Well I removed the mufflers aft of the Cat and left the resonators in hopes of a more authoritative sound. All I got was a little more noise but not the deep throatier sound I was looking for. Any suggestions?

 

V8 swap! lol jk.

deeper exhaust huh? ultraflows perhaps?

 

When I had a V12 XJS I (like umpteen others) experimented with different mufflers in an effort to get the right sound.

I ended up using chambered straight thru mufflers as shown here:


Chambered Mufflers, Power Sticks, Cobra Mufflers

I didn't use the particular brand/vendor shown in the link but used the same type of muffler from another manufacturer....Walker, perhaps.

Anyhow, I had already ditched the front mufflers and used the chambered muffler to replace the factory rear mufflers/resonators. Overall I was happy with the result.....nice growl, no drone. A little odd sounding, though.

Frankly, straight 6s with low restriction exhuast tend to sound a bit odd as well....at least to my ears. You might wanna listen to some YouTube videos of straight six engines to get an ieda for what you might be in for. Might save you some expensive experimenting.

If you hit paydirt with a good sound let us know. I've been hesitant to make any exhaust changes on my XJR because I'm not confident of getting a good tone.

Cheers
DD

 

whatever exhaust is on the eagle speedster.... get that!

 

Except the Triumph TR6. Of course, they didn't have cats.

 

Oh-my-god, I wonder how many TR6s were sold on exhaust sound alone ? :-)

Car makers have a much bigger budget to tune the exhaust for the right sound....plus there's some science involved with firing orders, single vs. split exhaust manifolds, true dual exhuast vs. quasi-dual exhuast, etc.

Cheers
DD

 

Well they weren't sold for practicality or durability, but they were pretty good looking too

The trick is to get one up on a hoist and map out the components and the lengths between components. Count the cat as a resonator.

Take the case of the V8's. There are a number of cars with great sounding exhausts from the factory. Some Aston's, Mustangs, and Audi's. If you look at them, they have certain characteristics in common. It would make sense then, that copying those traits would be a good idea.

 

Hey, since were all talking about exhaust, does anyone know how to get that ferrari lambo scream at high rpm? I mean im just wondering the v12 will make a deep low sound with open pipes 2.5in diameter like i had mine with the highflow downpipes beforr exhaust.

 

You ever look at a Ferrari or Lambo exhaust? They don't use big 2 1/2" pipes.

Big pipes are like a tuba. You can't make a tuba sound like a cornet. To get that higher pitched wail you have to use smaller pipes, maybe less than 2".

 

the difference between 2.25" pipes and 1.75" or 2" pipes on a 600 CFM car with dual exhaust is miniscule in NA form.

 

If you look at a typical V12, front engine Ferrari, the exhaust on each side is a set of duals.

Not a great picture, but this is a 275 GTB. The front three cylinders and the rear three cylinders on each bank feed their own branch. The mufflers are just perforated resonators. The pipes are relatively small, but that maintains velocity and increases the pitch and timbre of the exhaust note.

 

On a 4.0 XJS, I would try to duplicate the layout of an XKE or early Aston Martin inline six. Basically, the front three cylinders and the rear three would each feed separate pipes, 2" in diameter. Two perforated glass packs on each of the branches, no crossover or x-pipe needed.

Early XKE's sound amazing, esp at higher rpm.

 

You know...I bet a Jaguar V8 swap into an XJS to replace a 4.0 I6 would be a terrific mod. I do recall that Jaguar used 4.0 V8s in XJSs as test mules during the V8's development. Anyone...?

 

Lots of guys like the V8 swaps. Others...not so much. It was/is a popular choice among those having a dead V12 ....too expensive to repair but not wanting to throw the whole car away.

The 4.0 six cylinder seldom give trouble so I reckon very few are replaced with a V8.

Nowadays the price of early XK8s is low enough that those wanting a V8 Jag might be tempted to go that route and save themselves the work :-)

Cheers
DD

 

Good points Doug. I'm perfectly happy with the AJ16 in my car and plan no mods or changes. I'll drive the car as is until the wheels fall off.

 

If you want a ferrari type sound buy AJ6 Engineering's TT exhaust system. Their exhaust actually does make power changes to the engine. You have to send your ECU for re-mapping as part of the exhaust. All the other systems and home made stuff is just for show.

 

XK8s drop into XJS engine bay? Still rather have a V12.

 

I dunno :-)

What I was suggesting was buying an early XK8 (the entire car) as an alternative to converting an XJS to a V8

Cheers

DD

 

Has anyone tried using a cherry bomb glass pack exhaust ?
if so whats it like ?
Does the sound come in when you floor the throttle, or is it a tiresome background drone ?

 

at 4500-7000rpm it does wail, full throttle. hey, its 12 cylinders firing ,not lowly V8, at same RPM.

idles like a top fuel dragster, blubbity,blubbity. lot of CAM overlap.

and it doesnt drone at hi-way speeds.

2 1/2 " down pipes, left crosses under flywheel area, joins into two Cherry bombs, all blended into a 5" turn down tip,flat blacked,Yeah, its loud.