The threads on Dev´s spacers and tramlining, my own experience with higher speed (in)stability, make me wonder:
How much of what we perceive, experience with the car is based on feedback from the car versus our own actions/responses to the feel.
Take the door spacers making the tub more rigid causing the driver to be perceive the car understeering whereas it was himself overresponding to perceived directer ´over´steering.
My own experience stems from the removal of the power steering. The car ´is´ now way less nervous; less tramlining, more stable in a straight line.
As the car has not changed one bit, my perception is obvious nonsense. Yet it ís less nervous, meaning that I upset it les; that Í caused the perceived tramlining/instability. Well, up to a point; I amplified it.
Both the door spacer thing and my experience remind me of shimmy/speedwobbles on single track vehicles. Those are to a large extend ´caused´ by the rider. Between brackets because the oscilation ís there; it is the rider subconsciously responding/correcting who amplifies the oscilation.
Please share your thought, experience.... perception
As I'm the subject in discussion wrt Dev's door shut supports; absolutely it's perception.
You get used to the feel of a car and a lot of the driving becomes automatic. Change something and your perception is not in sync with reality. I think it usually takes a racing driver, or something with experience with "finely tuned" cars to notice what is happening and adjust on the fly.
I compare it to pro athletes. Their bodies are powerhouses;finely tuned machines for a task. But, if they don't eat right for a week, the effect is much much heavier on them than if I were to binge on pizzas for a week. Same with cars. The more you take out the "slack", the more sensitive to change it becomes, and the more you're battling perception vs reality. I guess the art of getting the balance right is what makes someone in good control of their car.
As for tramlining... That to me is a very obvious effect of geometry, tyre and wheel choices. If I drive my car down the Northumberland b-roads, with all the tractor tracks and all, I get constantly pulled into tracks, into cambered surfaces, etc. Not enough for it to be a problem, but enough to feel in the steering wheel.
Whereas when I took Helen's car...significantly less. In the Skoda...Nothing.
Quote from: shnazzle on March 7, 2019, 08:48
As for tramlining... That to me is a very obvious effect of geometry, tyre and wheel choices.
Obviously. Just like the shimmy/wobble I menstioned. They has to be an input from the car for the driver to respond to. If you changes tires on the same car and you perceive more/less there múst be a difference caused by the tyre. Now your experience with the door spacers shows that there may very well be a different effect than you perceive. Additionally I have léss tramlining and more stability by changing from power stereing to no power steering, which has nóthing to do with the geometry/tyres but only with the input I get. The car behaves exáctly the same yet gives a way different feeling thus is perceived differently: It is exactly as stable/instable as before, behaves the same yet ´behaves´ more stable.
You are spot on with being accustomed/subconscious actions. It is exáctly as with riding a single track vehicle, riding a horse, walking even: By training your nervous system gets hard wired. The most clearly illustrated by the steer left to go right of bicycling. we learn to do it ´instinctively´; it becomes a trained reflex we are no longer aware of.
It happens with driving a car too, as you found out with the doors.
In mý opinion the electric power steering also demands becoming accustomed to and forces us to relearn every time we change something on the car which makes it behave slightly differen because it so strongly amplifies our responses to the perceived change.
Mind you; not an issue at all; just a reminder of giving any change a bit extra time/experience before drawing a conclusion as you may very well ´notice´ your ówn actions and draw the opposite conclusion :P
Doesn't the power steering turn off above 20mph anyway though?
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Quote from: Call the midlife! on March 7, 2019, 12:09
Doesn't the power steering turn off above 20mph anyway though?
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It reduces gradually I believe. But bear in mind it's always "on" to some degree or you'd be battling the hydraulic forces of the unpowered rack.
Happy to be corrected.
Quote from: shnazzle on March 7, 2019, 12:30
Quote from: Call the midlife! on March 7, 2019, 12:09
Doesn't the power steering turn off above 20mph anyway though?
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It reduces gradually I believe. But bear in mind it's always "on" to some degree or you'd be battling the hydraulic forces of the unpowered rack.
Happy to be corrected.
Fair one.[emoji1303]
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Quote from: Call the midlife! on March 7, 2019, 12:09
Doesn't the power steering turn off above 20mph anyway though?
