Curiosity has stricken me and now I'm wondering about what gains could be obtained by changing every possible body panel/part for a carbon fibre/composite one. I mean stuff like the hood, the boot-lid, the doors, fenders, wheels, etc, etc. How much could these XKs benefit from that diet?

Approximate weight savings?
Approximate mpg gains?
Approximate 1/4, 0-60, 60-0, cornering and handling improvements?

Has anyone tried it? Is it feasible if you have deep pockets?

 

Does anybody even make all those components for these cars? If no, it would probably exceed the base value of the car I would expect.

 

40 pounds for 2 rear mufflers!

 

Funny that you posted this, giandanielxk8... I have been considering doing this myself in a year or two. I have years of experience in composites and have made thousands of carbon fiber and fiberglass parts.

I don't like messing around with the manufacture of composites anymore since it is so danged itchy and messy. I have found ways to make a living now, without becoming covered in the itchy stuff from head to toe. =) I have considered making cheap molds so that I can make the parts quickly and affordably for my own vehicle. If you REALLY want to be cheap, you can make 'splash molds' like this: Car Craft

By making the carbon fiber parts with a single layer of fabric and high-grade aircraft epoxy, they would reduce the weight of the car, I suspect by a couple hundred pounds. It's one of those things that I may never do, though. It would be a big mess in my factory again and I'm beginning to learn that, just because I can make many things as an industrial designer, it doesn't mean that it's worth getting itchy again. Haaaah!

The convertible is easier to make panels for since there is no roof/fender blend area. The problem with carbon fiber panels is that most companies would offer them as nicer parts than I'd want to pay for. I wouldn't want them as super-glossy. I'd wan't them to be thin and ready to be sanded for a paint job. If I made the carbon fiber parts for my car, then I'd have to justify removing luxury from the car to make it weigh even LESS, such as wood, rear seat, heavy comfy leather front seats in lieu of racing seats, removing the top and driving only in nice weather, ripping out all of the carpet, etc.

The other issue is that I bought the Jag knowing that it was not a lightweight. I've had lightened vehicles before. I look at my Jag as a 'geezer hot-rod' and I'm happy that it's an automatic because my aging 'shifter foot' has old tears in the Achilles tendon (horrible accident in '97) that get aggravated with shifting a clutch pedal in rush hour traffic. My whiplash damaged neck and back have nearly bone-on-bone contact and appreciate a smoother ride that a heavier car typically provides. By the time that I get around to thinking that I'll make carbon parts for my car, I'll be quite happy with my ride and probably decide to go have a beer instead of getting all itchy.

Aaaah, but it would still have its fun moments... hmm. I think if I did that I'd have to build a second one to be my current car's lightweight cousin to be driven on weekends. Hmm... I've got too many other things to accomplish.

 

Cat Man Do, I don't know if anyone does make them, but I guess a few can have them built to order.

Damn! Dave, can you really drop 40 lbs just from the rear mufflers?

Jeff I see what you mean. I think, however, that the weight savings could be significant. The body parts on these cars are quite heavy... What are they made out of?

 

Tony (XKR Racer) has done some lightening on his track car there's been plenty of pictures on the forum. He would have a good idea what weight savings you would obtain. He's eliminated most of the interior.

 

Considering such a job, I would actually like to keep the interior. I tend to chauffeur around many friends and dates, so I want the inside of my car to look just as good as the outside.

 

Do you guys who are in the hunt for more and more horsepower and weight reductions actually race the car either at drag strips or road tracks? Or are these basically daily drivers going from stop light to stop light?

Doug

 

I had thought lead, but after having the bonnet off, it might be uranium.

 

Can't speak for others but I don't race, not even at traffic lights. Mostly I just like to tinker and learn more about the machine.

From a practical standpoint, installing the twin screw took the car from more power than I need to way more power than I need but for me, there is as much, or more, enjoyment in making the modifications than there is in using them.

 

This.

 

My 2007 Corvette Z06 curb weight is 3132 lbs and has 505 HP w a 6 speed manual. The Z06 has a lot of light weight and even some exotic materials in it. Track days are a blast.

My 2003 Jag XK8 convertible has a curb weight of 4086 (3872 lbs for the coupe) and has 294 HP w a 6 speed slush box. And this weight is with an aluminum body.

Each car was designed with a very different goal in mind, even though the sticker price of the two cars is fairly close.

I think it would be very difficult and expensive to make significant weight reductions without compromising the beauty and functionality of the car.

 

Go for it! Just be sure to report back and supply lots of pictures.

 

Hey Norm--unless you changed the body I am certain the 2003 XK8 is steel bodied.

The mystery to me is what drives this type of desire in most men (myself included)? There is something mostly intangible when it comes to seeking the fastest, baddest, most exotic, over-the-top thing on wheels and I see plenty of these types of things in the Los Angeles area. By noting the types I see driving these cars I can say with fair certainty that none of these are raced or placed into any type of competition--basically go from the garage at home to the garage at work. The most "competition" they derive is the occasional drag to the next red light with lots of noise (a loud exhaust is de riguere) as they blast their Ferrari or GT-R or whatever past Camry's, Accords, assorted BMW's, etc. Whoop-dee-doo!

Since I would also be guilty of this weird pleasure, I have often wondered why?

Doug

 

It all started with Tonka Toys. It's their fault. =)

 

It's a testosterone thing. And given all the baby boomers correctly or incorrectly diagnosed with 'Low T' and now on booster meds, the perpetual search for more horsepower has increased exponentially....

 

Hah! I was having funky problems and had my T checked. It was CRAZY low. I now get monthly testosterone shots to keep it at a normal level. That has helped to stop my weight gain (fat). Dieting had stopped working for me and the fat started ramping up. I am now cleared after 2 hernia surgeries and started working out 2 weeks ago for the first time in years. It feels good to be at normal T levels now. It even had my thinking being 'foggy' when it was low.

 

Since my '04 XJ8 has an aluminum body I just kind of assumed the XK8 did too. That explains why an XK8 coupe and my '04 XJ8 are so close in curb weight.

Thanks for the correction.

 

If you're thinking about replacing all the body panels to save a couple-few hundred pounds, you've already removed the entire convertible top assembly, right?

Stop now. You're gonna need another car.

I second looking into XKRacer's stuff for ideas.

 

What do you mean stop now? It's not a daily thing. I usually just take short trips. Since I've had the car, almost two years now, I've only put 8k miles on it, and it's my Daily Driver!