So my mechanic is saying that the entire exhaust system should be replaced.

Here is the list of what he told me to buy.

4 Catalytic Converters. 2 front 2 rear
2 Center pipes
2 Center mufflers
2 Over the axle pipes
2 rear resonators

He told me that it's best if I buy the complete exhaust system all put together. He doesn't do any welding as he isn't a muffler guy so using him, Universal converters are out of the question and I'd have to buy direct fits.

I'm pretty sure it's so all he has to do is install it.

I understand that this is probably easier so he doesn't have to weld anything etc.

My question is where can I find a full kit if that's the route I go and what are the cheapest and most efficient options? Has anyone ever done this?

Can I buy performance parts that are direct fits with each other as I was hoping to get magnaflows etc.

If that's not utterly necessary are the Universal magnaflow catalytic converters and mufflers any good?

Finally, is the cost associated with having a muffler shop weld universal parts on not worth it and should I just go with direct fit parts?

If anyone has any experience with replacing an entire exhaust system on an 92 V12 XJS please chime in.

Would love to hear some recommendations on any good mufflers and converters.

Thanks in advance.

 

Has anyone used these before? They are smaller then the OEM units. Would that be an issue?

V12 Performance: XJS V12 Bullet Type Replacement Catalytic Converter Upgrade

 

I would do a search on V12 Performance customer experience before making a decision.

Okay, does your location require emissions testing? If not, omit the catalytic converters. Center mufflers and rear resonators are a personal matter. There are some youtube clips of various configurations.

I think it would be far cheaper to have a muffler shop fab something, but I've never paid for such a job, so I could be way off base.

I don't see how it could be too hard though, especially if you bring the car to them with the original exhaust in situ.

 

Thanks for the response Flint. I'm going to look into that for muffler shops. I'm in NYC.

Emissions testing is definitely an issue and many places online won't even ship certain exhuast parts to NYC however I do have a place that will pass the inspection for me with no prob no matter what shape the car is in. lol Gotta love those Bronx mechanics.

Anyway so you think it's a good idea to just have a muffler shop do all the exhaust work for me?

I'm not crazy about buying a ton of parts that won't increase performance as I've read that the stock application of the XJS exhaust system is pretty restrictive as it is. Don't mind deleting resonators etc.

I tried reading a few things out there to give me an idea however I'm not the most car savvy guy out there although I do understand basics.

Are there any diagrams out there that anyone knows of showing the exhaust system?

Trying to do the most cost effective application that will also give me a safe and reliable exhaust system.

Only thing I'm afraid of with not going the OEM route is having cats catch on fire or having a bad installation that will do a bad job of letting the engine breathe. (overheating etc)

Don't want to end up getting a badly welded job that will give me more problems in the future.

BTW I found this custom exhaust kit. I was wondering if I should just have a muffler shop try to duplicate this set up for me at a cheaper amount if possible.

http://thedrivenman.com/i-13575082-x...st-system.html

 

I was gonna say wtf seriously, but I guess you are in NY, so its possible the whole thing is toast.

Honestly, most shops do not charge much for welding pipes, I would just visit a few and ask them the cost of replacement. I would take the car by and ask if you bought the cats, mufflers, silencers, etc they would could make the pipes, some shops have the ability to bend custom pipes, and it can sometimes translate to savings.
The pipes over the rear axle aren't too expensive from what I recall, and the tips can also be had online, but I would go with whatever is cheapest of best fit for the mufflers. The main/intermediate mufflers are just a generic shape, and the rear silencers are a glasspack straight through type, which could also be replaced with a similar glasspack, but it may look odd because of the fit of the rear silencers and pipes.
If you are considering the driven man setup, I will assume you don't care if custom pipes go under the axle and have different tips. This could save you money. If you want to ask a shop about doing an X pipe like that, if serves a good purpose on the V12 to improve sound, which is why the V12 e-type had an X-pipe. It blends the two banks together and sounds more like a V12 than an inline six. As seen in the driven man setup, you can also omit the glasspacks and just go with normal mufflers. My recommendation is to look for videos online of exhaust setups, there are not many XJS videos, but there are some mercedes V12s, BMW, and others, which will give you an idea. The V12 is fairly smooth and high pitched, which isn't really inline with flowmasters, they are sort of setup for the lumping deep pitch of trucks and V8s. If i were looking for mufflers I would probably lean closer to Corsa or Borla and maybe magnaflow.

