S13 suspension: tie rod end hitting LCA at full lock

[evil86]

hey guy, im pretty sure someone has already covered this topic but i cant seem to find the thread, please forgive me.

Car - ae86

motor - 4age

use - drifting

problem - i have s13 brake setup, isc coilovers, adjustable castor rod, unknown lca, ae86 rack end and ra40 tie rod end. At full lock the tie rod end hits the lca and from my observation one side gets more lock the the other.

occurs/started when - only at full lock

personal situation - the setup works and all but im after more lock

[Sam-Q]

here:

http://www.ae86drivingclub.com.au/forums/showthread.php?t=12389&page=2

post #63

mod your lower control arms

[evil86]

s sam-Q your a legend. where would DC be without you:)

[Sam-Q]

err probably exactly where it still is now! :P

I might as well rename that other thread as well for future reference

[evil86]

yeah, maybe we should break tech articles into sub catergories. engine suspension, body ect ect. makes it easier to find things

[Sam-Q]

yeah it's not a bad idea and I can suggest it. I will be making all tech question titles as descriptive as possible from here on though which will make it simpler.

[ke70dave]

ive noticed something interesting about my s13 gear.

its perfectly fine going forwards with full lock.

but if i go full lock in reverse, at a bit of speed, say like pulling out of a car pack and continuing around in 360deg or so. if i go forward again and try to straighten up it feels like it binds a bit, its quite tight for the first 1/8 of the turn, then its fine.

i have a feeling this might have something to do with the castor i run (about 3/4 of what is possible id say) could just be a characteristic of the setup though.

[Sam-Q]

I have that on my ermm.. trike. On that it's because I made it so I can steer till the steering arm is pretty much almost a straight line to the steering rod, going backwards lets it go inline and it binds for a moment before going back. Have you got modified lower control arms?

[fantapants]

yeah i found that to dave, am hoping my modified knuckles will improve things :)

[ke70dave]

I have that on my ermm.. trike. On that it's because I made it so I can steer till the steering arm is pretty much almost a straight line to the steering rod, going backwards lets it go inline and it binds for a moment before going back. Have you got modified lower control arms?

nope just standard s13 ones.

im gonna ask a stupid question, but what is considered "modified" control arms in this context. adjustable length?

i intend on putting in some R31 arms soon, so cool wheels will actually fit without rearranging my front guards. i hear they are a direct replacement to s13 except you need to re weld the steering arm stoppers.

[Sam-Q]

nope just standard s13 ones.

im gonna ask a stupid question, but what is considered "modified" control arms in this context. adjustable length?

i intend on putting in some R31 arms soon, so cool wheels will actually fit without rearranging my front guards. i hear they are a direct replacement to s13 except you need to re weld the steering arm stoppers.

ah sorry have a look at this pic I will shamelessly take:

http://www.ae86drivingclub.com.au/dcimages/1/4/3/28436.jpg

thanks Dom,

modded in that there is a small relief for the rod end to move that bit more.

A word of warning though guys, this is risky territory here and I don't really like these mods.

[fantapants]

Yeah have heard the same thing.

smaller arms will have a negative effect thought, but its just whether anyone could tell seat of pants style :)


nope just standard s13 ones.

im gonna ask a stupid question, but what is considered "modified" control arms in this context. adjustable length?

i intend on putting in some R31 arms soon, so cool wheels will actually fit without rearranging my front guards. i hear they are a direct replacement to s13 except you need to re weld the steering arm stoppers.

[ke70dave]

*response to sam q*

ah stuff that....

ive got enough lock as there is. and

dont want to allow that rod end/steering arm to straighten up....that looks dangerous

pluss i think if i did that it would make my "problem" even worse?

fantapants: how does it give a negative effect?

i assume it has something to do with changing the arc of rotation of the control arm to be smaller.

[Sam-Q]

yes it may make it possible to have it bind to the point where it is stuck, scary indeed and hence my disclaimer.

Fanta: well if anyone was to do this I would asume they would rebrace it, but then again if they are the type to take such a risk in the first place then probably not.

[fantapants]

do what.... change to a r31 lca? :)

im actually thinking tubular lca atm to try and claw back some track, or r31 as the easiest option.

Had to use spacers to clear the wheels on the brakes. :( overall a bad thing to do.

When the engine is going again, i might look into going back to single piston brakes and see how they cope with fade - really wanna do some big grip days this year along with drifting but the single piston stuff means i dont have to run spacers which improves the front end geometry alot.

