Which is quicker off the line Twin or Single turbos

[Lextreme II]

To save money I would suggest u get a GT35R for light to light and for the freeway too.

 

[Pro]

i would say if you're taking holidays to do it, a min of 2 weeks full time to get everything fabricated, positioned, wired etc. and have it off to the tuners.

 

[stevechumo]

i would say if you're taking holidays to do it, a min of 2 weeks full time to get everything fabricated, positioned, wired etc. and have it off to the tuners.

Two weeks are the max time to get the system done. But that depends on several factors. How you run and build the manifolds, twin or single turbo, exhaust system, low boost, hight boost..etc all account for the time. If you're familiar with fabricating turbo systems and working on a low boost system, I'd say 1 week full-time. Eat with the car, sleep with the car...kidding.:veryhappy

 

[Lextreme II]

If you have the tools and parts, one week is all u need. However, if you are short of one part....delay...delay ...delay..... Here is my current slow moving project http://www.lextreme.com/forums/showthread.php?p=43081#post43081

 

[dass]

Jago,
Suggest you look at a gt3540 with a built in waste-gate (xr6 turbo type)
As for how long it would take really depends if you have a fully equipped workshop
or trying to do it at home in the garage with basic tools.Good luck with it and sorry for taking the piss. Darren.

 

[Jago]

Rock soild reply Dass, thanks for the info.
Lex, your project looks good. I can see what you mean with delays and what not.
Cheers Jago

 

[Nick M]

The old age some have of twins spooling quicker is completely backwards. I don't really know where it comes from either. You have half the heat trying to push each turbine. Apples to apples, if you add a second turbocharger to any setup, it will take longer to spool.

You can not say, well, smaller twins spool faster. That isn't what was asked. A single smaller will spool faster than two smaller turbos.

Yes, there are many factors that determine when a turbocharger will come to life. All factors being the same, one turbo will come on quicker than two. Twins are done for space on V engines, and high end drag cars where spool isn't a concern. If two spooled faster, you would see them on all the inline 6 heavy duty powerplants, where grunt is needed, and cost is not a factor.

edit: This reminds me of the Toyota 2JZGTE Supra. It does not use sequential turbochargers, they are staged. They are both CT12 turbochargers. A vacuum switching valve (VSV) operated by the ECM controls the wastegat actuator. It sends all the exhaust energy to one turbocharger, then both. If the flow was divided by two, it would take longer to bring them up to speed.

 

[Warpspeed]

Yes indeed, given a choice between twins, and a large single with a split pulse housing on an inline engine, the big single is always better in every respect.

But with a flat boxer, or vee engine with two banks of cylinders, twins can sometimes be more responsive if the turbos can be located right over the exhaust ports with minimal exhaust manifold volume.

Packaging comes into it as well. The more efficient big single may lose all its advantages if a very long and highly inefficient exhaust manifold must be used because of installation requirements. But if you can fit it in, a single turbo will always be better.

 

[Nick M]

But with a flat boxer, or vee engine with two banks of cylinders, twins can sometimes be more responsive if the turbos can be located right over the exhaust ports with minimal exhaust manifold volume.

Packaging. Many cars may not have room to run the manifold or crossover pipe under hood to a turbo which takes up space. So tiny twins right on the manifold are used.

Mercedes makes some heavy duty powerplants. Nothing in cars mind you. Tractors for hauling trailers.

The V6 has a single turbo, and the V8 has twins. The V8 is much bigger in displacement. On the V6, the displacement is too small, and they can not wait for two turbos to come on. So all exhaust heat is routed to one.

If you have a smaller turbo that responds faster due to less inertia, it will also move less air. When you have two to compensate for less air, the heat is divided between the two and response time increases.

Of course a smaller turbo in general will respond quicker than a bigger one, but two will take longer to respond than one. This being Lextreme, and not SF, I know everybody here will understand.


edit: being the internet, information is easy to get... just seperating the BS from fact is the hard part

I recomend research from turbo manufacturers, not kit makers. That would be Holset, Garrett, KKK, etc, not Precision turbo or turbonetics. Not to say anything about the quaility of their products. From Garrett;

What are the main differences between a Single and Twin Turbo setup?

A single turbo receives exhaust flow from and supplies air to all cylinders.

The most common type of twin turbo setup is the parallel system where each turbo is fed by ½ of the engine's cylinders. Here, both compressors supply air to the intake manifold simultaneously.

There are also sequential twin turbo systems, which run on one small turbo at low engine speeds and switch to two parallel turbos at a predetermined engine speed and/or load.
Furthermore, there are series twin turbo systems where one turbo feeds the other turbo. These are primarily used on diesel engines due to the extremely high boost levels that can be generated.

For this FAQ, we will just refer to the first two setups identified above.

Choosing between a single or parallel twin turbo setup is primarily based on packaging constraints in the engine bay, or a personal choice by the tuner. In most cases, for top performance, a single turbo is preferable because larger turbos are generally more efficient than smaller turbos. However, often there is not room for one large single, or the tuner wants the visual impact of twin turbos. The notion that two smaller turbos will build boost faster than one large turbo is not always accurate because even though the turbos are smaller, each one is only getting half of the exhaust flow. Sequential systems seem to have the capacity to support big power. In theory, the sequential twin turbo setup is a potent combination. A few O.E.s have produced systems of this type but control issues have proven significant, making them challenging to function seamlessly. One slight draw back to a sequential twin turbo system is that sometimes during daily driving (specifically, in cornering) if the driver is not constantly aware, the second turbo will spool and result in a lot of unpredicted power.

 

[Anaema]

im not pretending to know all this stuff, even though its easy to understand, but im pretty sure turbo size, spool time, and whether there are one or two has much less to do with 0-? acceleration. like ive seen said before, tires, transmission, gearing etc has much more affect on launch speed than the number of turbos in your repective setup(unless the turbos in question are grossly over or undersized.)

the first example that comes to mind is the 997 Turbo w/ Tiptronic. it has a much better 0-60 MPH time because the automatic transmission can keep the turbos fully spooled before launch(obvious advantage) and during shifting, which the manual transmission cannot. in fact, the automatic has a higher 1st gear ratio than the manual, and is down one total gear, but it still out accelrates the manual. just because it can keep the turbos spooled.

so basically, number of turbos is or should be irrelevant to how fast you want to launch from 0.

 

[jibbby]

For quickness from launch, root charger, NOS.... Combined that with a good torque converter (automatic tranny/s), and or aggressive differential gearing change, and most importantly good traction from launch....

Light to light with that crap you would be hard pressed to beat......

 

[JustenGT8]

Just a point of clarification on SC versus turbo for off line accel. It's totally irrelevant that an SC has boost from idle, when do you launch hard off the line from idle? With a manual you launch at decent revs and have virtually instant boost response. With an auto it's even better as you load the engine against the stall and again have instant boost. Look at any drag racing class where turbos are allowed...they are quicker.

This isn't a sledge against SC , they have their place and are a good option for a UZ no doubt. Great response on the street and can be somewhat easier to install.

As has been pointed out earlier, other factors on the car will be more important that whether it's single turbo, twin or SC when it comes to a fast launch.

 

[Nick M]

I think a single GT35R on a 1UZFE would just haul ass off the line.