So My husband and I exchanged valentine gifts early. He got me a valentine 1 radar and I got him a performance box. ( good thing we think alike because you definitely need the radar for testing)
Took the jag out and it did 0-60 in 4.4. this was in automatic sport dynamic mode with a full tank of gas and a passenger. I tried paddle shifting but i couldnt get 1st to 2nd timed just right with out it loosing speed in the shift not sure what RPM to use on the first shift. I think I was shifting around 6 rpm.

Eventually I'd like to get it under 4 seconds, but its a great start!

 

I'm right there with you in my 2010 XKR coupe... Frustrating because I know she's capable of a 4 flat. Just can't find the time and road to practice enough. I loose traction bad and haven't figured out an optimal launch method.

Anyone else have any 0-60 numbers with the 5.0 s/c? I've seen 4 flat in magazines, but not on this board.


Skeeter

 

Glad to see I dont just suck. The only place ive seen 4 flat was car and driver I think, but Ive seen lots of 4.2s. Im thinking I just need to get another 70 or 80 horsepower then it wont be a problem! Im going to the R academy in May, maybe I will learn how to drive faster there!

 

I feel the need, the need for speeeeed

Keep practising, but just remember, be careful out there

 

Car and Driver measure their 0-60 with a 1ft rollout, so they always look fast and it is not a true 0-60 IMHO. Let the flames from the drag strip crowd commence....

 

Sounds a "fuzz" low, Kelly....6k? maybe. Anyway, have fun and be careful...

 

Obviously it's K! I always just say the number without the thousand after it. I might be a girl- but I'm not that stupid when it comes to cars!

 

Hi Kelly, I'm sure your brake torqueing your launch but try to get it close to 2000-2500 before launching.

I would also suggest shifting closer to 5, 5.5 rpm at the most to stay in the upper end of the torque curve. Your torque drops right around 5.5 even though your HP maxes out at 6 to 6.5

 

Mike, I was not break torquing. I kind of baby my car, and I was also on a public street with a speed limit much lower than my target speed so I was trying to be as inconspicuous as possible. I will try shifting around 5, thanks!

 

Yeah, I try to launch at 2.5k and manually shift to second at under 6, end up loosing traction, the car wants to rotate counter-clockwise when it does. Brand new Pilot Sport PS2s, so I think I'm getting about as much traction as possible without going to larger than stock tires...

Interesting that nobody has reported a successful 0-60 result in the 4-4.2 range. We are all around 4.4, Kelly you are doing great. I just feel like the car has a power to weight ration and torque curve AND great transmission which should add up to a better time. Wish I had more time and an easy spot to practice.

What'd your performance box cost, what brand? I'm using an app on my iPhone, good reviews and supposedly as good as a G-Tech, but I have issues mounting it per their instructions and worry that my runs aren't being accurately measured. Maybe time to buy a dedicated box if there's something universally accepted as accurate...

Best,

Skeeter

 

I used to pull lower than 4.4 0-60 times in my Mercedes E55 AMG, a larger four-door sedan with less HP. Torque came on sooner, but still, with the weight advantage, the FAR superior transmission, and the excess HP, the Jag should be able to take the E55, a car made back in 2004-2006 (at least the fast version) that seats four with a large trunk and ultra-silent ride. Of course I'm confident that the Jag is much faster from a roll, especially at freeway speeds, though not measured yet...

Granted the E was no razor in the twisties, but ugly that a big honking 4-door could take me at a light. I have a friend who kept his E55, I'll have to set up a drag race in a big parking lot... See what's what.

If I can't get close to a 4, I'm going to have mods on my mind and it'll be hard to reign in the urge. Am I the only one bothered that we are in the mid fours while a $40k mustang will turn a 4 flat with 444 HP and 380lb.ft. of torque (at 4500 RPM no less)?(2012 Ford Mustang Boss 302 First Test - Motor Trend).

Something just doesn't add up. Bad weight transfer for the XKR? You'd think with these fancy electronically controlled differentials we'd hook up like crazy, but something is holding us back based on the raw numbers, and I'd love to find out what it is.

Skeeter

 

Don't go by Motor Trends numbers, they use a 12 inch roll-out when measruing 0-60 which means they are actually measuring 3 or 4 mph to 60.

Inside Line will give you the most accurate 0-60s

If you're using Dynolicious set your roll out to 0 inches but your Trigger to .20 G. This way it will start reading right off the launch but not mistakingly start when you release your brakes

 

I love the car I don't care if I hit 4.4's it's fast enough and it's beautiful. If you want speed, 0 to 60, and a rough ride buy a vette. I like my vette but I Love my Jag.

 

Yup. If you want sub 4 in a similar priced stock vehicle look at the corvette ZR1. Anywhere from 3.3 to 3.8 depending on prevailing conditions. The vette also has launch control which really helps to achieve optimum 0-60 times.

