Now I want to go back to the XJS. I was thinking the xk8 would be better but i really love the lines of the XJS. Im also looking at all the room in the xjs and the small engine bay in the xk8. Im happy im figuring it out now before i have a car. Hey ronbros, I have a 77 vette that has the side pipes. I love the look but i hate the smell after i drive it. Nice job on the car.

 

Just to clarify, the XKS and XK8 are built on basically the same platform, with changes front and rear to accommodate the newer suspension of the XK8. Under the hood it is basically a wash as far as space- each one will easily swallow an LS with plenty of room for service, etc.,. As far as engine accessibility, it is easier to work on an LS in these cars than in a modern Corvette..... So don't let underhood space be a deciding factor.....

And just to dispel any other recent misconceptions that may have appeared in earlier posts, electronically, a conversion in an XK8 is no more difficult than in an XJS, again, assuming the correct parts are used. As a matter of fact, it's actually easier in the later car as the electronic controls/format of these later Jags (that we integrate with) is nearly parallel to that of GM (fuel injected) models of roughly the same period. And keep in mind the later car also has many more modern features/amenities that we have become used to on our cars not like a complete automatic latching convertible top (you press only 1 button and do nothing else), automatic fully servo driven climate control (no vacuum needed), speed sensitive steering, separate memory settings for power tilt/telescope steering column and power seats, and more. So it's give and get there.

Lastly, the XK8 body shell, though based on XJS pieces originally, is HUGELY more rigid and solid than any XJS, even the facelift cars. Jaguar made great efforts in that area as the XJS was actually never originally designed to be a convert. The facelift XJS cars (93-96) were a big improvement over the 89-92 2 seater models, but the XK8 was an order of magnitude higher. Driving over train tracks with an XK8 and top down is solid with almost no cowl shake. No XJS comes close to that. And I think the XK8 coupes are also much more solid than any XJS coupe

I hope that helps. Good info for a good decision process....

Andrew
Jaguar Specialties

 

Than you for the information, but your killing me. now im really not sure where im going.

 

That's why you need a plan before you start. It took me about 18 months until my "right" car came around to suit my plan

Don't rush it, enjoy the research and then decide the path

Cheers
Steve

 

If you want an XKR or XK8 buy a nice one ready to drive, whatever you paid for it will most likely be 1/2 of what it costs to build a convert and all converts are compromised in someway unless uber amounts of time and money are spent. You might fall in love with it then upgrade it as you see fit engine, trans, suspension... you might not.

If you want an XJS buy a nice one, perferbly a facelift model I6 or V12, well maintained and enjoy it Coupe or Convert and enjoy it. There will be plenty to fix repair, maintain tinker with to keep you busy. You might fall in love with it then upgrade it as you see fit engine, trans, suspension... you might not.

If you want a project XK/XJS or otherwise. Make it special, take it far, build something you really really want and that CAN get done in a reasonable about of time for and budget. Time and budget parameters are unique to each person. If you're not sure...dont start, It wont get finished, or will compromised to such a degree that it will be worth far less than you have into it in the end It would help if it's useful but Unique, just another LS convert isn't that special anymore, great in many ways but not special. If you really have to have an LS powered XJ/XK with a 6 speed then do it, Jag Specialies can get the front 1/2 from A to B quickly. Keep in mind like i said before applying 100 extra HP to these car doesn't make them better it just makes them a-mess but this is true for most cars. Some people like a-mess but like a said before dont get crazy with power unless you fully understand what-is-what... But how could you?...Correct me if I'm wrong but I think you've never owned either and XJS or XK? Keep in mind, there are lots of LS power cars already built with Auto's / 6 speeds like the 2004,5,6 GTO, 201? Camaro, CTS-V, Mustang, E46 M5, Audi S4 and many more... most of these can be purchased and driven off for less than what it will cost to build something. I've also owned most of them listed and all are newer and far better than old cars in many many ways, looks not withstanding.

Personally speaking, I really love the XJC...I love they way they drive, the way they look and put uber amount of time and money into one. No limits, It's been a cruiser, a 1/4 mile car and now a road race car. I love they way after a track session and I'm exhasuted and pumped up with Adeline, then people come up to and are fascinated after seeing and hearing it with an open exhaust rev'in to 7200 down the main straight... trying to reel in much newer and faster cars... Conversely last track day I ran a Porsche, lots of Porsche's on the track, no-one could care less even though it's bright green and a much faster car. The XJC... It's never finished and never fast enough and that's OK it keeps me occupied and I know one of these years I'll be able to catch one of those pesky C7's on the track but I may have to buy a C8 to do it! One of these day's I'm going to build a TWR style and updated XJS right after I turbo the GTO, twin turbo my S8 and finally catch that pesky C7 in my XJC... LOL

