Merc63

Can I use a welded in H pipe to take out the resonator? Or should I just do straight pipes in replace of it?

OR, do I really need an X pipe?

BerBer63

Straight pipes will add to the throaty sound. X-pipe is going to tone down/smooth out the sound you already have.

Stock resonarot are 2 straight through pipes with some baffling and perforated holes in the piping.

If I would do it again just go straight pipes.

Dads C63

Merc63,
The resonator is your crossover. See pic below. It has a small tube from one exhaust bank to the other to balance the two. You either need to keep it,which I recommend, or put an X-pipe in place. I do not recommend replacing it with two separate straight pipes. They are already straight pipes with small holes on each side for sound reduction in the cabin. Be careful with the exhaust. Its well tuned from the factory.

mthis

I replaced mine with str8 pipe. It just loud but it fine.

nrgy

What is your personal recommendation as far as exhaust tuning goes, as you seem to have quite a bit of experience with it on the C63? I'm assuming LT headers are going to net positive gains as has already been demonstrated. It seems the stock resonator/H-pipe however is quite good and can be left in place. Is it worth bothering with the cats...2ndary or primary? Thanks.

veightkiller

curious to hear what this sounds like

Dads C63

For ultimate performance I recommend L/T headers, high flow front cats, and delete the rear cats. I would leave the resonator and rear stock exhaust in place. This is the set up I will go with as soon as MHP has it available. My MKB short headers produce the same amount of RWHP but falls short on the torque side which can only be achieved with L/T's. If you can live with the noise level a full 3" exhaust will produce the best results with this cube engine. Thats my suggestion based on my experience. Good Luck and have fun racing.

Sincity

That small hole looks like the same diameter as the H-pipe portion of the Renntech Sound Pipe.

Merc63

Yep. I've learned that the resonator wont do anything for performance, its basically to cut down on resonates in the cabin.