I was fortunate enough to meet up with Bill from GM today to get a feel for the Stage 1 kit. He had a 2010 SS/TC Coupe with the Stage 1 kit installed. The 2010 Cobalt does not come stock with the kit from the factory, but the kit will be available from dealers for the '08, '09 and '10 model years. There is is only one kit variation for all 3 years, they are not specific to a particular model year.

I took the car for a short 4-5 mile ride on and off the expressway and back along some main roads. It had rained previously during the day, as a result the roads were still slick and everything was damp.

During stop and go and normal driving, the car seemed to drive the same as my '09 SS/TC. Bill explained to me that the stage kit calibration is the same in 1st gear as the regular production calibration. In other words, the car acts exactly the same in 1st gear whether or not you have the stage kit. This is because if you upped the power available in first gear, all you would do is spin the tires more. We can already spin the tires at will in 1st gear, so additional power will not make you any faster in 1st. 2nd through 5th is where the stage kit shines.

As I merged on the freeway I didn't feel much additional pull in comparison with my stock '09. However, the boost gauge climbed to ~21-22psi, and I hit 80mph noticeably more quickly than I do in my car. While on the freeway I did a couple of stomps on the pedal while cruising at 60mph in 4th gear. The car seemed to wake up much more quickly and pull harder than my stock '09, which sometimes seems to lumber a bit when lugging around on the freeway.

Back on the surface streets I started from a light and shifted normally at about 3000 rpm from 1st to 2nd. I cruised in 2nd for a moment at about 20mph then mashed it. The car started to pull and soon the tires were spinning! This was not a No Lift Shift...I was already in 2nd and had traction...the additional power was able to break the tires loose...This isn't something I've encountered in my '09 (I can brake them loose in 1st while accelerating, but never noticed it in 2nd). The unexpected tire squeeling definitely put a smile on my face ;-)

Overall I think this kit is perfect for those of us that it seems intended for: people who daily drive their Cobalts, and want to maintain warranty while still having a quick and sporty ride. The stage kit helps wake it up a bit when you're going from partial throttle cruising to full throttle acceleration. Makes it feel more responsive, but not overwhelming. In daily driving, you don't even notice a difference unless you step on it. Well, I guess you might notice the 1-2 mile per gallon increase that Bill mentioned That's something we can all appreciate.

Thanks for the opportunity Bill! I'll be waiting for the day that I can go to the dealer and have my kit installed.

 

Sweet! I can't wait. I have the CIA downpipe with high flow cat and cia performance charge pipeing. I'm curious to see what kinda power itll put down , being im stock tuned atm. I wanna get 300whp , Ill probably add the stage 2 when it comes out

 

Sweet. very nice to see another review of Stage 1. Again when I have the funds, I plan on upgrading.

 

I too had the chance to meet Bill and drive the car today. First off I drive an '09 TC w/ side exhaust and HPTune. The TC with the Stage 1 was alot smoother in the delivery of power, my tuned car is much more violent. The boost just hits real quick while the Stage 1 has a steady roll in. For that reason I think my car feels faster but its very hard to tell since we did not line them up head to head. Its all perception I guess.

However for the realibility and warrenty of the kit, I would favor the Stage 1 over my aftermarket any day of the week. Peace of mind is worth something to me. Both tunes are a drastic improvement of stock but the Stage 1 kit doesnt throw you in the seat like my aftermarket car.

With that said, count me in for possibly a Stage 1 kit in the future.

Thanks Bill for the chance to drive the car!

 

you just hit it on the nail.

 

Dont get me wrong, violent is not a bad thing but it has almost gotten me into trouble several times when that boost hits while the wheel is turned.

The smooth boost build is nice for street driving and fuel economy. I only get about 23.5 mpg because I hit boost so often. Even in normal acceleration, I get to a point and full boost kicks in.

But there is nothing like being thrown back in your seat and I feel like thats the ONLY thing missing from the Stage 1 kit.

 

Bah! I had made a point to mention that exact thing. It doesn't give you that throw-you-back seat of the pants feel, because the torque curve is very smooth...it doesn't all come on at once. The car feels very domicile, but you'll get up to speed very quickly. Good comment!

