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More info to follow.....

 

More infooooo including a youtube video please!

 

Did you take out all the resonators or only the center one? How does it sound??? Going to have my center resonator taken out on Monday and replaced with an X-Pipe for more performance and a bit more sound. Curious of your impressions. And is it still 2 1/2" all the way back?

 

If going to put in X pipe, put it as close to the catalytic converters as possible. You will get no benefit what so ever the further down stream you go.

 

Hi, The secondary cats have been removed from the housing, the centre silencer has been removed and replaced with a proper X pipe and the rear silencers have had the passive valves removed.
I have video footage and db readings of before and after, just got to get round to editing it and uploading to youtube.

It is 2.5" all the way through now, the stock system internal diameter ranged from 2.1" to 2.4" at different points along it's length.

Andy

 

Got my X-pipe done last Monday. They removed both resonators under the cover. Took a long trip over the Christmas holiday and have some impressions.

1. I think it's actually quieter at steady state cruising and I don't think it's louder under WOT, which I wasn't expecting.

2. It took most, if not all of the decel popping out and has made the sound REALLY smooth. I like this a lot and I might actually look to change the mufflers now to get more of the sound I was originally looking for.

3. It sounds slightly louder when I'm going slowly in a parking lot or under trailing throttle while decelerating and the car is downshifting. Sport mode is also just slightly louder than stock but sounds so much cleaner.

4. Car feels much smoother all around. Seems like throttle response is crisper - maybe the better pull through and scavenging at work? I drive in D with Dynamic Mode on most of the time and it does feel better to me.

Should get a new dyno number when I take it in to get my pulley installed and maybe a custom tune (depends on what I can expect to gain and the amount of investment). I'll know more in about a week and a half.

 

Kyanite / Craneboy:

I have a 2011 xfr and just did k&n, pulley, tune and now I'm ready to make some exhaust modifications. I had a couple of questions...

I'm leaning towards removing the secondary cats (which does not include any sensors), removing the center resonator and replacing with an x-pipe while retaining factory mufflers.. Here are my concerns and or questions:

1) the dreaded back pressure / exhaust velocity rate. I'm wondering if anyone has noticed any drop in low end tq?

2) did anyone notice any increase in performance (butt dyno is better than no comparison!)

3) it seems like the x-pipe will smooth out sound (less popping / crackling?)

4) I believe you kyanite but I'm surprised that there is really no increase in exhaust sound? In the Mercedes 63 AMG's the same setup increases sound while giving it deeper resonance. I'm guessing that could be the difference in s/c and na?

I will write a full review of my eurocharged ecu tune / pulley I had installed when I have a little more time if anyone is interested.

My goals for exhaust mods are just to free up a little more hp (at an acceptable ratio of possibly losing low end tq), a little deeper/louder sound but not anything as loud as most of the cat back exhaust systems I have seen or heard.

Thanks guys and I will post results with whatever I decide to go with.

 

Hi, I'll try my best to answer your questions/concerns -

1) No drop in low end torque whatsoever - See 2

2) My car was dyno'd before and after within a day of eachother on the same Dyno Dynamics dyno and the exhaust gave +10 Bhp +20 lb/ft. Bear in mind not too many miles was put on the car after the exhaust was fitted so the car may have been adapting the fuelling to suit still.

3) The X Pipe does ever so slightly take a touch of the popping away. The sound is a lot smoother.

4) It has definitely increased the volume of the exhaust, but not by that much. It's given it a sound that's more suited to the car. Also, because I chose not to change the rear cans I get non of the drone that some others have complained of when they go for AN-Other aftermarket exhaust.
Cruising, you'd not notice any difference, but the moment you apply some throttle you notice the sound more.

Please note though that I have removed the passive valve in rear cans as well (I notice you did not mention you were going to remove).

HTH

Andy

 

Here's some pictures of the exhaust build -

When I finally figure out how to edit videos properly I'll add the sound meter video

 

 

That sounds like exactly what I'm wanting out of the exhaust! I am going to attempt to duplicate every thing you did with it, I wish you had it done in Texas so I could go to the same place for the work!

How did you remove the passive valves in the rear can?

What is the guy holding in the 2nd picture? Sorry, I have zero experience with exhaust - only engines.

Are you planning or have you already done the pulley / tune?

 

Lonestar:

1) I haven't had mine on the dyno yet. Should happen next week but no actual numbers yet. Don't expect much though, but wanted to take the decel popping away, which it's done a wonderful job of. Would have liked a bit more volume though.

2) Again, hard to tell. The feel/character of the engine has changed for the better, but not sure about power. Was playing around with my buddy with a stock, except for mufflers, 08 GT500 last week and he couldn't pull on me anywhere in the powerband and most of the time I gained ground on him. My other friend has an 11 S/C XF and it just barely pulled on the GT at the top end. I didn't have any experience before the x-pipe with him in my car though so don't know if there was any loss or gain.

