Well,

I've been struggling with the Mac Performance dual exhaust kit (MAC P/N TK2625) I added to my 'vert for several weeks. The exhaust sounded really good in general, but there was a BIG problem with drone/booming between 2100-2500 RPM. This was so bad it was nearly impossible to listen to the radio or carry on a normal conversation on highway trips, and turning the radio up just caused weird effects when the sound would go into and out of phase with the sound emanating from the exhaust.

A call to Mac Performance asking to speak to tech support (they didn't even answer emails) resulted in a conversation with a very young sounding and unknowledgable person that we'll call "Skippy" for the purposes of this discussion. I carefully explained the situation to "Skippy", including describing what parts were included in the kit THEY sell, and how they're hooked up, as he had no clue His only suggestion was the exhaust MUST be hitting the frame somewhere. I assured him that I'd checked that carefully, and rechecked after the problem was noted, and NOWHERE was their exhaust system touching anywhere other than where it was supposed to (i.e. at the pipe connection up front, and the rubber isolated hangers out back). "Skippy's" attitude at this point became "not our problem, take it to a shop, maybe they can figure it out". :angry:

Anyway, it's been raining steadily almost every day up in the Northeast lately, so I let things slide until we got a semi-beautiful day today. This morning I decided I was going to haul out the GT takeoff mufflers I had in the garage from back when I bought my body kit from Casco. 45 minutes of wrench spinning later, the Mac mufflers were off, and the GT mufflers were in their place connected to the MAC piping.

A long test drive revealed normal/acceptable noise levels, and no notable droning at all. Given this situation, and the poor response from MAC, I'm just posting the experience so that anyone considering the MAC kit has the info to make an informed decision.

My guess (and this is just a guess mind you) is that MAC may be using the same mufflers they developed for the GT in this kit. In talking to two different exhaust system designers in the past week or so, both of them were very clear that mufflers developed for the GT would be a very hit-or-miss affair on the V6. They might sound fine or even great, or they might produce major negative sound issues due to the different pulse pattern, resonance characteristics, flow volume and heat production of the two engine systems. One described it basically as "Russian Roulette" getting a design that was happy on the 4.0 My own personal experience leads me to believe the MAC mufflers are not in the "happy" category.

The end result is I'll be leaving the GT takeoffs in place. They're maybe a bit more "refined" than I'd like (I enjoy a moderately aggressive exhaust) but at least they're not going to cause neurological damage should I decide to hit the interstate...

 

That is most unfortunate, now that you have the piping in place...maybe you should put some Flowmaster 40's on. I hear they are quite aggressive. Perhaps you can send the mufflers back to MAC and get a partial refund...I would give that a try.

 

Past experience doesn't really encourage me to bother talking to MAC again. I'll probably just sell them off (if I can find someone with a GT who's interested). The car will be going into semi-retirement until Spring soon, so I'll probably just leave the GT parts in place until then at least.

 

darn... sorry about the sour experience. I cancelled an order with MAC just because of their terrible customer service... went with JBA and have been very pleased.

 

Yeah, I have to say calling their Tech Support dept, and getting handed over to a kid who didn't even have a clue as to what their product included shocked the heck out of me. NOT the way to impress a customer.

 

i had a MAC single exhaust on my six for about a month and couldn't take the droning anymore. the car sounds great when idling, but once you put down the gas, your ears are either gone from the droning, or your girlfriend yelling, "geez, could it be any louder?"

i opted for the GT takeoff single. very happy!

 

Now just imagine that X 2 :bang:

 

Wow, thanks for informing us as I was considering that setup. Your first thread on it got me pumped. Finding the ideal direct bolt on duals may take a while. I wonder if they would make a deal on selling their piping so finding the perfect mufflers is on us

 

I will say the quality of their piping is actually quite good. I'm not sad to have their plumbing under there at all. A kit with just the pipes would make excellent sense. The clamps they use are kind of cheesy though. I had one strip it's bolt threads (and I was being careful using a torque wrench). The Ford clamps are much better, but the dealers charge through the nose for them (like $20+ bucks apiece if I recall)

 

Flowmaster 40's For the Win! Hehe.. just my 2cents. Sorry to hear the kit didnt work out like you wanted, Ive never personally liked the sound anyway. Too ricey at times for my tastes. G'luck in the future.