 

Skeeter, I agree Im definitly thinking mods. I haven't found that much info on doing the ECU tune and Pulleys on the newer engine, lots on the 4.2. I'd like to see several other people do it first!
This is the performance box we just got:
PerformanceBox [RLPB01] - $499.00 : VBOX USA, GPS Data + Video Systems
My husband researched a lot and this was the one he picked out. It was easy to set up and seems to work pretty good at measuring everything. He just got a gallardo and its been at underground racing for the past 8 weeks getting a stage 3 turbo system. Should be home in about 3 more weeks. I guess Im just a little freaked out that his car is going to have twice the HP mine does... ( Im slightly competitive)

And yes, I agree if I was going for speed alone I would have chosen a different car. Probably the GTR, that thing is crazy fast and so easy to drive, but its not sexy... Like Usher, I want a lady in the streets but a freak in the bed!

 

Wow, that's a serious performance box, Kelly! Maybe beyond my requirements a bit. Very nice! If I were clamping a huge turbo on a Lamborghini, I'd want no less. Hopefully you'll get to swipe the keys and give us an idea of what it's like to be behind the wheel of such a beast.

Mike V, I'll plug those numbers into Dynolicious, that's what I'm using. While I'm at it, what numbers do you use for the car setup: Weight (I get different numbers, from 3,968 lbs. to 3,865), and Drivetrain Loss (%)? No idea what drivetrain loss is for these cars, can't find data... And does Dynolicious require the iPhone to be perpendicular to the car, clamped to something and secured in that position? Or can you just put the phone in the change holder (cover back) and push it up against the dash during the run? I have no means of attaching it with a clamp or mount, curious if you have a method of securing it at the right angle, if required.

And hey, I love the XKR and there are so many things that exceed expectations. But to say that asking a 500+ (barely) horsepower coupe with this much torque to turn better than mid 4 0-60 times is asking too much, I just don't agree.

I see countless cars with more modest specs and prices turn faster times, and it DOES frustrate me a bit. Not dampening my enjoyment of the car, haven't had much by way of contests from a dig to complain about. And of course, a car can make up for a deficit in one area with other qualities more subtle and harder to measure. 0-60 is just one stat in an ocean of specs.

But something doesn't add up IMO. Heavier cars with inferior transmissions and less power turn better times. Cheaper cars with less everything turn faster runs. I'm just curious if anyone has either figured out what the gating item is in our cars, or found a way to launch more successfully. Seems like a logical desire to me. Once identified, mods can be more tailored to the issue and involve less expense and deviation from stock.

For example, maybe the problem is weight transfer. Could it be that the rear shocks, adjusting 200x per second as they do, see the load as the car launches, and stiffen up too much, preventing the car from squatting down and putting the power down? Thus the rear tires don't hook up, and we can't put as much power to the ground as would be optimal. Possible?

If so, more power won't help as much as if weight transfer is optimal, so ECU/Pulley swaps probably won't help much. Given that the XKR-S does turn faster (published) 0-60 runs, they've overcome something by way of limitation. Could be just more power, or a number of other things...

I'm not sure what's up, but I will admit I'm surprised so many of us are ok having such a fast and powerful car under deliver in this one frequently benchmarked aspect. "go buy a corvette or GTR if you want fast 0-60 times" does not get the point or explain the numbers.

I'd think we would all agree that a sub 4,000 lb. car with 510 HP at 6,000 RPM, a healthy 461 lb.ft of torque all the way from @2500-5500, and an exquisitely tight and fast shifting 6 speed transmission would be expected to turn high 3/low 4 second 0-60 times. Which we don't see. And we would be talking about why, not that it doesn't matter, or shouldn't be expected of a GT.

I shall continue to ponder and probe...

Skeeter

 

Skeeter, I have the 4.2 XKR, which is a little lighter and after doing lots of research for a weight rating I found that MSN Autos had it right (two other sites agreed with these numbers, other sites had others) So for the 2008 XKR its 3814 lbs (full tank of gas) plus my body weight 236 lbs for 4050 lbs in the Dynolicious.

I use a 20% drivetrain loss which compared to stick shifts at 17% is fair enough, especially since the ZF transmission is fairly heavy duty.

For mounting the iphone needs to be facing top forward but at any angle from flat, 0 degrees, to standing, 90 degrees. What I do is lower the steering wheel, place the iphone upright on top, then raise the steering wheel to wedge it in right inbetween the speedometer and the tachometer. Usually the top button gets pressed but just hit cancel when asked to power off or buy a case that keeps the shut off button recessed.

The main rule is having the iphone someplace that it can't move

 

All right! I'll toss my coin into this debate!

First, let's agree; if you're after the Big Bang, you got the wrong car. The XKR will never be the baddest, fastest thing of the hill. Simply, because it is still heavy, soft and it does not have the aftermarket support to build it up, if one so wishes.

