[arm1tage]

OK, so I had some free time and decided to share some numbers I have come up with regarding this now official 2.0 turbo engine. The main assumption is that is uses essentially the same motor as the Ion Redline and Cobalt SS.

That 2.0 supercharged motor is rated by GM at 205 hp and 200 lb-ft. However most owners have dynoed around 220 whp / 220 lb-ft stock. Dyno chart for reference

Now since this is a supercharged engine, of course there will be parasitic drag, since the charger is powered by a pulley run off the engine. The supercharger is a M62 made by Eaton. According to Eaton, the charger uses about 35 hp at the high end of its operating range @ 10 psi. But the SS/Redline run at a peak 12psi, so about 37 hp drag (assuming a linear relationship in boost/drag). So its possible that this motor can handle 220+37=257 whp. (turbos also have drag but much less; also the torque curve will not be as flat due to spool time) Eaton M62 specs

Since the supercharged engine uses a Laminova air-to-water intercooler, it relies on the radiator to cool intake air. Most cars run the coolant fairly hot, topping out at around 170-180 degrees. The turbo motor will use a front mount air-to-air intercooler if we go by the Solstice turbo prototype spy shots. I don't know much about it, but it seems to me ambient temp is way better than hot coolant. And according to this article the air-to-air intercooler should be more efficient, allowing for cooler air and more power, so we could see even more than 257 whp.

The icing on the cake is that GM recently announced Stage 1 and Stage 2 kits for the Cobalt SS that are covered under warranty.

GM Performance Parts will offer separate Stage 1 and Stage 2 supercharger kits. The Stage 1 Kit includes higher-flow fuel injectors and an ECU calibration to provide a 31 hp boost to the Cobalt’s engine for a total of 236 hp and 205 lb.-ft. of torque. Add in the Stage 2 Kit, with its smaller supercharger pulley and drive belt, and the engine comes alive with 241 hp and 218 lb.-ft. of torque across a broad engine speed range.

link
Anecdotal evidence shows that the Stage 2 kit would boost whp to as much as 260-270! Don't forget to add that 37 hp for drag! So we are looking at a possible 307 whp on a stock bottom end. If you count 15% drivetrain loss that would put you at about 360 crank horsepower. Then consider that the Stage 2 kits are warranted by GM, they have obviously tested them to be within their "safety range". You could probably squeeze another 5-10% power out of the motor safely, putting you within striking distance of Vette territory.

Of course to make that much power you would have to do several mods, although they should be fairly inexpensive (compared to building the bottom end). Intake, downpipe, exhaust, ECU/boost controller, larger injectors, maybe a larger turbo, among others. However these mods would allow for near Mallett-V8 performance for a LOT less.

I welcome any comments and criticisms...

 

[brentil]

On average cars with LSJ motors are dynoing from 195-205HP when done in 4th gear correctly. It seems a lot of people like to dyno in lower gears to inflate the power rating. Also being a FWD car the engine sees more of a 10% loss in power compared to the larger loss of a RWD car. Forced induction motors also see a lower % drop due to they way they work usually compared to NA motors.

In reality the base engine more then likely makes 215~220HP flywheel HP, and with the Stage 2 kit the engine might make ~260HP at the flywheel, but we don't know since I haven't seen any dyno numbers for it yet. I keep looking though.

 

[Chip]

arm1tage; No criticisms here, but I do wonder about a turbo's worse enemy. That being heat, which induces compressor shaft / bearings failure. When I say heat I mean after the motor is turned off. How are modern turbo's designed now to keep the bearings from coking up and failing. Have modern design principals made the issue of heat destroyed lube. / destroyed bearings a thing of the past? I know that many of todays turbo's are water cooled, but when the motor is turned off the coolant stops as does the movement of cooler oil to the turbo's bearings. Right? Can you shed some light here?

 

[Thraxz]

On average cars with LSJ motors are dynoing from 195-205HP when done in 4th gear correctly. It seems a lot of people like to dyno in lower gears to inflate the power rating. Also being a FWD car the engine sees more of a 10% loss in power compared to the larger loss of a RWD car. Forced induction motors also see a lower % drop due to they way they work usually compared to NA motors.

In reality the base engine more then likely makes 215~220HP flywheel HP, and with the Stage 2 kit the engine might make ~260HP at the flywheel, but we don't know since I haven't seen any dyno numbers for it yet. I keep looking though.

Ummm... the lower gears wouldn't inflate the horsepower 20 or 30 horsepower Brentil. It'd triple it compared to fourth.

