Well, I was finally able to get in on the dyno for a few runs. The runs were performed on a Dynojet at Romar Automotive in Walden, NY. I arrived with the "installed by me" Magnaflow and that run is labeled as "Magnaflow1." We then switched back to stock, this is labeled as "Stock." The stock was then removed and replaced with the Magnaflow and it was properly tightened. Having the exhaust on the lift was way easier to properly tighten those clamps and also to make sure that the resonator hangers aren't rubbing. So, other than being quieter, it was a real treat to see it make more than the 3.2hp and 1.1tq put down by my leaky install! I was told that it's a common mistake to not tighten the clamps enough and that they need to be completed closed on the spacer inside the clamp.

So, the Magnaflow when properly installed got me 269hp/228/tq vs 260hp/219tq for the stock. Not bad for less than $500!

Note 1: The spike on run 3 and the weird dropoff after 6200 rpms is due to the auto which does not take kindly to dyno testing! Even in DS mode and paddle shifting with the VCM off, it would still throw an upshift to 5th right at 6500rpms no matter what. Therefore, ignore the graph after 6000 rpms and no, I didn't get 274.65tq. The real figures for torque I had printed out due this anomoly are 219 stock, 223 leaky Magnaflow, 228 proper Magnaflow.

Note 2: Run conditions were between 74 and 75 degrees with a humidity of 29%. All runs done in 4th gear.

 

Nice!!! Thanks for doing this and posting up, IronChef.

 

Thanks for the info!

 

thanks for helping out!

 

Ironchef, thanks for doing this for all the magnaflow guys, and those that are considering Magnaflow. I'm surprised your clamps were still loose even after u re-tightened with the deep socket you got, didn't u tighten them to the point where there was no gap in between the clamp and that piece in the middle of the bolts?? How the heck much tighter can they go?? Any other suggestions on what we can do on our own to get these clamps tight enough, I'm sure mine are not tightened enough if yours weren't.

Anyway, nice numbers and that's not even meaning nice numbers for the price we paid, because those numbers would be considered solid even if we paid 1k for this system. It seems the in house dyno u posted last week was right on the money, without a doubt Magnaflow and Hottexhaust.com FTW!!

 

Good Job bro...

 

thanks for posting the personal dyno

 

Well, I had the clamps at the tips and where the resonator meets the muffler perfectly closed. But the ones at the x-pipe were not as tight as they should be. Seems that me laying on the ground and thinking I had them tight was not good enough! The rears I could see because I jacked up the car from the rear. But those other ones were only half closed. Big duh on my part! As long as you can see that it's closed, you're good to go. Don't do what I did, get it done right and you'll be fine!

 

awesome!!!! great comparison!! u make me proud!!

 

thanks a bunch for posting! i'm ordering mine really soon!

 

If you could get it to the all the way to 7500rpm
you might had much more hp gain isnt it?

 

Power drops pretty quickly after 6500-7000 rpms on my auto tranny G37. Perhaps with the manual?