 

Koz, I posted this over on KillerBee's thread but thought you would like to see it here also,

Bill

I just thought you might want to here about the statistics of my weekend.

600 miles on the Red Cobalt SS Stage 1.

Boost levels to 23 psi

Scary Speeds

Way to many to count - WOT Accelerations

At Least a dozen NLS accelerations

Started in Grand Blanc Michigan Friday Morning. I had stops in:

Lansing
Royal Oak
Auburn Hills
Madison Heights
Grosse Pointe Woods
Clinton Township
Livonia
Warren
(Not necessarily in that order)

10 People were able to Drive and or Ride (their choice). All very nice people with awsome cars! It was a pleasure meeting you!

Only one wanted to do a test drive with traction control turned off.

6 different People have already posted their experience.

Thanks to all of the participants! Your comments are being collected and will probably end up in an article posted on GMTunersource.com soon about the experience.

 

Nice write up. I find it awesome that guys who are tuned are willing to go with the Stage 1 over their own aftermarket tune. Bill did his homework on this kit. The stage kit is great those who have not experienced it will and deff will change their minds about it!

 

I'll admit I've been driving a stage one upgrade car for two weeks now. Yes I am a GM engineer. I had the opportunity to take the car to milan two days before the woodward cruise. We ran the same event last year and it was an invitational from someone I know who owns a corvette restoration shop. The track is not meticulously prepared and the weather was hot. 84F and 80% Humidity so the air was awfull. Last year I ran the car bone stock with the exception of a CAI of my own design. I ran a best of 13.97 with a 2.20 60 FT. Trust me I launched it 16 ways to sunday and that is the best 60 I could get on conti's with no suspension work. This year I ran the car and went a best of 13.67 with a 2.15 60 ft. I also used the stock airbox with the snorkle removed and a 3 inch intake tube between the turbo and the air box (similar to what the ZZP guys run)
This year the car tended to spin the tires slightly in second which I think also hurt the et a bit but I've driven enough fast cars to know with a set of slicks, a down pipe and air bags in the rear springs the thing will run a low 13 high 12 with those small mods at the track.

An interesting story: The folks from Lingenfelter were there and they had some rocket SRT Jeeps that ran 12's and a twin turbo 800 HP Z06 there. (The point is you would think they would not be easily impressed, its lingenfelter for cryin out loud) However I lined up next to one of their Jeeps and tree'd the guy pretty well out of the hole. He caught me and passed me and on we went into the pits. On a later pass I lined up next to a resto 427 67 vette and that guy got smoked. So I'm in the pits fooling with the front tire pressure on the car and this guy in a white Lingenfelter shirt walks by. He gets about 50 feet away from me and the car and makes an about face and returns. Out of his mouth comes this statement, "Please tell me that thing ain't stock, its way to fast to be stock what have you done to it." Which I replied "Nothing much just a cal change and an intake pipe." His mouth fell open and he began to shake his head as he turned a 180 and walked off still shaking his head. I really didn't know what to make of it but apparently the car got his attention.



On the drive home I logged the highway fuel mileage to compare to my previous average and the car logged 33 MPG VS 30 MPG over a one hour freeway drive.

The factory cal is comming but I don't know any more than Bill would about the exact date. If you happen to see me around town and want to check out a car flag me down. My car is Sport tint red with a low wing and you can identify it because it has a turbo (lettering) emblem off of a solstice on the back of it in place of the stock turbocharged emblem.

Bill and the cal guys have made an excellent driveable package for the everyday driver. If your a track freak then an aftermarket tune might give you much more. However on the street my car is at the limit of adhesion in first and second and anymore than that on the street isn't going to make it any faster untill I get it in third and by the time you get there on the street your either winning or its already game over.


Please don't ask me for the cal or to help get it in advance. I don't have it and couldn't provide it if I did.

 

Can you shed some light on the stage 2 for the lnf? When is this to be expected?

 

Wouldnt hold my breath on a stage 2. We are lucky enough to get a stage 1 for now!

 

I think they will do a stage 2 if sales are successful on the Stage 1 LNF Cobalt kit. Everyone buy this kit so we can has stage 2! In a weak economy add on sales to cars like the stage 1 kit could be a great money maker for GM. Dealers make some cash on the install of these things, it's a win, win, win. GM and dealers make money, car owners make more power and have more fun!

