Even tho these have that little dongle (or what ever its called) for the 02 sensor

 

The rasp is caused by differing exhaust pipe diameters. Most test pipes and HFC's use a 2.5" pipe. Being mated to a stock Y-pipe which is only 2" will cause rasp (bigger opening going into a smaller one isn't optimal). Swapping to an aftermarket y-pipe will have 2.5" inlets, but has a 3" outlet; the stock mid-pipe is just under 2.5". So same problem.

I saw a thread where a guy had a cone shaped adapter inserted into his megan y-pipe that tapered a 3" to 2.5" transition. Supposedly got rid of all rasp problems.

 

Ill be running it with a HR Y pipe not sure what the dimensions are on that.

Also what would be the pro and cons from not having a portion of the honeycomb inners on the HFC

 

Mine do not hiss, but once the factory muffler section went back on (after there was a Magnaflow), the rasp returned mildly. I put up with it because mixed with the other add-ons the car has, it is too fun of a car to drive to be bothered by the little bit of rasp I hear.

 

Do you guys know if Motordyne HFCs are prone to breaking early on like other HFC's are?

 

Due to their location further away from the engine they don't fail because they run much cooler than regular HFC's.

 

Ill be running it with a HR Y pipe not sure what the dimensions are on that.

Also what would be the pro and cons from not having a portion of the honeycomb inners on the HFC

 

From what I've read Motordyne doesn't make HFC. They just offer a HFC adapter to go with the XYZ pipe. If you're looking for quality HFC I would go with fast intentions have heard nothing but good things about them.

 

The HFC module for the XYZ pipe is indeed a HFC and is more reliable due to lower operating temperatures. Never a single failure for all the hundreds of units in use.

 

the art pipes sound pretty good with almost no rasp, i personally am getting the resonated megan test pipes but they are still to come in i will be posting a video after i get them

 

I had major rasp/hissing with my art tp and ark grip exhaust combo. Decided to buy an MD TDX2 exhaustand now all my rasp/hissing is gone. Best combo!

 

Can you elaborate on this, please?

 

When installed the bolt sits fairly close to the heat shield. If the end of the bolt is sheared off it will eliminate any issues.