Ecomodding a Cobalt SS/TC

[armygreywolf]

Ok the tire/wheel combo weighs about as light as it can be, no the factory brembos will clear no less that 17 inch rims, and even then it depends on the rim. The car can stop on a dime, and in the cobalt forums everyone has brake problems EXCEPT me, maybe it's cuz I never USE them huh? Everyone around here is a light to light driver, I drive a mile out, time my lights and adjust my speeds even if it means doing 30 in a 55 or 25 in a 45, I always end up with a nice cushion and long stretches without ever tapping the brakes in town.

The tires supposedly average 20-24K miles before change, I have done the math, at the rate my tires are wearing I won't "require" a change by state law until 70K.

[armygreywolf]

one mod Im interested in is fog light cavity inserts that deflects airflow, although all told it may not be that much of a difference. The car is quite aerodynamic already. I plan to focus primarily on drivetrain, synthetic fluids, gear ratios, underbody smoothing, and weight reduction. I drive this car 128 miles, 5 days a week, so even small mods are welcome. If anyone has input for this unique car, I'm all ears. I've read through the ecomodding for beginners, 100 tips/65 tips and very few actually APPLY to this car. The design of the engine the forced induction and direct injection make this car a puzzle for most. I have the equipment to do tunes, so that is the first place I am going to look, analyzing everything and seeing where I can shape the fuel map and timing to suit the sweet spot in my daily drive, the 57-67 mph sweet spot I usually drive within 90 percent of the trip is where I want to trim things if I can.

For the person who said 89 octane, this car can accept any 87 or higher fuel you put in it, however, ambient temp and humidity seem to play hell on this car's overall performance and even mileage, where it affects a normal car, it is amplified with the forced induction. I escape this by running 93 octane, the car then utilizes full timing and cam phasing. We don't have 91 octane here, and 89 is actually 90. WIth the price difference being negligible and doing the math, I pay maybe 15 cents more a fill up for my car to behave perfectly when the weather is hot or humid...or both.

[BrianAbington]

I can guarantee you your fuel maps are set to be too rich. Prettty much every turbo motor is. But if you can get that down to where your still safe, you will notice a big jump in economy numbers.

[armygreywolf]

ill be installing thermocouples before and after turbo to monitor these things, I am a bit worried about EGTs when adjusting timing and fuel maps...

[99LeCouch]

Get a wideband O2 sensor to monitor your A/F ratios. Don't want to run your turbo beast too lean when you re-tune the computer.

[bhazard]

Gotta love the turbo 4's huh? Ultimate compromise between speed and economy. You dont hear much about cylinder deactivated v8s anymore huh?

[BrianAbington]

nope, I fear the v-8 will become a very expensive option and have a HUGE tax associated with it.

If they could get an active management v8 setup to shut down when you stop like a prius does, that would cause a huge increase in intown economy ratings.

[armygreywolf]

to answer your comment. The car comes with a factory wideband sensor.

And the car has everything on my personal checklist...

Blow the doors of a mustang gt...check
Blow the doors of a Honda...check
Looks good...check
Turbo...check
Direct Injection, Accurized MAF and Wideband O2 sensors...check
34mpg in a car designed to go very fast, make very hard turns, and stop on a dime...priceless

[motogp34]

If you get that kind of mileage and don't use the brakes and time the lights, don't speed. You must drive like my grandmother... WHY do you own a SS/TC ???

Buy a smart car !

[armygreywolf]

Why? Why not? Really it's the only sensible GM product out right now, everything else they have is a poor attempt at "green". This is probably the only turbocharged 2+ liter engine to get this kind of mileage. I am not particular about being eco friendly, I was more being mindful of gas prices and my budget for distance driving.

The turbocharged ecotec is a sure bet in the market right now, the LNF motor won design awards, it has been in the racing scene for 3 years now, 4 if you count the Saturn Sky Prototype. No matter how you look at it, on paper it is the most efficient conventional internal combustion engine available right now. If you measure output versus fuel consumption it would really make you think twice about hybrids.

And Binger was right, the maps are too rich. Since they don't test emissions here, I wasn't particularly worried about high NOx levels here running lean. The fuel map is set to run lean under certain conditions, namely manifold vacuum and rpm. The temperatures are stable and low, right around 850F during normal driving. Stock was even lower at these demand levels, around 700-750F. According to every bit of research I can get my hands, anything under 1100 will not significantly shorten turbo life. I can get away with lean conditions due to direct injection and a water jacketed turbocharger. I keep a close eye on oil and water temps.

I haven't been on in a while, tommorow I'll dig out my gas receipts, I've been keeping track. I'll post everything for the past month, that is all post tuning.