New Shock time?

[taminga16]

I'm running 34lb after advice was the 26lb I used before was too soft and not good for the wet.

And when it all turned to rubbish you didn't think that perhaps the higher tyre pressures (your own gauge or the delivery system at the garage?) may have been the cause, tyre and suspension tuning is a very precise practice, 8psi is an increase of almost 30%, any wonder that your car is skittish! , With or without crap tyres.
Greg.

[Silvia]

I'm sorry I'm not following you Greg.
The tyre pressure advice was from here ,and not from one but several contributors, I use my own, quality gauge..and what "all turned to rubbish?"

[taminga16]

On broken road surfaces the front of my NB 2002 (16" 205/45 tyres) can be thrown off line sometimes and as it has 85,000km up , could it be approaching time for new shocks? Can they be tested?
If so, for spirited road-only use, are the replacement ones (KYB etc.?) ok?
Is there a brand and model that can be fitted by local mechanic, give good life, and be reasonable price ?

When tuning tyres or suspension only ever alter one thing at a time and then in small increments (and record it all so that you can always go back to a datum) 30% is far to great a change and I would be suprised if you did not notice it, working on bikes, I make a point of one change, one ride, same route and note the results, cars are no different. Have you ever had new tyres fitted only to be dissapointed by the increased NVH only to find out two weeks later that the fitters have shot 50psi into your new rubber to set the bead seals and then not bothered to take it back to road pressures?
Greg.

[Silvia]

Well Greg it was no biggie.....simply tried a few higher pressures, decided that was not the problem, felt best at 27lb cold , done.
Jumping off line a bit on rough patches made me suspect the shocks, investigation here showed they should be still ok, next step, investigate alignment.
As soon as the floods go down I'll get that done.....I only wish there was a definitive setting recommendation ( for street sporty) as there are fairly wide variations (even toe in v's toe out) in the answers and I'd prefer not to experiment at $80 and a few hours a time.....
Maybe the technician will know.....?

[NitroDann]

The 'technician' doesnt give a sh!t.

Dann

[JBT]

..simply tried a few higher pressures, decided that was not the problem, felt best at 27lb cold , done.

But you said a couple of days ago

..I'm running 34lb...

....Maybe the technician will know.....?

Maybe and maybe his equipment is not regularly calibrated. Why not go with the recommendation by Charlie Brown?

[93_Clubman]

Its not that you ask the question, its that you take no notice of the answer!

OP has numerous priors for this, the various answers to which we have politely redrawn to his attention when he's enquired a second or third time.

Low maintenance car, high maintenance owner.

[Steampunk]

Its not that you ask the question, its that you take no notice of the answer!

OP has numerous priors for this, the various answers to which we have politely redrawn to his attention when he's enquired a second or third time.

Low maintenance car, high maintenance owner.

...I only wish there was a definitive setting recommendation ( for street sporty) as there are fairly wide variations (even toe in v's toe out) in the answers and I'd prefer not to experiment at $80 and a few hours a time...

For goodness sake, google "Miata wheel alignment" and the first 2 pages are chockers full of them. Pick one! Check the "Technical Guides" section for "MX5 Wheel Alignment" topic. Go in there and pick one!.
You don't seem to be of the type to be interested in track days, or a very spirited mountain (or otherwise) drive, so even the STANDARD ALIGNMENT settings will appease your "street sporty" goal because the MX-5 is a "street sporty" car.
So there's an answer that hasn't been given yet.
- Just go to any wheel alignment place,
- show them your owner's manual,
- ask for the settings as per written

...But as a driver of numberless vehicles over 50 years ...

So whenever you've experienced problems with any one of these "numberless" cars, what have you done? Sold it and bought a different one ad infinitum?
--------------------------------------------------------------------

And as for why people get indignant at you:
As mentioned, not only do you ask the most simple of questions, but hostility in your threads is engendered because people have been very patient and accommodating in answering them, and yet you ignore them.

I've been taught to respect my elders, but respect is a two-way street.

[Charlie Brown]

...........( for street sporty) as there are fairly wide variations (even toe in v's toe out) in the answers and I'd prefer not to experiment at $80 and a few hours a time.....
Maybe the technician will know.....?

Not casting dispersions at you Silvia but obviously money is a major consideration given you’re sticking with the old tyres and wanting to have just one alignment.

