Just fact, no crack.

 

You know, there's only one sure way we're going to settle this....

 

In the UK we have a choice of four engines - a superb 204 bhp 2.7 twin-turbo diesel, a 240 bhp 3.0 V6 petrol, a 300 bhp 4.2 V8 petrol and the range topping 400 bhp 4.2 V8 supercharged engine that powers our test car the Jaguar XJR. All models are fitted with the ZF six-speed automatic gearbox featuring Jaguar’s famous ‘J’ gate selector.

As the Jaguar XJR is an all aluminium affair which gives the XJR an unfair advantage in the all important power to weight ratio, it only weighs in at 1659 kg compared to 1830 kg for a BMW M5. The body shell is some 40 per cent lighter than that of the equivalent steel body, yet the XJ is 60 per cent stiffer than its predecessor.

carpages.co.uk/jaguar/jaguar-xjr-review-part-1-04-09-07.asp




No further comments from my side, is useless.Some people just can not have it when they are wrong...
1659 kg is exactly 3.732.75 Lbs in your language.
No apologies.Can happen.

 

The number they mention is for a XJ8, not an XJR.

Try this:

http://www.edmunds.com/used/2004/jag...195/specs.html

Or this:

http://autos.msn.com/research/vip/sp...ries&trimid=-1

I can give you more if you want, not one person has agreed with you yet. Bring the car to a real drag strip in the USA, if it is stock, it will not get into the 12's period.

By the way, what is your 60 ft. time and trap speed? Ever had it on a scale?

 

'As the Jaguar XJR is an all aluminium affair which gives the XJR an unfair advantage in the all important power to weight ratio, it only weighs in at 1659 kg compared to 1830 kg for a BMW M5.'

I think is clearly enough written, regarding the weight.It is for the XJR, and NOT XJ.

Anyway i tend to believe that maybe there are 2 versions of XJR, one for Europe, and another one for the USA, as i also saw that your tank capacity for example is 22+ gallons, and i only have 17.5 gallons capacity.
Maybe some different requirements in USA make the USA version heavier.I really don"t know.

 

There is indeed some difference if you compare the UK specs fromt he US one

http://www.jaguar.co.uk/uk/en/xj/mod...dimensions.htm
http://www.jaguarusa.com/us/en/xj/mo...ifications.htm

Here is some more interesting info on what can affect the times, where temperature for the supercharged cars plays a very important role.

http://www.matmoranmotorsports.com/index.html

 

Avos!
I think God must have send you, and you solved here our problem since a week!
I can see, that indeed the USA version is 300 lbs heavier, than my version of XJR, and this and only this, explains why i can catapult under 13 seconds, the 400 meters.( indeed 2.5 meters less than the 1320 feet). And i can understand now the frustration of my fellow usa drivers, who can not do that, and think am crazy.

So finally gyes, we were all right in a way.No hard feelings, against anyone.We are a special society with our cars, and as such we should deal with each other.
Again thanks Avos, good job.
P:S Sorry for your ...heavy cars gyes!! Hehe.

 

So how fast is a lighter XK8, with 650 HP and a limited slip?

 

Good morning JTO,
Should be around 11 seconds, according to ET calculator, from Mat Moran Motorsports .
You got one?

 

Hi Costas,

Avos does, but he doesn't talk about it too much. At least not when I ask.

 

http://www.matmoranmotorsports.com/ETcalculator.htm

Am sure car is like a rocket, but of caurse you gat a know the exact weight.But with 650 HP is ...irrelevant!It's under 11 seconds.

 

No not necessarily JTO,

I have a XKR cabrio, which I checked for weight and was with a full tank (no driver) 1820 kg which is I think 4012 lb. I rather speak of rwhp then flywheel HP, as the later is only a calculation/estimate and people are using different ways to get to this. In top trim my car has had over 450 rwhp, and am currently working to get to the 500 rwhp just to see if it is reachable. With these levels a LSD is a necessity, not a nice to have anymore. But to cut to the chase, drag racing is not so popular where I live, don’t even know where I could do this. But even with LSD, there is a lot of wheel spin due to the tremendous amount of low end torque, so for good times you would probably also need special tires. Am looking forward to do some drifting this summer though, and of course get to 300 km/h, but that would need a ECU tune to remove the speed limiter which I haven’t done yet.

Andre.

 

Thank you for the response. I was under the impression that you had written about 600HP at the flywheel for a 4.0L... So the same massive increases to a 4.2 would yield even higher results. The nice thing about timing the car instead of spinning it on a dyno is that the correction factors are alot harder to mess up. Have fun in the sun with yours!

 

I ran 12.95 @ 106mph with 245whp in my 1990 Eclipse GSX.

At a track 5,800 ft above sea level even.

 

@JTO,

Some tuners in the US use a drive train loss of 22% (not me), and as an opening for a post I used the 600 BHP once, but also with a question mark to underline this figure. It comes from a realized 470 rwhp with 22% drive train loss that equals then 602 BHP, so there you got it from.

I agree with the dyno stuff, as a BHP figure marketed from any car manufacturer doesn't negate to timings if that is what you are after of course being it 1/4 , top speed driving or racing. However the dyno does take out the guessing factor of certain changes to your car as long as you know what to do to keep it controlled/comparable. Measuring is knowing, that should appeal to you I would have thought.

If I ever get the opportunity to de a 1/4, I will certainly try, and post.

Andre.

 

Agreed on all points. I wonder if feeding an engine air of superiority makes a few extra ponies. That's one more mod I'm not in the position to test.

 

So what!

 

Costas:

60 Foot times?

Trap speed?

Should be very easy to answer!!! It is very clear you just don't get it.

 

Anybody that has had their car to the track will state the exact time they ran, not "under 13". How far "under 13"? How about averages? How about your best time ever?

 

@JTO, Haha, it works wonders, don't wonder there.