I went with resonator and silencer delete replaced with an x pipe , 2.5 inch piping back to magnaflow mufflers in the rear with black chrome dual tips , it sounds much more aggressive on start up and idle than stock but by no means overwhelming, but you know it's a V8 it has a great tone on partial throttle with awesome burble on downshifts, super mellow when cruising no drone but a nice aggressive note and when you open it up it sounds mean af!!!! it was exactly what the XFR needed to distinguish it and let it be known that this car is BADASS!!!

 

Good news i picked up a pair of quicksilver back boxes today. Fitting looks simple. But if anyone has any tips having done it please let me know.

 

Fitting is simple.
Can be done without jacking the back end up at all if you are skinny and dexterous, but a lot easier with it jacked up a bit.
Just make sure you put proper axle stands underneath, the correct support points are shown in the Owner's Handbook, and chock the front tyres.
You need a 15 mm deep socket for the pipe clamp bolts, a 10 mm socket or spanner for the rear hanger brackets, and a pry bar and lube (I use WD40) to get the rear hanger rubbers off the old mufflers and then back on the new mufflers.
The 15 mm clamp bolts can be a bit tight, so some WD40 beforehand and a good strong socket wrench or even a breaker bar may be needed, and you need to do them up again really really tight otherwise you risk exhaust leaks. I don't have a torque figure, I just use the old fashioned "two grunts and a fart" method!
Last but not least, the stock rear mufflers are very heavy and once you have loosened the clamp bolts and removed the rear hangers they could "fall", so be ready for that. They don't fall straight down, instead they twist and drop, but usually not until you pull/hammer them backwards a bit to break the pipe seal.

 

Thank you so much Ozxfr for such a detailed description most helpful. I will ensure the coast is clear when i tighten up the clamp bolts lol 👍. Im on a course for a week so carnt fit them until next weekend. I think i will put wd40 on today so it can work its magic.

what did you put on yours?

 

I put custom made straight through hi-flow mufflers on mine, but I put the stock ones back on after a few weeks. The custom ones sounded fantastic at WOT, but the rest of the time they were too loud and too droney, especially under medium throttle going up a hill. I spent a couple of hours one day in the back seat while SWMBO drove at "driving Miss Daisy" pace and they sounded 'orrible!

 

By the way, one method to get more exhaust sound. Fold down part of the rear seat! I have the Mina system which is great. But when out skiing a couple of months ago I folded half the rear seat to fit in the skis and the sound was even better still!

 

Quick question I want to replace my mufflers with high performance universal mufflers what shape do I need? Inlet and outlet for best fit?

 

You want offset inlet and central outlet to best match the stock mufflers.

 

Can you be more specific or am I over thinking it? I already deleted the center resonator? But too much interior drone? Thanks

 

Any idea of dimensions? The exhaust shop is looking for length, width and height?? Thanks so much!!!!

 

In the past I have used Magnaflow mufflers, usually from Summit Racing who have a big range of them.
The stock XFR mufflers are very wide and high but not all that long, but to minimise drone you want the biggest after-market one that will fit (without causing your exhaust shop too much pain with fitting).
I have found that the best compromise is 14" long by 11" wide by 5" high, but looking through the Summit Magnaflow catalogue I could not find one of this size that was also 2.5" inlet, offset inlet and centre outlet, they are pretty much 99% centre inlet and offset outlet.

 

Well tried to fit new back boxes today. Nothings ever easy is my experience. Got the 1st box off to find that the clamp had been spot welded onto the pipe. I could not get one from local suppliers to match the oem so had toget 2 horseshoe type clamps. Got the box fitted but the pipes were too short and hid under bumper. Easy i thought there is a bolt that holds the slip on tips in place. Loosen this off then you set the tips up to suit. The bolt sheered off. Choice words were said. I managed to set the tip lenght in the end by pulling the whole pipe back so the backk box did not sit so far on the slip joint.

On to the next one. Got the bolt off the clamp but could not budge the clamp at all. So im left with 1 quicksilver box and 1 oem. Why did i not just take it to a fitters and let them deal with it.

No one has mentioned that the clamp is spot welded. I just assumed once the heat/rust seal was broken the clamp would be free to use again. Looks like i will be taking it to an exhaust centre anyway.

 

Bloomin clamp. Spot welded in two places onto pipe. Not comming off

 

Yep, the clamp comes spot welded on from the factory. Every "bolt on" after-market system, including Quicksilver, is supposed to come with it's own pair of clamps.
I'm guessing you got second hand Quicksilver parts, without the clamps.
A trap for young players, sorry I forgot to mention this earlier!

 

Yep got a second hand set for a third of the price of a new one so dont mind missing clamps. Just was not prepared at the time. Its funny having a loud side and quiet side. Tips are almost identical.

Going to have another go today. Wish me luck..

 

Done it just needed a bigger hammer to loosen clamp. I then undid wrapping on second back box and guess what i found? 2 clamps. If id fitted this one 1st yesterday i could have saved half a day. Thats life i suppose. The new horseshoe clamps ibrought look much more robust than the ones i found so not entirely a waste of time.

My son and I are going out to tour the tunnels of surrey today. Got there in the end ��. Thanks Ozxfr for your help on this and the workshop manual. Cheers buddy.

 

Glad you got there in the end. The first time is always the hardest, I've lost count of the number of times I changed the exhausts on my XFS and XFR.
One little tip about the horseshoe clamps - whatever clamps you use you need to do them up really tight, otherwise you risk the pipes and mufflers twisting and the tips going out of alignment, and/or exhaust leaks. I suspect the horseshoe clamps might not take as much torque as the supplied clamps before they break.

 

Well back from our tour de tunnels and i would describe the sound as "naughty" very naughty. So viceral and the pops and bangs are musical.

If your considering changing your exhaust i say do it. The best mod by far. I havent heard spires in the flesh but my quicksilver is epic, to quote my 10 year old son.

Happy days

 

I used the tightening guide u suggested lol. Clamps are very tight as they are much thicker than oem and have 2 tightening points not 1. Cheers

 

Do I need a 2.25 or 2.5 size to replace my stock rear mufflers? Thanks so much