The cats should be fine if they are a good brand, the biggest issue is that they aren't any bigger than the stock ones, the same or smaller is fine. Again, a shop may be able to give you a good recommendation as long as you tell them you want a certain brand, because they can go grab a cat off the shelf and see how it fits. My land rover has magnaflow cats on it because the stock ones died, and they run just fine. You should actually see a good increase in flow with new cats, because newer technology allows for a better flow and your current cats are old and have degraded.I have no idea why the V12 website says 2 per car, it should be 4. You should consider replacing the O2 sensors at the same time.
So it really comes down to visiting a few shops and talking about the options and cost. Buying aftermarket exhaust for the XJS are outrageously prices and shouldn't be considered. If you are looking for ideas to talk to a shop about, also check out AJ6 engineering, they have a pretty cool setup for the XJS as well. If your regular mechanic doesn't have any welding ability and can only hook pipes up and bolt them in, I would definitely check out your other options. That is just very limiting on your options and costs, so I would expect him to be understanding.

If it seems like too much and you need sources for direct replacement parts, hit us back up and we can help you find them. but to give you an idea, I have only found one place that make replacement pipes to delete the center mufflers and they are between 200-300 dollars. I sent and email to a local exhaust shop, telling them the diameter of pipe, what I was doing, and about how long and how many bends it would need, and he told me it would be $35 per pipe. Ordering things specifically for an XJS can be expensive, but all the parts are basically just generic exhaust system parts, pipes, cats, mufflers, etc. Depending on the cats you go with and mufflers, you could hopefully see a lot of savings.

Personally, the exhaust tips, although small, really look like they belong on the car to me. Any custom exhaust tips I have ever seen look really out of place. I could definitely live with a custom setup, including going under the IRS instead of over it, but I would end up using the same tips.

Also see if they offer stainless steel and what the cost difference would be! It would make a world of difference in how long your new exhaust lasts in that climate!

 

I'm new here and don't have any experience with the Jaguar exhaust (yet), but since I'm in your area, I thought I'd add my two cents. A lot of general mechanics will only replace stuff with OEM. It's just easier for them, less liability, won't change performance, won't create problems.... Then there are specialized muffler shops on every other corner, but it's tough to figure out who is any good. As a start though I'd research what sizes are required, price those, and go to a couple of those corner shops and see who could do what for how much. At the least you could use them to get the car on a lift and take some measurements of the stock components and think about what might fit.

When I needed some work done on my truck I just yelped up exhaust in my area, and went to a guy (sort of far away) in Bushwick who had some excellent reviews and was pretty happy how it turned out (Muffler Master). It's sort of tough to find the right place, partly because there's so many places. And there are a lot of shysters around too, as I've learned the hard way.

There's also a shop called KC's Custom Exhaust across the GWB from you. I have NO experience with these guys... but I came across their site and obviously they take pride in their work and there's a bunch of photos of custom exhaust work on classic vehicles and such (some nice photos on their facebook), so it might be worth it to give them a call.

I would think that if you can find the right size Magnaflow, etc., free flowing cats and mufflers, and find the right shop to set it up for you, you'd come out ahead in terms of price and performance vs. stock. But that's only based on my experience with 'regular' cars. Magnaflow does list your vehicle in their compatibility site; but measure twice and all that.

It'd be great if you could update with how you make out as I'll be heading down this road at some point myself, I'm sure.

 

Sidescrollin,
Thanks for the detailed response man! Huge huge help. According to the car fax when I bought the car it was originally from Florida but was purchased and taken to Michigan for a long time. It's never been an NYC jag until I owned it. Has been garaged ever since I've had it.

I just spoke to a mechanic that's a friend of the family and works on my brother in law's cars as he owns and limo company and he recommended a good muffler shop that according to him, has superior welding skills. I believe he also has the ability to make custom pipes.

We're going to pick the car up from my Jag mechanic tomorrow and take it to the muffler shop.

This is what I have decided so far. Correct me if this sounds like a bad set up. I'm thinking 2.25 pipes. Keeping the front cats (buying some magnaflows) and the back mufflers (buying some magnaflows).

