Dropping the car off at Magnaflow next Monday
Thread Starter
Senior Member
Joined: 06-26-2008
Posts: 164
From: Corona CA
Got the car back last night.
Car made 250whp 249wtq sae on there dyno jet stock (1200miles/4th gear).
3" Catback made a tad over 7 whp
3" Catted down pipe (single cat) made the same
Together the car dynoed at 265 whp 269 tq
In my opinion its a tad loud (I don't like loud) with both peices installed. We are gonna do a 3" core resonator in the same place as the factory peice to try and make it a little quieter.
Car sounds good...nice tone
You can feel the extra tq
I think there is more to be had but the computer is gonna fight you all the way. The new PCM seems to adjust boost accordingly. The car actuually picks up power when the engine temp is at 200(compensates for heat with boost).
I think with a tune the car will make 300+ whp with DP/CB
I hope to have pics and dyno graphs later today(waiting on email)
Car made 250whp 249wtq sae on there dyno jet stock (1200miles/4th gear).
3" Catback made a tad over 7 whp
3" Catted down pipe (single cat) made the same
Together the car dynoed at 265 whp 269 tq
In my opinion its a tad loud (I don't like loud) with both peices installed. We are gonna do a 3" core resonator in the same place as the factory peice to try and make it a little quieter.
Car sounds good...nice tone
You can feel the extra tq
I think there is more to be had but the computer is gonna fight you all the way. The new PCM seems to adjust boost accordingly. The car actuually picks up power when the engine temp is at 200(compensates for heat with boost).
I think with a tune the car will make 300+ whp with DP/CB
I hope to have pics and dyno graphs later today(waiting on email)
Thread Starter
Senior Member
Joined: 06-26-2008
Posts: 164
From: Corona CA
http://www.magnaflow.com/04sound/04sport.asp#chevy
scroll down to the HHR section and click on the video. It has one launching and doing a drive by.
I would expect it to be a tad quieter once finished.
(gonna post pics and dyno graphs in SS section in a tad..just got info)
scroll down to the HHR section and click on the video. It has one launching and doing a drive by.
I would expect it to be a tad quieter once finished.
(gonna post pics and dyno graphs in SS section in a tad..just got info)
New Member
Joined: 06-26-2008
Posts: 19
From: Temecula, CA
Sounds good. I can't do loud inside though. I'll have to hear it for myself when you get the 3" cherry bomb installed 
Was that your car in the video clip? I wasn't able to tell since I couldn't see the monster size front license plate holder and rock chip
Was that your car in the video clip? I wasn't able to tell since I couldn't see the monster size front license plate holder and rock chip
Thread Starter
Senior Member
Joined: 06-26-2008
Posts: 164
From: Corona CA
If you get anything it's gonna have a whistle tip
Thread Starter
Senior Member
Joined: 06-26-2008
Posts: 164
From: Corona CA
Info/pics and dyno charts now listed in SS section....
https://www.chevyhhr.net/forums/hhr-ss-45/magnaflow-catback-down-pipe-prototype-16643/
https://www.chevyhhr.net/forums/hhr-ss-45/magnaflow-catback-down-pipe-prototype-16643/
New Member
Joined: 06-26-2008
Posts: 19
From: Temecula, CA
Thread Starter
Senior Member
Joined: 06-26-2008
Posts: 164
From: Corona CA
Nice thing is eventhough it's loud there isn't drone
Senior Member
Joined: 08-18-2007
Posts: 602
From: Warrington PA
and if you feel it's quiet enough after they make the change, that works for me....