 

ics, sounds like a great plan,, GO FOR IT, do it while you are young!
ron

 

Although this is in a generic sense a good approach, this does not really apply, virtually at all, to the XK8/XKR models. There really aren't many choices as far as "upgrades" for these models due to their small overall build volume. There is nothing as far as internal engine upgrades, no ECM tuning, and nothing for the transmissions; there are some very pricey custom exhaust systems (of questionable performance value) and of course the hipo supercharger pulley (I have wondered what value that might be, not to mention risk, if the ECM can't be tuned as well) . These are parts to bolt onto an already weak drivetrain that is close to its mechanical limit- they don't really hold up in stock form. Paying more for one of these cars in good running shape is fine, but that money is essentially wasted as there will undoubtedly, and soon, be a major mechanical failure that will negate any value for buying a running one in the first place. That's why we have several hundred of the XK8/XKR (and XJ8/XJR- same drivetrain) kits out there, most of which are on the road, and the rest in process of getting there.

Not sure where this comes from:

"all converts are compromised in someway unless uber amounts of time and money are spent""

This is probably true if you're trying to do the conversion on your own, making your own way, and making all of your own bits at the same time, and especially true if the project is your first time on that particular model. However, end users buy kits from suppliers who have worked out all of the details ahead of time so the user can skip the inventing phase and save " uber amounts of time and money". That's the whole point. If the conversion kit supplier is on his game, the end user doesn't receive a few metal bits in a box, but also full information on the complete solution to the whole project, top to bottom...... Not sure about others- that's what we do.

After building and driving 6 of these late model cars in house over the years, and getting feedback from customers on their experiences with converted cars of their own, I'm not sure this jives well with comment:

" ..applying 100 extra HP to these car doesn't make them better it just makes them a mess".

Just to clarify, most of our customers use engines that range from low 300's to low 400's hp, so, by today's standards. relatively sedate. But the numbers are deceiving- the LS engine's torque is what pulls the car along and it is vastly different, and comes at a lower rpm, than any Jag engine. But what I think ICS is missing here is that Jaguar went to major lengths to improve the chassis of these models, far beyond only the XJ6C and XJS cars he has driven and has experience with. The body rigidity and suspension refinement that these cars come with at a base level is an order of magnitude higher than the earlier models, whose suspension design, for example, dates back to 1968 (did you know that the front and rear suspension assemblies in a 1996 XJS, with the exception of the outboard rear brakes, are almost identical to that of a 1968 XJ6??). Not to put the older cars down, but we are talking apples and oranges here. The new models, by design, are set up to handle far more hp/torque than they come with from the factory, and that's been borne out by our experiences with mild LS engines in these cars, and some not so mild (including a 97 coupe with a 6.2 LS in Florida putting out some 430 hp at the rear wheels and 60,000+miles on the conversion- not typical power but a good data point)

What I like the best is that the chassis systems of the late cars are really quite robust- electronics, AC, etc.,.- and pretty reliable overall. Ford's ownership of Jaguar during the development of these models made a big difference in those systems (and your XK8 instrument cluster has a Ford logo on the back). That made for more reliable parts which is vastly different than what we see on the earlier Jag models, love them or not. Good info.

I wish ICS was closer to me so I could take him out for a ride in my new 97 XK8 coupe with 6.0L 361 hp L76 (LS2 with displacement on demand) and 6L80E (6 speed automatic) trans. I think he would get a kick out of it.....

(Here are some pics- nearly done- cover panels removed to show drive by wire pedal and wiring details; air intake still to receive heat shield to engine)

I hope that helps. Keep asking questions...

Andrew
www.JaguarSpeciaties.com

 

Speaking just for myself but, even as a devout Old-Jaguar-Lover, if I really wanted the level of performance that comes with 400-500 horsepower I'd be very very tempted to simply go out and buy a car that already has it. That's what seems sensible and logical to me. But, sensible and logical and "car hobby" are often at odds. I have full understanding and experience of that

I wouldn't mind hearing from both you and Andrew as to how much money is spent of some of these project cars/conversion cars. But, if you'd rather not say, I understand.

Cheers
DD

 

Sure, I can give you an idea- this is what I quote to customers, based on my actual experience over a half dozen of these over the last few years:

Basic XK8 LS Conversion Kit $1995 (includes specialty mechanical bits and electronic CANBUS interface)
Misc Other Parts Services $1750 (driveline work, exhaust fab/hookup, misc soft parts and other bits, AC hose fab and recharge)
Labor 70hrs A qualified shop or individual who reads the manual and accumulates the bits needed up front can do it in this timeframe

Engine cost- this varies widely but the range is pretty predicable. LS engines have many versions so here is a sample:

Base- 5.3L truck engine and trans package- 295hp, 335ft-lbs torque $1500
Mid- 5.7L LS1, Camaro eng/trans package- 325hp, 340 ft-lbs torque $4500
High 6.0L LS2, GT0 - 400 hp 400 ft-lbs torque $6500

A G8 engine package like in the XK8 above- L76 eng, 361 hp 385 ft-lbs torque with 6 speed automatic, would sell in the $5200-$5500 range.....

