Car losing traction in corners

[Chase1996]

Originally Posted by Calum

I drove a car with Sportlines before, it was atrocious and did exactly what you've described, pitched and rolled whenever the suspension was compressed from a corner and a tire hit a small bump. The ride/handling in that car was literally one of the worst I've ever driven that wasn't actually broken.

I disagree with sticky tires and stock suspension. Maybe my driving wasn't up to par, maybe my roads are worse... I don't know. But my experience was different. For me I ended up moving to RCE yellow springs to help the transition onto the bump stops with the otherwise stock suspension and stock tires. When I moved up to MPSS (yes, I know they are only a street tire, that's all I was using them for) I was back to unpredictable responses to mid corner bumps.

What I ended up with is RCE 0's. I like them a lot, and would recommend them in a heartbeat. They're rebuildable so you wont have to worry about replacing them when they wear out. They're very well damped, with enough head room to move to stiffer springs if you choose, but still very livable for daily driving. But that was the best for me and my price range. If I were you I'd talk to Andy or Myles from RCE, truely awesome guys and their whole business is built around getting the customer into the right product.

Aside from that, for the love of all that is holy, you need some more negative camber in the front. You'll destroy the outside edge of your tires in short order with 0 camber. I'm presently at -2.5 degs in the front and I'm thinking of getting camber plates so I can take it to -3.5, and some more caster. (My golf has more caster than this car, and it's front wheel drive. )

The rest of the alignment is pretty subjective. A lot of guys, myself included, are running around 0 rear toe. It does wonder a little more on the highway, but it's still very stable. The way the car rotates, though, more than makes up for any wondering on the highway. Based on your track record of cars and what you've described of your driving, I'd recommend this for you as well.

I'd leave the rear camber, it's pretty close to even and once you get the extra grip from the front camber you'll likely want that much rear camber. (If you only get camber bolts for the front, you'll end up somewhere around -1.5 degs camber in the front, in that case, I'd reduce the rear camber to -1 degs.)

Just one more thing. A sway bar, or anti-sway bar, is a functional part of the suspension. It helps to reduce side to side motion by transferring compressive forces from the outside tire to the inside tire. A strut bar is a brace that connects the tops of the struts. Strut bars are not functional parts of a suspension, they just help to keep the frame of the car from flexing. Putting a larger rear sway bar on a rear wheel drive car can make it much harder to get power down on corner exit because they actually reduce grip to the inside tire. That's fine if you want to move to a better rear diff, but I'm not looking to spend that much money.

Thanks for the info! I unfortuntely dont have the money for new springs or anything like that rn...what would you recommend I do to fix the issue?

[shiumai]

I had a similar experience when i had swift lowering springs with stock shocks. i didn't really notice it for daily driving to and from work, but once i got into the canyons i felt like the back end was very wiggly laterally. when i hit a bump mid-curve it would feel like it would 'wallow' for a second, and not feel as planted as it should.
switched them out to tein flex-z coilovers and that took care of the issue immediately. my alignment settings for the swift springs and flex Zs were the same, except that the ride height for the coilovers was a quarter inch lower.

[Calum]

Originally Posted by Chase1996

Thanks for the info! I unfortuntely dont have the money for new springs or anything like that rn...what would you recommend I do to fix the issue?

OK, given your low budget, I'd get a set of camber bolts for the front. Tell the shop to max those out first, then make them even. You'll likely be around -1.5 degrees. And that's fine, you can stay there and be OK. More would be better, to a point, but -1.5 on a street car will work fine. Next, have them set the rear to about -1 deg. The reason for this is that the rear has a lot more camber gain than the front and this will keep things pretty even, but still safe.

I might be reading your chart wrong, but it looks to me like the rear toe is in, not out. And to my knowledge, toe in is the factory recommended setting as it's more predictable. The tire wear issues from that much toe is pretty minimal so don't worry about that. If you want a setup that's more fun to drive at the cost of a little stability, move toward 0 toe all around. But even at 0 tie everywhere, the car is still very predictable.

But honestly, I don't see any of these fixing your issues, if as I'm hypothesised, you're having trouble with the transition on the bump stops. Did your springs come with new bump stops? If not, try pulling them off the car and cutting them as was mentioned. Another thing that was mentioned was going back to stock rims and tires. Obviously that's a set backwards, but it's not a bad idea. A comfortable driver in a slow car is often faster than an uncomfortable driver in a fast car.

[churchx]

Calum: wasn't toe in - negative, toe out - positive? Now i start wondering if i was reading chart right
P.S.
Imho most oem settings are about zero toe, to lessen tire wear most (toe affects it much more the camber). Including on ours. They got ease of power oversteer via chosen spring rates & purposedly selected tires with little grip. Of course slight toe-in won't increase tire wear that much but will add up some stability, especially on end with engine output, allowing sooner(or more) get on gas in turns with less traction loss.

[Kostamojen]

Originally Posted by Chase1996

Thanks for the info! I unfortuntely dont have the money for new springs or anything like that rn...what would you recommend I do to fix the issue?

Springs are very innexpensive... If you can't afford to buy shocks or coilovers, then you need to sell the Eibach springs and go back to stock until you can save up for a quality suspension.

[Calum]

Originally Posted by churchx

Calum: wasn't toe in - negative, toe out - positive? Now i start wondering if i was reading chart right
P.S.
Imho most oem settings are about zero toe, to lessen tire wear most (toe affects it much more the camber). Including on ours. They got ease of power oversteer via chosen spring rates & purposedly selected tires with little grip. Of course slight toe-in won't increase tire wear that much but will add up some stability, especially on end with engine output, allowing sooner(or more) get on gas in turns with less traction loss.

I just looked it up, because I couldn't remember either, negative is out.

