I wanted to make this post as a thing i could take to my tuning session to help the tuner out on tuning my turbo automatic 2.4. so any tips and help ican get on what we need to look for would be great. the guys has a partner in pcm for less that has tuned turbo solstices and will try and use that info for a baseline but he hasnt tuned a cobalt 2.4 ever before so i think any tips would be great so we can see my turbo 2.4 ss running the streets sooner than later. thanks guys. i have till the 24th before i take the car in. this will be using hp tuners for the record.

 

i thought there were a bunch of hp tuner people around here and no responses???

 

All I know is, I hope it works out for you. Let me know.

 

I think Vector would be the people to talk to about tuning your car for boost. I heard that they were involved in the Hahn turbo project tune.

 

the solstice & cobalt 2.4 have the exact same pcm if I remember correctly...if Alvin has tuned the solstice with little or no issues you should do fine with your 2.4 as far as I can see. The new pcm's are odd though in how they do things...more tables which is good & bad because from what I understand it will give you more depth at tuning if you know what your doing...problem is few actually know what they are doing hehe.

 

There are two issues I can think of. First, the Garrett instructions have you drill the oil return in the block using a jig they provide. With your automatic, there probably won't be enough room there. If there is, great! But I doubt it. You will have to drill your oil pan and tap in an AN fitting. Not a tuning issue, but an issue.

Second is going to be the shift pressures at less-then WOT. At WOT, you'll be fine. But if you have an aggressive throttle, the trans will slip. You will need to modify the shift pressure tables.

 

I've yet to tune any factory naturally aspirated car into a forced induction setup using HPTuners but I have with other engine management systems, so I'll give my 2 pennies for what its worth.

What I would do since these cars only reference VE for correlation checks (electronic throttle and MAF failure) is to swap the 1 bar MAP sensor for a 2 bar, but rescale the voltage reference in HPT. ie. instead of 5v being 100kpa its now 200kpa. That allows you to keep the 1 bar stock speed density calculations the PCM needs to run its correlation checks and also fuel for cam changes in case of MAF failure but also allows you to run a 2bar map without problems (you could also keep the 1 bar and just disable the DTC for MAP overvoltage but my way is much cleaner as disabling DTCs should only be done as a last resort).

Where the fun part would be is tuning the MAF to recognize the increase in airflow. I don't know if you'll hit the MAF's upper limit as far as frequency goes. If you run it as a blow through setup (MAF in the charge pipe) you'll probably need decent resolution on the MAF table, something LSJs don't have, but I believe LE5s do. If you run it as a draw through, which would be placed before the turbo, resolution wouldn't matter as much but you have a better chance of hitting the upper limit of how high of a frequency the MAF can output.

Talk with your tuner and see if you can get a little more info out of him. If he's tuned FI Kappa cars before I'm sure he'll have no problem tuning your car. Good luck and hope to see ya at Pittsburgh Raceway this season.

 

there is no VE table in the solstice or 2.4 cobalt pcm as far as I can remember so have fun with all that

 

well i think at the boost levels im approaching hp tuners will be ok. it looks like when i start to go above 300whp which stock internal engines on the solstices have been doing they have been using the ss/sc 2 bar. im still a noob in tuning pcms so its hard for me to understand all this right now.

 

The LSJ MAP sensor is actually a 2.5 BAR. And I understand that getting it to work with a different PCM is kind of a pain in the ass.

 

Not a conventional 2 axis one, but one with more than 2 variables, but that shouldn't need to be modified anyway. Since HPTuners doesn't support changes in commanded cam angle, modifying the VE would drastically alter fueling when cam phase changes.
Should be a piece of cake actually. Just modify the kpa value that the new sensor would output at 5v as shown below.

 

where should i get a 2 bar sensor that the ss/sc uses if it comes down to needing that?

 

Call up a chevy dealer and ask them for an LSJ map sensor.

The main reason I would put a 2,2.5,3 bar sensor in there even though you would be keeping stock 1 bar VE table is so the PCM can continue to run the electronic throttle tests because technically, the MAP wouldn't be out of range if you upgraded it. Worst case scenario if you don't is probably losing functionality of the cruise control or any other etc based functions.

 

well we can try it on stock 1 bar and see how well it runs and if need be change it over later. by the way, do you guys want me to let you know when the day of tuning is so you could come and check it out? i think we will be dyno tuning on thursday the 29th in allsion park if the hardware install goes well.

 

tuning day is either this thursday or friday is anyone wants to be there for the 1st 2.4 auto turbo dyno tuning session...

 

Where are you going... and what time? I work normal day hours, but I might swing by to check it out depending on where you go and when.

Also, any fitment problems with your kit? Is it on yet? Did they modify any of the piping? Details!

 

well so far i know that fitment is not the best, the water lines in the car had to be moved and the exhaust and downpipe or 2 different sizes and no room to work by the turbo so far thats all i got. as far as the times im not sure since the kit isnt fully installed yet. but the place in on route 8 in allison park called auto service and performance. ill give tuning details the second i get them.

 

https://www.cobaltss.net/forums/general-cobalt-68/turbo-2-4-automatic-fully-installed-pics-52517/

pics of my new setup

 

well tuning will be on wednesday between noon and 1pm we will start.