So in general what I quote customers is $3750 + the cost of engine package + labor. If you figure $100/hr labor ($7000 total) a complete XK8 LS1 conversion should be something in the $15k range.

And of course for an end user doing this on his own, the $7000 labor cost goes away. In that case the whole LS1 conversion would be some $8000 +/-.

Nice cars, with major mechanical issues, can be found for $1000-$2500 depending on the year. Overall, for what it is, a definite bargain.

And just to answer another question surely rolling around in many minds, the converted XK8's, when done right and in nice shape, sell for mid teens to low 20's based on the several sold in the last few years. That's easily 3-4 times what the stock running/driving XK8's sell for.....

I hope that helps.

Andrew
Jaguar Specialties

 

i have an LS2 in a Buick GN , 4L80 box, great car resonably fast, lot of suspension mods ,and brake upgrades!
i wont put pix because not allowed! its in my profile pix!
ron

 

Andrew... Thanks for the offer but I really have no interest in a 361HP XK. I'm sure the XK is a great car but it just doesn't appeal to me and that HP level isn't interesting to me at all. I'm not missing anything. Very presumptuous of you think think I'd gt a "kick" out of a 361HP automatic transmission XK8 which offers about the same power to weight ratio as a V6 Toyota Camry.

Here's a MAJOR COMPROMISE - HOT AIR INTAKE. having a boy racer hot air intake inches from an exhaust manifold... Major compromise. Why not even a baffle ?
As for "Converts being compromised"... they are. No covert I've ever driven, professionally or other wise felt like an manufactured built car. Quite frankly any car once taken apart, never goes back or feels quite the same. Really haughty on your part to think you can achieve something major manufactures do with millions in R&D. If you can do that... Put down the keyboard, Tesla really needs you right now. Other compromises include, adapters, 30+ year old engine mount technology, and setting the engine 5 to 8 inches further forward than it needs to be... and dont tell me it has be be this way... you know I make my own adapters that use modern hydraulic mounts AND set the engine much further back in the chassis. Those are just a few compromises I know of off the top of my head. The hot air intake is laughable. Did you even design the mounts or are you just reselling Suncoasts mounts ?

Hot air intake? LOL

Andew, you asserted that the 1968 and 1996 Jaguar suspension are "almost identical with the exception of outboard brakes." This is not the case, there were many upgrades to the design over the year and Aston used it until 2003. Here what i know of... and You're not telling the complete story in this case too.

- 1968 to 1971 Front Suspension used non vented front and rear rotors
- Early 1970s, saw the addition of 4 piston calipers, vented front discs
- 1974... With the introduction of the Series 2, Changes in lower control arm geometry to increase castor
- in the early 80's the rear hubs were redesigned to resist cracking and the front subframe was redesigned for increased strength, corners were gusseted larger wheel bearings were used and lip seal for better grease control. The steering rack ratio changed from about 2.9 to 2.7
- in 1988 Front and rear hubs were redesigned to allow the addition of ABS sensors.
- In 1992 Jag switched to a ZF rack-and-pinion and also introduced the "Jaguar Sport Rack" , Big changes came to the diff with a low bias Power-Lock, and a completely redesigned output bearing arrangement and non-vented rear outboard brakes. U-joints are sealed type with no grease fittings and drive shaft spline count was changed to ease servicing.
- For MY 1994 the V12 returns to the XJS and with it the IRS got rear vented rotors.
- in 1997 The XJ's suspension returned to the USA under the DB7 with very few changes from the last XJS in 1996
-in 1999 and until 2003 Aston used it but redesigned both ends... fronts got different lower control arms for more contemporary scrub radius , stronger rear control arms and upgraded bushings, added Brembo brakes. The, early DB7 used an adapter bracke for the Brembo's, the, late use a new spindle design with pressed in wheel bearing. The IRS also rear toe adjustable at this point.

The last and best iteration of the XJ suspension design was put under the Aston Martin DB7 GT. It's was faster around the Nuremburgring than a XKR. The DB7 GT managed a ring time of 8:23, years later in 2005 the XKR could only manage an 8:25. Aston made very substantial upgrades to rear suspension and fitted very short high rate springs and large Bilstein stocks up front

As for prices...everyone gets to spend their money the way they see fit but for me 15k for a car that will get out done by a new Toyota and is something of a compromise... I dont get it. Does nothing for me. There are many far more interesting car to be had for the same money or less... If someone already owned a really nice and well maintained XK and was then faced with some sort of catastrophic engine failure and was looking for a DIY retirement project then perhaps a swap is reasonable from a value perspective. As with most "projects" they cost more and take longer than planned.

