Supercharged XJS
 

Hey folks, I've got a 96 XJS convertible with an AJ16 engine. Just wondering if anyone has swapped the supercharged AJ16 from an XJR into an XJS? Would the ZF hold up to the increase power and torque?

Seems like this would be the easiest and best power gain for my car. I'm not really interested in the V-8 swap, while I know that is the most bang for the buck.

I've heard of at least one guy making the swap...and heard it was difficult. All third-hand information so I don't know the details but I *think* the XJS engine bay is narrower (or differently shaped?) so he had fit problems....as well as electrical architecture problems. Maybe another reader here knows more about it.

At minimum I'd want an XJR donor car alongside so I could get ALL the engine managment wiring, ECU and trans modules, intercooler radiator, etc etc.

I suspect that Jaguar selected the 4L80E trans to use with the supercharged because they felt...or perhaps knew....that the ZF wouldn't hold up. The XJR/6 engine is one torquey mutha ! :-)

Cheers
DD

I suspect your right on the transmission.

I'm surprised as to the fitment as I was thinking the engines were one in the same with exceptions to the supercharger. I guess that is actually mounted down low on the drivers side. I found a pic of one on the web. While I've never seen an XJR, I just figured it would be topside somehow.

I have a few friends that have Supra Turbos and they want to fab a single turbo set-up on the stock engine. This scares me a little but there convinced they can have the car running and tuned on E85 for less then $4,000. This would be a low boost 350-400 hp application. The E85 comes into play as the AJ16 has moderately high compression in regards to boosted applications. 9.5:1 if I understand correctly.

I will admit that having a turbocharged AJ16 XJS is about as cool as an XJS gets. I'm thinking about. Worst case scenario, I can buy a used engine to replace mine if it all goes bad.

sounds doable to me , so have at it!

hard to beat a pressurized inlet manifold!HAHA

that sounds cool.
have'nt heard about any XJS with a "pressurized inlet manifold" yet :icon_razz:
thought alot of the supercharged 6 before I decided to go for the V8.
even if you going for the supercharged engine or turbocharged the existing, I'm looking forward to se how this goes:icon_wink:

Well if, and that's a big IF, I was to undertake all this it wouldn't begin till winter. I live in northern Minnesota and we have short summers and long winters. I don't want to take the car out of commission during the summer.

Can anyone tell me if the AJ16 can be mated to the 4l80e transmission? Perhaps the trans in the XJR would bolt up with no modification?

Doug,

If I remember correctly Jaguar World Monthly had an article about a guy trying it (it may be the same one you're thinking of). At any rate, it was a bear to sort out. The easiest part was re-jiggering the supercharger parts. The hardest part was the electronic bits which required quite a bit of soldering, fabrication and the like. Had Jaguar decided on making an XJSR-6 it would have been a nice car IMHO. It would likely have taken sales away from the V12 though.

Mike

Are you asking if the XJR/6 4L80E will bolt up to a normally aspirated 4.0 ? Not sure but I don't think so. Either the supercharged block had a different bolt pattern or some sort of adapter was used. I can't remember which.

Since Jaguar was already using the 4L80E behind the V12 I *think* the most logical solution would be an adapter to bolt it to the six cylinder block...eliminating the need to specify yet another bolt pattern from GM.

The 4L80E directly from any GM vehicle will not fit at all, if that's what your thinking, as the the 4L80Es built for Jaguar had a unique bolt pattern.

All that said, are you contemplating adding the XJR/6 supercharger to the standard 4.0 engine? If so, that won't work at all. Among other things the compression ratio on the standard 4.0 is too high for use with a supercharger.

IMHO the only way to even consider this swap would be to get *everything* from an XJR/6 donor car, including all engine/transmission management controllers and wiring.

Cheers
DD

Yes, I think that's the one !

I agree the the supercharged 4.0 would have been a nice combination. A *great* combination, in fact.

I'm not sure why they didn't do it. I don't really think it was a matter of jeopardizing V12 sales, though. Circa 1994-95-96 the V12 XJS production what whittled down to a mere fraction of the total.

They obviously felt there was a need to offer a "performance" sedan but perhaps their plate was too full to include the XJS. Or perhaps felt the elderly XJS wasn't worth the effort, especially with the XK8 just around the corner.

I dunno. I just wish they HAD built it.

Cheers
DD

Doug,

I think you got it right about the reason; the XK8 and XKR would be in production fairly quickly. However, maybe you can convince your client to build up an XJS with this: 555 ci big block Chevy from Edelbrock that puts out 700 hp. Superchargers? We don't need no stinkin' superchargers.:icon_teeth:

http://www.edelbrock.com/automotive_.../chevy/655.jpg

There were reportedly a limited number of XJR/6 built with a 5 speed manual Getrag transmission. A very tough and smooth shifting transmission.

supercharged 6 + 5 speed manual = great gobs of fun.

