Saturn ION RedLine Forums banner

1 - 20 of 44 Posts

·
Registered
Joined
·
31 Posts
Discussion Starter #1
Automobile Mag dyno tested the turbo in a Red Line


(excerpts)
You’re also probably aware that the Red Line version gets a limited-slip differential, a performance-tuned suspension, and dual exhausts.

But forget all that. The most interesting thing about the swiftest Sky is without question its engine. And this isn’t some half-assed, hobbled-together, turbocharged old lump we’re talking about. Need proof of the new-think? Saturn fills the thing with Mobil 1 synthetic motor oil at the factory.

This state-of-the-art, turbocharged and intercooled, sixteen-valve in-line four is GM’s first direct-injection engine in the US, and it’s been renforced to better handle the turbo’s 20 psi. The powerplant also has the highest output--and the highest specific output--of any engine in the Ecotec family: 260 hp and 260 lb-ft of torque. That’s a lot of power for a 2.0-liter engine.

By injecting fuel directly into the cylinders, GM was able to maintain a relatively high compression ratio (9.2:1), which helps the engine make more power off-boost and also contributes to better overall efficiency. Continuous cam phasing on both the intake and exhaust cams further increases efficiency and helps reduce turbo lag. For example, at low revs, the engine computer will allow a small amount of valve overlap, opening both the intake and exhaust valves at the same time. This increases the volume of gases flowing through the turbo, keeping it spooled up and ready to produce boost.

To wit: Mash the accelerator from idle and the twin-scroll turbo starts building boost almost immediately. All too often, having a turbo small enough to spool up quickly at lower revs means that it runs out of breath as the tach needle hits the fun end of the spectrum. But that’s simply not the case with the Sky Red Line. The 6300-rpm fuel cutoff might be relatively low, but the little motor pulls hard all the way to the top, and all the techno goodies work together to make the displacement-challenged Red Line drive more like a normally-aspirated car with a big, honking motor.

We were impressed with the Red Line’s ability to make power all over the rev range, but why should you take our word for it? We took it to a chassis dyno so you can see exactly what it puts out. And the Sky’s rough and tough exhaust note made everyone turn around and listen. So, naturally, we grabbed the video cameras, and you can hear it for yourself.

On the dyno, the Saturn Sky Red Line put 228 hp and 248 lb-ft of torque to the rear wheels. Those are very, very impressive numbers. The peak torque number is quite a bit higher than we expected, but more impressive still is the shape of the torque curve. This little monster put down more than 200 lb-ft of torque from 2000 rpm to almost 6000 rpm.

The Ecotec isn’t a particularly smooth or refined engine, but the dyno run backed up our impression that it provides truly world-class power delivery. The next time you see someone driving a Sky Red Line or its mechanical cousin, the Pontiac Solstice GXP, you’ll know that their ear-to-ear grin isn’t just due to their car’s gorgeous looks.
Video of Dyno Test: (Windows does not seem to be working... the QuickTime does):
http://www.automobilemag.com/multimedia/video/0609_2007_saturn_sky_red_line_dyno/
 

·
Registered
Joined
·
1,197 Posts
That is pretty sick...suprised though...I thought the 260/260 would be underrated as well...shame...
 

·
Registered
Joined
·
11,403 Posts
Project_Redline said:
That is pretty sick...suprised though...I thought the 260/260 would be underrated as well...shame...
I'm sure the engine is more underated than this shows. More drivetrain power loss here than on the Ion. Everything I'm seeing is pointing to the turbo sizing holding things back, too.
 

·
Registered
Joined
·
2,041 Posts
Does anybody else see this thing not being easily tuneable right from the factory? The turbo is pretty much maxed out and a special system (twin scroll) that isn't that upgradeable. So if you were to replace it with a bigger non twin scrolled turbo, it might take A LOT of work to get the whole system working together smoothly. I say this because everything in that engine is designed and tuned as is to work at it's close to max state. For example, as the article mentions, the cam design to overlap the intake/exhaust valves to spool the SMALLER turbo (that wouldn't do as good of a job with a bigger/different turbo). The direct injection into the cylinders are most likely tuned to feed the engine in its max performance state (just like our injectors were maxed out from the factory).

I dunno, I could be wrong, but it just seems like all the different type of engineering that went into this engine/turbo application that you don't normally see in such systems, that it's going to not like to be modified. Pretty much just like our cars, but even worse.

I'm sure it's still upgradeable, but it will take a lot of money, time, and work to get a higher performance mode out of this engine. I don't really see a factory stage kit helping this powertrain either. The torque drops for the entire rev range, and the power peaks before redline. The turbo is already close to, if not maxed out, so more fuel wouldn't really create any more power.

I'm not trying to badmouth the car or engineering behind it, the turbo Ecotec still a blast to drive in any of the cars (thank you working for GM this summer :-D). I'm just seeing people having a lot harder of a time upgrading this car as compared to the more simple supercharged Ecotec...What do you all think?
 

