Recommendations for Reducing Body Roll?

[ctsround3]

Alright so I searched and didn't find much on this topic in particular. I don't need a "how to make my car auto-x ready" response because this is my DD. Here's the specs:

2009 Yaris 3 door, manual 1.5L

-Tein S-Techs
-Tokico Blues
-TRD rear sway bar
-Konig Feather 16x7's on 205/50's.

In hard cornering, I get a tremendous amount of body roll toward the front. Being lowered, the body roll results in tire rub on whichever side the weight is shifted. My suspension setup has less than 1,000 miles on it since install.

What is the next step for me in stiffening up my suspension to reduce body roll? Strut tower bar? Mid braces? Thanks in advance to anyone with personal experience or advice!

[KCALB SIRAY]

Start with your camber.

[Jason@SportsCar]

Originally Posted by ctsround3

Alright so I searched and didn't find much on this topic in particular. I don't need a "how to make my car auto-x ready" response because this is my DD. Here's the specs:

2009 Yaris 3 door, manual 1.5L

-Tein S-Techs
-Tokico Blues
-TRD rear sway bar
-Konig Feather 16x7's on 205/50's.

In hard cornering, I get a tremendous amount of body roll toward the front. Being lowered, the body roll results in tire rub on whichever side the weight is shifted. My suspension setup has less than 1,000 miles on it since install.

What is the next step for me in stiffening up my suspension to reduce body roll? Strut tower bar? Mid braces? Thanks in advance to anyone with personal experience or advice!

Stiffer springs, and shocks with enough rebound to control them... The springs you have are only marginally stiffer than stock, and the shocks are basically an OE replacement, you need a proper suspension setup.

The braces will just add weight, more inertia to roll, spend the money on a quality set of coilovers.

[IllusionX]

Don't swaybar reduce body roll? But simply stiffening the front require a much larger rear sway bar, otherwise, you would end up with massive under steer.

[CoryM]

Jason has the right idea for performance. A larger front swaybar will reduce roll, but likely create more understeer. Only other viable option is to widen the track width.
Cheers.

[sickpuppy1]

Also, the rear say bar from trd is 18-19mm which is much better than the stock (nothing) but still allows body roll. You may want to consider a bigger one to reduce front roll too.
http://shop.microimageonline.com/Ult...R-AR23-100.htm

[IllusionX]

The rear sway bar is going to reduce inside wheel spin. You will still crush the front outside coil when doing your weight transfer you are still on the soft side at the front.

Going too large at the rear will also get unmanageable oversteers. You really need to find the best combination coil/shocks setup and front/rear sway bars.

I believe the Mi springs are the most stiff without going with coilovers, but you need a rear swaybar to control the under steering.

[Bluevitz-rs]

If you're rubbing, your rim offset isn't right or your tires size is too large.

[ctsround3]

Tire size is 205/50 and offset is +40mm. I don't see how Tokico Blues are considered "OE replacements" when all others who use or sell them claim them to be revalved to support 2" drops.

I won't go with coilovers because anything $1k or less is junk and I'm not investing what it would take to get a good ride on coilovers in a car worth what a Yaris is worth, haha.

[IllusionX]

I believe OEM 16" are 16x6.5 with a +45 offset.

[Jason@SportsCar]

Originally Posted by ctsround3

I don't see how Tokico Blues are considered "OE replacements" when all others who use or sell them claim them to be revalved to support 2" drops.

I won't go with coilovers because anything $1k or less is junk and I'm not investing what it would take to get a good ride on coilovers in a car worth what a Yaris is worth, haha.

The Tokico, much like the TRD offering, gives you a very slight increase in rebound/bounce control and are a good match for off the shelf lowering springs. However, like those springs it is essentially enough of a change (10-15%) to compensate for the the drop, and to help maintain ride quality and control.

You are still working with street parts, these are not competition duty items, and are no where near the range of what will actually make a significant difference on the track. If you want to make the car handle better you need to be looking to double or triple the rates over those "drop" springs, and you will need a proper shock that can control it.

If you don't want to spend the money to upgrade just work with what you have.

