Technically there is no "stage 2" although an aftermarket supplier might call it that.

GM only had a stage 1 for the HHR SS

 

Good to know... didn't realize that, I thought there were GM Stg2 & Stg3 turbo kits?
Stg2 added larger & stronger Intercooler (without plastic ends) and more Tuning.
Stg3 added same Stg2, plus larger Turbo and fuel system? Thought I read somewhere the Stg3 was basically Track / Racing only.

 

The RPM Moto does offer an advanced Tune... they can send you a tuner that they remotely use or you can purchase one.
The larger Intercooler & non-plastic Charge Pipes to improve on the additional tuning.

Since I have 2 Panels, 2.2L Auto & 2.4L 5sp, I could use the Tuner for those too, which is why I was thinking a purchase of the Tuner.
I'm playing with thoughts... no decisions yet.
Still looking at exhaust systems too.

 

I believe that was Cobalt that GM did that for... Because the configurations are different some of those parts may not fit, even though the engines are the same.

Just going by what I have read, I'm no pro on this.


It does seem at this point aftermarket would be your only choice though.

 

seems you’ve answered all your questions

 

Closer... still examining and comparing.
ZZP provided some good info this evening to consider too.

 

OldBlue, You're Correct... I think that is the route for all sources... after examining several sources they all use the same HPTuners hardware, software & credits.
The current model is the MPVI2, all the sources sell the exact same unit and they are reference the need of the same software & credits per vehicle.

Comes down to the Tech that is remote.... doing the actual tuning.
There I have no idea whom is who, who's better... they all indicate they have an expert tuner performing the Tune.
Some package it with other components... but price reflects basically the same per item.

I am surprised how this is still a popular project.. the LNF engine appears to be very popular.

 

I know! Very popular, after all these years , but the LDK is even better!

 

The 3rd Gen LDK does look like the way to go if the LNF ever gives it up some day. At full block prices, really not that bad considering either the little gains! Amazing, this has been such a strong performer & reliable powertrain over so many years with minimal changes.

 

No need to spend all that money at the dealership, just buy the map sensors and flash it with gms1 via hpt, but I would only use it as a base file and start logging and revising