 

sounds sweet, I finally got my ss broken in and i got the hang of NLS now. I can't wait till I can put the stage one on and still keep my dealership happy. I am also hopeful that with stage one we will see less issues with aftermarket intakes ~crosses fingers~. Regardless this tune sounds sweet.

 

Then maybe if sales go well for the stage 2, they'll release the offroad stage III LNF kit, lol. Nitrous parameters would rock, along with an adjustable rpm band. I'd of course lower the redline, so as to not go to far past the new peak power point.

 

be sweet to set your own launch control rpm.

 

The SRT Jeep was not a Lingenfelter vehicle. LPE brought three vehicles and a jeep was not one of them. To the best of my knowledge they usually stick to GM Vehicles.

 

The RPM associated with peak power generally isn't the RPM after which you should shift. You want to shift at the RPM where the tractive effort (force at the tire contact patch) is greater in the next gear than it is in the current gear. This can change from gear to gear, depending on the gear ratios involved, and what torque the engine outputs at each RPM.

The tractive effort is basically the engine torque multiplied by the drivetrain gear ratio (transmission ratio, final drive ratio, wheel radius) and drivetrain efficiency. Since engine torque varies with RPM, and drivetrain gear ratio varies with which transmission gear you're in, what you end up with is a tractive effort curve for every gear. If you have a 5-speed, you get 5 tractive effort curves, for a 6-speed, you get 6 curves. The curve for each gear has the same shape as the engine output power plot (dyno plot)...it's just multiplied by some drivetrain ratio.

These curves can all be plotted on a single graph, with tractive effort on the Y-axis, and vehicle speed on the X-axis. Here is a picture of a slide from an Automotive Powertrains class I took last year, that shows a tractive effort plot.



(Credited to Prof. Zhang, Mechanical Engineering Dept. University of Michigan Dearborn)



The 1st gear tractive effort curve ends up in the top left portion of the graph, followed by the 2nd gear curve a bit lower and towards the right (tractive effort decreases with the smaller transmission ratio, and vehicle increases in 2nd gear with comparison to 1st), followed by 3rd a bit lower and towards the right...and 4th and 5th and 6th. The highest gear is the lowest on the Y-axis, and furthest over to the right on the X-axis (lowest tractive effort because of the smallest drivetrain ratio, and highest vehicle speeds).

To find out where to shift for max accel you want to stay in the highest available tractive effort possible (tractive effort is what moves your car! The more you have, the faster you can accelerate and higher speeds you can achieve). So if your 1st gear curve intersects your 2nd gear curve (such that after the intersection, the 2nd gear curve has a higher tractive effort than the 1st gear curve at a given speed), then you want to shift into 2nd. Ditto for 3rd, 4th, 5th, 6th....You want to stay in the gear with the highest possible tractive effort. Usually the tractive effort is higher in a lower gear (1st, 2nd,...) at an RPM ABOVE the max power rpm (due to high powertrain ratio multiplication) than the tractive effort at max power rpm in a higher gear (due to a lower powertrain ratio multiplication). However this isn't always the case...just depends on the particular engine and transmission.

All this typing is a long-winded way of saying that just because the peak HP is at a relatively low RPM, doesn't mean that you want to shift right after you hit it! As long as the tractive effort in the current gear is still higher than the tractive effort available at that same vehicle speed in the next gear, then you want to stay in gear because you have more force available to accelerate the vehicle!

When engineers design transmission ratios, a good amount of design work is matching the ratios to the anticipated engine output at various rpms, to come up with the best compromise between fuel economy, and acceleration performance (the best looking tractive effort curves). Changing the transmission ratios (as well as final drive ratio, tire radius, etc) changes these tractive effort curves, and changes the dynamics of the car...thus changing the optimum shiftpoints for best acceleration.


All that being said, for most sports-oriented cars, the tractive effort curves in each gear don't even intersect....as a result, your best bet is to stay in each gear until redline, because when you shift to the next gear your available tractive effort decreases (even though your engine output may increase!) due to the decreased drivetrain ratio.