2009 cobalt ss/tc blown piston ring land, tune review

[hhenri60]

hello guys i just purchased a 2009 cobalt ss/tc knowing that there was something wrong with motor, so i took it apart and found cylinder #1 ring land broken since leakdown test was at 100% on that cylinder

now question is i have the tune that came originally with the car that i pulled with hp tuners, i wanted to see if any of you guys could see if is a very aggressive tune or mild???, car was boosting around 23 psi according to owner.2009 cobalt ss tune.hpt

mods are as follows:

zzp downpipe 3"
aem cold air intake
treadstone intercooler and piping
straight piping from downpipe

also the head had alot of carbon built up on the intake valves which ill be cleaning

for now since i dont have lots of money i will install 4 new stock pistons, since cylinder wasn't damaged, to get it to pass emissions and to get the title in my name, title is in my friends dealer name,
and also the transmission has a bearing noise that i need to repair or swap transmission if not i will replace with forge pistons

[5FDP]

I don't know much about those vehicle but you can always compare it to a stock file to see some of the differences.

[ECaulk]

I'll try to take a look at the file later. Not the most knowledgeable like some on here, but can see if there is something way out of wack.

Also the noise your are talking about could just be the LSD in the transmission, they're loud and don't like the cold. When I first got my cobalt I was worried about the same thing, 50k later still making the same noise and the transmission is still fine.

[Area47]

sounds like someone beat the shit out of the car. file didn't look horrible other than a boost spike setup down low. which could have caused the pop.

[hhenri60]

i did try to compare to a stock tune but some of those tables dont make much sence since im not an experienced tuner ill i have done is tune a l61 turbo cavalier that is the reason i have hptuners

[hhenri60]

I'll try to take a look at the file later. Not the most knowledgeable like some on here, but can see if there is something way out of wack.

Also the noise your are talking about could just be the LSD in the transmission, they're loud and don't like the cold. When I first got my cobalt I was worried about the same thing, 50k later still making the same noise and the transmission is still fine.

thanks for willing to look at the file, also the transmission noise sound like a loud bearing going out and this car is not equiped with the LSD option so i thing its something else

[hhenri60]

sounds like someone beat the shit out of the car. file didn't look horrible other than a boost spike setup down low. which could have caused the pop.

yes it does look like it has had a rough life, is there anything you recommend doing to the tune to make it sort of safer and prevent blowing another ring land? is there such of thing or just basically going back to stock tune will be the best??

i am pretty good about maintenance on my vehicles so that won't be a problem its just the tune that worries me that would cause another ring land to blow, i have heard alot of things like intake not been tune right making the car run lean causes broken ring lands

[FLASH1970]

CobaltSSoverbooster has an LNF thread with links to lots of good info on tuning the lnf. he also has tuning videos that are really helpful. ive watched all of them multiple times. id say start there.

Area47 said there's a boost spike down low so maybe lower the wastegate duty cycle in that area to keep the boost down.

I started with a stock tune, except the values for the 3 bar MAP sensors. from there I calibrated the MAS and adjusted my Injector Constant (I have bigger injectors) to get my fuel trims in check. there are tunes you can download off of here but I would not recommend just copying the values. HP Tuners allows you to compare tunes so I looked at what was different in my tune versus the one I downloaded and started increasing things like the WGDC table, the Desired Airload Table... slowly. increasing boost after a few datalogs to adjust those tables among others. increase things a bit more, datalog, adjust, repeat.

[MikeM173]

Do not adjust timing based off of knock you see in a log. Most knock I've seen in logs is false knock and lowering timing will just cause more issues.

Do a stock tune, adjust for 3bar maps if you have them, and calibrate for fueling. That's probably the safest you'll get unless you want to pay someone to do it.

[T-Man]

I'm in Mesa and would be happy to help you but my time is not free

[hhenri60]

CobaltSSoverbooster has an LNF thread with links to lots of good info on tuning the lnf. he also has tuning videos that are really helpful. ive watched all of them multiple times. id say start there.

Area47 said there's a boost spike down low so maybe lower the wastegate duty cycle in that area to keep the boost down.

I started with a stock tune, except the values for the 3 bar MAP sensors. from there I calibrated the MAS and adjusted my Injector Constant (I have bigger injectors) to get my fuel trims in check. there are tunes you can download off of here but I would not recommend just copying the values. HP Tuners allows you to compare tunes so I looked at what was different in my tune versus the one I downloaded and started increasing things like the WGDC table, the Desired Airload Table... slowly. increasing boost after a few datalogs to adjust those tables among others. increase things a bit more, datalog, adjust, repeat.

good info man thanks for your time and ill be looking for those videos to see if i learn how to tune this myself

[hhenri60]

Do not adjust timing based off of knock you see in a log. Most knock I've seen in logs is false knock and lowering timing will just cause more issues.

Do a stock tune, adjust for 3bar maps if you have them, and calibrate for fueling. That's probably the safest you'll get unless you want to pay someone to do it.

yeah probably ill stick with the stock tune till i have some money to pay to get it tuned properly thanks

[hhenri60]

I'm in Mesa and would be happy to help you but my time is not free

i wish i had some money to tune it properly, now with all the repair im low on cash but thanks for the offer

[FLASH1970]

http://www.hptuners.com/forum/showth...357-LNF-Guides