3) It definitely takes out a lot (almost all) of the popping in my configuration. Craneboy's modifications were a lot more extensive though and that might be where the popping was reintroduced. More on that below.

4) Like I said, it's a little more aggressive in certain situations, but still very subtle. I doubt anyone would guess I'd done any exhaust modifications at all if they didn't come from one that didn't have the x-pipe done. They would notice a difference in sound character, but not perceive any more volume except in the three scenarios I describe below, and then only slightly. My muffler guy said that larger pipe equals more resonance (deeper tone and increase in sound) and that the x-pipe will take out a lot of that resonance. Not all, but more than half. Craneboy's exhaust tubing is obviously significantly bigger from the photo he posted. Craneboy also took out the secondary cats and I have no idea how much sound that would put back into the mix. I took a ride with AJMarton with his stock setup, except for the Mina exhaust, and I felt it was far too loud for what I wanted. Also had a lot of decel popping. It was fun, but not something I'd like to try to talk on the phone over or hear over 4-5 hours on a trip. So I'm very sensitive to the sound but I barely hear it unless at very low speeds, decelerating or in sport mode. I also still have the valves in the mufflers, so that might be keeping things more subdued than Craneboy's. I'm also wondering whether the center resonator adds a lot of the decel popping sound on purpose? Maybe it's Jag trying to make it sound meaner than it actually is and trying to get the exotic sound but still pass sound testing? I know S/C vs. NA can change sound, but have no idea how much that is a factor.

I would definitely be interested in learning more about your impressions of your tune and pulley. I have one of their pulleys that I'm having installed soon and have a local company looking to do a custom tune. The question is what he can change with the Jaguar software. Will know more next week on that as well and will share as soon as I can. Hoping to unlock the fuel portion which should give us a lot of options.

I'm really curious about the valve delete on the stock mufflers. That might be my next move. I really like the tone and character of what I have now, I'd just like it to go from a 1-2 volume wise when I'm freeway cruising to a 3 at most (on a 0-10 scale, 0 being can't hear it and 10 is too loud for anything but a track car). Then go to a 6 or 7 when I'm on it hard instead of the 4-5 I have now. Don't need it to sound like a muscle car, just a bit more exotic sounding and to be a bit more engaging when driving hard. It's almost scary now how mellow it is when it's really going way too fast for the street. I punch the gas, hear a little intake/supercharger and exhaust noise, then I'm going 110-120. And as you all know, that takes very little time at all. In my friend's GT500 (with Flowmaster GT40's - drone is horrible BTW) you can get up to about 80 and you feel like you are doing something. I always put exhaust systems on my motorcycles, as I think it actually keeps you from going as fast because the audio is engaging and gives you more feedback. But I don't have passengers or talk on the phone on my bike. So different priorities for the Jag.

 

Took the words right out of my mouth!

 

The passive valves were removed by grinding the external part of the valve away to expose what's on the inside. It's easy to see what's in there and all the parts that were removed are pictured here. Its a lot more simple than it may sound.

My welder is holding the std slip joint from cats to centre section, this measured 1.9" at its narrowest part!
The system is now a true 2.5" system from front to rear. That's the other pipe he's holding just for comparison.

I am planning pulley and tune, but no-one here in the UK seems to have the software to perform a true custom tune (despite what they may advertise). Options and people are being contacted in Germany to see what can be achieved.

Cheers,

Andy

 

 

You can get a free AP for your IPhone for the DB readings. A DB Meter for free!

 

Craneboy, really appreciate the advice on the valve removal. I had it done last week and my exhaust is finally what I wanted. First, I removed both center resonators and replaced with an x-pipe. Smoothed out the sound but didn't make it appreciably louder. Was looking at possibly getting a custom exhaust made, but GN4HIR (thanks again Joe) was giving his exhaust away and I thought it was a perfect way to try the valve delete. So glad I did. The car has more character and I'd never consider it loud, absolutely perfect for me. Had the girlfriend in the car last night and she said the car sounded great. And she isn't interested in the performance of cars whatsoever. The combination of x-pipe, tune and pulley, and valve delete has completely taken away the decel. popping I intended to remove from the beginning and given me a more exotic sound as well.

 

Can somebody please detail the process on the valve removal?

 

The XFR mufflers have a valve that is opened with increasing exhaust volume. Keeps it quiet at small throttle openings bit still flows at WOT. You take the mufflers to a muffler shop, have them cut out the valves and put a cap over the resulting hole. Then you just have a muffler with no restrictions. If you search for posts by craneboy, you'll find pics, etc. On the mobile site so I can't give you a link.

 

I'm assuming only the XFR mufflers have this valve, and not the XF / XFS? My XF mufflers have the same round shaped thing on the back side of each can, but I haven't been able to find a picture of a XFR muffler to compare how they look.