rear swaybar installed...but understeer?

[overb0ost]

got my progress rear swaybar set to the stiffest setting which is equivalent of a tanabe bar.

went to test it out and normal driving the car is awesome, rear is really planted and more predictable.

i give me friend a ride and i do my usual stuff and do circles and shit, but i get crazy understeer. i have federal 595s in the front and some bald winter tires in the rear. i go from 1st to 2nd, and i turn in to start my circles and it won't even go sideways unless i clutch kick at least once or twice. before i was able to do it with ease.

whats going on? if i take a corner hard while gripping i wont understeer tho.

but when im doing some 60km/hr circles it understeers, i don't get it.

keep in mind i have stock sway bars on my s14. I'm running on springs and gr2s, so no coilovers.

i thought i would get some crazy oversteer but its actually the opposite affect.

i'll try again when i have time but i'm pretty sure this result will be the same again later on.

don't get me wrong i can still get sideways, but its leaning more towards an understeer. i cant even do 2 full rounds of a semi big circle without having to pop the clutch or ebraking it to extend it. before i just had to turn out and back in to get back sideways.

someone please enlighten me. thanks!

ps: could it be that the vlsd fluid wasn't warm enough? the engine was semi cold, not at the 1/2 way mark on the thermostat.

[Gumballf355]

It would be hard to help you without knowing your whole setup... being that your front tires are crap thats a large part of it.

[LB.Motoring]

VLSD is where you should be directed.

Im sure it wasnt warm or something.

Unless you changed something else.

[overb0ost]

my front tires are federal 595s compared to some semi bald winters?

i would say the feds win by a large margin.

would it be that the rear is TOO stiff, causing understeer? since the car is more planted = more grip

the vlsd fluid was changed 10months ago to redline. went to 2 track events, and drifted in the winter.

maybe its the combination of my rear swaybar on full stiff + solid endlinks.

most people get tanabe but run polyurathane bushings, so theres still some room for flex as opposted to full solid endlinks? maybe it makes a huge difference?

[cdlong]

Originally Posted by overb0ost

my front tires are federal 595s compared to some semi bald winters?

i would say the feds win by a large margin.

how warm was it? if it was cold out, there's a good chance that the winter tires were gripping better than the fronts. the rears could have been in their operating range while the fronts were too cold to grip.

[spool_sample]

A front sway bar will help balance the car out a TON. The common belief is that upgrading the front bar will make the car understeer more, which isn't necessarily always true.

On cars with crappy front suspension geometry (i.e. most cars with McPherson struts up front, like the S-chassis have), a bigger front bar will improve camber curves, thereby leading to less understeer as well as better turn-in.

Also, it never hurts to have the car realigned after working with the suspension. Crank up the camber and zero out the toe up front... maybe a little toe out if you don't mind the wear.

[turtl631]

Originally Posted by spool_sample

On cars with crappy front suspension geometry (i.e. most cars with McPherson struts up front, like the S-chassis have), a bigger front bar will improve camber curves, thereby leading to less understeer as well as better turn-in.

Slight correction- not to nitpick, but a bigger bar doesn't change the camber curve, it just alters where you are on it. The only thing that changes the actual curve is altering the suspension mounting points, caster, etc. etc.

[MrChow]

uh... Wow.. are you weight transfer any??
My S14 I'm stock front and whiteline in the rear sway bars and i'm stock spring with only gr2's in the front.
for tire traction T/A in the front with 85% left and used stuff in the back. There Poteza thingys...
What's spring are you running and how old are your shocks??
I pop oversteer easily if I do some weight transfer.

[drew935]

Too stiff in the rear will not cause it to rotate around a turn thus causing understeer. Soften the setting up. So why did you upgrade the swaybar before doing the poly bushings?

[1Via!]

If you have stock struts, springs and a rear sway, there are other areas you should address before you start complaining about understeer.

Start with getting a front sway bar also.

[overb0ost]

^^ i actually got a front swaybar sitting beside me but i didn't have time to install it and i wanted to feel the difference with just a rear swaybar.

im not on stock springs and shocks, they are some aftermarket springs (yellow) and KYB Gr2s for shocks. car is lowered 2". car came lowered as is when i got it.

i noticed that i had more oversteer when off throttle, like gripping a turn when coming in hot.

but when trying to do circles at full throttle, all i got was understeer. even when i got it to get sideways it would catch grip every so often.

i'll probably end up setting it to medium and see how that does.

and about my front swaybar, it would probably add even more understeer wouldn't it? thats teh reason why i wanted to test having a rear swaybar then putting the front on.

[ronmcdon]

hmm, usually isn't it the case that a stiffer and/or larger rear sway (or suspension for that matter) actually promotes more oversteer? or maybe your front swaybar is set to a position thats too tight? (edit* nm, read that you have stock front sways.)

by the way youre explaining things, it seems as though there's something not working right to begin with. my hunch is that it doesn't have anything to do with the sways, but i'm just guessing here. check out the simplest things first (set the sways to softest position, check tire pressure, check vsld fluid, check bushings, brake condition, etc)

as for the tires, you really ought to replace the them anyways if they're balding. might as well take care of it now for the sake of further diagnosis.

