Thanks for the feedback!

I'm using the OEM Camaro SS catalytic convertors (all 4) and it does a pretty good job quieting things down. You certainly know the exhaust is there on the highway, but not what I'd think is significant drone. That said, all of the 2k miles so far has been with the windows down (black on black in Texas sun/heat with no AC until this week doesn't work with windows up), and the 45 minute ride on the highway was the longest so far with windows up. I'll try to get a mov/mpe/mpeg file of it on the highway for the sound. I know it's not likely to ever be as smooth sounding as the Borla "Touring" setup on my truck.

What are you using for exhaust on your LS2/T56 Jag other than the Magnaflow?

 

The system is 2.5", all mandrel bent, no cats, was X pipe after the downpipes changed to that big resonator (with X pipe built in which is neat), and two Black Widow Venom 250's at the rear. The tone is really good, it's just the drone that's killing me. I chose the Black Widows as I have them on my old Nova, and there's essentially no drone at cruising speed (their tagline one was "all tone no drone"), but on the Jag it's not the case, very few RPM bands it will quiet down. I'm wondering if I should have put the mufflers forward of the axle, and pipes over and out. There was much more room to put them at the rear however, you'd need pretty slim ones to fit nicely ahead of the axle. The resonator tucked up perfectly in the tunnel where the stock one lived.

Hope you can sort out that flange vibration. If you're using a bolt on flange adapter I wonder if a shop could balance it assembled to ensure it's made correctly. I went one piece driveshaft also, and used a one-piece Sonnax adapter made for BWM I modified by enlarging the pinion pilot hole. A little spendy but trouble free mercifully.

 

The driveshaft is flanged at both ends and Jaguar Specialties included a machined adaptor for the trans to driveshaft with the kit (there's a photo of it within PcolaPackers build thread) and I purchased a second one for the rear. The original JS design spec apparently called for a smaller flange, which is what the driveshaft shop in OK used to build mine. However, the rear flange adaptor I got from Andrew was the newer spec one, so I had to swap the rear flange on the driveshaft itself to match. When I remove the driveshaft for rebalancing, I will include/keep the machined adaptors on each end so that the whole thing can be assessed.

 

Here's a vid of the car yesterday cruising at highway speed. Shot on an iPhone so quality is what it is... Not too loud, but you know there's a rumble for sure.

 

Sounds good, looks like it rolls out pretty smooth also. Also sounds like you have a fair plan for your driveshaft. It's funny with these swaps, I think most are purchased non-running, so it's total roulette to see how everything else in the car reacts (clunks, rattles, vibrations, etc).

 

While the driveshaft is out for rebalancing, I decided to see if I could improve the pedal feel on the accelerator pedal setup as it's way too stiff for my liking. As mentioned earlier (and like Pcolapacker did), I'm using the OEM Jaguar throttle cable to operate the electronic throttle pedal from the donor Camaro, which is mounted in the passenger side binnacle where the Jag ECUs were. While the setup works and I get full travel from both, the Camaro pedal has a much heavier "pull" to it to actuate things, light throttle tip in is tough to manage at times.

When I learned that the GM pedals typically have 2 springs in them I figured I'd remove one to see how much things would improve. I also considered changing the pedal setup to use a universal drive by wire pedal conversion mount for LS swaps into older chassis (think: square body GM pickups, etc) and just moving the Camaro pedal to the driver footwell. Well, the layout of the Jaguar pedal assembly, shape of the firewall itself and the positioning of the steering column linkage made that impossible, even though the aftermarket pedal mounts have a very small mounting profile.

Pedal feel is now much, much more "OEM-like". Once driveshaft is back in car, will report back with more detailed observations.

Pics below outline what I did, with descriptions for each. Posting them up for future reference in the event someone else does a similar swap.


On the Camaro pedal the cover has to be removed because the drift pins holding the spring cover in place are blocked on one side by the potentiometer assembly. Cover is held on with snap clips all the way around it, then lifts right off.

The potentiometer sweep arm can be (gently!) pried off. Make close note of its positioning, the arm has ridges to line it up.

This is the cover under which the springs are located.

Two small, metal drift pins hold it in place. (Yes, that's a shattered rear stop light housing in the background. Am going to try and get a replacement one 3D printed)

Use a punch of appropriate size and tap them out. Keep your thumb or something over the cover as you remove the final pin. It didn't launch itself as the final one cleared, but I didn't feel like looking for little drift pins if it did.

A double coil setup in the OEM Camaro pedal.

The springs sit within ringed recesses in the cover and base. I took out the outer (larger diameter) spring and left the inner one. Reassembly is just reversing things from here. Was about 10 minutes or so if I'd not taken photos.

