Handling Write-Up, Suspension Tuning, Aerodynamics and other blurbs Options

[BonzaiCelica]

i'm trying to mount my go pro camera to my chassis so I can get the suspension in action. for both the front and rear.

anyhow have you guys ever thought of moving the front end link mounting point. it seems the way its mounted on our doesn't leave much room for travel on the control arm. perhaps moving the mounting point tab to the front shock like it is on the celica below. of course you woudln't mount it that high. the end links on superstrut are mounted onto the shock as you can see in this pic



below is a pic of a 7th gen celica gts chassis and a integra type r dc5


This post has been edited by BonzaiCelica: Jan 15, 2013 - 5:29 AM

[Special_Edy]

Maybe Im not understanding but you are talking about the sway bar end links?

They move up and down in unison with the control arm. When the control arm moves upwards, so does everything else. Many of the vehicles Ive seen in my life have to sway bar attached directly to the control arm, an end link is unnecessary and Im not sure what advantages or disadvantages it has other than adding more unsprung weight.

The only purposeful logic I can come up with is that the mounting point or use of an endlink would most likely be to keep the sway bar from binding. The sway bar pivots on the sway bar bushings, so any travel follows the curved radius around this pivoting point. The suspension components such as the strut and the control arm have their own curved travel(nothing moves linear, its all curved travel to keep camber and just inherent design).
So I imagine the designers of the suspension chose locations and made compromises that best take these curved motions of travel into account. Hope I answered your question.

This post has been edited by Special_Edy: Jan 15, 2013 - 3:03 PM

[BonzaiCelica]

the reason(i'm assuming for 7th gen celica) have their sway bar end links attached to the shock is because the end tie rod gets in the way. I don't know I'm just seeing if perhaps we can get a different length sway bar end links and mount an end link tab to the bottom of the shock for our 6th gen celica's i'll try to get a video of the front suspension in action so perhaps i can better understand.

[Special_Edy]

Does the strut get into the way of the control arm? How about the spindles or the wheels? Will the control arm hit the strut because the strut is blocking it? Or does the strut move up and down in unison because it is indirectly attached to the control arm?

The sway bar is not a rigidly mounted object, it moves up and down just like the control arm and the rest of the suspension. It is actually a torsion bar. It twists inside the sway bar bushings and brackets, and so the ends of the sway bar where the end links attach actually rotate up and down(around the center, the sway bar bushings). If one side of the vehicle hits a bump, it will compress the suspension on that side. The control arm on that side of the vehicle will move upwards, and so will the sway bar. But the neat thing about a sway bar is that it will twist, and store torsional force like a spring(kind of like the springs on the garage door). If the two sides of the suspension are at different elevations(or levels of compression) the sway bar will become twisted, and will apply an opposite force on each side of the suspension to try to make them even. This is why it is called an anti-roll bar or anti-sway bar. It attempts to keep both halves of the suspension equal, so the cars body doesnt roll around a corner.

Does this answer your question? Or am I still misreading?

[BonzaiCelica]

the whole reason i brought up this discussion is because zzt321 has McPherson setup like ours. even the ST182/ST184 5th gen celica have mcpherson. if you look at the mcpherson design from the 5th gen you can see its different from ours. and so is the 7th gen. toyota changed the design of the mcpherson a bit on 7th gen so it must be better right. well once i get the video i'll know more.

also youtube vid of mcpherson vs double wishbone...

http://www.youtube.com/watch?v=ftf3KYHTOYU

This post has been edited by BonzaiCelica: Jan 16, 2013 - 3:55 PM

[rdyzz]

i have ran my car without a swaybar with up rated springs, it takes bumpy roads way better since the wheels are independent. with the swaybar it seems like transitions are alot better during turn-in and steering wheel input.

as for rear swaybars, i dont like it. really stiff rear swaybars seem to always make one wheel lift. i run without one and compensate for this with spring rate, it makes the rotation alot more predictable for me. i can still rotate with lift throttle.

