What is the easiest/cheapest/best way to add a few HP to my 2.4 LT HHR?
Is there a good chip or do I need to go another route?

 

Here are my suggestions, though others with more experience can add to or correct me. Here is what I have done:

1. CGS Intake. Cost about $200
2. Magnaflow 18" Stainless exhaust. I only did a muffler and not cat back. Happy with the results. Cost about $150

I am about to use the services of Trifecta to tune the ECM. You can have them send you the equipment with a deposit to be refunded on return; or you can use a local agent. Cost will be about $250

Others I'm sure will have more information for you.

Mark

 

Same set up as Mark!!!

CSG + Magnaflow Stainless exhaust (close to the same price as well)

I just unplugged the ECM fuse for an hour to reset the ECM and very pleased with the sound and performance results on the installed upgrade to my 2006 2LT HHR...

 

CGS looks good, sounds good, but will lose a few HP. No way around it. Drawing hot underhood air (less dense) will drop HP. IOW, CGS is NOT a power inprovement. The stock intake is UGLY, but efficient with no restriction and is a true cold air intake drawing ambient air from outside the engine compartmant.

Magnaflow... I've got one too. Nice mellow sound. In dyno tests only showed about 1 - 2 HP gain, which is questionable being so small. The stock muffler is a good design.

A good tune will result in gains of 10 - 15 HP, much of it through the power band, better response and even better fuel mileage if done right.

For the '08 2.4 crowd... GM switched to the E37 ECM for the LE5 in '08, same one as the 2.2 L61s since '07. HPTuners does not support it yet. To my knowledge, the only options right now are Trifecta and Vector Motorsports for E37 tuning.

 

My suggestions would be the GMPP intake (or K&N), custom exhaust, nitrous, and a tune. My 2.4 is a pretty hot running little station wagon now.

 

Use higher octane gas? =)

 

Interesting! This is the first I have heard about a HP loss. I choose CGS because of the Intake comparison at:

http://www.socalhhrs.com/page/page/3473615.htm

There it showed the following comparisons of HP and Torque:

Stock 159.08 HP - 167.07 T

Airaid 156.53 HP - 166.78 T

CGS 167.16 HP -- 175.09 T

Not doubting your assessment; it is just counter to the comparison that I found previously.

Didn't think to unplug the ECM to reset it after the changes. Will give that a go. Thanks!

 

The good side of the Trifecta Tune is there is no need to change the ECM. Just plug in the tuner, press 3 buttons and in it goes....

OOPs, Am I letting out my new secret....

 

Speaking of tuning and flashing your ECM. For visits to the Dealer is it easy to revert back to Stock tuning? And if so can't GM tell if the ECM had been flashed with another program previous to reverting to stock tuning?

 

Yes,the dealer can tell if you've been flashing. :-D