Conversely, I maintain... a well bought XJS, with a modest LT or very low cost LS engine swap as an un-hurried DIY project is interesting, rewarding and could be a good value especially as a convertible. Low cost being the Key becasue a $7500 LT or $15,000 is still gonna get it's butt kicked but a new Camry.

 

Forum members-

I'm not sure what to make of this last post here so I'm not going to even respond except to say this: I apologize if anything I shared earlier was so egregious to cause another forum member to take this thread in such a negative, aggressive, and (in my opinion), unprofessional direction. For whatever part I may have played in that, I am sorry. My reputation in the Jaguar sphere is well established as a willing, able, supportive, and interested party for the hobby. The tone of this thread now is not what I, or Jaguar Specialties, am about.

As an enthusiast as well as a supplier, I enjoy the forums as both a place to share interesting tech with other Jag owners but also to read about the projects of others. Although I do not post often, when I do it is to:

1) Share details of a project we have worked on that I think might be interesting to other forum members
2) Comment on a thread where I have direct personal experience or knowledge that may be of interest or use to the readers
3) Offer information on threads that I am aware are propagating information that I am pretty certain is incorrect, and often it is in the realm of conversions

Item 3 above, in my opinion, is very important, and for a very simple reason. People read these posts and to me it's important that what they read, particularly about conversions, is correct. The why is pretty basic- readers see these posts and often act on them. Bad information leads to bad decisions, which wastes money, ruins projects, and quite often also propagates an overall negative feeling about the process itself. For example, I get at least 2-3 calls a month from Jaguar owners interested to do a conversion and think Jaguar has used GM transmissions in all of their cars since forever because they read that on a forum somewhere. I want to be sure that what I share is good info, based on actual knowledge, that I know will be valued by those interested.

This is a thread that started as a search for Jaguar-LS conversion information. That is something we pioneered and have developed into a nice product offering for a wide variety of Jaguar models. No other company has taken on the challenge or made an investment like this to push Jag conversions in this modern, exciting direction. For those actually interested, I am happy to share what I know if it will be helpful. And on this thread, that is what I shared.

Thanks

Andrew

PS- As a side note, some 6-12 months ago, we were contacted directly by ICS who wanted to sell (license to us) his design of some new Jaguar V8 engine mounts. We reviewed the details and respectfully declined. I just wanted to share that

 

You never reviewed any "details". More inaccurate info. I never sent a picture, or discussed anything other than what is below and that it uses a CTS-V hydraulic mount which can handle very high HP and remains refined. That's not "details". It was just part of another email about my AJ16 Coupe that sold well enough on BAT. I was just offing becasue your mount design seems dated makes a few odd compromises . I have ZERO interest in selling such a product but it was fun developing it for my own use. Post a picture of it if I'm wrong. A screen shot of the email is below. You seem to be trying to suggest I'm somehow Jilted which is laughable, I'm not that fragile. What I do find odd is the relentless hawking and mis-representations. I'm just puting out my view.

You know the XJS can't handle much more than 350HP with out major upgrades, that's why you're pushing the XK in the XJS forum

The "uncompromised" product you offer has clear compromises with the hot air intake. fab a real air box or get someone to do it for you.

Are you reselling Suncost conversion mounts or not?

Did you call me 3 or more times over 2 days to try to intimidate me like you've done to others who try to says anything derogatory, accurate or not? I recall your VM stated you want "to discuss something I put on the forums" Outrageous behavior? I think so. I wonder if I can find the call logs? Can you explain that here to? This thread is shot and way off course so defend yourself.

 

QUOTE "You know the XJS can't handle much more than 350HP with out major upgrades, that's why you're pushing the XK in the XJS forum"

Thats complete bullshit. The XJS can handle more that that as a street car. Not everyone drags or races or has sticky feet. (I'm running about 325 and it needs more please)

Icsa, you need to back the truck up mate. You are not God. You don't know everything and there are many ways to skin the cat.

I am still trying to fathom why you would spend countless hours and money on an XJ coupe with body welds and tubes and major chassis strengthening all to place a 4.0L six into it?

But that's anther story.

Andrew... Keep trucking mate, you have a place in the market and I will exploit your knowledge again on another project.

Craig

 

I think we agree- this thread is dead.

Anyone interested in further info on the original topic probably knows how to get in touch with me....

All the best

Andrew

 

I think so too. Thread closed.