I'm not quite understanding what you're saying about 10% powertrain loss and FWD.

Yes, I want to see those dyno sheets too.

 

[Rampant]

I think there are a whole lot of assumptions and comparrisons that just shouldn't be made IMHO.

First of all, when talking about a "vette killer," it is much, much more than just peak hp. Traction, gearing, weight, balance (when talking about handling), should ALL be taken into consideration when talking about overall performance. Besides, what are you talking about "killing" in the Vette? 1/4 mi. times? Road track times? AutoX? Or are you just talking about dyno queens?

But, let's just say you are talking about peak hp (which is pointless in my book, but good for fourm fodder none-the-less).....

While I love to play the guessing game as much a the next guy, starting with a supercharge FWD and saying that will be close to a turbo RWD is really not a fair assumption in my book. Especially since GM has said it will be the most powerful Ecotec yet -- which means we have no idea how much it will be stock.

- Torque V. HP -
First, Eaton's have much more torque down low, which can help pull a car to quicker accellerarion times, but may also reduce traction to the point of actually hurting times. Also, you need to look at area under the curve. If a blower is making less peak hp, but greater power throughout the curve, it would be a more powerful engine in the long run.

- HP per Amount of Boost -
Turbos typically have higher efficiency (which means they should make more peak hp on similar boost -- but it comes later in the RPMs). So, question #1 is how much boost will it run stock? You should be able to up the boost on a turbo as it tends to be less stressful on the engine (and is much easier to do so than a supercharger).

- Drivetrain Loss -
RWD cars are less efficient getting the power to the ground than FWD cars, so this can hurt the dyno sheet. However, RWDs are also better for off-the-line traction, so it would help accelleration times (again, which is more important?).

So... in the end, all we have is pure speculation and nothing more.

If you really want to build a Vette killer, talk to Mallett ;-)

 

[aloch]

arm1tage; No criticisms here, but I do wonder about a turbo's worse enemy. That being heat, which induces compressor shaft / bearings failure. When I say heat I mean after the motor is turned off. How are modern turbo's designed now to keep the bearings from coking up and failing. Have modern design principals made the issue of heat destroyed lube. / destroyed bearings a thing of the past? I know that many of todays turbo's are water cooled, but when the motor is turned off the coolant stops as does the movement of cooler oil to the turbo's bearings. Right? Can you shed some light here?

This was/is a problem of older turbos and dinosaur oil. As you mentioned, water cooling helps significantly and especially synthetic oils. Also the operator can help alot too. Don't shut down a turbo engine right after a hot run (on the gas, in the boost). One of my old turbo bikes had a recomendation to idle for two minutes after a high speed run to allow the turbo bearings to cool with a constant supply of oil. If you really are worried about bearing coking, get an Accusump turbo oiler, that continues to supply oil the the bearing after engine shutdown. Bottom line, unless you're racing and never change your oil, this shouldn't be a concern.

PS I like arm1tage's analysis. Isn't the 2.0 turbo ecotec in the Saab 9-3 already? I think it's only 210hp. Hope it's tuned up significantly for the Sky RL.

As for Brentil and dyno response to gear selection, that would only be the case if the dyno wasn't picking up engine and wheel speed correctly and not recalculating for this. On a dyno the power should be the same in all gears if calculated properly. It is better to dyno in higher gears because there is less chance of tire slippage at higher wheel speeds. If you've seen something different, it's because the dyno operator isn't calculating power correctly.

 

[need4speed]

i recall reading a post on turning the 2.0 ecotec into a monster... its a complete tear down and rebuild for take the monster hp... i think i read it on solstice forum?!

 

[brentil]

PS I like arm1tage's analysis. Isn't the 2.0 turbo ecotec in the Saab 9-3 already? I think it's only 210hp. Hope it's tuned up significantly for the Sky RL.

There is A 2.0L Turbocharged ECOTEC in the SAAB cars but there's one thing GM mentioned in the press info that seperates this from all other ECOTECs in existance. Direct Injection. That alone hints at some sort of all new engine. I wouldn't be suprised to see it based off of the new VVT ECOTEC. There are very few Direct Injection [*]charged engines in existance, so we're getting ready to see a new generation of engines with more performance based technologies in them. LA Auto Show website kinda slipped up yesterday too and said it was 260HP 260 ft-lbs for the new GXP engine.