The graph I have in Toyota docs. is not shining in exactness so the numbers are aproximations.
It shows it starts asssiting less from about 20 mph. till it is at half strength at about 70 mph. and from there deminishes véry little till top speed when it is some 40%.
Assuming part of that will be needed to compensate for what Shnazzle mentions my guestimate is that it goes down to 20% effective.
This concurs to my experience that you need to be well above 100 mph before the steering gets more twitchy like with p.s.
The crux is that within legal road speeds you will have 100 to 50% power assistance.
On narrow twisty bits that will thus be closer to 100 power steering most of the time.
Furthermore the pump has an additional trick up it´s sleeve. From 0 to about 55, the amount of steering angle also affects the level of assistance. The graph has no third dimension for the angle but only provides a 20% lower output line for limited/no steering angle.
All in all explaining why this power assistance needs a bit of getting used to for spirited driving.
The power steering's a bit dodgy on my MR2 (not sure if on all), if you turn the wheel fast it sometimes can't keep up, so the steering weights up a lot. Almost caught me out on track the first time, as straightening up from a slide took more force than you'd expect (say from 3/4 turn to straight). Which lines up with what Petrus posted?
Isn't that just universal joint issues? Or your pump being knackered?
It is not impossible that the pump cannot keep up but I have not experienced that. I háve had the occoasional odd moment that I thought it was a bit óverenthusiastic.
Came back just now from Antequera over the interior mountain road. There is no wáy I could have driven the way I have, with the ps in place. The surface is changing continuously with tarmac from fairly recent to worn shiney to several generations of patches on top of fairly smooth to undulating to bumpy to bumpy over undulating with the aforementioned tarmac variety through the most wonderfull series of swooping, tightening, opening, blind to lóóng clear view swoops.
The feel of in particular the front gives you só much more control. You dírectly feel how much grip the tyres have, what they are doing; what the car will do befóre it does that. Lóve it :D
Succinctly put; you have in your hands that the front is on the limit of steering before it starts understeering.
Interesting discussion. I believe the car is like a tuning fork. If its out of tune or if there is less signal to noise ratio when it comes to precieved fine vibrations it can greatly impact the driving experience.
I came to a point where I started caring less about stiffness and grip and would rather have a more enjoyable drive where I am the master of my car or any car, at any speed.
There are a lot of cars that have all kinds of numbers on paper but they lack feel so they can get those numbers.
I think there is a distinction between a fast car and a fun to drive car and the reality is they keep pushing metrics that don't really matter for the street. This is true with a lot of other hobbies where they have maxed out the metrics to such an extent that humans can't perceive a difference. This causes consumer regression to an earlier time when things were simple but yet again the marketers get involved by co-opting a sentiment and ruining it for everyone.
Quote from: Dev on March 7, 2019, 19:35
Interesting discussion. I believe that the car is like a tuning fork. If its out of tune or if there is less signal to noise ratio when it comes to precieved fine vibrations it can greatly impact the driving experience.
I came to a point where I started caring less about stiffness and grip and would rather have a more enjoyable drive where I am the master of my car or any car, at any speed.
Spot on.
This why I will leave the springs and anti roll bars alone.
Not fitting any more bracing either: Apart from the OEM X over the engie, a front strut brace and your bushings are giving enough stiffness.
Dropping in TEINs , lowering the body 30mm. would reduce roll as would a stiffer rear sway bar but on real world mountain roads nót increase feel, reduce road contact and most definitely ruin comfort.
Will also stick to as close to OEM with rim/tyre dimensions.
QuoteI believe that the car is like a tuning fork. If its out of tune or if there is less signal to noise ratio when it comes to precieved fine vibrations it can greatly impact the driving experience.
Is imo underlinning the subject to perfection.
I like the feedback of the car to be linear and predictable. You can get used to that, hard wire you brain and ride ´around´ theoretical suboptimal metrics.
You should have seen us off-road rallying our Volvo 340 variomatic :D
nothing to contribute, but great reading.
Oh, Dev, didn´t per MY 2003 Toyota increase wheel travel by 10 mm.?!
QuoteIs imo underlinning the subject to perfection.