[evil86]

another questions about the s13 setup. What springs are you guys running? what ever came with the setup coilover or did you change it. i found out that my isc coilovers at 10kg springs.. too stiff for my liking. im getting 6kg on the way. to match my 4kg ksport coilovers on the rear

[ke70dave]

excelent question evil86!

i originally had ~11kg springs on my first set of JIC coilovers. back when i was a noob. but then i had some 8kg springs made to suit. but of course the JIC's were valved for 11kg, so they still hurt my spine.

i have since acquired some bridgestone coilovers, which come standard with 8kg. with adjustable damping, so my spine gets a break.

id rather get some 6kg at some stage though...or maybe 7's. but then id prolly need an upgraded sway bar (s) to keep it from rollling to much. more $$$$.......

does the money spending ever end?????

[fantapants]

ive found that shocks have way more impact on ride comfort than spring rates.

Spring rates allow the shock to work through a given shock range at a given speed.

The way the shock treats the dampning required is the harshness people often attribute to high spring rates :)

Ive got 8kg hsd on softest and 6kg trd on softest. Even my mrs isnt overly fussed on it being uncomfy ...

[evil86]

indeed. i found out that my ksport rear coilovers are 4kg according to the site. but its hell stiff.... my fronts are so stiff i think the weight is not getting pushed forward and tyres are doing all the work

[ke70dave]

yer i think your right fanta,

with these bridgestons the softest setting is good, but a tad bouncy. like it needs a tad more damping. but the next level up (only got 4 levels, AGX style) is a little too harsh. i guess thats the problem with only 4 adjustments, not much resolution in the adjustment.

btw this is for normal driving here, for spirited driving, setting 2 and 3 is fine. but on that level my spine sais no more!

some may call me a weak, but this is a street car after all...

this sort of discussion is somewhat offtopic, but i feel that the original question has been answered?

[resol]

when i was running s13 front end in my rolla with stock arms and slip on rack spacers the steering would bind at full lock.

as mentioned, this is because the steering arm and the tie rod extend beyond the line of action. you can fix this to a degree with modified knuckles but when chasing more lore that can only help so much.

best mod i have seen to fix this was to either move the rack further forwards, thus changing the 'line of action' and the binding wouldnt occur. this will not affect the amount of lock either.

or run offset rack ends, this is the simpler/easier version of the above. where by only the rack ends/tie rod ends are moved forward.

-dan

[Sam-Q]

either way that sounds like suspension geometry fail, probably applies a stress on the rack and pinion engagement too but I could be wrong

[resol]

either way that sounds like suspension geometry fail, probably applies a stress on the rack and pinion engagement too but I could be wrong

well your correct, i dont think ke70's were meant to run 325mm LCA, S13 silvia hubs and struts, or even rack spacers for that matter :P

the car handled very well though, it had a epic amount of lock which bound up at the extreme end of it. which i have heard was also the case with ae86 PS arms and AJPS style rack spacers. offset rack ends arent too uncommon, i agree that they would be dealing with some excellent shear forces but they are a cheap solution. moving the rack would be a much better fix but for more difficult for the average street car/not worth the time.

-dan

[boost+k]

this is how the silvia boys fix theres and end up with two different speeds of steering, although i don't think it reduces achermann tho

http://www.gtfactory.jp/cms/e107_files/public/1206663071_2_FT2084_p1030143.jpg

http://www.gtfactory.jp/cms/e107_files/public/1206663071_2_FT2084_p1030159.jpg

http://www.gtfactory.jp/cms/e107_files/public/1205548310_2_FT2084_dsc00035.jpg

[Sam-Q]

am I the only one who thinks that looks scary?

[resol]

am I the only one who thinks that looks scary?

nope, every cut/shut steering arm i see looks scary. you can buy complete new hubs froma few places (hey man) but they are above the $1000 mark. which is a lot for some extra lock :P


-dan

[fantapants]

hey sam, thats the knucle kit i have.

it wasnt a setup i was going to try and do myself, for obvoius reasons. :)

Had it welded by a friend of mine who is a very talented fabricator. In his opinion, and the opinion of another customer of his who is a race engineer/ scrutineer, if welded properly, it should be safe as houses.

The second gen ones available now, the ones i have, DO effect ackermans.

[Sam-Q]

with that big safety pin in there it has a decent support. Like Dan welding steering arms makes me uneasy. I know it might be my emotions over logic though.

[FAST EDDIE]

this is how the silvia boys fix theres and end up with two different speeds of steering, although i don't think it reduces achermann tho


dont see too many people running those knuckles :S:S

[FAST EDDIE]

oh and sam moving the rack fowards is far from a geometry fail, i have done it in my 86 with 86 xmember 86/s13lcas and s13 sus and its briliant, also did it to my ke70 with entire s13 sus and it works brilliant, i have no binding at all now!!!!

I also have a jig to make custom shortened s13 knuckles coppied off the ones in my 86!!

[boost+k]

dont see too many people running those knuckles :S:S

just money really.... there latest design also has a sweet sytem so you have adjustable lock stoppers

but yea why spend a $1000 when i can rock out the grinder and welder for next to nothing :sunnies: