Making changes to Cobalt SS Stage 2 tune - Newby question

[Quiksilverss]

Hi Guys,

I have a 06 Cobalt SS Stage 2. I want to add a larger Throttle body as well as a meth kit. I want to only make the changes on the tune so that I can run a healthy a/f ratio in the low 11's. I am aware that for the larger TB I will need to change the ETC Scalar area to compensate for the larger TB. I am also going to run a 2.9" supercharger pulley. I have a progressivly controlled meth kit that I want to set to turn on at 7psi and be full spray by 12psi and up. I plan on using the smallest meth jetting.

I am aware that with the addition of the larger TB and pulley it will lean the car out (up to one full point) and I am also aware that meth richens the a/f up (approx 0.5 points with 50/50 mix)

I was told that in addition to changing the ETC SCalar area I would have to have my tuner make some changes in the pe table to help command the a/f ratio I want.

Can someone help me figure out what step by step changes that need to be changed in order for this to happen. I want to keep the stage 2 tune as close to stock as possible but to make sure my a/f ratio is safe accross the board

Thanks in advance

[Sunburst_SS]

Hi Guys,

I have a 06 Cobalt SS Stage 2. I want to add a larger Throttle body as well as a meth kit. I want to only make the changes on the tune so that I can run a healthy a/f ratio in the low 11's. I am aware that for the larger TB I will need to change the ETC Scalar area to compensate for the larger TB. I am also going to run a 2.9" supercharger pulley. I have a progressivly controlled meth kit that I want to set to turn on at 7psi and be full spray by 12psi and up. I plan on using the smallest meth jetting.

I am aware that with the addition of the larger TB and pulley it will lean the car out (up to one full point) and I am also aware that meth richens the a/f up (approx 0.5 points with 50/50 mix)

I was told that in addition to changing the ETC SCalar area I would have to have my tuner make some changes in the pe table to help command the a/f ratio I want.

Can someone help me figure out what step by step changes that need to be changed in order for this to happen. I want to keep the stage 2 tune as close to stock as possible but to make sure my a/f ratio is safe accross the board

Thanks in advance

well, in a nutshell....between adding meth, and a bigger throttle body....it won't look much like a stage 2 tune at all after you're finished. For the throttle body to work you will need to change the ETC scaler for 4500 I beleive. Then you will need to go through and get your fuel right, and make sure you're not seeing any knock up high. Now as far as injecting meth, you will probably want to aim for for an AFR closer to 12.0:1 while injecting.

[Bika]

yes.
set your meth to begin injecting at 5psi (about 130kpa) and while you're at it you might be able to throw a couple more degrees of timing at it on the top end. just dont go crazy. stage 2 timing sets you at 20-21 degrees i wouldnt go more than 23 under meth, just to be conservative.