I’m about to purchase a new car, and the owner says it needs a few things?


Common reason for low miles on old Jaguars - they spend so much time in the shop! And I’m not joking.

With everything we’ve said, why are you still asking?


Doesn’t everyone who is selling a used car make that same claim?
Or, to put it in other terms…
Isn’t that the most frequent lie spouted by people selling used cars?


Of course the owner says that , Good Grief . Do you think that they would give you negative statements.


I smell a troll


In addition to that new Jaguar you seem intent upon buying, I’ve got a bridge to sell you.

It is a very limited time, exclusive offer, offered only to potential Jaguar owners, new or used.

You can collect tolls, pretend to go places and even park your Jags in different places along it for new and exciting photo ops.

But the real opportunity is in the toll collecting, you will get a 100% return on your investment in under 6 months…you cannot lose. The bridge runs Straight and was recently painted.


I worked with the shock company Bilstein in the mid 1980’s. Thier aftermarket shock facility was located in San Diego, CA.

They would typically rent a test car from an owner to develop aftermarket shocks. They would measure for physical size and then ride and drive the car to get the internal valving correct for a nice ride and then add it to the catalog. The chief engineer told me they searched for months and months to find an XJ6 (the 6 cylinder sedan) and an XJS that had the original engine. All they could find were small-block Chevy conversions. They finally gave up and developed the valving FOR the V8 conversion and stated they would work OK for 6 and V12.


Today - that can all be done on a computer.


Actually it can’t. At least not totally.

Unless you have the CAD drawings of the actual car, it still must be physically measured and then a CAD model of the shock created. Aftermarket suppliers don’t usually have the CAD models unless they are also OE suppliers. You can get the damping levels close with computer modeling but the final development and confirmation is still done with actual physical rides. There are too many component mass and stiffness that are unknown to model effectively and all affect how the car rides. Ride testing is actually quicker. Even for the OEM’s, who, theoretically have all the data, it is still finalized manually.

You can computer model aircraft, spacecraft or ships, but cars have random inputs from the road surface that makes it more difficult. Plus shocks damp far more than just the ride. They are tuned to damp engine vibration, steering wheel vibration, floor oil-canning and a bunch of other things that should have been addressed other ways but were not.


That can easily (and I mean easily) be simulated. 20 years ago …not so much. But today that type of simulation is fairly trivial and can be performed on a decent laptop with the right software.


Sure, if you like paying high $ engineers to sit around twiddling their thumbs. Those videos of the end product of the simulation are nice to watch. Do you know how many computational iterations that took to generate? I have guys now with top of the line desktop systems with boatloads of memory that take 3-4 hours to complete similar type of simulations. One the mechanical guys worked remote and had a pretty decent laptop setup we paid beaucoup bucks for that rig. Special everything, top of the line uP, graphics, hard drive etc. He would start the simulation before going to bed and hope it was done the next morning when he got up…

In the end, simulation gets you close. Nothing beats empirical testing. When it comes to ride quality, a computer is a lousy substitute for a human butt…


Yea…Do you? How long ago was this work done? My laptop today is easily 100 times faster then the high-end desktop I owned just 7 years ago. 32gb of Ram and 1tb SSD. And a company that is going to do this type of work will be running this on a high-end server for even faster speed. These systems run over 200 gflops range. That’s over 200 BILLION floating point operations per second.



Yes, my data is current. Again I am refuting your assertion this can be done easily on a laptop. Your own statements now talk about using high end support hardware- so get off your horse…

I know you do not work in this kind of engineering environment so I suspect you have no real background to speak about this kind of work…


OK, so you cannot test drive it, and you are going to believe the lie it runs and drives fine? It does not run and drive, THINK!


There is a reason why many Jaguars have a bumper sticker “My other car works.” Plus some other ones that are not complementary to the Jaguar.

Never buy a used car without a trusted mechanic checking it out for you. That is the solid rule. Be it a Jaguar or a 1 year old Honda Civic.

And good for you for asking the question. I hope we haven’t scared you away and the advice is useful.


+1 to Twin Turbo. Absolutely spot on!


I was only rebutting Mustangs statement saying that it couldn’t be done. Vehicles are almost exclusively designed on computers these days. They don’t need to build clay models for wind tunnel testing. That can all be done on a simulator. Engine design, suspension, dynamic braking can all be done on cad with sophisticated simulators. The software is available to run on a laptop and it will work, just take a lot longer. I agree a company that makes money doing this type of work would be stupid to do it on a laptop…they would want a high-end server.


Yeah, I’ll go so far as to say almost everything is originally designed using computer aided design tools these days. The specific example MM mentioned, generating an equivalent to the original without benefit of the original design files would be best accomplished by measuring the physical sample and then entering that data into the computer design suite. If all you’re doing is designing one sub-component, it would be onerous to generate a model of the entire system- super complex. I copy your shock, add my own fine tuning to make improvements for a specific application, generate prototypes and then I run them to verify the result. That would be the fastest and least expensive way to get to the end game in that scenario. Of course, if you’re designing the whole car or an alternate suspension system, it makes more sense to model the car itself. And you’re right, as long as you have the memory capacity, it can be done, just takes inordinate amount of time.

We have some pretty sophisticated software and hardware for this, we do these kind of things day in/out. But we are small potatoes compared to the big boys. I’ve done numerous developments as subs for the likes of NASA and Lockheed Martin. We launched an electronics package as part of GPS block III a few weeks back. Some last minute verification required a complete re-analysis of the shock and vibration capability. We estimated >24 hours as a distributed computational review using all of our resources. LM said they could do it in <3 hours and we sent them the data package to do it.


Having access to alien technology at Area51 has its up-side. :wink:


You will need a tow truck to go with it.


An 85 Jag that doesn’t start, and for sure needs a new battery and a fuel system cleaning, isn’t going to command much money in the used car market. Not b/c it’s car w/no merit; just b/c old cars with known problems aren’t in demand. As there will be few buyers, you should be able to get it for a very low price, considerably less than $1000; probably more like the 300-500 dollar range. If the seller wants more than that, make an offer in the above range and let the seller think on it. Make your offer contingent upon the seller agreeing you can have your own mechanic do a pre-purchase inspection which you must approve before writing any checks. You might wind up with this Jag yet. As posted above, expect considerable maintenance and repair costs to keep it on the road. But if you have the needed money in the bank already, and no other use for it, why not? If you can find some recent issues of the magazine “Classics Monthly”, they’ve been restoring a classic Jag, so quite a few articles about what’s involved there.