Deleting the center mufflers and the rear Cats. Two things I'm not sure about are the resonators and the deletion of the rear mufflers. What is the benefit of keeping the resonators? What is the benefit of having them off?

Also same thing with the center mufflers. You said it might be too expensive to delete the center mufflers?

Will there be issues with overheating to the engine system or transmission with the rear Cats or mufflers off? Will the car run too rich with this set up and use up more gas?

Once I get everything measured and start searching I'll definitely be taking you up on your offer and will be hitting you up for advice on parts I think might work. I'll be very price conscious when buying parts but I def don't want to buy crap either so your advice would be greatly appreciated.

 

Hey man thanks for the heads up. Luckily I believe I shall be in good hands with this muffler shop in the Bronx that I should be visiting tomorrow.

I'm going to be taking measurements tomorrow and searching for parts so I'll keep the thread going.

I heard this muffler guy I'm going to is very affordable since the mechanic I know uses him quite often. I'm going to be giving KC's custom exhaust a call tomorrow too though just to hear what they have to say. Also took a look at muffler master. Wow this guy has great reviews!! Will definitely be giving them a call as well.

Thanks for the heads up.

 

1

 

BTW is this the correct exhaust diagram for the 1992 XJS Diagram attached.

 

did the exhaust ever change? I would assume maybe it did for the 6.0, but I don't think it changed for the 5.3, so that should be all correct.

 

Center muffler delete pipes are pretty easy for a muffler shop to make. The only tricky part being the upward curve, with the flare immediately after the curve. When I first started playing around with modifying the stock exhaust on SpeedDemon, my muffler shop cut those off the rear of the original center mufflers, and, simply transferred them, and the 3-bolt joint flange onto their shop-made muffler delete pipes. However, that option wont work for you if you are going up to 2.25", as that small section of stock diameter pipe will cause a large bottleneck in exhaust flow. A well-stocked muffler shop will likely have an assortment of flanges which will allow them to create a functional joint of their own design.

 

So if I delete the center mufflers I should have a smaller diameter in that area so the exhaust won't bottle neck?

I understand you're putting your stock exhaust back.

What type of exhaust configuration would you recommend being that you've done this before. I watched your videos man. Thanks for sharing. The vid with the exhaust off sounded amazing. I'd get pulled over every other block by the NYPD driving something that loud lol.

Also, I live in NYC so I definitely don't want my system to run rich as I wouldn't like to have my exhaust give off strong emissions or lower gas mileage as it's already going to be expensive.

As for sound, I want it to sound a little better than stock but not too loud as again, I live in the city and don't want too much extra attention when I'm driving around.

I'll try to post some pics of my current exhaust before the mod once I go check my car out tomorrow.

According to my mechanic there were some bad welds on the stock exhaust by the previous owner. Have to see what they were.

 

the mufflers deletes shouldn't be expensive at all. To buy, they can be 250 or so from places like AJ6. I described them to a shop once and he told me it would be $35 per pipe

 

Noooo. If you're going with muffler delete pipes, you want them to be the same size as the rest of your system, in order to avoid bottlenecks. Sorry if I wasn't clear on that in my last post. My system was otherwise stock at the time I had the delete pipes made. That's why the muffler shop was able to just cut the flared curve off the back of the center mufflers, and weld it onto the back end of the delete pipe. However, if you go with a larger size pipe, your muffler shop will have to create their own type of joint which will allow you to separate the front of your system from the portion that runs through the cage. They may decide to just do a standard slip-fit with a U-shaped clamp.

No. after looking at my old, stock exhaust system (with muffler delete pipes), I decided to stick with the custom 2.5"setup which deletes all 4 cats (there is no emissions testing here in Mississippi). I originally thought it made the car run significantly richer, but, after examining the stock system, I see heavy soot deposits in every pipe section, and inside the rear mufflers, indicating that the car has been running rich for quite some time. The Catalytic converters in the stock system may have burned off some of the unburnt fuel entering the exhaust system, thereby partially masking just how rich the car has been running. I plan to make incremental adjustments to the ECU, in order to lean it out a bit, in hopes that the car will run better at partial throttle, have no black exhaust smoke, and will get much better gas mileage.

