I’m so glad I get to witness these technological marvels.
Is there a need for all wheel steering?
- Thread starter Shel_B
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How many models 2023/current offer this?? That will demonstrate some relevance. I don't know of many but you can sure show me the light.
Years ago I messed around with RC cars. I couldn’t buy new for a while but did buy a couple of used ones from friends. One had a crummy AWD drivetrain but had 4WS. Iirc the rear steered about 1/3 of the front. If the miniature scale means anything, the slalom prowess was uncanny.
What's with the hostility? I'm neither for or against 4 wheel steering. Only pointing out that it's been around a long time and it comes and goes.
I was always amazed to see it on firetrucks when I was a kid.
Doing anything with the heads does not change displacement, only compression ratio.
This could still have certain advantages, but not due to a change in displacement.
The idea was for variable compression ratio for maximum performance both on and off boost, saab loved playing insanity with turbocharging.
SammyChevelleTypeS3
$50 site donor 2023
Exactly my thoughts. There comes a point when manufacturers just can't help themselves from making up more and more "options." Things like options nearly no one really needs. Options that end up costing way much more than a little extra money while they in fact end up being very much unnecessary. But to each his own.... and to each's own pocketbook. One of my bosses used to give us guys laughing fits at stuff like this with his comments like "Well. Whatever blows their dress up!"
A better mouse trap or scraping the bottom of the dustbin of history barrel, nothing more.
The key word here is "anything".
Saab said they were working on an engine the head which was hinged on one side.
A telescoping tube would've been the cylinder of increased displacement.
There was no further news.
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It would have to change stroke too... so I'm not following either. Moving head in or out would change compression ratio.
Unless if I am mistaken:
The piston moves up and down the same amount (aka displacement) in this proposed scheme. The open air at the top of the cylinder, inside the head, is what the piston displaces into, and is what drives the compression ratio. If the cylinder was 0.5L, and the combustion chamber in the head (imagine a flat top piston that is level with the deck, just to keep it simple) was 0.05L, then 0.55L of air&fuel is pressed down into 0.05L. If you lift the head and the combustion chamber is now 0.1L, then you have 0.6L being compressed into 0.1L. Although the combustion chamber has to be taken into account here for the static compression ratio, it's not part of the stated displacement of the engine, and since we want a high compression in most cases, it's a small discrepancy.
You are not mistaken, displacement is entirely a function of bore and stroke, if you're not manipulating either of those, displacement isn't changing, sorry, end of story...
If I were a serious off-road guy, I'd be all over a capable off-road vehicle, with 4 wheel steering. It would be so much more than just a gadget.
This is why Every monster truck since Bigfoot has 4ws. It makes it much easier to turn around. Back in the day when GM brought out their quadrasteer technology they had it at an automotive test area at the Denver Auto show. I thought it would/Should have become standard as it made a difference.
I think it really has more to do with the size of the indoor arenas, and their turning area, not so much about them going off road.
Same principal. Whether it is the limited space of an indoor arena, or very little space between a mountain face on one side, and a drop off on the other side.
I'd like to know what safety features keep these from developing a mind of their own (similar to the unintended acceleration deal) at say 70 mph down a freeway? Even the ones they have on cars now? A manually operated locking pin?? 
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No hostility meant. My point that I did not make well is 40 years later it hasn't become a standard type of offering.
Kestas
Staff member
It's all about cost vs benefit. I know I wouldn't benefit from this technology.
There is a whole subset of people would buy it just to show off.
There is a whole subset of people would buy it just to show off.
All that’s going to do is lower the compression ratio. Only way to increase displacement is to lengthen stroke or cylinder diameter. Maybe I’m not understanding.