 

So, while waiting to parts to arrive to finish the driveline repairs on my LS-swapped '00 XJR posted elsewhere within this forum, I decided to try and make an airbox/baffle to try and reduce the amount of hot air that could be pulled into the air filter. When the car was last at the tuner, they noted some very high intake air temps, especially when stopped or in stop/go traffic with AC on. Theory being that the proximity of the high speed (right side) fan to the air filter is causing the air to be pushed towards the filter. I thought about adapting an OEM airbox and making a new lid, but the configuration isn't right and would make finding a filter that would work inside it difficult. So, I tried out my metal fabrication skills... Having not done something like this before, I think it came out ok. I found an image of the Mina Motorsports setup when I was done and I think is pretty close to what that one does, but for the changed intake tube location. The gold reflective insulation is to try and minimize the heat transfer as much as possible. These LS engines throw a ton of heat and it's why I'm doing this in the first place.


I made templates from cardboard that followed the contour of the passenger fender well and up to the height of the existing bodyline/weatherstripping for a close seal to the hood insulation. I then transferred to sheet metal. (I forget what gauge I used, but I could cut it with my jigsaw and metal scissors).


I made the longitudinal piece such that it slid between the crush tube and fender well, and extends under the radiator support out towards the back of the headlight. It ends right next to the headlight adjuster knob. It's riveted to the piece that curves on the wheel well.


After measuring 3x, I made one cut to allow the intake tube to pass into the closed off area. The piece along the wheelwell is screwed to the inner fender and also the wheel well, hidden under the wiring loom in this pic.


I'm pretty happy with the finished product. It closes things up nicely. I used underwood weatherstripping from a Mercedes that I scavenged at the local pick-n-pull to close the gaps at the top and bottom of the cut pieces and press up against the hood insulation. Next step is to have to the tune adapted to accommodate the revised intake characteristics.

 

LS Swap Update: I have been contending with very poor throttle tip in characteristics and low speed drivability ever since the last tune was done a few weeks ago and after the persistent driveline vibration was resolved.

What I thought was completed via the prior tune was, in fact, not done properly - at all. The car would stumble and stall in parking lots, pulling into driveways at low speeds, etc. Stop and go traffic was a nightmare. Not characteristics that make for an enjoyable drive in any car, let alone a Jag (regardless of powertrain). I also wanted to have the tune adjusted for the airbox I made after the last tune to deal with the extremely high intake air temps I was seeing (posted in the "what have you done lately thread" and not this one) as that would change the intake air temps for the better by blocking off the engine compartment and high speed fan from the filter. I have to say, I should have had this dyno tune done from from the get-go. Everything about the car is changed for the better - across the board.

We found that the prior tuner altered the air/fuel ratio such that there was so little airflow set in the base tables that as soon as the throttle was released, the car would stall. We also found that the torque converter lockup was turned off in all gears until at least 230mph was reached. (). Transmission line pressures were also not adjusted as they should have been and so on. Oh well, all part of project car building and tuning. It's always the last 5-10% of "stuff" that takes the longest time to find and resolve.

Now, the car pulls insanely well, with firm shifts up and down, and low speed drivability and throttle tip in is on point. Not that I care, but with the air/fuel back where it should be, I might even pick up some mpgs from this effort. I wanted a "safe/reliable" tune with excellent driving characteristics that maximized power within the parameters I'm working with (stock injectors, torque convertor, etc) and the redline it's set for (5,500 rpm). This latest tune was done for 93 octane, retained the stock WOT shift points as the transmission still has the OEM torque convertor and assumes aircon is always on. There's certainly room to increase the power quite a bit if I increase as the camshaft is just starting to get into its horsepower peak at 5,500rpms. But - I don't want to blow up the differential either...

Based on the components I used to build the engine, the expected flywheel output is 501hp/451 ft/lbs torque. The dyno sheet (from the Dynocom dynamometer) shows that with the fully dressed engine, AC installed and operating, the car puts 356hp/387ft/lbs to the wheels at 90 degree ambient temperatures. The tuner (a very well respected LS engine builder) indicated these numbers are exactly in line with build expectations given the parameters I'm working with. About 20% drivetrain loss for the 6L80E is "normal" with another 5% loss from there from the AC being on (I am in Texas after all and it's been over 100 twice this week). Clearly - there's room to further tweak it for more power but I'm never going to notice the extra 50-60hp and associated torque that could be squeezed out. The dyno operator did note a driveline vibration at 126-127mph but I don't think I'll spend too much time chasing that down as everything was nice and smooth until then. Time for an oil change (again) and getting the miles to start adding up!

