2 1/2" Mandrel bent Aluminized steel tubing.
My order arrived much faster than I expected! The packaging was really solid, and it came with clear, easy to understand instructions (with pictures on the back even). I'm not a mechanic by trade, so my wife's cousin helped me install it. It took us about an hour and a half. They sound amazing! The start up has a fantastic growl, and like some people said, there is a drone at certain rpms (around 2000 rpm on highway) but hey, it's a muscle car not a Prius!
I was excited to get my BB resonator delete kit... It arrived quickly and had easy to understand instructions.
At idle, it sounds beautiful, when manually shifting gears it sounds fantastic and when manually down shifting it's a thing of beauty.
Drone does occur at certain times but once you get to cruizing speed, you hardly even notice they are there.
Only one problem I've noticed is that I'm getting alot of backpressure when I take off slower and it seems to choke the engine a bit... I've not driven with them long enogh to narrow down the specific instance.
I don't know if this issue is related to the MDS but I only feel it when running full auto... I do not feel this when paddle shifting.
Overall, this is a good solution if you don't have the money to throw a full cat back system in.
After looking at everything exhaust related and listening to YouTube examples of what they could do I finally decided to bite the bullet on the BB res deletes, figuring that if I didn't like the sound I could just ebay them off and get a cat-back or something else later. Did the self install, turned the engine over and was greeted with a velvety smooth rumble. Damn these things sound fine. My car now has the growl and snarl of a classic Hemi, and cruising round town sounds like a ticked-off Incredible Hulk huffing under the hood, ready to thump someone he doesn't like. The drone is definitely there when cruising on the highway, but it's controllable by finding the right rev range. And to those thinking of buying these but worried that they might not be able to do the installation, well, I'm a mechanically challenged college professor so if I can pull it off, I'm pretty sure you can too. Hats off to BB for making these things. Simply a ten out of ten from me.
Went back and forth for a while on whether to do the full resonator delete. Definitely glad I went for it! Has that classic Hemi sound now that the car always deserved. As many have said before, it's a small price to pay for a great mod to your car. Has a deep rumble from 2-4,000 rpm and then between 4,000-6,000 rpm it has what I call the classic HEMI rasp - it definitely turns heads. Again, if you like your windows down and hearing your engine roar this is the kit you're looking for.
Truly an awesome product. Great sound for a very small price. Installation was a breeze. It literally took 45 minutes from start to finish with nothing more than a sawzall and a couple of sockets.