doradox

Let me make this easy for. I don't think it adds to the discussion. That is in no way shape or form telling you not to bring it up. And I seriously doubt you are in any way discouraged by anything I have to say about it. I'm asking YOU. Do you have an answer? Lower spring rates, roll stiffness, and damping leads to increased suspension travel, and therefor angles, in operation. On the S30 you can't change suspension geometry and any alignment settings except toe-in to compensate. The fixed suspension and steering geometry would need to be tailored so the vehicle with the most change in suspension and steering geometry during operation would still meet handling and ride requirements. Think about the aftermarket ball joint spacers that are used by some when LOWERING their car to compensate for a change in the roll center. Was chassis and suspension geometry design biased toward the version with lower spring rates, roll stiffness, and damping? Maybe. Certainly not inconceivable. This whole, and I'm paraphrasing, "blah blah blah not made just for the US market blah blah" is really getting tiresome. I'm not saying the S30 was designed for the US market and all others were secondary. Just that it's not inconceivable that some US market requirements drove compromise in the design and may have had a higher ranking than a similar requirement for another market. And vise versa. You shouldn't be afraid of admitting that this is a possibility. It doesn't erode your core belief. I just know in my experience some customer requirements are given more weight than others. Sometimes you can achieve 100% of both requirements and sometimes you can't. That's life in engineering any product.

My modern 240Z would be a lot like the original. Small and light. I'd add a little more power but how the engine sounds, responds, and feels are more important to me. How Mazda has continued to upgrade the Miata without destroying it's original character is the model I would look to. My 240Z is to 370Z what the Miata is to RX7. Steve

Still adding nothing. And I in no way told you you couldn't bring it up. Get you facts straight. You have no specific performance requirements that you can point to to make your point. Yes, all these things bolt on but that's only part of the engineering challenge. Now they have to work together with all the compromises to meet performance specifications. Do you have any knowledge of what those might have been for various markets? If not then you have an assemblage if bits with no understanding of why a particular bit was used or how that bit may have changed to work in the whole. You seem very reluctant to admit that the US market may have had unique performance targets that required specific changes to the whole. Your premise seems to me to be that any US market requirements easily fell within the range of the whole gamut of requirements specified for the world market. That is naive. It could well be so. But you don't know it. This seems to prove my point about your assumptions. How would you know that softer springs and dampers would "fall within the parameters" and be given equal consideration? In my experience all design requirements are NOT given an equal ranking. That's Engineering 101. A car is a mass of compromises and without a guide to use to rank order importance you have no way to guide your decisions.

Still no reason to bring it up in our discussion. It adds nothing. All variations were equally easy to make the combinations of various parts work together to meet the design requirements for a particular market because they were all done at the same time? Interesting. And you would have some evidence of this? The project I am currently working on has dozens of different configuration across several customers. My team is designing and engineering everything all at the same time yet some customer requirements conflict with others and require extra effort to integrate into the whole. How I wish I lived in your world where all engineering challenges are of equal difficulty.

In the context of the comments between HS30-H and I it is irrelevant. As in, it adds nothing to our discussion. They might well have been easier but neither you nor I know that. Assuming it was easier makes no sense. I think it was pretty smart to offer what they did for the NA market at the price they were able to. Do you have any reason to believe more cars would have been sold in the NA market if a "smarter" configuration had been sold?

I take no offense from the standpoint of features that were omitted. But, from an engineering perspective the engineering requirements were meant to suit the market and it doesn't make sense to say the vehicle was dumbed down. A seemingly simple requirement might have taken a more sophisticated solution to achieve. I might agree that in some cases the market itself is dumber though mostly just different.

I know that's sticking point with you but since I have not made any sort of "An American Car" comment it's irrelevant to the discussion. Simply that the requirements that needed to be met by whatever was sent to the US aren't automatically "easier" to meet. Certainly just leaving off features is easy enough. But during design of the chassis to perform with different suspension bits for different markets who's to say the requirements for what eventually came to the US were easier to achieve. That a softer suspension setting is less difficult than a firmer one to make work with the myriad of other competing requirements. That they were all designed together is irrelevant. The requirements weren't the same so the effort to achieve them might not have been either.

A specific set of requirements and cost targets for a particular market. Why would it have been easier? If we don't know the specifics of the design requirements for the US, or if you prefer North American, version then how can we assume it was easier to meet them. Especially if it was already designed with a different set of requirements. An automobile is a very complex system and even a small change to one part can have a large influence on many others. Simply changing a spring rate without considering the overall effect can lead to unintended consequences.

Working to a brief or a concept is usually early in a project where there is a time spent looking at what is feasible and refining the product requirements. That's not the time that all options are defined. Many concepts have gone by the wayside long before any business decision is made to actually sell them. Someone says "hey how about putting in xyz feature and engineering says it can be done at this cost? Or one asks "if we wanted to achieve this end what products do we already have designed that could meet these requirements and if they can't how much effort will it take to modify them to do so"? That information is used to make the business decision. My point is engineering functions and business functions are not mutually exclusive. They are part of a whole that is used to conceive, create, market, and sell products. Where I work engineering is involved throughout the entire process as it is at virtually all successful businesses that design and manufacture products. Yes, the ultimate decision was likely not in engineering's hands but it is likely to have had some hand in the process leading up to that decision.