[ctsround3]

I understand what you're saying and I can agree that none of the parts that I've installed are "competition" ready or auto-x worthy but I'm not going for that sort of handling, just a more responsive cornering ability and a stiffer feel. I have no complaints with ride quality or handling other than the above mentioned body roll that I'm experiencing. I'm sure I can credit a large portion of that to my larger tire and lower wheel offset but there has to be SOMETHING I can do to level out the shock absorption without stiffening it so much that I just get wheel spin on tight turns

[justjesus]

Jason knows what he's talking about. I'd listen to him.

Easiest answer? Judging by your comments, get stiffer springs. The MI springs will help some.

But keep in mind you can't expect go-cart handling on a street car, especially when you don't want to spend the coin to do so. Quoting Jason, "work with what you have" and deal with the compromise of what you want with what you are willing to accept for the amount you want to spend.

I had a similar setup to yours, using MI springs, and while I still got rub on the hardest of turns, I dealt with it because I didn't want to "upgrade" to a stiffer set-up because of the added cost. It was a daily driver, after all, not a racecar.

edit: I wrote my response while you were writing your last entry. I'm not sure there is much more you can do to reduce that body roll, without going stiffer on spring rate.

[IllusionX]

Originally Posted by justjesus

edit: I wrote my response while you were writing your last entry. I'm not sure there is much more you can do to reduce that body roll, without going stiffer on spring rate.

I would get a larger front swaybar, and see how it handles. If there is too much inner wheel spin, then a larger rear sway bar would be necessary. This is a way to not compromise the ride comfort. So you don't necessarily need to get stiffer springs.

MI front springs are probably the stiffest you can find, but it doesn't drop as low as the TEIN.

[IllusionX]

I am quoting from another forum...

Springs affect the cars attitude when it takes a set in the longitudinal axis. (straight braking and accel)

Springs + Bar affects the cars attitude when it takes a set in the lateral axis. (Steady state cornering)

So the relationship of the springs to bars will dictate the difference in "Sprung Weight Position" from a longitudinally set position to a lateraly set position.
I feel that it is best to keep the sprung weight CG from moving too much durring transition, such as a car with low spring rates and high bar rates would dive while braking, more than it would lean in steady state cornering, thus the transition from straight braking to mid corner would raise the front of the car up as the bar starts to load up the springs durring turn in.
I feel that a good relative balance between bars and springs keeps this transitional attitude change to a minimum.
Set springs for good straight braking feel and good on throttle feel, then tune bars for steady state cornering attitude and balance.

[CrankyOldMan]

I run Tokico Blues with MI springs, and really like the handling. That said, for what I've spent on those and the Tien S-techs, I could have bought an entry level coilover set. For a good idea of price/performance range, check out the selection at TH Motorsports.

If you just want sharper cornering response, run more negative camber. You can get OEM crash bolts that will take you to -1.5°. That's what I run on mine and it's significantly tighter than OEM cornering. The tradeoff is accelerated tire wear, but for $40 and an afternoon with some big wrenches, you can't get much more bang for your buck. Anything more than that takes aftermarket crash bolts, and starts significantly reducing stability at speed.

[ctsround3]

So feel free to point out the flaws in my thinking if what I say is incorrect. Much like how the rear sway bar acts to keep the entire rear of the car as a whole, the larger front sway bar will force the front coils from "rebounding" or unspringing as they would if they were able to compress as a single unit vs being more together due to the front sway bar linking them?

Again, my thinking may be way off. Just trying to clarify.

Also, in theory all of this makes perfect sense but what would be the best thickness for the front sway bar to coincide with my existing 19MM TRD rear sway bar? Tanabe offers 23MM and it looks like Ultra offers 25MM. Any others that I'm missing?

[jcboy]

since youre running a bit thicker rear sway bar, go with A BIT thicker front sway bar. this way you don't induce understeer, the understeer you wanted to correct with the rear sway bar in the first place.

the stiffer spring rates help, but since youre talking about body roll while cornering, the sway bar plays a big role over them, as what illusionx has quoted. you might want to look into adding upper strut bars too (rear, more than the front, but i would do both lol)

creating a daily driven weekend warrior is really more of an experimentation and more importantly, a matter of preference/tolerance to the ride harshness a track-purposed car can give.