there is no drone while cruising with a IMCO T924 on a HHR and it is only a little loud when you first have it installed. after a few weeks it is only throaty when you put your foot in the throttle.

there are sound clips of a couple HHRs with the 924 on it and you can find it if you do a search.

my daughter has a cobalt and it had the same stock muffler on hers that the HHR comes with. it has this drone with the OEM muffler between 70 to 80. we put the T924 on her cobalt with a 22 in it and it works better with her Cobalt than with the HHR. the really cool this is the drone is gone and the Cobalt is actually quieter overall and especially at cruise.

i can tell you that w 2 different cars using the same 2.2 engine and T924. the muffler is a winner.
all you have to do to find out is get one your self

 

You could stay on my good side Joe - if you could ever get anything right.

Link to testing: Testing Video

We tested HHRs back to back, on the same runs with the IMCO against stock. There is a definite improvement. Additionally, we tested Magnaflow and Flowmaster mufflers and they didn't get past the "fall-flat-on-your-face-the-first-time-you-drive-down-the-street" phase of testing.

Bottom Line: the HHR engine likes to see a certain amount of free flow + back pressure to produce power. The IMCO provides it.

End of story.

 

Murieta Raceway? I know exactly where that's at!

 

EZ... dyno figures showing increases through the whole rpm band is what I was after as well. NO ONE's released charts, not even Mike. I'm not really sure why that is, but, seeing that he footed the bill- he's got every right to do what he feel's is best with 'em.
On the other hand... I guess I should have clarified earlier... the ~8hp gain previously stated was *with* Mikes mod's (synth's, muffler, stickers AND the CGS INTAKE). I too wasn't overly concerned with top end #'s - but since I don't have the extra flow to throw around, beggars can't be choosers.
If you have access to a (cheap) dyno to do before and after pulls ---> !!! BE SURE TO POST THE RESULTS!!!
If not- completely understandable. I'm in total agreement ... net hp gain of just the muffler itself may be 2-3hp max.

 

From what we can tell (my car was never dyno'd stock vs. the IMCO), the muffler gain is 3-5hp max. If you are a sensitive driver, you will have no problem feeling the power improvement when going from stock to IMCO. The HHR breathes easier and pulls right off idle stronger than stock. I would imagine torque increase is closer to 5ft/lbs.

Of course, anyone here is more than welcome to take their stock HHR, dyno it, then add the IMCO and dyno it again. At $100/hour for the dyno we use - all to get "figures" for a muffler swap, I have MUCH better things to do with my time and money!

As I've said previously, Both in my personal automotive life, and during my career as a magazine editor, I have swapped and dyno'd hundreds of mufflers and exhaust systems and not only seen, but felt the results firsthand. Once you get that kind of experience under your belt, it's pretty easy to tell by changing mufflers and doing some timed runs down the street whether the new muffler is helping or hurting performance.

Let's put it this way, Gibson called me 3 weeks ago to take my HHR in for a full Cat-Back install for free and I declined...why would I do that? Answer: a) I can't stand the "ricey" sound the current cat-backs produce, and b) I'm quite satisfied with the performance I'm getting from the IMCO setup.

And yes I understand my saying this online might "hurt" my cat-back sales, but that's how I feel about it.

As usual, most of those with negative comments about the IMCO's benefits don't have them on their HHRS! (I mean really...c'mon, buck up, make the $50 investment and THEN come down hard on it!) I'm sure most any HHR owner who does have the IMCO installed will sing it's praises easily.

Hope it helps,

 

I hope that wasn't directed at me simply for asking if anyone had a dyno sheet??? I'm curious that's all, and no where did I make a negative comment about it.

 

Nope, not towards you at all. Rather some old members who just love to beat a dead horse. Try the IMCO though - you won't be disappointed.

 

I don't think anyone has? I called it cheap but I was just referring to the price because it is cheap compared to most high quality mufflers like Magnaflow, Borla, or the like.

 

That's just a general statement. We've been down this road before with not only the IMCO, but the intakes as well. All he is really saying is that it is not cost effective to have a dyno test done for a muffler that sells for less than $50. It's counter-productive and money that could be better spent on research and development of other products.

Each person who installs this muffler is going to draw their own opinion, based on their driving style. It's an inexpensive mod and those of us who have done it are pleased with the sound and performance. You should try one...and if you don't like it, you can put the old one back on and list the IMCO here in the classified section. I'm sure there are lots of people who would snatch it up in a heartbeat.

Bottom line...try it...you'll like it.

Signed...a very happy HHR owner with an IMCO T924

 

I don't think anyone wants to buy a used muffler? If you try it and don't like it you're probably better off tossing it in the garbage.