I like the feedback of the car to be linear and predictable. You can get used to that, hard wire you brain and ride ´around´ theoretical suboptimal metrics.
You should have seen us off-road rallying our Volvo 340 variomatic :D
Predictable is good however there are some situations I found where you don't want predictable.
I like the car to be little wild and playfully fights me back to keep things unpredictable and raw. A little bit of steering wheel shimmy when taking a slow tight turn. I also like a car to punish me when I get it wrong and reward me when I get it right.
This is why wide tires or very sticky tires is counterintuitive to the experience.
Many cars these days are going for refinement. Too much refinement is boring, like taking dystopian high speed rail.
Quote from: Petrus on March 7, 2019, 21:00
Oh, Dev, didn´t per MY 2003 Toyota increase wheel travel by 10 mm.?!
Im not aware of any changes in wheel travel for the refresh.
I believe in 2004 they increased the spring length for some kind of safety requirements in certain markets.
Quote from: Dev on March 7, 2019, 22:08
Quote from: Petrus on March 7, 2019, 21:00
Oh, Dev, didn´t per MY 2003 Toyota increase wheel travel by 10 mm.?!
Im not aware of any changes in wheel travel for the refresh.
I believe in 2004 they increased the spring length for some kind of safety requirements in certain markets.
Maybe that increase of 10 mm. bottom clearance has me confused; afaik it was model year 2003 and for all markets but the info is not transparent. Hence my question.
It could just as well have been in the changes for MY 2004 and for some markets (the EU) only.
Quote from: Petrus on March 7, 2019, 22:50
Quote from: Dev on March 7, 2019, 22:08
Quote from: Petrus on March 7, 2019, 21:00
Oh, Dev, didn´t per MY 2003 Toyota increase wheel travel by 10 mm.?!
Im not aware of any changes in wheel travel for the refresh.
I believe in 2004 they increased the spring length for some kind of safety requirements in certain markets.
Maybe that increase of 10 mm. bottom clearance has me confused; afaik it was model year 2003 and for all markets but the info is not transparent. Hence my question.
It could just as well have been in the changes for MY 2004 and for some markets (the EU) only.
Its hearsay but from past discussion it was done for some sort of pedestrian safety not for the car.
There are at least 2 different lengths of aftermarket rear spring. I fell foul of this from a Maxtrac catalogue the other week (353mm and 360mm).
The KYBs I'm planning to buy are 360mm , but KYB only quote 2000 to 2002, and 2002 to 2004. No idea what 2004+ would be
re: the original topic - I'm massively over sensitive to car noises (beyond mechanical sympathy) and yet other people aren't bothered in the slightest by rattles and unusual sounds in their car.
Quote from: Dev on March 8, 2019, 05:39
Its hearsay but from past discussion it was done for some sort of pedestrian safety not for the car.
The pedestrian thing is to do with minimum hight of the front so there ís an angle there but as no rules have changed concerning that and a bíg thing with the SW30 was compliance with all markets (hence we in Europe got the Californian pre-cats per example) I think it unlikely.
Does not really matter; some of the later MYs were 10 mm. higher off the ground.
I share that bothersome über-sensitivity. Most un-fun.
Yesterday had a whale of a challenge to convince my charming company that she had to put her seat either one click more upricht or move the seat one forward: The creaking of the seatback against the rear cubby distracted me to the point of despair.
@Petrus (https://www.mr2roc.org/forum/index.php?action=profile;u=25573)
quote "The creaking of the seatback against the rear cubby distracted me to the point of despair."
I do the same. Slide passenger seat right back then 1 notch fwd.
Just came back at the farm in the mountains after two days of twisty mountain & coastal roads.
Réaly pushed it.
A big, and I mean HUGE, advantage of no p.s. for me on those roads is that me moving about is no lnger upsetting the car. I am no longer introducuding instability.
I will explain:
Even when the tarmac is as perfect as can be, the road is undulatin, the cambers changing as do the centrifugal forces.
Pushing the car, you wíll move about and additionally you wíll move/brace yourself against the forces.
The net result is that with the strong assisitance you inevitable moving about moves the steering wheel moves the wheels moves the car.
So even though the car itself is just as stable as it was wíth p.s. it behaves a lót less twitchy without because Í make it twitch a lot less.