I am thinking about taking this 03 XJR to the next level. Has anyone done this perforrmance upgrade? If so, did you notice any difference? Also Master Jaguar Tech what do you think?

 

Mike @Eurotoys says the KB supercharger will take 1 second off the 0 to 60 time and move the quarter mile time to around 12.7 to 12.9 seconds @118 mph. That is pretty FAST!!!

 

Avos has done it, and others are considering it. It is definitly the way to go. More boost, cooler temps, and less power to turn...

 

It's a really good mod, but expensive. $6000 plus labor. You have to ask yourself if its worth it considering the strain you'll put on the drivetrain also.

It's probably better to go with some upgrades and get closer to 475-500hp.

@Brutal I was considering the Eurotoys/PSE Superchargers porting and pulley upgrade. They claim the porting gains 30hp and the pulley will get 30-35hp. What do you think?

 

I asked Mike @Eurotoys LTD if the supercharger would do any damage to the powertrain and he said "No".

 

The drivetrain is pretty strong, have had several twin-screw setups on my car now for over 80.0000 miles, and so far mine is holding up very well (most of the time about 430rwhp).

The kit I have developed is based on the 2.6H Kenne Bell, and would also fit the 4.0 XJR.
Am currently investigating if I split it in a Stage 1 and 2 versions, but that will depend on some more test I am currently conducting. I do hope to have it sorted in the coming weeks.

 

I'd love to do a twin screw conversion a newer XJR 4.2 or Super V8. I'm shying away from my current 2003 XJR simply because I have over 90k miles. If it was in the 50-60k mileage range, I'd be all over it.

 

I have now 160Kmiles on my car, with 90K I would say the engine is nicely run in ;-)

The advantage of a twin-screw is that it consumes less power from the engine, at least 30 rwhp in stock form and similar PSI, and the difference becomes bigger compared to a twin-screw if you start spinning the Eaton faster.

So adding 30 rwhp more with an Eaton, is more stressful to the engine then getting 60 rwhp with the twin-screw.

One of my older setups with a 2.1L Kenne Bell delivered about 375 rwhp with 12 psi compared to 315 rwhp with the Eaton in stock form. That setup wasn’t even close to the efficiency I have now, but I think you get the picture.

 

the biggest strain to the drive train would be putting slicks, or drag radials, tuning the torque convertor to increase stall. Then you could worry about driveline strain. the ecu on shifts is still going to cut torque output temporarily by shutting off the fual injectors to smooth shifts(you can see this with a air to fuel gauge hooked up in the car) and with traction control will also limit power and wheel spin. As power goes up and you turn off traction control, then your tires will limit stress to the drivetrain cause theyre just gonna go up in smoke without prudent gas pedal usage. I wouldnt be concerned with the increased power output as Avos has pointed out through his real world experiances with his cars. And Jaguar built their own 510hp supercharged 5.0 useing basicly the exact same drive train. And since they will not push a car past its capabilties for warranty issues and cost, you can rest assured theres more to be had safely. If something is gonna break, its gonna break stock too. Please remember that forums are good for evryone coming and looking for answers to BROKE cars, so it can seem like theyre alot of failures, but as a % of the cars out there and the failure rate. It is still small

 

That is very interesting. Did you get the twin screw setup from Eurotoys?

update: nevermind, I see that you developed it yourself. What is the cost? Lead time?

 

no he built the system himself and has a source for the twin screws. per his posts he's close to bringing his work to market

 

Agree fully with Brutals post, the TCM indeed sends a torque reduce request to the ECU when it wants to shift (yep another mod for the dyhards ;-)). Would also like to add that an LSD also puts more stress on the drive train, but so far it has worked out for me though I know the extra styress it brings.

I am trying to figure out if I can still make efficiency improvements, will need about 1 more week, chances are that I will split it in different stages as mentioned earlier, and then the good news is that stage 1 is ready.

Please send me a PM if you are interested.

 

Avos how would you describe the performance of the KB compared to stock (performance figures). Also, how would describe the performance compared to the new and previous generation BMW M5 and MB E55 AMG

 

The previous generation E55's are monsters. 0-60 in 4.4 stock, with mods they are running 4.0 sec 0-60 and under 12 seconds for the 1/4 mile. Competing with the Merc AMG's is a lost cause, they start out with 469hp 516tq for the 55 AMGs and the 63 AMGs are running sub 12sec 1/4 mile from the factory. I almost bought an E63(stuck with my G55), but you have to remember.... there are a billion E-classes on the streets. Cars like Maserati's and the Jaguar have character rather than just blending in with the crowd.

AVOS' KB setup will have at least 75-100hp(I'd guess closer to 150hp) over the stock. You'll be able to run with the E55's and M5's 0-60 no problem if they're not modded, but they'll get you in the 1/4 mile. Most people run from stop light to stop light so dont worry.

 

please remember too that twin screws like Kenne Bell, Whipples and TVS's are TRUE compressors. Not an air pusher like a typicle roots(Eaton) the twin screws build max boost almost instantly instead of the linear climb of a typicle roots blower. So you have to look at what you get for power below peak also, its alot more power output lower pound for pound. And that can make a huge difference on everyday driving and stop light warrioring

 

I find your comments about the E55 amusing as I have not yet installed a twin screw supercharger but have done every other mod possible & 2 years ago with a 3.27 non pozi diff fitted to my car I have seen as low as 4.06 seconds 0-60 on a cold day. I now have a 3.58 pozi & within 2 weeks will have a 3.77 pozi fitted. I would love to see any E55 stock or modofied try to keep up with me.

 

When my car was stock it made about 310 rwhp, and assuming a 17% drive train loss that would be about 364 engine HP. Will have to do some new dynos as my previous ones early this year where not valid, those showed 550 rwhp, wrong setting in the dyno software…

Not sure yet what the max power is that can be had with this kit, will do some more testing the coming weeks. But I already had 470 rwhp (stock ECU tune/Stock Exhaust/relatively mild pulley combo) which would be about 553 Engine HP, and I am hoping on more than 500 rwhp (602 Engine HP), let’s see.

So this kit would bring at least 150 extra Engine HP (if the 17% drive train loss is about right), probably closer to 200 engine HP pending some other mods.

Am not familiar with an E55, but do you think they can keep up?

 

Under your name I see it says 2000 XKR. Is that the rear end you are talking about gear wise? I was looking for rear end gears for my 99XJR when I had it and could not find much info out there. I am looking to get another X308 XJR and would love gears so I dont have to spend as much on engine mods to get it moving reasonably.

Thats all the Mercs and Bimmers have on us is a better gear setup. Acceleration vs MPG. Unfortunatly we get MPG. If it wasnt for the presence of a clean Jagaur, they really wouldnt be appealing to many for the price vs competitors in its class.

If you do have gear info please let me know.

Thanks

 

The parts & technology exists to change your gearing on an XJR/XKR with the Mercedes trans. You can do 3.27 3.58 3.77 or 4.09 all with a LSD option.

 

The stock E55 engine starts with 469hp, just like my G55(I have 621hp with 690tq). My cousin has an E55 and only has 570 hp, he's running 0-60 in 3.9 with 10.8-11.2 1/4 miles.

You undoubtly did a heck of a job with the Jaguars, but you are still fighting a losing battle vs the Mercs.

I LOVE my Jaguar because of its character and I wish it came with stock 450hp, but to try to put $15k-$20k in mods just to keep up with a stock E55 is a bit off the wall.