Spend 10 minutes on YouTube and you'll see that lots of people don't handle 500-600hp well at all.

Cheers
DD

 

Yes--the classic video that was making the rounds a while ago were two idiots in Corvettes dragging from a stoplight in what looked to be a local highway and one of the guys lost control wiping out both cars.

Doug

 

I'm used to performance American V-8's.

The 7000 RPM redline is exciting and the 5 speed automatic in my '01 XK8 helps with the performance of the small cubic inch motor (vs 3 or 4 speeds).

That being said, I have have to say that if the shifts were more firm and not slow slushy feeling, the elapsed times would be greatly improved, all other thing remaining the same.

I understand the luxury/comfort behind the shifts, as they are.

 

You are exactly correct about the shifts. With previous cars I installed shift kits and/or shift programming to make the shifts firmer and harsher since it felt sportier. When I got the Jaguar I thought something was wrong with the shifting since I could barely feel the shift. Then I would come across articles in JWM or other places that talked about "slurring" of the transmission through the gears in these cars which was touted as intentional and a good thing. And the more I read the more it was obvious that the XK8/XKR were designed for refinement (a word used a lot with Jaguars) rather than excitement.

Doug

 

But what "compiled" means ? I see a single number: 6.4s for the 0-60 for the XK8. Is that an average, the best time amongst several reviews ? And what are the magazines in question ? After all, it may well be the manufacturer data ! :-)

Never mind, the way the V8 expresses its performance cannot be reduced into a simplistic 0-60 thing. It is all about its softness and liveliness, its overalll abilities across the rev spectrum. And once a proper exhaust is fitted, the noise is just poisonous. No need to drive fast to fully enjoy it, that's its real beauty I think.

Once I get hold of the review of Auto Motor & Sport, I will post a few more numbers. That was very detailled and precise - a typical "made in Germany" kind of thing.

 

com·pile (km-pl)tr.v. com·piled, com·pil·ing, com·piles 1. To gather into a single book.
2. To put together or compose from materials gathered from several sources: compile an encyclopedia.
3. Computer Science To translate (a program) into machine language.


I am not responsible for that article, but the way that I took it, it seems to me that they mean that they looked at various road tests and so forth from American Standard XKs and picked a middle ground.

I recall looking at several such tests and, as I recall, I saw various times from them going from a low of 6.2 secs for a coupe up to 6.7 for a convertible in another. Most of the ones that I saw were in the 6.4-6.6 range.

Most of us are very well aware that this car was not designed or intended to be a drag racing vehicle.

I don't know what is going on with these attachments, I did not attach anything and can't remove them.

 

On the other hand there is some guy over at the S-TypeR section that keeps posting youtube videos of his car blowing away everything and anything including cars you would not expect to be outrun, such as a recent Boss Mustang. I am amazed that the S-type is so fast but I did notice he upped the pulley on his supercharger.

Doug

 

XK 0-60 times aren't nearly as impressive as it's 60-120! ;D

 

I think that's right. It takes a lot to get these hefty cars rolling off the line but once they are underway they are pretty responsive at speed.

Doug

 

I've done a couple of runs from about 70 to a little over 110 and the thing is that it feels like it is coming on more and more as you speed up.

That's the thing about European cars, they have always tended to rev higher than American cars and the power comes when you get up into the higher revs, whereas the old style American muscle cars just had immense torque right from the starting line, partly because of the huge displacement.

 

I also think it is characteristic of the way that power comes on when you have a supercharger or turbocharger. I used to have an Audi 5000 Turbo that was dismal from a standstill but had lots of responsiveness once you were moving.

Doug

 

Well yes, with either, you don't really start to get a lot of boost until you have some RPM going. That is the advantage of a supercharger over a turbocharger, the supercharger reacts immediately to higher rpm, while there is a "lag" for the turbocharger to pick up the increased velocity of the exhaust gasses and provide more boost.

Of course, they have done a lot to rectify that problem over the years.

 

+1 now your in the sweet spot!

 

You would forget it knowing how well it handles with 600 hp.

 

So true... this twin screw XKR is a ROCKET off the line! Thank God for AVos and his brilliant engineering.

 

Auto Motor & Sport - Review published in 1997 – X8 Convertible 4.0

284hp measured on dyno, at 6,100rpm
Gear ratio: 31.9mph (51.3km/h) at 1,000rpm in 5th gear

Cx: 0.37

Acceleration:
0-62mph: 7.6s (0-100km/h)
0-75mph: 10.1s (0-120km/h)
0-87mph: 13.6s (0-140km/h)
0-99mph: 17.8s (0-160km/h)
0-124mph: 33.6s (0-200km/h)

1km drag race (0.62 mile): 27.8s
1km distance, with start speed of 100km/h (62mph), then kick-down: 22.2s (at 198km/h/123mph)

Max speed at 6,700rpm for each gear:
1st: 45.4mph (73km/h)
2nd: 77mph (124km/h)
3rd: 112mph (180km/h)
4th: 169mph theoretical (272km/h)

Maximum speed of 154mph (248km/h) obtained in 5th gear at ~4,830rpm

Weight balance: 50.1% front, 49.8% rear

Braking distances:
62mph-0: 37.5m (cold) / 40.2m (warm)

Average fuel consumption measured: 13.7l/100k => 17.4mpg (US)
Maximum fuel consumption measured: 18.3l/100k => 12.8mpg (US)
Minimum fuel consumption measured: 9.9l/100 => 23.8mpg (US)

Pros:
Charm/pleasure delivered by the engine,
Top notch road handling (globally)
Rigidity (for a convertible)
Plenty of other stuff (global comfort, gizmos available, outstanding style etc..)

Cons:
Gearbox ratios are too long for a really dynamic driving style, large gaps between gears
Little space inside the cabin, rear seats not useable by adults
Suspension too hard on small potholes / small irregularities of the road
Tendency to over steer when suddenly taking the foot off the throttle in rapid curves
Safety features: no roll bar, nor lateral airbags available (even as an optional extra)
Lack of rear visibility (with the roof on, obviously)
Roof mechanism too slow
High maintenance costs, few dealerships (in Germany)
Proper spare wheel only available as an optional extra

Main competitor in Germany, at the time: Mercedes SL500 V8, 5.0l, 320hp, 1833kg. 0-100km/h = 7,1sec, 0-160km/h = 16,3sec, 0-200km/h = 28,4sec, max speed = 250kmh

 

I guess I should clarify that the original post and question was in regards to the XK8, as were my comments.

We know that there are a lot of different things that can be done to the XKR to increase performance dramatically, but that is not so much the case with the XK8.

 

I wasn't reffering to how much extra power you could get, but to the chassis and strenght of the components it can take.

 

On which car? All this time I have been under the impression that while the XK8 and XKR have essentially the same body style, except for the hood and the grill, that they are fundamentally different cars mechanically.

While they both use the same engine block, I though that many, if not most of the components were different, not to mention the supercharger on the R. Also, I thought that the R uses a different transmission and a different suspension system.

Now, I will take your word for it that the body and the ch'assis components are the same, if you say so, as your expertise in working on these cars far, far exceeds mine.

My statement was, "Most of us are very well aware that this car was not designed or intended to be a drag racing vehicle." and then I clarified that I was referring to the XK8, not the XKR, and I stand by that statement.

Thanks for your business and efforts to offer those people who want to "improve" upon their cars.

I think that you offer a tremendous service for those people who want to customize or improve the performance of their cars. Hopefully, you will continue to do so for years to come.