If I were to build a new, out-the-rear system for one of my cars, knowing what I know now, it would be a mixture of both my current systems. We'll assume that it runs out of the stock cast iron exhaust manifolds, because the price of headers for these cars is outrageous, and few people can afford to go that route. So I'd have either Euro downpipes (they don't have the front cats incorporated in them, and are VERY hard to find here in the US these days), or, US downpipes that have had the cats cut off of them, and a section of 2.25" pipe correctly bent & welded in place of the cats. I would have diamond-shaped two-bolt flanges welded to the end of those pipes, as well as onto the central exhaust pipe it connects to. This is much nicer than a slip fit joint secured by a U-shaped clamp. The entire system would be 2.25" pipes. I would have Dynomax Super Turbos for center mufflers, because I like the way they keep exhaust noise and drone out of the passenger cabin while still allowing for a good, agressive exhaust note outside the car. Both the delete pipes, and my Flowmasters are a bit noisier inside the cabin. I would run the pipes under the rear suspension cage (careful placement here is key), because doing so eliminates a lot of twists and bends that can restrict flow. You need to make sure your muffler shop creates a mounting point to the cage to help support the weight of the system. Otherwise the entire weight is placed on the rear mounting points, as well as on the joints at the downpipes, and on the downpipes themselves. Then I would have dual-tipped, slash cut Monza resonators coming out the back, as they do on JagZilla. The Monza resonators incorporate fiberglass packing around an internal perforated pipe, like glasspacks, so they help tune the sound coming out the tips, making the car sound like the European thoroughbred that it is.

I'm undecided about putting an X-pipe, or H-pipe in the system. I like the way the H-pipe changes the sound on SpeedDemon, allowing the sound of all 12 cylinders to come out both exhaust pipes, but, it also makes it harder to diagnose some problems, such as misfires, and backfiring. Because both pipes are tied together, blending the exhaust pulses of each engine bank, you can't just place your hand behind the exiting exhaust and feel which bank is misfiring or backfiring.

A final note about emissions issues. If you are subject to emissions testing in NYC (and as crowded as it is there, I'll bet that you are), you will need to have at least a pair of high flow cats in your system. If NYC also requires a visual inspection, you will also need to keep your stock downpipes in place, because they have the front cats built into them, and the inspector will be looking for a total of 4 cats. Depending on how clean your car tests with stock downpipes the first year, you may later decide to pick up some additional power by gutting the cats in the downpipes. You would have to do that yourself, as no above board mechanic or muffler shop will do it. Federal law has pretty stiff penalties for shops caught modifying the emissions system, even one that is as restrictive as what's on the XJS.

 

Basically the same but there are two types of joint, spherical joint and slide joint. I think yours has slide joints, so if you are going with the OEM ones, it would be better for you to make sure that you are buying a correct exhaust which has correct joints.

 

jagzilla, if you didn't want to make a compromise and like the X, you could always get the cheapo cut-outs that just have a plate bolted to them. They are inconvenient compared to electric cutouts, but if you are only using them for diagnosis, it would work perfectly fine.

im pretty sure they usually run $15-30

 

Nah, I'd have to get the electric cutouts, if, for no other reason than just to scare the **** out of young punks in Mustangs and ricers, who pull up next to me at a traffic light, revving their engines, in hopes of goading me into a drag race

 

JagZilla
Wow I typed a whole novel responding to you and it got deleted as the page reloaded on its own. Everything deleted. haha Hate when that happens.

Anyway I think I remember what I typed but will try to keep it shorter. Didn't make it to the muffler shop today as I planned as it was raining in NYC all day but def going tomorrow. Will try taking pics of the stock exhaust before we get to work on her. Will try and post em.

Thanks again for the response as it's definitely helped me to understand what applying a custom exhaust system on this would require. You and sidescrollin have been a huge help.

I didn't even know that euro downpipes without Cats attached even existed on these cars outside of the US. (learn something new each time I log in)

I know this shop in California that specializes in dismantling Jags. (It's where I found my replacement ECU) They have a few XJS's they're parting out now. I'm going to give them a call to see if they might come across one.

So after reading what you would do, I really like the system you would build if you had the chance to do it again.

I don't plan on installing new headers as this whole thing is on a budget and trying to do this as cheap as possible as I want to tackle the cooling system next.

The plan is to hopefully have the shop weld off the old cats and keep the stock downpipe in place and weld some new high flow magnaflow cats in place. Fingers crossed that they can accomplish that and that the downpipes are in good shape.