Instead of dumbed down I would suggest highly engineered for the intended market. Is it so hard to imagine that it was a challenge to so successfully meet the US market requirements? That a US market version might have been more difficult to engineer?

Exactly my point. Engineering involved before the decision was made to offer the clock at all. Or am I misunderstanding the whole "seemed that it would not have a clock, but then - in practice - it did" part.

We agree then. As to the clock, you seem to be assuming that the wiring, apeture, etc. existed before any decision was made whether or not to offer it in a particular market. I would suggest that engineering was involved before the decision was made to offer a clock at all let alone in what markets it might be offered in. That the chassis can accept different engines and so forth seems to show that there was a lot of forethought given to the design requirements. Engineering would have provided estimates of the cost of this flexibility so that a business decision on whether or not to offer a particular option in a particular market could be made and the impact on the profit margins across all markets could be evaluated.

And engineering input was likely a part of that purely business decision.

Hence my lamentation that the US market got short changed. Steve

One of the things I think was missing for the US market was no "real" options. A '70 Camaro had literally dozens of engine, rearend, and transmission combos to choose from not to mention body trim levels. In a way it makes the Z look kind of boring. If you've seen one 1970 240Z you've pretty much seen them all. I know some will disagree but when compared the to the vast range of just drivetrain options offered by my Camaro example any options the Z had were a big yawn. So I vote, as mentioned earlier, for more engine, trans, rear end, and suspension options. Steve

Work is force * distance and has no time element. Power is (work/time). To do lots of work in a little time you need power, the more the better. Torque is a twisting or turning FORCE not work or power. Power is a measure of how quickly you can do work. Like how quickly you can do the 1/4 mile. HP is torque * RPM. More torque at a fixed rpm OR more RPM with the same torque increases POWER and power is what gets work done quickly. You can multiply torque with gearing (which reduces RPM exactly by the ratio of torque increase) but your power will remain constant when you do that. 10,000 lb-ft of torque at 52.52 RPM is 100 HP. 1000 lb-ft of torque at 5252 RPM is 1000 HP. I know which I'd rather have. Torque and RPM, and lots of BOTH. AKA HP. Steve

Did you have problems before you started using that practice?

Plenty of products have a specification for the amount of ZDDP they contain. Is there a single one that makes any claims of actual wear reduction based on the sequence IVA procedure or Sequence IIIG? http://www.swri.org/4org/d08/GasTests/IVAtest/default.htm http://www.swri.org/4org/d08/gastests/iiigtest/default.htm Note that flat tappet engines are used in these tests. You would think they'd jump all over that if they really did reduce wear over the proper specification oil alone. It's gotta make you wonder. I use Valvoline syntec 10-30. My Z seems fine with it and my flat tappet 240SX is going on 251,000 miles and runs like new. Steve

I was thinking about this and something didn't seem quite right. If a liquid held at a constant volume is heated past the critical point how would the "gas" that now exists be any different than the liquid. Apparently it isn't. http://en.wikipedia.org/wiki/Phase_%28matter%29 "At the critical point, the liquid and gas become indistinguishable. Above the critical point, there are no longer separate liquid and gas phases: there is only a generic fluid phase referred to as a supercritical fluid. " So a gas can be compressed to at least a state which is not a gas anymore. Steve

Would you say the damper is for the benefit of NVH or? Steve

I entered engineering after 20 years of wrenching as an ASE Master tech and really loved learning the math and physics behind all the things I had learned from experience. It made even thermodynamics kinda fun. Steve

Yeah, your right, it was a little hyperbole more than anything. Steve

Superheating. Not commonly defined as you have but I agree that it's not relevent. http://www.answers.com/topic/superheating http://www.wordiq.com/definition/Superheating http://en.wiktionary.org/wiki/superheating Any vapor "can" be compressed enough so it won't turn to vapor at any temperature. But the fuel pump in an EFI system is regulated to a max pressure therefore if the fuel temp is high enough it most certainly can vaporize. Whether or not this is called vapor lock is another thing altogether. I'm with you on the definition though as vapor lock has been around since the dawn of carbureted IC engines. Pop your hood when you park for short periods on hot days. Cheap. Move the fuel filter to the pressure side of the pump. A restricted filter lowers the pressure on the inlet side of the pump. Marginal if any benefit. Get an electric pump and mount it low in the engine compartment or move it completely out. The high mounted manual pump means lower fuel pressure on the inlet side of the pump and exposure to some of the hottest air in the engine compartment. Electric radiator fans with a thermostatic or timed cut off and wired to run with the ignition off will create air flow and help reduce heat soak. Make sure your battery is up to the task though. Steve

That, I think, stems from the definition of "vapor lock" which seems to have now evolved to mean any vapor related drivability problem. In the 70s maybe not so much. Steve