After all of the discussion regarding the removal of the center muffler and the high cost of some of the aftermarket kits available I decided a few weeks back to see what Exhaust Pros could do with a custom system from the catalytic converters back. Yesterday they installed my system. For much less than even the Mina system I had a custom 2½" system bent up with a custom H-pipe and 2 Flowmaster 40 series mufflers where the original rear mufflers were. The car has a nice low rumble and a fairly aggressive tone but is not too loud at constant speed. It might be a bit much for some, but I like it.

Here is the custom H:


Here is a view of the passenger side muffler and tip (car needs a cleaning again ):


Here are the new tips (ignore the fact the car is a bit dusty ):

I elected not to go as big as some of you guys have.

Here is a quick diagram of the system, green is stock, red is what I replaced it with. This isn't 100% accurate, but you get the idea:


My system is very similar to this one: With an H rather than an X and a little less cackle.

Update! New Videos:

In Car, Top Up:
Light Acceleration: Moderate Acceleration: Heavy Acceleration:
Driveby:
Light Acceleration: Moderate Acceleration: Heavy Acceleration:
UPDATE: 9/12/2011
I was cleaning the car today and I realized I've never been completely happy with the look of the exhaust system. The tips are great, but the pipes and mufflers are a bit too visible for my liking. They are tucked up like the were stock, so I decided to paint them with a bit of high temp, flat black spray paint. I also did the rear muffler clamps which were starting to rust.

BEFORE:



AFTER:




For $6 and about a half hours time, I wonder why I didn't do this sooner

 

That sounds great. The 'H' between the two pipes is exactly what I did and after 5000 miles, no problems with expansion and contraction. The sound is similar with stock mufflers, perhaps not as much rap but close.

 

Nice, so you only had two rear silencers to start with, not the ones before and after the rear axle?

How much did your 'custom' setup cost, just for comparison to other systems and a few of us who just hacked their stock one.

Good vids, I can hear the tone of the exhaust, but if the wind wasn't affecting the mic, it would be clearer and the volume better judged. Is that a twister behind you? (sarcasm as to the velocity of the winds during filming)

 

I had the stock system before this (5 mufflers). I replaced everything from the catalytic converters back with 2½" (rather than stock 2¼"). The H fits where the beginning of the center muffler used to be and the middle two mufflers are completely eliminated leaving the Flowmasters to sit where the back two used to. So everything I showed in the diagram in the first post is new.

The cost:
2 x ~$120 for the mufflers
2 x ~$ 40 for the tips
Total cost for parts, labor, taxes=$554.90

 

Stock is actually less than 2". Basic rule of thumb is that 2 1/4" is good for 400 horsepower and 2.5" is good for 500 hp. 2 1/4" should be plenty for the Naturally aspirated.

 

That's interesting. When I would hang around the Mustang guys they would say up to about 300 HP for 2¼" and around there and above go 2½" That's why I put 2¼" on my Cougar, which makes a little over 200 HP maybe that's because I was dealing with a 5.0L V8?

I also could have sworn that stock Jaguar was 2¼, but I could be wrong.

 

That's the same as I've done, I had the "H" slightly further back and had it done in 2 1/4" stainless. The old standard pipe was down to 1 3/4" in places!!!! also I personally feel that's it's best not to go too big for a mainly street driven car as I want to keep max torque in the low/mid range. The rear silencers are as Tony Banks fitted, the car sounds great, a nice deep rumble at low revs and acceleration, But! there is an annoying drone at 1500~1700 rpm which is usually easy to avoid on local runs. I drove up the full lenght of Wales last week and it got too tiring for me so I'm going back to Tony to have 2 more silencers fitted just before the axle. I've asked for very minimal extra silencing as it is only that one small part of the rev range that I don't like.

 

So is this all about the sound, or did you get any extra power by removing the center muffler?

 

sound and feel, whether or not it's appreciable in some calculator... IMO

 

If you are curious about just removing the central muffler and going without a crossover or adding an H or X pipe, check out this thread: https://www.jaguarforums.com/forum/s...ad.php?t=21246

Personally I found it a bit too mild and while I was going to be adding different mufflers and changing things up, I just decided to do the entire system.

I really liked the MacLoed X-pipe system (http://www.minagallery.com/jagxp/Jag...nce/X-pipe.htm) so this is partially based on that design, only an H rather than an X and Flowmaster 40s in the rear. I managed to do it for roughly a quarter of the price. It might not be quite as efficient as there were a couple of extra bends to get the mufflers I selected to tuck up right, but I'm quite happy with the result.

 

Sounds great! That system will outlast all of us!! I think your system is the way to go. It gives you the chance to pick the muffler that you want for the tone that you want. I also think that all of these cars should remove the before muffler resonators.

What systems are on the Aston's? They sound like a sports car and they are the sister to the Jaguar. The Jaguar doesn't have any sound at all. Not everyone wants to hear exhaust "noise" but there NO exhaust "noise" at all on a stock XK8/R. Every thing is too restricted.

An engine is an air pump, the more air that you can suck in the more air you have to blow out.

Good job!

 

Today I had 2 more silencers fitted just before the axle and the sound is perfect for me now, the silencers on mine are Longlife freeflowing (minimal silencing). I would say power increase is small, my car feels a bit more snappy now, like being in sport mode?? There is one definate difference and that is that the traction light comes on more during hard acceleration up to 100 mph in the dry. (I therefore assume more power??)
While I was experimenting with different layouts I found the car most sluggish with - H-pipe, standard before axle silencers and straight pipe at rears. Best was when I had H-pipe, removed before axle silencers and refitted the standard rear silencers!
I've just realised I'm in the XK forum, my car is a 2000MY XJR but I think they are similar enough.

 

How is the drone? I had a Charger with Zoomers Exhaust http://www.zoomersexhaust.com/
and it was great. No Drone on the freeway, sounded great around town

 

No drone at all. I am quite impressed. The system is barely more audible than stock at speed. Hopefully Monday or Tuesday is nice and I can take better videos.

 

^...without tornadic winds?!?

 

Hopefully! Looking at the weather makes me less than optimistic though and I will be out of town for a while starting Wednesday, so you guys might need to be patient.

 

Added/Changed some pictures in the first post. Better videos will have to wait a few weeks while I'm out of town.

 

New and improved videos added…at long last [see first post] I have a few more I'm going to add later.

 

WOW, that's much better at demonstrating your exhaust! thanks for taking the time to amend the originals.

 

Where are they - I am lost in the links! DaleD