The video file below shows one of the dyno pulls, the pic is view of engine with the new airbag while at the tuning shop.

 

I thought I wanted an XJR but I came to this forum to realize what I really want is an LS swapped XJR. Great read!

 

Thanks! The stock XJR is a great vehicle, I just happened upon one that needed a lot of work to run right and was in the right mood for a project. Was a lot of fun. The 2001 XJR I daily drove while building this one was great fun and is now in Indiana with a Jaguar enthusiast that also just completed an LS swap on an XJ8. He used an LS1/4L60E from a GTO. Be sure to check out @pcolapacker thread here for his LS-build. He used an XJ8 and kept the swapped Camaro drivetrain stock. He's quite pleased with his results too.

 

It's been a while since last update and as of yesterday, I've put 3,030 miles on the swap. So far, all has been pretty good. I did have it back at the tuner recently to continue refining the low speed/stop and go traffic driving characteristics. The car really didn't like being in extended stop and go traffic situations or low speed/low throttle input scenarios at all. It's much better after this last visit and I'm debating whether it's worth the effort to keep after it as I'm likely pursuing smoothness that the Stage One cam isn't likely to deliver without switching to a higher stall speed torque converter (which isn't actually a requirement for this cam profile). The tuner did confirm that my homemade airbox contraption works quite well as the intake temperatures he saw were consistently reading at or only slightly above ambient air temps, a big improvement from it not being there.

That said, only issues to date have been a slight coolant leak at the radiator where one of the little plastic hose fittings that I reused for a rubber line leaked due to the clamp not being fully seated and a similarly small leak the tuner noticed at the right rear steam port on the head. I repositioned the o-ring on the machined plug and so far, so good. Oddly - but "goodly", the weeping I'd noticed from the aluminum oil pan seams appears to have stopped when I switched back to Mobil 1 branded Dexos synthetic oil. It didn't weep with this oil at first fill, started weeping with another brand's Dexos synthetic, and stopped as soon as I switched back. Interesting molecular chemistry at work somewhere...

Car/chassis had 109,971 miles when I started and the Camaro drivetrain had 76,063. It's good fun startling a wide variety of cars at stoplights, the exhaust rumble always draws a question or two and consistent thumbs up at gas pumps. AC in this car is much, much better than the system in my 2018 Ford F150, though I blame the latest version of "freon" that Ford uses for that. It's nice having the traction control active now that it's raining again here in Texas. Pulling out of my road this morning on wet roads, it came on and did its job quite nicely. I have an SRS light on that I suspect is a loose connection as it came on after a thorough undercarriage wash, but could also be the clock spring. Will deal with it soon. Until then, I'm going to keep driving it...vroom.


Exactly 3,030 miles from swap starting point of 109,971...

 

Sounds like a successful project so far then.

 

I'm at 5900 miles since the swap. No problems.

 

What are the specs of your cam? I just ordered one from Comp Cams and think I may have gone too aggressive (want the chop, but don't want to lose street manners). I don't have stall speed to worry about, but the stick alone is a hassle in traffic, not wanting to make it worse with poorer idle quality. Funny isn't it finding a balance of "livable hot rod". Nice work with the air box.

 

This is the cam I used: https://www.texas-speed.com/p-5760-t...-camshaft.aspx. I did the whole conversion to the 3-bolt setup when I put it in.

Were I to build another "dedicated" LS swapped X308, I'd not do the cam upgrade as it's really not necessary. The car would be plenty fast enough without it. But, I built the engine before I started on the swap itself with the idea that if I didn't like the swapped car, I could pull the drivetrain and ECU and use it for whatever my next inspiration might be. Would then be super easy to put "any" LS engine/6L80E transmission/ECU back in and sell it as a drivable car.

 

I did a "6,000 mile" check in under the Jag this weekend after finishing up the long postponed front suspension and steering refresh to see how things were faring. I noticed that some of the exhaust wrap on the left downpipe had come loose and the excess heat was damaging the plastic collar that sits at the top of the steering rack, where the shaft comes in from the column. So, I added another layer of the titanium exhaust wrap with some additional stainless steel zip ties to hold it in place. I also added some reflective heat tape to the side of the collar as well and cleaned up the wrap I'd done earlier on the hardline on the rack. It was still good but I didn't like how it looked. I also added, at the suggestion of the welder who modified my oil pan, some high temp JB Weld over the weld seams that appear to weep some oil. It wasn't terrible, but was there and I suppose it's the remaining Jag DNA trying to assert itself and retain some of the OG Jaguar "character"...

