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Supercharged XJS

Old 06-25-2011, 02:00 AM
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Originally Posted by MNMKIV View Post
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
The ethanol content is similar to the previous method of alcohol injection. The difference is that it is already in the fuel straight from the pump.
Old 12-15-2011, 01:03 AM
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A bit of a thread revival here

I don't normally visit the Engine forum much but thought I would take a look

I know for a fact the XJR engine has been fitted to XJS's a few times, JagWorld magazine done a write up on it some time back, not the easiest thing in the world but do-able

I took a slightly different route, shame I dont have any finished pics!

Not a lot was standard about my XJS, I fitted the XKR engine with a tranny from a Dodge Viper (6 speed manual), had the whole lot running on a Motec M800 ECU..... Time passes, I did that 12 years ago!!!
Old 01-14-2012, 04:04 AM
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I know this is a very old thread now but people might be interested to know that several DIY AJ16SC XJS conversions have been performed. I helped get one of these running myself. It was LHD. When I worked at Jaguar we actually built an AJ16 powered XJS prototype but the project never went any further. As Doug suggested the best quality conversion would use the complete powertrain from and XJR6, but you could cross your fingers and retain the ZF4HP24E gearbox. It isn't really up to the job which is why the XJR6 uses the GM Hydramatic 4L80E. However, I would accept that using the 4L80E and its TCM will make the wiring much more complicated. I would still argue that putting an AJ16SC engine in an XJS is easier than turbocharging an AJ16 NA engine or fitting a different engine that was never designed to go in an XJS.
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Old 07-05-2014, 04:11 PM
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Aston Martin used a supercharged AJI6 engine in their DB7 which was built on a platform of an evolved Jaguar XJS. Left hand drive cars were exported to the US and Canada.
Old 07-05-2014, 05:19 PM
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I have given a bit of thought as to why Jaguar did not put the super charged AJ16 in the XJS. It dawned on me that it probably had as much to to with the upcoming release of the XK8 as anything. How would it have looked to have a in line 6 putting out more horse power the a new V8 would?

There is no doubt that Jaguar could have made it work if they had put the energy into the conversion but on the LHD cars it would have taken a bit of fit work with the brake booster etc. I am sure with just a year left to go before the release of the XK8 that Jaguar just could not justify the resources to get it done. Oh well, as the saying goes " what could have been".
Old 08-11-2014, 05:12 PM
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I have a xjs with aj16 xjr6 motor in it. the standard aj16 differs from the S/C motor. different comp ratio etc. best to find a complete unit from a xjr6 and take the ecu and harness too.
Old 11-06-2014, 11:43 AM
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This is a very interesting idea. While reviewing the documentation for my recently purchased 4.0, I found that the transmission (Getrag 290) came from an XJR (although nothing more than a coincidence as it'd be the same manual in the NA X300).

Point being... it's something to consider. XJRs seem to be available, and not terribly expensive (there was one local to me for 3.5K). Theoretically I could by one, swap, and have both an absolute supercar rivalling an Aston Martin, and a leftover XJ6 (XJR with the rare "supercharger delete option") for getting groceries (or sell for cheap). Tantalizing thought.

Obviously I'm a Jaguar novice, and these things always sound so easy on paper, and it will be a full year before I even have my car up to snuff and where I want it - so a total pipe dream at this point. But a very intriguing one.

For XJR Engineer and Hippy, and anyone else, what are you thoughts on the SC AJ16 XJS? Sometimes there is too much of a good thing, and radically increasing power can change a vehicle's dynamics and wear it out. But the XJS can obviously handle a (heavier?) 6.0 V12 putting out similar or more HP depending on tune - I don't think brakes and suspension would be overstressed. Drivetrain / diff?

Hippy, care to comment the driving experience? Did you build your car or buy it that way? What are some of the hurdles here? Obviously you'd want all the engine management from the XJR. I've read the immobilizer can be problematic but I bet XJR engineer could disable that function or there's another workaround? On an LHD car, was there significant engineering required to deal with the steering?

Like I said, it's an intriguing proposition. I'm already halfway there with the correct transmission, and the actual motor wouldn't require much (I don't think?) in the way of fabrication or anything. It seems like it should just "drop right in" although of course it's never that easy.

If anyone knows of any write-ups, or can find that JagWorld article, I'd love to see more on this. I found an article in German here: XKJaguar | Jaguar XJS SC

" During the renovation of the unit because of the modular Jaguar construction method well is hardly encountered any significant problems, but also the ECU, so swapped the engine management system and connected according to the wiring harness of the vehicle had to be what was probably the real challenge of the project."

The engine looks to sit in there quite nicely.

Last edited by 95 AJ16-5; 11-06-2014 at 11:49 AM.
Old 11-06-2014, 11:59 AM
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Supercharged AJ16s been done many times

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This one is working OK now

I'm fitting anothers XJS right now with a XJR V8..... There is some talk about it on another thread
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Old 11-07-2014, 01:28 PM
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Very cool XKR, looks right at home in there.

Any comment on the process or the result?

Old 11-07-2014, 01:50 PM
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Yeah its not bad, the car goes well but you do hit a wall unless you pump in serious money...... Sure it feels faster than any other standard XJS I have been in.... Much quicker than the V12s however the characteristics of the car have changed the sound of the supercharger and the intake is most noticeable..... Don't get me wrong it's not bad..... Just different.....

However the V8 will be another animal again....... If you facebook you can follow the progress and of other models at Modified Jaguar
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Old 11-24-2014, 10:49 AM
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On topic but off. I have had a little bit of experience with the m112 on a v6 as opposed to the m90 and well...The m112 just never seemed to perform well or any better than the M90. Now I had a 4.6 v8 with an s port m90 and it hit a wall at a bit under 400rwhp. Now I have absolutely no experience with the inline jag 6 however I had purchased a magnum powers MPX (m90 case) and had the inlet modified to work. Picked up close to 30rwhp at the same blower drive ratios. Has anyone here tried out the Magnum Powers MPX case? Basically it takes the Eaton M90 design and adds the latest inlet port technology from eaton to it. Worth a shot if you are hell bent on keeping an M90 but want more power.
Old 11-25-2014, 05:43 PM
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Originally Posted by Gandalfthegray View Post
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.
interesting project;

i wonder which is a better engine for turbocharging, the Jag XJR-6 or the smaller Toyota 2JZ inline 6, 3.0L.

could the xjr6 make 1000hp , a lot of 2jz are that and more!

pix of a lowly 720hp all wheel drive Nissan Skyline. i cared for it at my Daytona shop, but driving it was to aggresive for my liking!
Attached Thumbnails Supercharged XJS-nissan-r33-skyline-720-whp-006.jpg   Supercharged XJS-nissan-r33-skyline-720-whp-009.jpg   Supercharged XJS-nissan-r33-skyline-720-whp-017.jpg  

Last edited by ronbros; 11-25-2014 at 05:46 PM.
Old 01-28-2017, 03:16 PM
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Did you ever complete this project ??
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