So from what I understand, deleting the center mufflers can create a drone noise inside the cabin??

I definitely don't want that so the center mufflers are now staying.

I also like your idea of the diamond-shaped two-bolt flanges. I plan on deleting the rear Cats for sure.

As far as emissions, I have a shop that used to do inspections for me and pass me each time if I just paid them a little more when I had a really old Camry with bad and expensive oxygen sensors. haha

I plan on taking the Jag to them. In two more years the car will classify for classic status here and it will be exempt for emissions inspections as per NYS DMV law. I just don't want the car to smog up the road too much so want to at least keep two on.

I don't think I'll have a problem with the shop removing the cats for me either and only installing two.

Also plan to do the piping at 2.25" throughout.

The dual-tipped, slash cut Monza resonators and the Dynomax superturbos are interesting though. You don't see too many V12 set ups on Youtube with these.

I watched a few Youtube videos and the sounds differed on different set ups. What I gathered from watching a bit is that the Dynomax definitely have a deep lower growl than the Magnaflows youtube videos I've watched.

The Monza resonators also had a lower sound that any magnaflow resonators I've watched.

Am I right?

I definitely want a different sound than the stock I just don't want it to be too loud as I def want to avoid a drone sound in the cabin and I definitely don't want to get the attention of the NYPD when driving around.

The car is going to be mainly driven on weekends to visit family or the beach next summer but there will be some city driving periodically.

So what I think I want the exhaust to look like when speaking to the shop.

Original downpipe with 2 cats welded on, Rear cats delete, 2 center mufflers, 2 rear resonators.

Any other resonators you'd recommend other than the Pacesetter/Monza? How do you feel about Magnaflow resonators? Still a good sound without being too loud or too quiet?

Was thinking of just doing everything Magnaflow. Also I really like the price points of the Dynomax Super turbos. They can be had pretty cheap from what I see.

Thanks again and I'll check in after I get this project going.

 

There are also honeycombed inserts at the top of the downpipes which need to be deleted. These have become commonly known on various Jag forums as "preheaters" for the cats (see photo). They're very restrictive and can clog in portions. The downpipes must be removed from the manifolds in order to deal with them. If I understand you correctly, you are going to have the cats in the downpipes replaced with high flo cats. Make sure the muffler shop welds them in such a way that you have (relatively) clear access the the studs on the manifold, for future removal and installation ease. Also make sure they leave you plenty of clearance to access your oil filter. The stock cats are pretty large diameter, so, access there is tight.


DRONE:
Any number of things can cause it, and it's difficult to pinpoint the source, or which direction it's coming from inside the cabin. On JagZilla, I'm not sure if it's caused by the large diameter hollowed out area in the downpipe cats, or if it's from the Flowmaster center mufflers (themselves basically large diameter hollowed out areas with metal noise deflectors welded inside them). I only get it a little bit, and, then only in about the 1700- 2200 RPM range (most of your "around town" speeds will fall into this range).

SOUND
I can't really comment on Magnaflow products in this application, as I've never heard them on a Jag V12. Those YouTube videos can only give you an estimation of how the various mufflers/resonators will sound on your car, or, even how one manufacture's muffler will sound compared to another, because, the system setups are different from each other, the engines are very likely different from one video to the next, and none of the manufacturer's demo videos are for a Jag V12 engine, which has VERY different harmonics than any V8, and, even different from other V12s. The best comparison videos I've seen, where the car, motor, and system remained the same, and only the mufflers were different, is Flowmaster's comparison of their own line of mufflers. You can see the series here:

Here are some sound bytes of how the 2.25" system sounded on JagZilla, back when I had my original motor in the car (it seems to sound a little lower and deeper with the new motor) The thing I like most about the setup on JagZilla is the sinister grown it has when driving in an area that echoes, as in a parking garage, or tunnel.
Idle & Rev.wmv
3000rpm Drive-by.wmv
6k Drive-by(1).wmv
40mph.WMV
3000rpm 80mph.WMV
6000rpm 105mph.WMV


Yeah, Dynomax Super Turbos do represent an amazing bargain, especially compared to my Flowmaster Deltaflow 40s, which are more than twice that price, per muffler.

I hope this helps. Let us know what you end up putting on the car, and record the sound & post here, if possible.