)

Thanks for answering my question guys! 👍 It is just that I am curious about Supras! I really love them! You see, I have several videos of a supra running onthe freeway against another car. I read that one of them was using a BIG single Turbo while another is a Twin Turbo. There is just to many debates going in my heads wondering which would be better. Sometimes it gets me to think that its better to buy the non-turbo supra than the twin turbo(2JZ-GTE) Just put a big turbo in the nonturbo and WALLAH! Save buncha money! But in that case, I heard that the non-turbo engine isnt as strong as the 2JZ-GTE...so things are a bit over spolling around

Although we see turbos usually placed in 4 and 6 cylinder engine, how come we dont see V12s being put with a turbo? I can at least assume that the person buying an Enzo wouldnt care much for how fast it goes I guess, so they just leave the car stock. V12 cars are also RARE compared to less 4,6,8 cylindered cars so companies would think its a waste to make a turbo for a V12 when they are so scarrce on the street Have anyone ever seen a V12 with turbo before?

If you like supras you should visit www.t04r.com lots of big hp supras with single and twin setups i think.

The MercedesBenz SL 65 AMG twin turbo V12 makes 612hp and a whopping 738 Torque lb-ft is that enough turbo for ya? yes I think so. Freaking awesome.

 

[McLaren'sAngel]

If you like supras you should visit www.t04r.com lots of big hp supras with single and twin setups i think.

The MercedesBenz SL 65 AMG twin turbo V12 makes 612hp and a whopping 738 Torque lb-ft is that enough turbo for ya? yes I think so. Freaking awesome.

Hiya! Meow! (='.'=)

WOW I6-4-eva! Thanks for that SUPRA LOVELY site! A bunch of ky00T Supras there to look and drool over! MOTIVATES ME! CANT WAIT! NEED BACHELOR and GET SUPRA AS GIFT!!! THANKS ALOT YOU MADE ME WANT TO RUSH!

And jeez that SL 65 AMG! That's just crazy CRAZY amount of torques.... perhaps too much to have! Goddess, just looking at that really does show some more support of how luxury cars are getting faster too. They shouldt be looked as a golden slow box meant for cruising and showing your riches anymore.

 

[JNasty4G63]

That better not still be the 7-bolt in there!
I can't believe you are running low 11's with an air meter still!! Time to ditch that.

Its a 6-er. And the MAF is hollow. Just there for somewhat sleeper-ish. When some people don't notice the GM MAS, they think its still stock air flow. You can see the GM right past the BOV on the IC pipe. I'm running the AEM EMS, so the stock MAF was one of the first things to go.

Hilg