·
Registered
Joined
·
8,036 Posts
If anything is underrated from the factory its that damn 335i Twin Turbo Coupe! 300/300 claimed...dyno shows 275rwhp and 299lb/ft!!!
 

·
=[ÜBER MODERATOR]=
Joined
·
9,519 Posts
vandy0419 said:
I'm disappointed in the rwhp #s...
I am not at all, this engine OCULD NOT have been underated like ours. Any GM engine going into production from 2005+ get indipendently dyno'd. It is an effort to get ALL automakers to do this, so automakers don't make BS claims about HP.
 

·
Registered
Joined
·
8,036 Posts
NoRemorse said:
I am not at all, this engine OCULD NOT have been underated like ours. Any GM engine going into production from 2005+ get indipendently dyno'd. It is an effort to get ALL automakers to do this, so automakers don't make BS claims about HP.
Ah, for insurance reasons and stuff? How did out 06s and 07s stay underrated then? Or is it just when a new model is released they do it? Doesn't make sense with that BMW then.
 

·
=[ÜBER MODERATOR]=
Joined
·
9,519 Posts
vandy0419 said:
Ah, for insurance reasons and stuff? How did out 06s and 07s stay underrated then? Or is it just when a new model is released they do it? Doesn't make sense with that BMW then.
GM is doing it with only ENGINE put into production after 2005.

Like she SRL's LNF.

It is comepltly voluntary though, automakers can choose to do it or not.
 

·
Registered
Joined
·
8,036 Posts
NoRemorse said:
GM is doing it with only ENGINE put into production after 2005.

Like she SRL's LNF.

It is comepltly voluntary though, automakers can choose to do it or not.
Oh okay, just making sure. Sounded like you were saying they were trying to enfore it on everyone.
 

·
Registered
Joined
·
8,036 Posts
sheek360 said:
thats preety good for a rwd 4 banger man, 19 psi huh? must be a tiny turbo. that thing looks plenty fast dude. i for one am impressed!
Its a twin screw though so the torque is really nice...I just was hoping that the whp #s were higher. This means someone with one of these stock from a roll vs someone with a IRL Stage 2, the ION would probably win.
 

·
Registered
Joined
·
1,197 Posts
vandy0419 said:
Its a twin screw though so the torque is really nice...I just was hoping that the whp #s were higher. This means someone with one of these stock from a roll vs someone with a IRL Stage 2, the ION would probably win.

...and would have been able to do it for much less money...

although we do not have a near 50/50 weight distribution and coilovers from factory...lol
 

·
Superd00d
Joined
·
22,040 Posts
The torque is damn sure underrated... 250 wtq = 275-285 crank...

228 whp = ~260 crank...

So the motor is putting out 260/275... I'll take 'er...
 

·
Registered
Joined
·
1,197 Posts
Sp00ner said:
The torque is damn sure underrated... 250 wtq = 275-285 crank...

228 whp = ~260 crank...

So the motor is putting out 260/275... I'll take 'er...

But unlike ours, it falls really quick after it spikes...
 

·
Superd00d
Joined
·
22,040 Posts
Project_Redline said:
But unlike ours, it falls really quick after it spikes...
Ours is flat, and the STOCK sky makes more torque over most of the band than a stage 2 redline with a 2.8" pulley.

Also, please note the dip in hp/torque near redline, must be were she's bleeding boost. I'd think another 10hp is there for the taking in stock form...
 

·
Registered
Joined
·
3,865 Posts
NoRemorse said:
GM is doing it with only ENGINE put into production after 2005.

Like she SRL's LNF.

It is comepltly voluntary though, automakers can choose to do it or not.
In Japan I don't think any car be rated over 277HP, so ever the Skyline on paper states that number...riiiiight!
 

·
Registered
Joined
·
11,403 Posts
KSC said:
In Japan I don't think any car be rated over 277HP, so ever the Skyline on paper states that number...riiiiight!
It was 276hp that they "capped" it at, but I don't know if they still do. Furthermore, the US ratings used to cap NA engines on imports (only on certain countries, but Japan was one of them) to 120hp per liter as well. There's all sorts of stupid stuff like that out there.
 

·
Registered
Joined
·
12,221 Posts
Sp00ner said:
Ours is flat, and the STOCK sky makes more torque over most of the band than a stage 2 redline with a 2.8" pulley.

Also, please note the dip in hp/torque near redline, must be were she's bleeding boost. I'd think another 10hp is there for the taking in stock form...
That's exactly what I was thinking as I looked at the dyno sheet. I can see the ol' boost bypass bleeding boost for sure. I would also bet that GM has it tuned down just like our cars, and will release stage kits for the SRL as well.
 
1 - 20 of 44 Posts
Top