Don't get too excited, i've looked at the ECU .bin file for my X350 XJR, and looking at it in Hexadecimal, Decimal & Binary, I can find no obvious "155" to change for the speed limiter.

Maybe it's different with the ECU file for the X308, but seeing as they are both Denso ECU's, I can't imagine there being too much difference.

The problem is that you need to be able to de-code the file, looking at it as raw data it's impossible to decipher. There are devices that already have the coding in place.

One device used to re-map Denso ECU's in our cars is called a K-Tag, Alientech - K-TAG i don't have one, & the Master version is the one capable of editing ECU's, the Slave version can only load pre-made files.

More info here Remapping Tools - Kessv2, K-tag, Powergate, Ecm Titanium, Cables

 

Have had my 2001 V.P. at limiter 155mph, fast enough for me on U.S. roads. Although it was late and the middle of the night on I-75 . The only modification to the car is I fabricated and installed a 3/4 bellypan. The car started to pull really hard at 130 and was about out of 'wind' at 155. This is a Canadian import car with 38,000mi. the car felt solid at speed but wind noise was very high.

 

Any pictures of the 3/4 belly pan?

Did it improve gas mileage as well?

 

with a twin screw, blue solenoids, upgraded tires and everything buttoned up properly...i have no doubt the XJR's could hit 200mph in a wide open setting...

the upgraded e55's(same tranny) and less hp are hitting 202mph at nardo in italy...

Is there a way to turn the rev limiter up to 5000 instead of 3000?

 

I totaly agree with you princemarko, the gear ratios of the 722.650 (from XJR/XKR) is exact the same as the 722.643 of the W211 E55/SL55

The only differece is the rear diff.

A interesting point would be the aerodynamic of the XJR in realtion to the E55.

 

While I'm sure with more power it can be done, it seems our cars are bricks in the wind relative to the Merc, look at the and read the acceleration above 100mph here....

2000 BMW M5 vs. 2000 Mercedes-Benz E55 AMG, 2000 Jaguar XJR – Comparison Test – Car and Driver

 

at 650 hp(which is certainly attainable with the twin screw and extra mods) our XJR's/Super V8s can top 200mph by overcoming the .37 drag coefficient... Lightening the car would certainly help. I would just be worried about parts flying off... 200 mph is not safe in any car. Everything would have to be buttoned up, checked, rechecked, made sure engine/trans, everything is in proper working order.
But I would LOVE for one of us to find out....

The 4200 lbs E55 Estate hit 202 at Nardo which is a long oval track and slows the top speed down slightly, and that had 575 hp I believe... I'll look for the link again.... Kleemann also got a 2003 E55 to 211mph on the Papenburg raceway in Germany with 607hp strapping on their own supercharger.

 

For myself i can tell you the XJR is way quicker than the E55 ( at the moment my father drives the E55 S210 estate as our work horse and my younger brother has the E39 M5 )
A good friend of me drives a C55 W203 ( second cats removed, 390hp on dyno ) and if the weather is cold and the intercoolers of my XJR also, we raced from 60 kmh up to 230 ( start in 2nd gear)
Up to 200 the XJR was a half car in front of the C55 but then he slightly pulled away (dont know if its because of the drag or the heat soak of the intercoolers? )

In comparsion to the M5 of my brother, from 60kmh he constant pulled away...

New Audi RS5 Convertible (2 person) vs XJR (me alone) cold weather, the RS5 was not so much faster than the XJR, from 60 up to 220 maybe 1 1/2 - 2 cars


I think with about 550hp a XJR could reach the 200+ mph range

 

I'm not so sure... I think it would need that extra 50hp at 600hp to top 200. The drag coefficient is .35-.37 vs .27-.29 for the e55/63's and it makes a difference... I'd love to try it once i actually get avos' twin screw.

 

I read this on the internet a lot, but manufacturers disagree.




And so does Tiff Needell. In a Jaguar.


In a perfect world, a trained driver can virtually always keep control of his car. But the world isn't perfect, people don't have perfect attention spans, and sometimes enough is happening that paying attention to everything and reacting accordingly is impossible. Even we're talking about the perfect driver who isn't affected by any environmental considerations, no car gives the driver the ability to modulate throttle and brake for each wheel independently, simultaneously, and that technology gives superior control over a vehicle compared to one steering wheel, one throttle, and one brake pedal.

In the end everyone is entitled to believe what they want to believe, but the science speaks for itself. F1 drivers - arguably the best in the world - turn better lap times with fewer incidents with drivings aids than without. I'd say that alone speaks volumes about what the technology brings to the table.

 

i live in Cali too. Go to El Mirage. Spend $15 and go enjoy a day of top speed runs on a 3 mile long dry lake bed.

 

Having run the San Bernardino to Palm Springs jaunt back when there
was not so much traffic, I can certainly tell you that what looks like nice
flat even roadway....is not, when you reach certain speeds.

 

I got an indicated 140mph from my XJ40 once, with a slight downhill to help get there. The front did get a bit floaty, but then the shock top bushes were shot on the front end. No real desire to try maxing my XJR, if you can go that quick then it's the wrong sort of road to enjoy driving on. It does feel like it'd pull to silly speeds when I've taken it to 110-120mph a few times though.

 

Me too I did 140mph on my 220hp xj40, and that with the car loaded up to the roof and honestly there were still some margin left to push the gas pedal
I did around the same speed on 290hp xj8 on autobahn and boy there were plenty juice left to squeeze from it, unfortunately (or fortunately) neither traffic nor the weather allowed for more
But me think 155mph from xj8 is a conservative estimate