I'm not a dyno expert, I just know that one image he showed above has been floating around for a while in the LSJ communities and has really never been matched by members getting their real cars dynod. Everyone else gets about 195HP~205HP for 2005 models and the new 2006 models are making about 200~210. I've seen one 215HP but the dyno I saw was done at 4 degrees F (Canada). I will admit though I'm suprised to see the increase to an everage of 205HP from the 2006 model. That's one benefit of [*]charged systems though is they're much easier to get extra HP out of over time with revisions then a NA engine ever will be.

 

[brentil]

i recall reading a post on turning the 2.0 ecotec into a monster... its a complete tear down and rebuild for take the monster hp... i think i read it on solstice forum?!

That's the ECOTEC buildup book, you can get it from GM for free now.

http://www.gm.com/company/gmtunersource/html/race_shop_build_book.htm

 

[arm1tage]

The ECOTEC buildup manual does describe the 2.2L engine as having "consideration" for direct injection, it is in the introduction. So this may be the case for the 2.0L also.

Good point about the dyno testing Brentil. 3rd is 1.18:1 and 4th 0.89:1 so 3rd gear would read higher and 4th lower than actual output.

But lets just say it makes 195 whp. Add the 37 hp for drag and you get 232. With a 10% drivetrain loss (which I think is quite low, my Prelude SH has about 18%) that puts you at 257 crank hp, which is likely very close to what GM will rate it as. Will they also release upgrade kits for this motor? I don't know. It would stand to reason if they did, the actual output might be lower. And with GM in dire financial straits, I'm betting they will try to squeeze every last dollar out of the enthusiast. I'm all for it GM! Take my money!

I also want to make clear this is just conjecture for fun. I am not trying to make predictions or whatever, just trying to determine how much power the motor would likely make, and how much it could make. For anyone looking to upgrade their engine's performance, this would give you an idea of how much work and money is needed to reach a specific output goal. My target is 270 rwhp on the stock turbo, which should be easily attainable.

Rampant, the "Vette killer" in the title is just a gross exaggeration to get views. You might get the car to handle as well as a Vette, but 400 hp is not really practical. The Cobalt head starts getting anemic around 270 hp, the manifold can flow 350, the rods are on the hairy edge at 400. Of course these parts will have been redesigned for turbo application. But the motor could potentially make 400, at least for a short while.

Regarding torque, hp, and FI. My personal belief is turbos are superior to superchargers for making power. It comes down to efficiency. For the same block, a turbo will make more usable power, probably weigh less, and have more adjustability. A supercharger produces more off the line torque and is easier to maintain, but that's about it.

We know the motor will be the "most powerful ECOTEC", but that is just a number. They might say it's 245 hp or 260 hp. But what we're really concerned with is the actual output. Are they going to underrate this motor for insurance purposes? Probably not. The whole idea is to steal some market share from Honda, Mazda, even BMW and Porsche.

BTW a turbo timer is a great addition to any turbocharged vehicle. You can get one for under $100 and there are some that will automatically calculate the cool down time needed based on driving time or even engine load.

 

[aloch]

Good point about the dyno testing Brentil. 3rd is 1.18:1 and 4th 0.89:1 so 3rd gear would read higher and 4th lower than actual output.

As said below, ... , that would only be the case if the dyno wasn't picking up engine and wheel speed correctly and not recalculating for this. On a dyno the power should be the same in all gears if calculated properly. It is better to dyno in higher gears because there is less chance of tire slippage at higher wheel speeds. If you've seen something different, it's because the dyno operator isn't calculating power correctly.

Yes, it's Christmas Morning, just got done putting out the kids gifts. Merry Christmas and Happy Holidays to all.

 

[kingarthur]

But lets just say it makes 195 whp. Add the 37 hp for drag and you get 232.

It's certainly interesting to speculate on the possible HP of the new engine,but I think assuming that the turbo causes no parasitic loss is a mistake.
The power driving the turbo wheel comes from the engine pumping out exhausted air. While it has to do this anyway, it certainly will require much less
force from the engine to pump out the exhaust w/o a turbo blocking the way.
I think you'll find that direct injection will be a major factor, by providing more complete combustion as well as reducing detonation tendencies that would otherwise have to have been addressed by scaling back aggressive timing, etc.

 

[Thraxz]

Aloch is spot on.

 

[SkyCaptain]

As said below, ... , that would only be the case if the dyno wasn't picking up engine and wheel speed correctly and not recalculating for this. On a dyno the power should be the same in all gears if calculated properly. It is better to dyno in higher gears because there is less chance of tire slippage at higher wheel speeds. If you've seen something different, it's because the dyno operator isn't calculating power correctly.

