As I'm supercharged do you think switching from the stock manifold to ZZPs long tube header with 1.75" primaries would require a re-calibration to get the full benifit (I have to rely on Trifecta)?

 

I believe you will be fine without a retune, there is a chance that you set an O2 sensor code. If you do retune you will be able to maximize your gains from the header.

 

It's not really needed

 

I already have it installed and I am not throwing any O2 codes. I just put it on and I thought it would be a noticeable improvement over the stock as it is very restrictive in comparison. All I seem to notice is a drop in low end torque, but maybe it's my imagination.

 

No you need a tune to see any gains in performance

 

No you don't, if the header flows better than stock there will be gains up top even without tuning. The ecu used on the l61 it not a torque based ecu that limits power to a certain level. To get the most gain safely you need a tune.

OP if you have a wideband make sure your afrs are in check for WOT and that will tell you if you need a retune