For me my XK (not XKR) is a "prestige" car that separates me from the Camaro, Mustang, Polyester crowd. It makes me feel good, a kind of "Rights Of Passage" thing that one arrives to at a certain point of their lives. That is what the Jaguar is all about, at least for ME. I got the XK over the XKR because I fully realized that I was buying it for the exclusivity and the beauty and not for the absolute performance, of which, even the XKR would not live up to my standards.

Now, when I get home I can change from my stuffy aristocratic dress into my Superman outfit and take out my still gorgeous rice rocket, that 3rd gen RX-7, modified to the tilt. 500HP and 2600 lbs with killer, razor sharp handling. I am the king of the road, there is nothing out there that can touch me in that chariot.

Oh, yes, I could have afforded a brand new XKR, for sure. But, I rather spent just under 50K on a used, like new, XK that has all the looks and the prestige and spent an other 35-40K building up the rice rocket that has all the unbeatable performance, acceleration and handling both. People not willing to play the mod game could just hand over the 40K for that 302 Boss Mustang and still whip most everything on the road and even on those occasional track days. You simply can not beat American iron for bang for the buck.

In 1983 I purchased a brand new Mustang GT and drove it home. 4 hours later my wife begun wondering what happened to me, as I still have not made it into the house. She opened the garage door just to find the brand new Mustang on stands, all of its new parts scattered around the garage floor, the car half taken apart. She screamed: "What happened???" I said: "Nothing Honey, just taking it apart and making it better". After all the mods it ate alive my V12 powered Lamborghini both in acceleration and on the track. All this for peanuts compared to the price of the Lamborghini, which, of course was gorgeous and super exclusive.

One thing I realized early in my hot rod years; there is always a car faster than mine and there is always a driver who is willing to take higher risks to drive faster than I do. So, trying to have the absolute fastest toy is a loosing proposition. The XKR is gorgeous, exclusive and plenty fast enough. It that is not sufficient for you, you're in the wrong car.

Albert

 

Hey Albert,

Sounds like you have had some interesting cars...

I get that the XkR isn't only about speed. But, to repeat myself:

"I'm not sure what's up, but I will admit I'm surprised so many of us are ok having such a fast and powerful car under deliver in this one frequently benchmarked aspect. "go buy a corvette or GTR if you want fast 0-60 times" does not get the point or explain the numbers."

Remove the image, cover the body in cardboard, and estimate 0-60 based on the numbers. I don't know about you but I would predict at least low 4s. It is not too heavy at the specs I cited to be a low 4 or even high 3 second car. Soft suspension helps in a drag race, so that's missing the answer also.

Why is the answer to numbers that don't seem too add up that the XKR is a "prestige" car and shouldn't be expected to be fast?

Can we agree that the numbers indicate more? Seriously, less than 4,000 lbs, 510 HP, 461 lb.ft from 2500rpm=... 4.4? Can't find another car that slow with equally impressive power and power to weight (with so much torque).

The prestige value of the car is irrelevant. Those numbers should produce more than I can produce. The board seems to be putting down similar times. Why?

"Because it is a beautiful car" is NOT an answer. Why are we so eager to downplay speed expectations of a 510 HP car? A car that feels like a missile from 40-100, or from 75 to 155?

Can we please talk about that rather than why we shouldn't be driving our silk slippers like a cheap Mustang? In a safe environment, I drive my car VERY hard. Not abusively but hard Prestige be damned, these cars go like lightning and have godlike brakes... I spare nothing keeping it in perfect shape but bought it to enjoy it in all aspects, hence the XKR and not the XK. The fact that the car is incredibly elegant is no explanation to what the thread is asking.

Sorry to sound argumentative, I'm really curious about this issue, no hard feelings to anyone, just want to focus on the explanation to what looks like a riddle.

Skeeter

 

Skeeter

My suggestion in searching for performance; take your car to a dyno and check the actual wheel-HP numbers. What the factory claims is not always true. Italian exotics regularly overstate their power ratings by a bunch. I had seen a dyno sheet posted on this forum for a 4.2 liter XKR that indicated "ONLY" 296 rear wheel HP, if I recall correctly. That is seriously short of the advertised 420 engine HP, even if figuring the usual drive train loss numbers. It may be that Jaguar is over stating the power of the engines.

My point is that the XKR at 4000 lbs will never be competitive with a car, such as a ZO6 Vette, with 505HP and 3100 lbs. Even less so against that 630-some HP Vette ZR-1 that sell for nearly the same price range. Even if you match the power-to-weight, lbs/HP, numbers between two cars, a car that is nearly 1000 lbs lighter will always run circles around the heavier car.

I would be interested to find out what is the actual dyno HP for the 5 liter XRK package.

Albert