Let’s just clear up a few facts:

Toe. If you study the posts, normally the ONLY time people put toe-out into the front wheels is for competition use. It gives better turn in on corners but has the negative effect of tramlining and diving around under brakes. You should not consider toe-out for “sporty street” use. NEVER put toe-out on the rear wheels.

Camber. If you use Lanny’s American road settings you’ll still experience your skittishness on rough Australian road corners.

Your technician should know his business for a multitude of cars; he has the specification sheets loaded into his machine.
The figures I’ve given you have been tried and tested by performance MX-5 alignment specialists over the last 20 years, as used by Club members.

[Silvia]

Excellent CB! Thanks so much for the great explanation. Had just sent you an email hoping for just such information.....thanks again. Will let you know how it goes...
I have poured a lot of money into the "new" car getting it right...just changed the gearbox oil myself, using MT90, and that's feeling very good.

[JBT]

These are the respected "Lanny's Settings" from Miata.net
Rear
Toe: 1/32 inch (0°4.5' or 0.075°) IN per side
Camber: -1.75 degrees

Front
Camber: -1.2 degrees
Caster: 5.0 degrees
Toe: 1/32 inch IN per side

Assuming 1/32" is close to 1.5mm it helps to confirm things

Actually, it's close to 0.8mm. So those settings would not provide much front toe in once moving.

[Silvia]

For the record, these are the official Flyin Miata specs. they use for road cars....
Note Toe in remains the same .15 deg as Lanny's above...
Front
Caster: 5.0 degrees
Camber: 1.0 degrees negative
Toe-in: 1/16", 0.15° or 9 arcminutes total (1/32", 0.075° or 4.5 minutes per side)

Rear
Camber: 1.5 degrees negative
Toe-in: 1/16", 0.15° or 9 arcminutes total (1/32", 0.075° or 4.5 minutes per side)

[JBT]

1/16" or 1.5mm total toe in is half that recommended by Charlie Brown. The front wheels of a rear wheel drive car tend to toe out when running. 1.5mm total static toe in may result in slight toe out once running and the car may feel darty, tend to tram line or dive left/right under brakes.

[Silvia]

I don't understand a skerrick of it all, sorry to say, and when Miata net. etc. come up with quite different "ideal" settings, well what are we poor shmucks to think?

I think some confusion stems perhaps from the Toe-in figures sometimes being per wheel and sometimes in total.Plus inches,degrees,minutes,mm, arcs etc being used at random

CB made a point that U.S. conditions are different to ours.....?
Just trying to point out how hard it is for the non-technical and inexperienced to get a handle on it.....we just want it to steer good

Anyway I'll go with his figures and let's see how it goes...

[hks_kansei]

Some basics:

Camber:
The angle the wheel sits when viewed from the front or back of the car.
Negative camber is when the top tilts towards the car like this /car\
Positive camber would be like this \car/

Castor:
The angle the wheel will pivot on when steering.
Think of a Harley Motorbike, it's steering is at a large angle, it has a LOT of castor.
Now think of a kid's scooter, the wheel pivots on a near vertical axis, that's no castor.

Toe:
Stand up.
Look at your feet.
With your heels apart turn each foot so your toes touch. That's Toe-In.
Now do the opposite, have yuor heels tough and toes apart. That's Toe-Out




Basic cliffnotes on how they affect things:

As you corner the tyre will flex and bend under the car, negative camber means that as it (outside tyre normally) flexes it still has full contact with the road and doesn't want to tuck under. Think of it like a motorbike cornering, it leans into the corner, negative camber on the outside wheel makes sort of lean into the corner.
As with anything, more isn't better, too much won't benefit and will cause irregular tyre wear, too little and it won't grip as well in corners.

Caster is similar to camber, except it only occurs as the wheels steer.
It's extremely difficult to explain in text, google it and you should find a video or something demonstrating it much better than I can explain.

Toe out on the rear will mean that as the outside rear wheel weights up in a corner it will want to travel the way the toe points. Toe out at the rear will make a tail happy car, toe in will be more controllable.
Nitrodann had a really good explanation of this a while back.





Anyway, the end result is:
If knowing what settings do what is over your head, just let the experts decide.
Take it to an alignment shop (preferably one recommended on here) and discuss with them what you actually do with the car, and what you want it to do.