Ecomodding a Cobalt SS/TC

[dwtaylorpdx]

I end up with long term rental cars a lot due to work.

Caddy CTS, Dodge Pickup(Hemi) Seemed to do well for their size, weight etc.

Not saying VDT is the answer but its pretty cool how well it works...

Dave

[motogp34]

I was taking about stock for stock, not who's done what to what on a track.
Who cares if the car matches its efficiency, its all about 0-60 or top speed and how fast it goes around the track...

[armygreywolf]

stock for stock I'd still give the nod to the Cobalt SS/TC, not because I own one, but because I've seen it, being in the service for a while you get to see most of the latest cars and go fast stuff guys buy when they get back from Iraq, one such was a brand new mustang gt, it was pretty quick, but the weight of the car is just not ignorable. I had him as soon as I shifted into second. He got me on a launch every single time for obvious..wait a tic, aren't we supposed to be ecomodding? Ahah, anyways, yea, I don't wanna diverge too much here.

I'm very close to 40mpg, my avg and tank avg mpg is all over, but my commute mileage (the actual durations I attempt to be frugal, which is 5 days a week hehe) stands just shy of 38mpg. If anyone can read through this and give me an idea, I'd be grateful, cuz next is tires.

[motogp34]

I find it hard to believe you lost mileage taking the big wing off, when is produces to much drag and it wont reach top speed with it on ?

[armygreywolf]

who said it won't reach top speed with it on, it does destabilize because of it's flexibility, but the car has no problem reaching 162 stock with it mounted. And I believe it works like diverters found on SUVs it's designed more to direct flow in a uniform direction, the way the cobalt is designed, I believe without the wing it produces a dirty air current when air mergers between the roofline and the door. Kinda obvious the way the antenna vibrates in the vortex , probably even worse without the wing, though I wasn't paying close attention to that particular detail. GM had no problem with a recorded top speed on the 'ring at 163MPH during the test lapping. The wing isn't the issue I think it has alot to do with conditions whether or not the car will behave, it is extremely susceptible to cross winds, reduces my mileage, even when I slow down to compensate, more than it should IMHO, that's the only downfall of the car, if that engine was in a honda, I'd bet on 40mpg for sure by now. Cobalt didn't really have aerodynamics in mind, oh well though.

[motogp34]

I read a review on the SS/TC about the big wing produces to much drag and wont reach top speed, so i figured it would get the worst gas mileage ? I drive a little aggressive, So i ordered a 09 without it...

Do you know of any 17 rims that will clear the brembos ?

I was also told that the SS/TC has a learn down computer, meaning that it doesn't matter what mods you add to the car it will only produce 260/260 unless you retune the car.

Have you tried the car with just the small wing ?

[armygreywolf]

Nothing I've found, BUT you can shave them, then any 17 except OZ will fit. It's very very close, but most will fit just fine. I want 17s because I want drag radials...is that too much to ask

There is something about the wing, I really don't have a clear answer for you, whether variances in road conditions, weather, or I just drove slower (not likely) I really got better fuel mileage with it on.

Two things you should do as soon as you have the chance. One is to remove the muffler, it's not quite 50 lbs of dead weight and there is just a little bit more open tone to the exhaust, the turbo does good to keep it quiet anyways. Two, buy some of that corrugated plastic sheet, Cover up everything under the trunk out to the bottom lip of the ground effects use large head rivets or something equally strong enough to handle constant wind road elements and rain. I also did the front but may have lost a bit of intercooler efficiency. It's actually rated higher in capacity than what it comes with from the factory. Next, and probably the only true benefit without any real work involved, a tune.

Ohh and you wanna see awesome, pump your tires up to 40 front/38 rear. The factory conti sport2s are ok, but they take overpressure pretty well. Anyways, I haven't got terribly evasive yet, If you walk by the car, it looks like a Cobalt...pretty much stock, go underneath it and it's obvious I've been making an effort to keep it somewhat aerodynamic.

[payne171]

I did a little research on turbocharging and I thought you might find it useful. From what I gather, you would be able to install an electronic boost controller along with a wastegate set for a (much) lower boost threshold. If you coupled this with a dual map ecu, you could theoretically have one map for lean burn/maximum economy and another for spirited driving, perhaps even bumping power up into the 310 hp range (at least that's what a solstice gxp is capable of with the same engine, an ecu upgrade and bolt ons). I would expect a virtually no boost 2L ecotec with direct injection and your driving style to consume little fuel on your commute and many mustangs on the weekend.

[armygreywolf]

It's taken me six months to figure out tuning on direct injection turbocharged engine. I have been very very conservative and for a long time I was using a PsychoSteve tune without a single problem (one of the people I believe knows his stuff without question.)

Anyways, my ECM was "locked i.e. certain factory settings are not accessible with the tuning software I had. I have since acquired the same software Vince uses and unlocked the fuel pressure tables, and some other useful things. The car at present is just under 300WHP with quite a bit more torque than I had previously. I have also upgraded the intercooler, downpipe to a (gasp) off road only catless downpipe. These are my only mods at present tune not withstanding.

The tune itself is much like the Trifecta tune, simply stating it has the aggressive tune and the eco tune. The eco tune is tamer, mostly because I use cam phasing and timing to give the engine the longest possible duration to take in air and least amount of time to get rid of it. This slows down the turbo, demand for fuel to keep the mixture in the right spot is also minimized. Theres so much I just don't understand completely about tuning yet I am not comfortable distributing tunes for other people at present. Besides, my tunes are slightly tamer than even superchips.

Anyways, because the engine can phase the cams, it is forced induction, small, direct injected, and I use all synthetic fluids, I put myself at 40mpg regularly now. My goal has been achieved. Sorry for the run away monolouge guys but If there is ANYTHING y'all would like to ask about direct injection, tuning or forced induction I'll do my best with it. And I will have updated pics for the car when the weather presents me with a brighter day.

[armygreywolf]

Ohhh I forgot, I removed the wing entirely and opted for 5 roof mounted vortex stabilizers since then even though they don't do that much at the speeds I drive cleaning up the air movement over the roof in even a small way helps.