on the 7th gen celica the swaybar endlink seems to be mounted to the strut because of space limitations. if you notice the tie rods are really low, this doesnt allow the sway bar links to be mounted under and onto the control arm without it hitting the tie rod. there isnt a reason other than this, there is no gains imo since a swaybar only really needs to be mounted to the chassis and two ends mounted to the suspension parts you want to connect it to, to have it work.

most modern cars seem to have more caster into its engineering than our older cars have, but i still dont feel caster alone makes a production level car handle better. if the car is not engineered with alot of caster adjusting caster can affect a cars bumpsteer, or the amount the wheels toe in and out during compression and rebound. this can make you turn the steering wheel more and more as the suspension compress during a turn, or work in the opposite fashion where you may have to unwind the steering wheel from the direction you are turning. this is mainly due to the way the steering arm is casted into the knuckle. so anytime it is tilted up or down further than factory specs it runs in a different sync than the lower control arm causing bump steer. lowering can affect this to, thats why over lowered cars have alot of bump steer. i've had to correct my bump steer by grinding 14mm off the knuckle, toe in now moves less then .006" from static height to full compress, but not from being over lowered mainly from using a RCA kit which changed the geometry a good bit.

as for alignment i have found that macphersons front work well with alot of negative camber, even though my car has a RCA to correct the geometry my car performed best with -2.5-2.7 degree's of camber. i have ran -1.2 before as a conservative setting and it showed alot in how it performed and on the tires. i usually run .10 to .15 toe out up front and 0 to .05 toe in on the rear. i like this better since my rear suspension is sprung alot stiffer than my front suspension.

what i have also found out to is running less SAI has helped with my cars handling, i know its supposed to make caster and other geometry changes count more, i experimented with this and running more SAI, since more would slightly benefit camber curve but would reduce wheel rate due to the angle of the strut. i liked the feel of the car best with less SAI, i used a eibach camber bolt and dialed in as much camber as i could, -4.3 degree, and pulled my upper top mount to the positive position. i ended up with -2.7

i also tested running with a wider front track than rear, 50mm total. i used 2 25mm front H&R spacers. i knew this would bring my scrub radius into the 2" positive range. since with my current 8" wheel setting with a +20 offset, my scrub radius measured in the positive 1.2" side. i was ready for the torque steer of running more positive scrub radius, but it didnt feel to bad actually. not as much as what the moto iq site would make you believe.

all in all at the last pdx here it was really fun and actually transformed my handling quite a bit. i run on direzza star specs and i kept up with some pretty good drivers driving sti's and s2k's with better tires, the only disadvantage i had was out of corner exit since i didnt have an lsd i could not throttle out as early. and any time i tried it was one wheel wonder.

sorry to rant so much, i just thought id share some of my experience and maybe some knowledge, but its still to each his own, thats the thing that makes suspension tunning so interesting, because there is no one way that works best (but you can make it worse), you have to find out what works for you and your driving style. i can also saying out of the whole aspect of tuning a car i think suspension tuning is somthing im into the most.

This post has been edited by rdyzz: Jan 16, 2013 - 6:00 PM

[BonzaiCelica]

well check out the multimedia section, i posted a video of front n rear suspension movement. I can see that the sway bar is very much needed to bolt on to front lower a arm

ya i only understood about half of what you said. I'm not that technical with suspension set up just yet.

This post has been edited by BonzaiCelica: Jan 20, 2013 - 7:28 PM

[Manos]

The original post started ages ago, but I only read it now. Some thinks I fail to understand though:

you put a GT-4 front bumper with a custom fabricated hood and a little more custom fabricating connecting the top grill on the bumper to an opening in the hood and you could have a front spoiler similar to a Lotus or a Ferrari!

How would this work?


Thanks
Manos

[delusionz]

I thought I'd add one thing

Driver experience/skill also alters a cars handling characteristics.

Novice and inexperienced drivers tend to drive in an understeer inducing manner. This makes people want to increase the natural oversteer by installing a rear ARB and such,

my rear ARB is still sitting on a shelf at home, I'm not ready to install it until I can make my car oversteer and be able to control it like its 2nd nature.