[overb0ost]

^ before putting the rear bar in everything was the same. was very easy to break traction. it seems harder to break traction now since it feels more planted on the ground. i'm thinking that maybe the chassis has stiffened up signifantly that now i cant drift low speeds without some sort of weight transfer.

and with bald tires, i should be spinning out. the rear tires would actually help with oversteer. i just want to drift them off till the cords and put new tires on the rims.

the things i will try in chronological order:

1) try again on a hotter night by myself, maybe it wasn't hot enough for the tires.
2) set it to the medium setting
3) change vlsd fluid

[Wei240]

you should install front sway bar too,

just increasing rears to some super stiff bar will lead to snap oversteer later on

other suspension components might help too

and you can't change the vlsd fluid, just diff fluid, the vlsd fluid will die out on it's on eventually and can't be changed....

all in all, seat time helps too, not sure if it's the weight transfer thing.. i had issues on that during my first time on track, it's like wtf, then i realized i suck...

[McRussellPants]

outside rear tire is loading up super fast causing the vlsd to shit its ass and freespin the inside.



done, VLSDs are only good when you're poor and have no mods.

[overb0ost]

Originally Posted by McRussellPants

outside rear tire is loading up super fast causing the vlsd to shit its ass and freespin the inside.



done, VLSDs are only good when you're poor and have no mods.

is the rear tire loading up super fast because of the swaybar is too stiff with the combination of my springs and shocks? if it was on a softer setting it wouldn't do so?

ya i got a nismo 2way that i'm going to install, just not sure when to install it.

i also have coils waiting but after i put on the swaybar it helped A LOT, so i was gonna go to a few track days first before i put on the coils.

i probably will install coils, then 2way.

[McRussellPants]

Originally Posted by overb0ost

is the rear tire loading up super fast because of the swaybar is too stiff with the combination of my springs and shocks? if it was on a softer setting it wouldn't do so?.

probably a little, maybe maybe not.

[yokotas13]

Originally Posted by McRussellPants

outside rear tire is loading up super fast causing the vlsd to shit its ass and freespin the inside.



done, VLSDs are only good when you're poor and have no mods.

exactly what i was thinking


that, and you rely on your body roll so much to drift without it you suck

tires
2way
coils

that order, go do it quit whining

[overb0ost]

Originally Posted by yokotas13

exactly what i was thinking


that, and you rely on your body roll so much to drift without it you suck

tires
2way
coils

that order, go do it quit whining

ok smart guy, tell me how do you drift an underpowered car without weight transfer? (yes there are other ways but weight transfer is the most efficient) You do realize body roll is a form of weight transfer right?

[1Via!]

KYB GR2s are stock replacements.

Get an open diff. Weld it, or get one of your buddies to. You'll never have to wonder about whether your vlsd fluid it tepid, lukewarm, or boiling. And... youll be able to do your circles for days and days without having to worry about inconsistent results.

[Ian]

This is more than likely just bad driving coupled with inexperience and you expecting to feel a difference.

Also, your unknown springs and GR2 shocks (which are practically stock replacement) aren't too much of an upgrade

[pr0tus]

" i give me friend a ride and i do my usual stuff and do circles and shit, but i get crazy understeer. "

I don't know if you only tried this with your friend in the car, but I can tell you getting oversteer in my stockish 240 is way harder with a passenger. I have some fat friends though..

[sideview_180sx]

umm...........i thought macpherson strut design was superior. which is why porsche uses it front and rear. the only things better IMO would be cantilever, or pushrod setup.

[cdlong]

BMW uses it too, but that doesn't make it good, it just means that porsche and BMW are good at macpherson struts. their camber curves aren't great (they don't gain enough camber during compression) and the travel is often short. but with a stiff spring, that doesn't matter as much.

the best setup depends on the vehicle and your definition of "best." but it's generally accepted to be an unequal length A-arm system like those used in formula one/indy/champ. push/pullrod/direct action usually has more to do with packaging and aerodynamics than anything else. with the right tuning, they can all be made to work more or less the same. i'm not really sure what a cantilever set up is, and a pushrod isn't really a complete setup, but a shock mount.

[!Zar!]

Ugh. Why are we getting into the whole macpherson debate.

The understeer is coming from the vlsd.

[overb0ost]

what would you guys change first.

the vlsd to 2way

OR

my shitty springs and shocks to stance coilovers (already ordered them, so please don't suggest other brands)

i'm thinking coils....track a few times, then hit the 2way up.

[jmauld]

Originally Posted by overb0ost

what would you guys change first.

the vlsd to 2way

OR

my shitty springs and shocks to stance coilovers (already ordered them, so please don't suggest other brands)

i'm thinking coils....track a few times, then hit the 2way up.

Your tires first.

[Replicant_S14]

Originally Posted by jmauld

Your tires first.

......and then drive it.... a lot.

I've gone from a stiff aftermarket rear bar, ...to a softer one, ....then back to the oe rear bar and inducing oversteer is never a problem. Give it a shot before you turn your car into this.....

[ronmcdon]

Originally Posted by jmauld

Your tires first.

yeah, pls do not hit the track with balding tires. I really doubt you'd pass tech inspection anyways, but then again there are some pretty bad grps out there.

[cdlong]

is there something wrong with doing both? i'm all for seeing how mods affect the car seperatly, but the 2 way and coils will change the car enough that you will have to re-tune or re-learn the car. just put all the parts on then tune it.