In a perfect world, maybe. I challenge you to pull it off in the real world. In all my years, I have never seen a dyno perfectly replicate a power curve in different gears. Theoreticals are nice, but here in the real world everybody who operates a dyno knows the closer you are to a 1.0 ratio, the more accurate your curve. And it has nothing to do with the skill level of the dyno operator.

 

[SkyCaptain]

as well as reducing detonation tendencies that would otherwise have to have been addressed by scaling back aggressive timing, etc.

Right there is the #1 advantage of direct injection. The closer you spray the fuel, the more piston cooling effect you get from it. This is why supercharged 3800s have a different injector location than normally aspirated engine blocks.

 

[kingarthur]

Originally Posted by kingarthur
as well as reducing detonation tendencies that would otherwise have to have been addressed by scaling back aggressive timing, etc.


Right there is the #1 advantage of direct injection. The closer you spray the fuel, the more piston cooling effect you get from it.

Whether it's the #1 advantage I can't say, but the spray mist is certainly not going to be as susceptible to droplet formation compared to port injection -
that it, the fuel mist doesn't suffer from the movement it is required to make in the port injected version. It's as close as you can get to positioning the fuel in precisely the right place, at the right time, and in the right state.

 

[soslowgtp]

In a perfect world, maybe. I challenge you to pull it off in the real world. In all my years, I have never seen a dyno perfectly replicate a power curve in different gears. Theoreticals are nice, but here in the real world everybody who operates a dyno knows the closer you are to a 1.0 ratio, the more accurate your curve. And it has nothing to do with the skill level of the dyno operator.

I have seen runs in different gears withing 1-3% ..... as in 300-400hp cars run in 2nd, 3rd, and 4th, all being with 3-10hp of eachother..... In my book that is clse enough, also the same gears didn't provide the same changes in each car.... 3rd was best for some 4th for others..... 2nd is mostly only older autos

 

[Lee Willis]

Hi. I'm new to the thread, interested in maybe picking up a Sky (rode in one about a month ago, but that's another story), and I'll qualify myself my saying I've build over 20 hot rodded engines in the last 35 years included an Eaton supercharged LS6 four years ago and the C5R (427 cubic inch) with a centrifugal supercharger now in me vette. If you want to see pics and specs, go to

http://www.corvetteforums.com/albumphoto.asp?albumid=4&asortType=2&apage=1

With all due respect, I believe you are trying too hard to rationalize and almost double count power that really won't be there while ignoring some problems that will be there.
1) Very likely the SC requires 37 HP. You'll never see it and all you are doing is pointing out that the crankshaft can take that power plus whatever you see out the back end.
2) I really doubt that any GM engine is going to produce more RWHp that its rating. The Sky will be released under the new SAE HP standard and it requires pretty accurate ratings. I'd guess about 175-180 RWHP, but let's pass by this.
3) Generally, with any modern (Gen III, Gen IV) GM engine, you can get about 30-50% boost in power before you start running into stress problems in the stock block rotating assembles. That means the upper limit for this engine is probably somewhere around 275-300 flywheel HP. I'd also guess this just from the size of the SC. Its an Eaton 62 (62 cubic inch impeller displacement) and as a rough rough of thumb an Eaton is good for a max of about 5 times its displacement (flywheel). My 112 made a max of 575 flywheel HP on a fully tricked out LS6, although I know of some who rev the units past their designed limit and get about 610 flywheel.
4) It will take about 360-370 flywheel HP to equal the straightline performance of a stock C6 vette in a car with the Sky's weight. To do that, I believe you will find it necessary to rebuild the bottom end, lower compression slightly so you can use more boost, and got to about 16 lbs of boost, using an Eaton 90 cubic inch blower. That is certainly do-able for about $8K, I'd guess, and would be fun.
5) The Sky ought to handle as well as a vette in tight turns but I don't see in generating as high cornering forces: the vette is noticeably wider, weights only about 8% more, but runs bigger rubber (and can run much bigger rubber).
Overall, I think if you want vette-like performance, buy a vette. They are great cars. You get different things when you buy a Sky and that's its appeal, which is why I'm seriously thinking of getting one.

 

[LS2 MN6]

To improve the DI to over 300 HP should only take a few modifications, maybe a Cold Air Intake, Turbo back and cat Back Exahust upgrades, possible new Cams. This engine can easily hit 350 HP with enough mods.

 

[brentil]

More then likely just larger injectors and a ECU reflash to change the Turbochargers boost levels would get you close to 300HP with this engine.