PDA

View Full Version : I Need Sharper Steering!


vadr45
02-16-2012, 08:58 PM
I've read all the posts about whether to buy a front strut tower bar or a rear one; whether to strengthen the front sway bar; whether to defrag the modopulator; and whether it's safe to go to warp speed without Scottie's okay. But I still don't have an answer to the question - what will sharpen my steering control in what is essentially a low-end street car.

Thanks to the previous owner, I have a full complement of upgrades to make my '09 Base 3-door into a street slut:
[LIST]
AFE Intake
NST Complete Pulley Set
Megan Racing Header
Custom 2.25” mid-pipe
Megan Racing Axle-back exhaust
Toyota Premium Horns w/ splitter
“Big Three” wiring upgrade
Short Shift Kit w/ bracket
TRD Rear Sway Bar
Tanabe DF210 Lowering Springs

Nonetheless, I still have a sense that the steering could be tighter, sharper, clearer. I want over-steer and I don't have it. I have read Tanabe's poem:
"Stiffen the front, induce understeer.
Stiffen the rear, induce oversteer."
But I'm not sure what I can do to achieve it. The TRD sway bar should give me what I want, but it doesn't. Will the addition of a rear strut-tower bar give me the sense that I have merely to jerk the wheel to the right and I'll achieve 90 degrees in an instant?

I recall putting a rear strut bar in my JCW MINI and noticing the enhanced steering instantly; the front strut bar did nothing but add weight. Do I need some sort of transverse bracing in the Yaris to achieve my goal? Do I need to over-inflate my tires? Do I need to lower my expectations?

I hurl myself upon your knowledge, People! What can I do?

enviri
02-16-2012, 09:05 PM
you lowered your car, add struts/shocks to increase stiffness. those stock struts are SOOOFFFTT. buy some really low grip eco tires in the rear if you REALLY want oversteer lol.
you can try to add more bars, like the selection offered by GTSPEC. They offer rear spring perch bars that you can use?

Black_griffin6
02-16-2012, 10:34 PM
I would get some of Ultra Racing's rear braces.

I have the Ultra Racing 23mm rear sway bar, and it's much stiffer then the TRD one you have. This is the one I have: http://shop.microimageonline.com/Ultra-Racing-23mm-rear-sway-bar-YARIS-UR-AR23-100.htm

Also get better springs and shocks. Especially if you're still on OEM shocks, a good set of coilovers or more aggressive springs and shocks will stiffen your suspension a lot more and make it more responsive. I'm currently running on Tanabe coilovers and they have improved my handling a lot, granted they aren't the most stiffest coilovers.

But bear in mind, no matter what you do this IS a front wheel drive car, and front wheel drive cars naturally have a tendency to understeer. You'll have to stiffen the rear a lot to induce oversteer.

cali yaris
02-17-2012, 02:13 AM
The TRD sway bar should give me what I want, but it doesn't.

No, it shouldn't. It's a step in the right direction, but not by itself. The other posts have great advice, plus:

1. Take EVERYTHING out of the back you can do without, the spare etc. Making the rear lighter will have a huge effect on your handling.

2. You didn't mention what you have for wheels and tires. Lighter wheels/sticky tires make a world of difference.

3. There are no struts in the rear of the yaris, so there is no "strut bar" back there. Knowing what suspension you have and what the parts are will serve you better, I promise.

4. If you're not going to do 1-3, take the front sway bar off. It's one way to induce more oversteer, and I know people who race with that set up.

SAV912
02-17-2012, 02:28 AM
If you want hooligan oversteer, you're in the wrong car entirely.

However, I had my first super fun/caught-off-guard lift off oversteer a few nights ago in the rain. Stupid tire shop put two replacement tires up front and put the ones with about 17K more miles on the rear. New tires ALWAYS go in the rear, regardless of drive wheels.

Needless to say, I went and had some fun with it before swapping them back around this morning. Good advice in this thread. If you're on TRD/Tanabe springs and stock shocks/struts, all the rear bracing in the world isn't going to get you where you want to be. OEM shocks are ridiculously soft. TRD Sportiva, Koni Blues (daily friendly) or Reds (not so much) should be your next step.

I'm a little baffled at what exactly it is you're after. "Sharper steering" (thread title) isn't something I exactly equate with what you're after, which is essentially lift off oversteer. Sharper steering could be mostly achieved by something as simple as unplugging the EPS fuse.

Also, listen to Garm. He doesn't own a 387 bhp track monster by happy accident. :drinking:

-C

Viperoni
02-17-2012, 02:55 AM
Struts wouldn't neccessarily help oversteer.

Overinflating your rears will help, along with adding camber and toe out in the front.

To be honest though, if you're asking this kind of question, I'm not sure you're ready for more oversteer...

SAV912
02-17-2012, 03:05 AM
Struts wouldn't neccessarily help oversteer.

Overinflating your rears will help, along with adding camber and toe out in the front.

To be honest though, if you're asking this kind of question, I'm not sure you're ready for more oversteer...

No, not necessarily but stiff springs and OEM struts isn't helping his case.

TOUGEghost
02-17-2012, 03:50 AM
Run wider tires in the front.

vadr45
02-18-2012, 02:43 PM
Thank you all for your help, especially Garm and SAV912.... I've learned much, some of which I shall implement. When I do, you'll get pix.

As I distill what you've suggested, to get the sharper steering I want, I'll need a stiffer rear sway bar and stiffer shocks all around. My MINI Cooper was much the same, but the John Cooper Works package provided the rear firmness I needed and the rear strut-tower bar was pure icing: It is possible to have oversteer in a FWD car.

Sorry I don't speak your Yaris patois yet, but I've been concentrating on older cars (Morrises and Austins) for the last seven years and I'm only just getting back to modern tuning.

SAV912
02-18-2012, 03:28 PM
Sorry I don't speak your Yaris patois yet, but I've been concentrating on older cars (Morrises and Austins) for the last seven years and I'm only just getting back to modern tuning.

I'd love to see some of the older cars, if you have pictures. I'd trade my Yaris for a second for a good condition original Mini. Richard Hammond had a pristine example in the Top Gear India Special that aired over Christmas. :cool:

Good luck with your goals on the Yaris. If you have more questions, don't hesitate to ask. We're all here to help.

-C

why?
02-18-2012, 10:58 PM
coilovers are really your best bet. Fully adjustable ones are the best bet, something where you can firm up the rear end as much as you can while keeping the fronts soft. MI has a great selection. Try those before spending money on braces and other things first.

I know what you mean about front wheel drive oversteer. I had a saab 9000 and the thing oversteered without warning. Fun as heck.