Front swaybar deconnection....anyone tried it

[dsc_pat]

has anyone tried to disconnect the front swaybar on a liftback ?

I think that the stock springs might just not be up to the task w/ the front swaybar disconnected.

i totally forgot to try to disconnect one front endlink at last track day, and I am not back on track until august 19, so I need food for thought...

for whom is wondering what the heck I an talking about, note that the impressively huge front swaybar on the yaris contribute to its excessive understeer (even w/ a rear swaybar). I am trying to fight against it but I don't want to go with the springs and shock route for now.

thanks to share if you've done it

[Biggie™]

The Yaris is already under sprung, you're just going to have to bite the bullet and buy springs and shocks...

[dsc_pat]

i've seen much worst than a 2007 yaris undersprung wise...

the spring market sucks for a yaris atm, everything produce has look in mind.

can't wait for koni and ground control to come out of the closet.

[cleong]

You can just try raising the tire pressure on the rear to bring the traction balance up to the front tires. Or lower tire pressures in the front.

By the way, a local shop says they have Yaris Koni absorbers in stock already. I'll believe it when I see it tomorrow, so take my discovery with a pinch of salt in the meantime.

[Biggie™]

Originally Posted by dsc_pat

the spring market sucks for a yaris atm, everything produce has look in mind.

That's because people looking for performance don't buy progressive replacements.

[dsc_pat]

show me where I can get custom rated springs for my yaris and i buy them right away

i really don't understand what you're tyring to say there

have you driven your yaris on a race track ?

there is NO suspension set up offering what I am looking for atm, and let's not talk about k sport or megan...that is far from what I am seeking.

I asked if anyone disconnected their front rear bar to fight the massive understeering and traction problem the yaris is facing...i don,t care for anything else.

thanks for the tire pressure trick. It's been optimized already tough !

P

[Jerkratt]

acually i have seen a front sway bar.... c-one i beleave makes it i made a topic on thsi a while ago and got flamed..... ahhh here it is

[jdium]

Originally Posted by dsc_pat

show me where I can get custom rated springs for my yaris and i buy them right away

i really don't understand what you're tyring to say there

have you driven your yaris on a race track ?

there is NO suspension set up offering what I am looking for atm, and let's not talk about k sport or megan...that is far from what I am seeking.

I asked if anyone disconnected their front rear bar to fight the massive understeering and traction problem the yaris is facing...i don,t care for anything else.

thanks for the tire pressure trick. It's been optimized already tough !

P

Wow, somebody is too sensitive. I'm pretty sure he was belittling how most people don't buy progressive springs that are actually meant to help handling. The average consumer buys "lowering" springs to help looks. Settle down on the butt hurt, nobody attacked your manhood or your mothers sexual habits or anything like that...

[cleong]

Let's work this out in a logical manner. The anti-roll bar, as the name suggests, helps the car to corner in a flatter attitude than without, and helps maintain a better tire contact patch. However, it also distributes weight from the laden wheel to the unladen wheel. You may lose some traction in this exchange, but it'll be a net gain in front end grip.

Armed with this theoretical knowledge, I would say that if you uncoupled the anti-roll bar up front, you will understeer more than before, because you can't keep the car from rolling around in the corners, so you don't have a good tire contact patch, and thus you will have a net loss of front grip.

Oh, and try tweaking your camber, it does not look like much but it helps corner speed a lot. You might need more than two degrees negative, the way you make the Yaris sound like a terminal understeerer.

And this is where I may offend, but have you tried slowing down for the corners? The Yaris as I know it turns-in very well, with its short wheelbase, front end weight bias, but only if you entered a turn at a sensible speed. And it might not be slower, because if you adopted a slow-in-fast-out approach, you can get on the throttle sooner to build up speed coming out of the it.

[dsc_pat]

this is the kind of discussion i am talking about

as for the guy telling me to calm down, w/o my intervention this topic would be only filled with crap; you tell me who makes the conversation now. just keep your comment for yourself, and contribute to the topic with something that's worth it, else just go away...

Yeah, I believe you when you say that OEM spring rates were chosen considering there IS a massive front bar, and disconnecting it will just make it worst....this is the kind of opinion i wanted.

As for slowing down, you're very right, it could be a problem coming from the driver, of course. My case is car-related, the chassis was tuned for severe understeer in OE mod, but the rear swaybar just doesn't cut it with sticky tires....i am not a profesionnal race car driver, but i,ve got my load of experience with FWD and race track.

I'll try to disconnect the front bar anyway @ my next event and see how it feels...since I am not modding my yaris any more than tires and brake pads...

thanks

[WRBlue]

Softning the front bar decreases understeer - similar to increasing the rear bar, which increases oversteer.

Removing the front bar all together probally is too far though - too much body roll overcomming the adhesion of the inside tires. Disconnecting usually will cause issues with suspension geometry - the bar is a spring which also keeps things aligned. For example, a big bar on a WRX actually decreases understeer on most cars because the suspension geometry doesn't change as much cornering. I've only seen the removal of front bars done for drag racing to lower weight cause they don't have to turn.

BUT most Lotus 7's were built without sways at all...

My suggestion would be bend your own. Its not too hard, especially if you've got the OEM one off. Technically any cage building shop can bend one cheap. Strength increases and decreases to the 4th power, so just 1mm can make a big difference.

If you look at the equasion for sway bar strength:
................................500,000 x D^4
K (lbs/in) = -----------------------------------------
....................(0.4244 x A^2 x B) + (0.2264 x C^3)

..................B
.......----------------
.A|../......................\ C
...|./........................\

A - Length of end perpendicular to B (torque arm - inches)
B - Length of center section (inches)
C - Length of end (inches)
D - Diameter bar (inches)

You can see that by increasing the center section, the torque arm, or the actual length of the bar end will decrease stiffness, while diameter increases it.
If I were to bend a thinner bar, I'd also drill multiple holes on the ends to make the torque arm and bar end longer or shorter to tune the bar. Theoretically you could make a thinner bar that goes from stiffer than stock to weaker than stock and be lighter than OEM with just adjusting the end links.

Originally Posted by dsc_pat

My case is car-related, the chassis was tuned for severe understeer in OE mod, but the rear swaybar just doesn't cut it with sticky tires....

I don't know about Canada, but US liftbacks don't have a rear bar.

[dsc_pat]

thanks a HEAP

the rear bar is a TRD, wich isn't stock. it is pretty weak imo...the design looks good but it doesn't feel performance oriented like a progress or other rear bar wich have a more direct design. It could also be that there is so much understeer and body roll to fight against, that the effect isn't very noticable.

as for having a custom bar made, this is a great idea and i've got a pretty good plug in a chassis/cage shop since I went for jobs there a couple times.

thanks

Patrick

[cali yaris]

I have Tanabe springs, and TRD shocks, struts and rear sway. Kumho street tires. I went to the track today and after my first session, I increased rear tire pressure, so the fronts were 30 and the back were 35.

I experienced VERY neutral steering with my Yaris, it was really fun and I was keeping up with much better race-prepared vehicles -- well, in the turns at least I braked early -- late braking is, IMO, the most common culprit in understeer.