I think it was 207 built with the manual trans. I'd love to have one.

I'm told that Jaguar used the 3.27 (vs. 3.58) differential in the XJRs specifically to allow the manual transmission version to reach 60mph with only one shift....thus keeping the 0-60 time below 6.0 seconds. I think it was 5.7 seconds to be exact.

That may be ho-hum by today's standards but back in '95 that was really honkin' for a 4200 pound sedan !

Cheers
DD

The problem is that, as I understand it, the supercharged equipment just doesn't fit very easily under the bonnet of the XJS. The blower hardware is on the left side of the engine. Also under the bonnet on the left side of a US spec car is, like, the steering column, plus some other miscellaneous hardware. I seem to recall reading that someone converted a RHD XJS to XJR firepower with some difficulty (the result was impressive!). But to do the same on a LHD XJS - exceedingly difficult. Just park an XJS and an XJR side-by-side and focus on the left hand side of the engine compartment - you will understand why the factory never did it (with the US being the biggest potential market for such an upgrade - if you can't do the US spec car, why bother).

+1

They should have talked to some drag racers. :D

Any info on the bellhousing/pressure plate?

One of the best sources for XJR/6 info is Andy Stoddart. He was an engineer at Jaguar and involved with XJR/6 development. He regularly posts here:

Jaguar XJR6 Owners Site.

He owns a manual trans XJR/6 and knows them in-and-out. He can fill you in on clutch specifics, etc. Actually I think the clutch was the same as used on all other manual trans X300s but, since it's all only a dream for me, I've never bothered learning the details.

Cheers
DD

I just wanted to chime in with a few idea's regarding this potential project. I am the one in gandalfs ear suggesting to go to a very basic turbo setup. Here are some of my thoughts. I figured using a very simple log style manifold custom built (locally) and using a internally gated turbo with response and fast spool in mind would keep things simple and very torque friendly.

Please keep in mind this is nothing more than a idea at this point but i do however thinks it is very doable. I was assuming that this motor had a bit higher compression than 9.5:1 but that will make the overall setup a little more boost friendly. knowing things such as head flow engine V.E. would help in choosing the right turbo for this motor, but i figured something alont the lines of this might do the trick
BorgWarner EFR 7064 Turbo - Full-Race.com
I suspect that it would result in a very low boost threshold of maybe even 1500rpm and spool silly fast with the already strong tq curve. i think the goal of 300-350 rwhp and 400+ tq could be easily done utilizing e85 fuel that we have at many local gas stations. all this with out running much over maaayybe 15-17 psi of boost. and sice this is a turbo we are talking about it could be easily dialed back to a moderate 5ish psi and take it easy on drivetrain components.

in regards to engine management i want to use a map-ecu2. this is a piggy back system that eliminates the maf sensor and uses tps input rpm and manifold psi to manipulate the ecu's signal to the injectors. these systems are easy to install and can have very good drivability. i have installed and tuned it on my own car with amazing results. it also has the ability to piggyback the timing signal.

at the end of the day i believe that any motor can be turbocharged assuming one is willing to put in the time to do it right and have a reasonable goal in mind.

it would be testing the durability of this inline 6 but i have a lot of faith in and i6 as they have treated me very well :)
please feel free to add input as this is a learning experience for me as well in regards to this motor.

well finally someone who is realistic , TURBO , good idea, E85 fuel =105 octane, engine managment system(so you can tune the project),simple log manifold.

an engine drivin supercharger! way to much work,(like machining, welding, pulleys and belts flyin off.

theory says, 15psi in the inlet makes 100% increase in power, YUP turbo the way to go,, plus ,lots of info out there on how to do it,correctly!

HEY, MNMKIV, is that a 2JZ by chance?
ron

and gandalf, make the power 1st, then when tranny blows , you can do something to it!

its BASIC hotrod stuff, make power 1st, then worry about the other stuff!

i think my father said it best, dont put the cart before the horse!! haha.
ron

funny thing about e85 with boost is that yes it is only 105 octane (winter bled e70 even less) the cooling properties of the ethanol is amazing for fighting detonation. many, my self included have made more power on straight from the pump e85 than on c16 leaded race gas (120+ oct and 15.00/gallon)
and to boot e85 make 30% more exhaust energy (spools a turbo faster) and you can throw a stupid amount of timing at it. all this means great tq
yes it is a 2jz stock 125k making 700 hp and 680 tq on e70 30+ psi

Just wanted to note that's rear wheel hp & tq. Generally on the Jag forums people quote flywheel hp. Not that 700 flywheel is bad, but didn't want sell the little 3.0 Toyota short. :)