Dual scroll turbos?

[2QUIK6]

Was just reading about the new turbo Sky and Solstice coming for 2007 using a ecotec 2.4l producing 260hp / 260 ftlb. Uses a dual scroll turbo which has the exhaust passage split in two and you can see twin exhaust housing scrolls. Claims to get tons of low end torque and eliminate turbo lag by using that and SIDI direct injection and cam phasers.
This was in GMHTP, thought I'd mention it here wondering if a dual scroll type of exhaust housing could help spoolup ona Buford...or maybe this is old technology that just doesn't work on our cars.

 

[GNVYUS 1]

Mitsu has been using the twin scroll on the Turbo 2.0 for some time. I am sure it does work considering its only 122 cubes and those cars would need as much help as possible spooling.

But those exhaust housings are more rectangle with 4 bolts, our 3 bolt housings are already smaller in total volume. We somewhat have a better spooling exhaust housing due to the smaller size.

If you look in the Stage section, you will notice some guys are modifing the headers to fit the bigger 4 bolt housings.

 

[2QUIK6]

Yeah I've seen alot of the 4-bolt stuff, the exhaust passage into the housing is square as well. The picture of this one still maintains a round exhaust inlet port but with 4 bolts, but it is not a square pattern with the bolt...like the 2 on side are close together and the other 2 on the other side are far apart. Oh well, I can't to go test drive one of these with 260hp with a 2900 lb car.

 

[grocerygetter]

have ya'll seen Honda's version for the new Acura RDX SUV? Turbo four cyl 2.4 L AWD @240hp and @260 tq.
Pretty sure Honda is using an actuator to control the volume of the exhaust housing to make it spool faster down low. Looks like dual scrolls with a flap valve conneting them.

 

[BandAid]

Pk then why is it listed at 260hp and 260tq,you would think if they were tq monsters it would read 260hp 340tq... :wink:

 

[raflyer]

Pk then why is it listed at 260hp and 260tq,you would think if they were tq monsters it would read 260hp 340tq... :wink:

DOHC 4cyl's make HP not TQ so having the TQ the same or higher is consider'd at "tq monster" :wink:

I have an 06 CobaltSS that dyno'd 270hp and 275Tq and it is a supercharged 2.0, INSTANT boost = fun 4cyl and 12sec timeslips and 32+mpg :biggrin:


The dual scroll won't work on the buick since it sees the benefit from the way the 4cyl firing sequence is on 2 cylinders at a time feeding the exhaust a stronger pulse.

 

[2QUIK6]

The dual scroll won't work on the buick since it sees the benefit from the way the 4cyl firing sequence is on 2 cylinders at a time feeding the exhaust a stronger pulse.

Almost like its 2 tiny turbos packed into one since a pair of cylinders are completely separate from the other pair all the way thru the exhaust housing but spining the same turbine so each aids the other in spoolup.

Looks to be a really neat motor with lots of innovation for GM with the direct injection and contoured piston dome and oil jets to cool the tops of the piston. The article later said to look for alot more hp in the following years after the initial year of the turbo because the stock bottom end can handle much much more abuse than what 260hp/tq are going to throw at it.

 

[raflyer]

It's actually, i hate to say, 1000 times more amazing than the old 231 :redface:

The block and crank will handle over a 1000hp, at 10K rpm!!! Stock rod's in the 2.0 will take up to 600hp. Only weak link is pistons but aftermarket handles that. Sound familiar?? :biggrin:

Thats why my CobaltSS is for sale and i'm picking up my GN #5 this week :biggrin: :biggrin:

Just can't get past the rpm and fwd thing. Still a great job by GM

 

[nocutt]

DOHC 4cyl's make HP not TQ so having the TQ the same or higher is consider'd at "tq monster" :wink:

I have an 06 CobaltSS that dyno'd 270hp and 275Tq and it is a supercharged 2.0, INSTANT boost = fun 4cyl and 12sec timeslips and 32+mpg :biggrin:


The dual scroll won't work on the buick since it sees the benefit from the way the 4cyl firing sequence is on 2 cylinders at a time feeding the exhaust a stronger pulse.

Works fine for this buick engine...

 

[Dennis F]

Twin scrolls also use larger exhaust housings.

All the Mitsu twin scroll housings are 10.5cm^2 compared to a single scroll which is a 9cm^2.

Even with the bigger housing the spoolup is just as fast but there is more power potential.

 

[LUCKY1313]

I have often wandered about the GT4088r turbo, its twin scroll & the results I have seen on some other six engines is amazing. But the headers have to be built to work with the turbo or the benefit is not found. Possitive boost quick in the rpm & able to make 800whp, sounds good to me. These turbos are very efficant and flow more than there maps show them to. I seen a Toyota Camery V6 spool one to possitive boost on the convertor before 3000 rpm, then I seen a Honda make 850whp with one. 2 to 4 psi boost on these is making power unlike some others that have to get to 10psi to make power. the response of these turbos is sweet. But you do have to build your headers to accomidate them or they dont work right.


Jess

 

[GDNF2ET]

Check out this setup http://www.year2032.com/ecotec.htm

 

[LUCKY1313]

Check out this setup http://www.year2032.com/ecotec.htm

So does this car have a duel scroll turbo, if it does I missed it in the reading. It said they where running a Innovative turbo & I didnt know Innovative even had a Duel Scroll turbo. It meantioned a Scroll Type intake. Maybe I need to go back & read it again?


Jess