All else was in good shape. Everything tight, clean and solid. I've decided my next step is to get an x-pipe muffler added to the exhaust to reduce the drone and reverberation, especially at highway speeds. Still averaging 11-12mpg in stop and go commuter traffic, 19+ on the highway.



This is the collar that I noticed as getting heat damaged, and the visible side faces the downpipe when the steering wheel/gear is oriented for straight ahead travel.



Here's where I added another layer of heat wrap, the clearance is really tight. You can see the hard line that I rewrapped too.



And a view of the collar wrapped with heat tape. Fingers crossed this slows the deterioration.

 

So, I reached a key milestone with the Jag this week in that I've driven 10,000 miles since the build was completed. Car had 109,971 when I started, and it's got 119,976 as I type this. Since my last post on this thread a year ago, I've continued to tweak and refine things, with only a few more items on the to-do (maybe) list.

Late last spring with 7,000 miles on the build I was still chasing down the driveline vibration that's out there on a separate thread. In May I replaced all the u-joints in the rear axles (they had no symptoms of wear/failure but I'd done just about everything else) with no improvement. In June I decided to completely re-do the driveshaft after connecting with another LS-swap owner who had experienced the identical issues I was having. Third time was the charm as the new aluminum driveshaft solved the issue completely. I highly recommend anyone reading this ahead of starting their own build follow what we did and build a flanged driveshaft. It's not cheap, but it works. JS was amazingly supportive throughout the diagnosis and root cause analysis.

The rest of last summer was spent chasing down several electrical issues that surfaced after I lost the high speed cooling fan due to the wire connector failing on a 103 degree day in stop and go traffic. AC system released some refrigerant thanks to the relief valve that GM AC compressors have on the back. In doing the repair, I found that the way the AC shop had originally tied the high speed fan in for AC operation was also causing the AC to activate whenever the GM ECU called for high fans, regardless of HVAC panel setting. Thanks to some excellent support and guidance from several forum members with deep Jaguar electrical system knowledge, and their own LS swapped X308s, a combination of improved wiring, a resistor or two (I forget how many) and diodes to prevent back feeding to the GM ECU got things working properly. When the GM ECU calls for fans due to coolant temp, they activate without issue, and when the AC is activated from the panel (regardless of coolant temp) the fans come on. There's logic within the GM E38 ECU that caused an intermittent P0481, the GM code for an issue with the high speed fan. As it's working as intended, that MIL trigger has been coded out.

In January of this year I decided to add vents to the hood to help with heat extraction when the car was not running. Everything flows well when it's running/in traffic/etc, but the Jag engine compartment is so tightly sealed otherwise that I get initial coolant temps of 110+ when the car sits overnight in hot weather - which we have plenty of here in Texas.

In February, I also found that the rubber engine mounts specified with the Jaguar Specialities kit did not hold up well and both were toast after about 8,500-9,000 miles. I suspect the vibration I'd had due to the original driveshaft design weakened them. I replaced them with polyurethane versions and in doing so, was able to simplify how the original mounts were installed to the block with the JS adaptor plates.

Now I need to decide if I want to put in a Magnaflow X-pipe muffler to quiet the car down. It's just a bit louder than I want for a daily driver... I am also looking at getting a custom made torque converter to properly pair the built LS3 (cam, etc) with the chassis it's in. Will help with around town drivability and align the engine power band better within the 6L80E. And finally, if/when all that's done, I may turn my attention to the paintwork to deal with the scorched earth patina that's present on the flat surfaces. Not likely to do a full paint/resto, but instead am looking at a solid color wrap. Perhaps seafoam green, dark silver/grey - who knows...

Photos below of the various tweaks/repairs:


Here's the toasted connector for the high speed fan. Looks like the clip broke off and the connector vibrated loose until it melted.



Measure once, twice, or even 33 times for proper alignment...


And then might as well cut the holes, as you're committed at that point.


Finished look is exactly what I wanted. Lots of ambient heat released when car is off.


One broken engine mount...


Second broken engine mount. Interestingly, the mount on the passenger (RH) side was in much worse shape than the one on the left - which is the one you'd expect to break from engine twist...


Support bar was perfect way to hold engine while swapping the mounts.


This shows how the replacement poly mount eliminates the need for the stacked washers the JS kit specifies with the rubber mounts.


One of two pics that show what a properly made, $1,600 driveshaft looks like. Sonnax flange to attach to the 6L80E output flange.


Sonnax flange for the Jaguar rear diff, adapted from a different GM model. Needed only the pinion locator hole to be slightly enlarged. Bolt pattern is the same.


Larger diameter tube still clears driveshaft tunnel with no BFH induced modifications needed.


Good clearance at the rear as well.