For several months now I have been running LTs and high flow cats on my LS3 with the stock catback. At first I was very happy. But over time a few things bothered me:
- At high RPMs there was a very loud slapping sound.
- The LS3 deacceleration pops were very loud
- Overall the sound was raspy and somewhat high pitched.
After listening to many sound clips and other Camaros and Corvettes I decided to make a change. I would add an axle back system and get rid of the giant cans.
I did not want my exhaust to be overly loud and definitely no drone. With LTs you have to be careful if you want to keep the volume low. I enjoy long trips and not waking up the neighbors and my dogs late at night.
So i researched and listened to more clips. At the end I chose the MagnaFlow Street series Axle back. This system is reasonably priced and came highly recommended. The other axle back I considered was the Borla Touring which is also the street GMMP axle back. I chose the Magnaflow because I could find it cheaper than the Borla.
So I ordered it. Several days later the box arrived. The installation went smoothly. I was afraid to cut my mid-pipes too short so I made the first cut with the Sawzall close to the mufflers. Then I mounted the muffler with the extra connector pipe so I could mark the exact spot to cut on each side.
I used lithium spray grease on those pesky rubber connectors to make things easier. Then I made the last two final cuts and put on both mufflers and connector pipes. After that I went to the back of the car and made sure both tips were in the right spot and evenly matched. Finally I tightened down all the bolts.
Fitment was perfect and all the parts looked high quality. The only tight spot was on the drivers side where the pipe came pretty close to the BMR sway bar grease fitting.
After starting up the car I loved the improved sound. Much deeper and less raspy. THen I took the SS out for a long drive to visit my aunt and uncle out by the Mullica river.
- The MagnaFlow Street is perfect for me with the LTs.
- Great sound all through the rev range. The slapping sound is gone. The MagnaFlows are a bit quieter at full throttle.
- The deaccelertion popping is still there but very muted. Quieter than the stock exhaust without the cats.
- My gas milage seemed to improve a little. I was seeing a 33 mpg average going 55 on a flat road. I never saw numbers like that before. Is this possible? (Edit: Now that the computer has adjusted to the change the milage is back to normal LS3)
- The car seems a little slower. Maybe this is just beacuse the MagnaFlows are a bit quieter than the stock catback at full throttle. Hopefully this is just an impression. (Edit: After a few drives the fun is back!)
I recommend the Magnaflow Street series for anyone who wants a great sound with LTs while not making big noise.