Not to sound like a jerk but I highly doubt swapping just your muffler to a cheap muffler is going to get you 8 HP on our tiny 4 cylinders. 8 HP is what both Gibson and Magnaflow are claiming for their entire cat-back systems I believe.

 

I agree with CH, there no way you can get 8+hp by just swapping a muffler.

 

Thanks Scoot! Yes, I don't want to start a flame war by any means. I'm just real curious and cautious, and it sounds like you've been in my shoes before having OEM perform better than aftermarket, so I'm sure you can see my concern.

Scoot stated that was with different intakes as well. I will search for the thread when i get a chance.

 

i got one of the first ones and i love the sound and there is no way there will be a 8 hp difference w a muffler but i will tell you that 1 to 3 might be more like it. the OEM does not perform better than the Imco T924

doesnt matter to me. these are facts with the IMCO T924
1. less weight- several pounds less
2. wonderful low sound
3. more pickup than before hands down
4. about a 1 around town and 2 on the highway mpg increase

for me the sound alone was worth the money to change it out. mine was $89 installed total.

 

Bottom line is, adding the IMCO T924 is something a great deal of people are doing. It's not going to turn our HHR's into rockets by any means, however, in my opinion, it sounds much better than the stock muffler and I can feel the increase in power after having it installed. For less than $100 you can buy the muffler and have it installed and hear and feel the difference yourself. Dyno numbers or no dyno numbers, those of us who have installed the T924 are very happy with the sound and performance.

Appears to me we are once again
But just so I can hopefully satisfy the curiousity of some...please read below.
Hopefully, this is not opening up another

I belong to the other forum as well and found this information over there that was posted by Mike from SoCalHHR's. Not nearly as many posts to search thru over there.
Hopefully this should clarify some things.

MY HHR has been dyno'd 5 times now to prototype various HHR parts. With the change to an IMCO Turbo muffler and synthetic oil I am putting out right at 180hp (crank), compared to stock FW figures.


My claim of 180hp at the crank was just that - a claim. But never for a "stock" motor. Here's how we arrived at the number.

Stock 2.4L engine = 172hp + Mobil 1 Synthetic = 3hp, + IMCO Turbo Muffler = 5hp (minimum). Total = 180hp (crank).

Having modded cars for the past 34-years, and having changed and dyno'd hundreds of mufflers (as an automotive magazine editor for 20 of those years), I'm giving a conservative estimate with the benefits of the IMCO muffler. We have tried several mufflers here and found the IMCO T-924 provides the best combination of flow and back pressure the HHR's Ecotec engine likes to see. It's long been accepted in tuning circles that a switch to synthetic oil can net you an easy 3hp just from friction loss, so perhaps now you can see where my numbers came from.

We're not selling any snake oil here - just ask any of the members who have installed the IMCO muffler. Many had already tried other brands and can vouch for the superior driveability the IMCO offers. It's not the answer to a full cat-back system, but instead is an affordable mod which gives a modest power increase at a budget price. For the guy who can't afford a cat-back now, the IMCO will improve power while sounding "deep & throaty" rather than "ricey." It's a great entry-level mod that sets your HHR apart from the rest.

BTW - I don't sell them, but rather refer owners to a site that offers a good price on them.

 

Thanks CourtHouseDeb. I know this thread wasn't supposed to start a flaming war, and I hope it doesn't, but I'd like to see an actual dyno so I can see where the hp and tq increase is and at what RPM. I'm not concerned so much with peak numbers as I am with the results of the entire range.

The hp "guess" you quoted is what's referred to as ricer math, and I don't believe in it.

If it was only sound I was looking for, then yes, I'd probably be out in my driveway right now installing one of these.

Who knows, maybe I'll be the one to buy one AND get a before and after dyno to share with everyone.

 

SoCalHHRs: "We have tried several mufflers here..."

Link to "testing": http://www.socalhhr.citymax.com/imcomufflerinstall.html

 

It is possible to dissagree without being disagreeable! You guys are doing great!

 

If Sindy's comment about "disagreeable" was aimed at me, it wasn't meant that way. Just pointing out what was stated and what is on the web site.

EZ, the sad fact is that there are no valid numbers that I've seen on the IMCO or any other muffler, whether on a dyno or strip. And how accurate are any manufacturer's claims?

No doubt, many here are happy with the sound and price of the IMCO.

One factor about the sound issue is that if it is too loud there can be an annoying drone while cruising. It can be especially bad in a wagon-type body like the HHR where the back is open.

On the HP issue, until someone can substantiate numbers, I would question any statement. My guess is that if there is any gain, it would be minimal. On the 2.4 the exhaust is 2.25", which should breath pretty good. There are other areas where real HP gains can be made.

In the meantime, go for the sound or the looks!

 

My comment was not aimed at anyone. It seems that although there are varying opinions, everyone is remaining peaceful about it. I have seen other dissagreements that have gotten way out of hand.
I was making a compliment to everyone for stating their opinions without getting nasty about them. (Unless I missed something somewhere.)