It is finally time to make the Growler growl a bit. I am deleting the primary resonator and replacing it with a crossover pipe. I will record the before and after results and post them here.

 

Looking forward to hearing the modified exhaust. I've got a 2004 XKR, same color, that should probably growl a little louder....

 

Been researching this and found the following info on H vs X. I going with the H....

X-pipe: Mid-pipes built with a crossover, or "X" shaped design, purposely cross exhaust streams to even out flow and streamline exhaust gasses through the rest of the system. X-pipes are generally raspier and louder than H or Y-pipes and have been shown to provide slightly more power than their counterparts. You are likely to see most of the power gains higher in the rpm band with an X-pipe.

H-Pipe: An H-pipe is better at balancing sound and produces a more consistent, classic muscle car growl. It does less than an X-pipe in the way of balancing exhaust gasses but still flows quite well. H-pipes maintain the back-pressure necessary for torque gains earlier in the rpm band, as opposed to the top-end power seen from an X-pipe.

 

Just got back from the shop (Audio Advantage in Prescott Valley, AZ). I am pleased with the result. It is more vocal without being too shouty.

 

Did you keep the rear mufflers? How does it sound during non-spirited drives at say 50-70 mph?

Whose X-pipe did you use? I have a very short x-pipe compared to your much longer unit.

 

The sound is very mellow under normal acceleration and cruising conditions, just slightly louder than the stock exhaust. It perks up very nicely under hard acceleration and at RPM's over 3000. with just a hind of overrun when you lift off. Prior to the mod I could not hear the exhaust with the top down, now it is at a very pleasant level. It can be heard but it is not obtrusively loud. I have to find a tunnel...
I kept the other resonators and mufflers in the system for now. I did not want to go too far. I may change that later.
The X-pipe was custom fabricated, as I wanted to maintain the system dimensions to make it easy to return to stock. As an added bonus the car is 15 pounds lighter with out that big resonator under it.

 

I like the sound of the modified exhaust--not too loud but beefier than the stock. So a couple of questions. Obviously the middle muffler is removed and replaced with some piping (X-configuration or H-configuration). Are these pieces readily available from somewhere or do the exhaust shops fabricate them? Also what is the total cost of doing something like this--I would guess a few hundred dollars?

Thanks,

Doug

 

The pipes I put in were custom fabricated by the shop. It cost $140.00 out the door. There are several firms offering components for the XKR and XK but the ones I saw were way more expensive than having it custom built.

 

Excellent CapnPete,
I think I will take your pictures and head to the muffler shop next week.
Bonus 15 pounds, I won't have to give up Pie.