Re: Chevy Cobalt DF/S and maybe keep it streetable
 

A few quick updates on my parts I ordered in the middle of the night last night:

Ordered HP Tuners with 2 credits.

Mid-length headers with 1.5 primaries and 2.5 down pipe (with catalytic converter because "street legal")

I have the parts for a fuel sample valve but will leave that to a professional to install because I might set the whole thing on fire.

I am strongly considering running Sunoco 260 GTX (as opposed to VP C-10).

Re: Chevy Cobalt DF/S and maybe keep it streetable
 

Quick update:

Unfortunately the test and tune night at Houston Raceway Park this past Friday was rained out so I haven't had the chance to make a full quarter mile pass with most of the modifications; but the local brackets are eighth mile and I have gone as quick as a 9.96 at 69.11 MPH.

A good number of my eighth mile passes were in 3 to 4 hundredth spreads with each respective major change.

Done:

Slicks, front runners, and light weight rims
Mid-length header (1.5 inch primaries, 2.5 inch collector) and down-pipe with 400 cell catalytic converter
Removed upper intake manifold and just running open throttle body (though car is now throwing DTC for the MAF Sensor
Fuel sample valve had been installed
Best run was at 2,850 LBS running 93 octane

Have not done:

Did not flash the ECU with HP Tuners. Walt Walker made some changes to the tune related to when the cooling fan comes on and how much torque is applied (he did not mess with any fuel related tables); it would not sync up properly as it was not recognizing the credits that I purchased with the device. As soon as I can get tech support to resolve the issue, I'm flashing the computer.

Need to drain the remaining 93 octane from the fuel tank, change the fuel filter, and replace with Sunoco 260 GTX. For the record, attempting to run a car that gets 28 MPG until it runs out of fuel is such a pain in the butt. I drove the 30 miles home from Baytown with the Low Fuel warning hoping it would run out of gas so I could dump in the race fuel to make it the rest of the way home.

When the mechanic across the street installed the header and down pipe, he hooked it into the stock exhaust, so I need to open things up a little.

Going to buy a tow vehicle on Monday because the Suburban crapped out in December. Need to get that inspected and registered by Wednesday so I can high-tail it out to No Problem Raceway's Thursday Test and Tune to try and get this car under the index.

Re: Chevy Cobalt DF/S and maybe keep it streetable
 

Made it back from Chandler, AZ an extra $700 lighter in the wallet due to a breakdown on I-10 with this ramp truck I bought; and probably in for some more as it's in the shop getting the check engine light related stuff taken care of. My comment on this; yes I knew what I was getting into but that's why I bought a truck with a 350 engine....everyone can work on it and parts are easy to find. I can have Jegs or Summit ship a long block to me for about $1,600 if this thing decides to spin a bearing or kick a rod. Ultimately I was happy to hear that the No Problem Raceway LODRS was postponed because I wouldn't have been about to make it out there.

But I digress....back to the DF/S

The Cobalt is completely switched to Sunoco 260 GTX. I drove to the track Friday night and managed to get a best of 26.8 MPG to and from.

The one thing that went wrong was that I couldn't unbolt the resonator from the down-pipe to go completely unmuffled. One of the nuts holding together was at an awkward angle and I wound up rounding it off with my impact wrench. I'll just have an exhaust shop cut it off.

I'm almost at the index. I started off with a 15.90 @ 85 MPH off the bat, followed by 15.94 @ 84, 15.86 @ 85, 15.89 @ 85, and 15.98 @ 84 (heat soak and fog was rolling in). Although the barometer was moving around a tick between 30.02 and 30.05; the humidity was parked at 93%; dew point at 59*, and temperature only varied between 61 and 62 degrees.

What was promising about tonight was that my sixty foot times were in the 2.32 - 2.35 range in this "meh" air and I went quicker in the quarter compared to two weeks ago; but two weeks ago my sixty foot was quicker. I hope that correlates to hitting the index or better when the air is better and they have a LODRS track prep. I still haven't even reflashed the car with HP Tuners because I was on the road and couldn't call their customer service guy about getting the credits on there to work.

Re: Chevy Cobalt DF/S and maybe keep it streetable
 

Very cool! Thanks for the progress updates and info.

I've been looking for a cheap daily driver, and this thread is making a Cobalt look pretty good... :D

Re: Chevy Cobalt DF/S and maybe keep it streetable
 

I see you must have figured something out you went a 15.64 almost the index. If you could figure out how to cut a better light your car seemed real consistant. I applaud your efforts.

Re: Chevy Cobalt DF/S and maybe keep it streetable
 

Traction control is acting like a throttle stop. I've had the same problem with a 2007 Dodge Charger and an Ecoboost Mustang which I bracket raced. I'd run the number all day but RT's were crap. The "free" solution to all of this was banned in Stock over 15 years ago: deep staging.

Re: Chevy Cobalt DF/S and maybe keep it streetable
 

The traction control is, most likely, using the ABS to pulse the brakes.
How about disabling it by backing off the solenoid module on it?
Just a thought..No experience with Cobalts.

Re: Chevy Cobalt DF/S and maybe keep it streetable
 

Mike : enjoyed our talk at houston. Us slow pokes need to stick together.Glad to see you getting close to index. It's always nice when you get to the one out of ten things you try that actually works instead of the nine others that slow you down. See you at Dallas.

Re: Chevy Cobalt DF/S and maybe keep it streetable
 

Thanks Bill. Hopefully I can get a tune file back before Dallas. Since I won't be racing the Houston Nationals or Tulsa that should be sufficient time for cams and a valve job before No Problem.

Re: Chevy Cobalt DF/S and maybe keep it streetable
 

Can the Cobalt be run in EF/S? Thanks