After a proper inspection at another muffler shop, it was discovered that my over axle exhaust pipes are in good condition. The other muffler shop had told me that they were rotted out. In fact the rotted part was the gasket that goes between the flanges.
I am going to keep them for my other car.
On the conversion, I had all new 2 inch pipes installed, with redesigned down pipes to clear the steering rack tower by more than an inch and on the passenger side by a lot more.
Two XLERATOR turbo mufflers (11x8 oval) made for the last model T-bird. This was then flanged and piped under the differential and into my very,very good original mufflers. Pretty quiet.
It is set up so I can remove the rear section of the exhaust system if I ever have to remove the rear end for service. Attached are some not so very good pictures. I will raise the car and take some better pictures over the weekend

 

If you don't mind me asking, what does something like that run?

Cheers
DD

 

@ Doug: Parts and labor. $730.00.
Would have been $570.00 but since I requested the flanges and band clamps for the rear OEM mufflers, they tacked on an additional $160.00.
They charge for each weld in addition to the labor to create the bends the way I wanted it.
The first couple of bends for the down pipes were unsatisfactory to me so they charged me for wasted pipe and labor($60.00) In the end I got it the way I wanted it.

 

I used the original jag rear mufflers (they are new) original over the axle pipes (new as well) the mufflers in front of the cage New and come flanged from factory so the cage can be removed easily

The main middle muffler has 2 in and 2 out pipes (muffler is from a XJ8 ) only needed 2 S shaped pipes to connect the XJ8 muffler to the original JAg XJ6 mufflers in front of the cage.

I used stainless down pipes (that had to be modified because they did not fit originally) then on each side flanged header extensions with O2 sensor bungs and finally a short extension to connect the header extensions to the front of the XJ8 main muffler. total cost 150.00 this was the cost of the new Jaguar XJ6 mufflers and the over the axle exhaust pipes I snagged from EBAY. Stainless down pipes cost me 230.00 and would NOT buy them again. They did not fit and had to be reformed because the lower flange interfered (came into contact with the starter), and were too close to the steering rack gaiter as well. **** poor fabrication. JUNK.

So there you have an alternative. But I still need about 100 bucks of welding to be done . Came in under 500.00

 

BTW, I get a freebie. When I convert to TBI they will install the O2 sensor bungs free of charge. Right now I am very happy with the results. It is nice and quiet and easy to take apart if need be.

 

@sanchez

Looks like a great custom job. Glad to know there are still good shops out there than can create.

While you are taking pictures, could you measure the clearance you have under the pipes under the cage to the road surface. It looks low, but looks can be deceiving

 

Sanchez:


Look like you found the right shop. Willing to work "outside the box" and for a reasonable price. Nice work. I am a bit concerned as to a couple of things, but quite picky, so I'll remain silent on them. No cars needed, that saved a chunk of bucks....


Doug:


I think the big variable in locations is labor. When I did mine, two of the three I shopped lacked enthusiasm and expressed it in $'s. Each of the two wanted the cats up front, very close to the manifolds. Not good in my choice. The third far more willing. He had done a few in past years. Saved $'s by having down pipes in place, and reusing the Jaguar mufflers, all four. No need to wortk through or under the cage. Two cats cost !!! Had to be CA approved and numbered as such.


I gave him the two big pancake cats that came with my enhanced engine/trans package. used and unfit, intended for trucks!!!!
Although refitting used cats is supposedly illegal, had they fit, he would've used them.


Carl

 

Even though we do not have an inspection program here in Florida, the muffler tech told me that my car should have cats. He did a work around for me.
@ Sarc; the clearance between the pipe and the floor is 4 3/4 inches. Cage to pipe is 1 inch.
This morning I took it on a 170 mile round trip to to check out the motor, transmission, fuel economy etc, and also to see whether the clearance would be an issue. Went through some areas, sometimes at speed, to see whether the full upward travel of the suspension will make the exhaust touch the ground. So far, so good.
Car runs smooth up to about 80 mph. Above that, I believe I have a driveline vibration.
I am going to replace the motor mounts which I bought, thanks to Roger Mabry who posted the part # on this forum. In my other post on "LUMPS....HOW TO" I had mentioned that I was using the JohnsCars setup and since he would not sell individual parts, I "fixed" my bad mounts by making them solid. That can cause some of the high speed vibration I have. I am also going to remove the driveshaft and have it balanced in the next couple of weeks.

 

Is the drive shaft inclination set up ? Can you shim trans / engine to bring it into the right plane ... to get driveshaft in phase - all relative with the pinion shaft on the diff?

If you don't have the planes right (and being that you did some mods on the motor mounts) and rubber mounts are not present (welded them solid?) this may be your problem. My 2 cents

 

Great, thanks for the info. I would think if you were getting 4 3/4 inch of suspension travel at the rear, there would definitely be something else wrong. I am pretty set on doing the same thing on our 76 Coupe.

 

i found the over axle pipes on amazon

https://www.amazon.com/Walker-54014-...ywords=exhaust

 

@ Alyn: They are not welded solid. I purchased a polyurethane mix from Energy Suspensions. This mix is used for modified front wheel drive cars to keep the motor mounts from tearing apart under excessive torque twist. It just may be that it is too stiff for my application. As stated in my other post, the holes in the mount were filled solid.
I will replace the motor mounts first then work on the driveshaft.
Wouldn't the driveshaft inclination plane issue show up at lower speeds as well?
Do you have a simple method of checking this? I will do some research or leave it to the experts.

 

Sanchez:


Comments:


1. Good work, down to tuning the thing in a bit more.


2. Agree, making the "modified" old Mopar joints solid or to close
to it may be great in a semi- race car, but not in a car that is noted for smooth, quiet travel.


a. Run the engine and throttle up and down from within the bay. Any engine torqueing? Should be a bit, but not a lot. A bit, the mounts work, a lot, nope. A somewhat "delicate" balance needed.


b. Find Roger's article on finding new rubber and affixing it to the Johns cars mounts.


c. I've no issue with them in my car.


2. You do have a one piece shaft, huh? Drive shaft angle in these cars is forgiving. Little up and down by the engine. Even less by the caged differential. But, phasing as Alyn says is critical.


3. If you had a drive line shop make up the shaft, balance should have been done there. I expect they would check if asked. Chucked in a lathe and strobed is one way... Best option, I think.


4. There is a DIY method, but fussy and not always successful. Not worth the effort, in my opinion. Use a worm clamp and tie on a small weight. Drive and feel in the seat of the pants. Still shaky? Move the weight a few degrees and try again. If you find a sweet spot. Affix the weight there. Weld is best...


4. If you have no inspections, the the cats have two purposes.
a. Income for the shop.
b. They do improve the air we breathe.


Carl