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bmxtrev
2008.06.09, 05:49 PM
What exactly is on and off power steering? If I tune for more on power steering, does that mean my car will have more front grip when accelerating?

For example, if my car oversteers on throttle, i could give my car less on power steering [by using toe out, dps preload, etc.], and then i would have less front grip on throttle. Is that what on and off power steering is? or am I completely off? :eek:

Thanks,

Trev

bmxtrev
2008.06.09, 10:13 PM
Does anyone know? :confused:

restated question [i realize that my explaining skills are subpar, lol]: does on and off power steering refer to how much grip the front tires have when accelerating or coasting/braking?

hmmmm... im pretty sure im correct, but hey, what do i know :D

color01
2008.06.10, 01:50 AM
Basically you're right, steering can be thought of as the amount of front grip in relation to rear grip. Try thinking of it like this:

On-power, weight will be shifted to the rear end, so pressure on the front tires decreases and pressure on the rears increase. How much front grip you have left is dependent on how much weight shifted backwards -- a stiffer rear suspension, for example, causes less weight shift, a smaller change in pressure on the tires, and thus more on-power steering.

Vice versa for off-power steering. The weight shifts forwards, so allowing the weight to shift more forwards (via softer front springs, etc.) will give you more off-power steering. Hope that helps.

bmxtrev
2008.06.10, 08:37 AM
i was confused because i thought steering was the physical turning of the wheels, but in this case, it refers to steering input combined with front grip, and that equals the actual direction of the car.


its not really important, but why does toe in/toe out affect the steering like it does? [ex. toe out gives less on power steering, toe in gives more] :confused:


yes that does help^.
Thanks color! :)

andreophile
2008.06.10, 08:56 AM
I'm not entirely sure, but I believe it's because the outer wheel (which travels the most while cornering) turns a greater degree with toe-in than with toe-out. If Mini-Zs had provision to control the Ackerman angle, there won't be any need to have extreme toe settings to achieve the desired steering characteristics.

Aurora
2008.06.10, 08:46 PM
i was confused because i thought steering was the physical turning of the wheels, but in this case, it refers to steering input combined with front grip, and that equals the actual direction of the car.


its not really important, but why does toe in/toe out affect the steering like it does? [ex. toe out gives less on power steering, toe in gives more] :confused:


yes that does help^.
Thanks color! :)

There are a few settings will cause oversteering/understeering when the car is on or off throttle; but there are some that will cause the car to under or oversteer, regradless of on/off power. Toe-in/toe-out is one of the latter.

Actually, more toe out at front always cause the car to oversteer more (more easy to turn in), regardless of on or off power; and vice versa. The drawback of having a lot of toe out at front is less straight line stability.

In terms of rear, very very rarely (or virtually never) a toe out will be given, and more toe in at the rear will cause the car to understeer(again regardless of the on/off power steering), and vice versa.

Color01's do speak of the truth, and they are important pointers when considering the suspension setup.

Hope this helps. :)

andreophile
2008.06.11, 04:27 AM
@ aurora: As per my personal experiences, I found that steering with different toe settings is still amenable to on and off power conditions.

Let me quote one of my posts (http://mini-zracer.com/forums/showpost.php?p=304364&postcount=10):

I played around with five different toe settings today from +2.3 (toe in) to -0.6 (toe out). I practically verified with my MA-010 what's common knowledge about toe settings. That is, real car toe characteristics work out identically for the Mini-Z too. Here's what I've verified:

http://img232.imageshack.us/img232/3674/chartke2.jpg

marc
2008.06.11, 10:32 AM
Does camber effect this as well as toe?

bmxtrev
2008.06.11, 05:17 PM
doesn't more neg. camber just give more steering at high speed, and less at low speeds? [regardless of on/off power]

Aurora
2008.06.12, 02:14 AM
@ aurora: As per my personal experiences, I found that steering with different toe settings is still amenable to on and off power conditions.

Let me quote one of my posts (http://mini-zracer.com/forums/showpost.php?p=304364&postcount=10):

I played around with five different toe settings today from +2.3 (toe in) to -0.6 (toe out). I practically verified with my MA-010 what's common knowledge about toe settings. That is, real car toe characteristics work out identically for the Mini-Z too. Here's what I've verified:

http://img232.imageshack.us/img232/3674/chartke2.jpg

Andreophile,

That's interesting result you have gotten. And I should assume it is the front toe you are talking about? I usually benchmark my results with others on track and as well as all the setup cheatsheet for 1/10 scale cars.

IIRC, Xray, serpant or even the Hudy setup system could confirm what I said. And I think their approach of 'corner entry', 'mid corner' and 'corner exit' when dealing with suspension setup is collectively exhaustive and mutually exclusive.


bmxtrev,

I haven't a chance to test or view camber in a hi/slow speed cornering prospective. But personally, I would adjust camber as a mean to achieve max. tire contact patch, and unless other settings couldn't help, I then will resort to camber as an adjustment. Generally speaking, I too can confirm that more camber at front usually yield more steering in a corner, and less camber will cause car to understeer.

bmxtrev
2008.06.13, 09:48 AM
Aurora, you are totally correct about camber.

I think that depends on the shape of the corners - your camber will depend on how much your car will or wont lean during the race. So you aim to compensate for the lean by adding camber to provide even tire wear and vise versa.


Thanks :)

color01
2008.06.13, 03:43 PM
Regarding camber... from what I can tell, for RWD cars at least you can only go up to a certain point. 1.5 and 2deg provide a bit more corner speed than 3deg for my MR02, and in addition, with 3deg the front tires undergo "coning" (profile wears VERY unevenly).