As for what's better, that's purely subjective as far as feel. I've never looked into the effects of toe on powering out of a corner. You very well might be right. I'll offer my very anecdotal information, and say that I haven't had any issues with powering out of a corner. But I went from relatively stock alignment and dampers with RCE yellows, to RCE T0's and my present alignment at about the same time.

[Calum]

Originally Posted by Kostamojen

Springs are very innexpensive... If you can't afford to buy shocks or coilovers, then you need to sell the Eibach springs and go back to stock until you can save up for a quality suspension.

That's really not a bad idea. Selling the Eibachs and getting a set of yellows would be fairly cheap, especially if the OP can find the yellows used. He might even break even. Even just the stock springs would likely be better than the Eibachs.

Then it would just be a matter of saving up for a set of B6's or Konis.

[Chase1996]

Originally Posted by Calum

OK, given your low budget, I'd get a set of camber bolts for the front. Tell the shop to max those out first, then make them even. You'll likely be around -1.5 degrees. And that's fine, you can stay there and be OK. More would be better, to a point, but -1.5 on a street car will work fine. Next, have them set the rear to about -1 deg. The reason for this is that the rear has a lot more camber gain than the front and this will keep things pretty even, but still safe.

I might be reading your chart wrong, but it looks to me like the rear toe is in, not out. And to my knowledge, toe in is the factory recommended setting as it's more predictable. The tire wear issues from that much toe is pretty minimal so don't worry about that. If you want a setup that's more fun to drive at the cost of a little stability, move toward 0 toe all around. But even at 0 tie everywhere, the car is still very predictable.

But honestly, I don't see any of these fixing your issues, if as I'm hypothesised, you're having trouble with the transition on the bump stops. Did your springs come with new bump stops? If not, try pulling them off the car and cutting them as was mentioned. Another thing that was mentioned was going back to stock rims and tires. Obviously that's a set backwards, but it's not a bad idea. A comfortable driver in a slow car is often faster than an uncomfortable driver in a fast car.

The bumps tops have been put on

[Chase1996]

Originally Posted by Kostamojen

Springs are very innexpensive... If you can't afford to buy shocks or coilovers, then you need to sell the Eibach springs and go back to stock until you can save up for a quality suspension.

SO lets say I do do that, which set of coilovers would fix this issue, and be best suited for my car based on tires, rims. etc.

[_gt86_user]

Originally Posted by Chase1996

SO lets say I do do that, which set of coilovers would fix this issue, and be best suited for my car based on tires, rims. etc.

There's no best coilover for your, it's up to YOU, not gonna find the answer on a forum.

[Kostamojen]

Originally Posted by Chase1996

SO lets say I do do that, which set of coilovers would fix this issue, and be best suited for my car based on tires, rims. etc.

What are you actually using the car for? Are you actually taking it out to VIR, or is it more of just a daily driver?

[cwpbrz-ji]

What:

Front and Rear Sway (anti-roll) Bars _or_ Roll Center Adjusters _or_ Murphy’s Law (leave it alone)

Why:

OCD: Because sometimes I will spend over 8 hours on a 20 minute job ...attempting to seek tolerance/balance perfection.

Background:

I am not a stranger to suspension and am aware of slight differences between stock and modified when adding coils and LCA.

I am also aware that, sometimes less (parts) is better when considering adjustments.

During my last alignment I had the Ohlins and SuperPro LCAs set for “close to factory specs” and “grip”.

On a flat, smooth, blacktop surface they seem to work perfect.

On a road which is not flat or smooth, I am getting a little more roll than anticipated when cornering.

Although I am getting used to this roll, I would like to eliminate it, and have spent the past few months reading everything I can find on anti-roll/sway bars and roll center adjustment.

Update: The more I test this roll, the more I get used to it.

—————————————————————————————

Questions:

Re-adjust current alignment?

_or_

Install front and rear sway (anti-roll) bars? [I have selected 22mm front and 19mm rear]

_or_

Install Roll center adjustment?

_or_

Live with it?

—————————————————————————————

Modifications on my 2015 Subaru BRZ Limited:

Wheels:

Size 17” x 8.0” ~ Bolt 5 x 100mm ~ Offset +42mm ~ Hub 56.1mm

Tires:

BFGoodrich G-Force Comp II (245/40R17)

Suspension:

WORKS/Ohlins Stage III ~ SuperPro Rear LCA

Alignment:

Set for “close to factory specs” and “grip”.

Current Alignment Front:

Camber: Left Front -0.8° ~ Right Front -0.8°

Caster: Left Front 5.3° ~ Right Front 5.7°

Toe: Left Front 0.01° ~ Right Front 0.01°

Front: Total Toe 0.02° ~ Steer Ahead 0.00°

Current Alignment Rear:

Camber: Left Rear -1.8° ~ Right Rear -1.8°

Toe: Left Rear 0.01° ~ Right Rear 0.00°

Rear: Total Toe 0.02° ~ Thrust Angle 0.01°

—————————————————————————————

Partial Research:

Body roll

https://en.wikipedia.org/wiki/Body_roll

Roll center

https://en.wikipedia.org/wiki/Roll_center

Structural Performance Analysis of Formula SAE Car (PDF)

http://www.academia.edu/9654723/STRU...ORMULA_SAE_CAR

Design, Development and Analysis of the NCSHFH.09 Chassis (PDF)

http://www.mae.ncsu.edu/academics/du...pdfs/broad.pdf

Nonlinear Control of Roll Moment Distribution (PDF)

http://soliton.ae.gatech.edu/people/...l/00370716.pdf

Summary of Standard K&C Tests & Reported Results

http://www.morsemeasurements.com/tec...n-of-kc-tests/

Suspension: What are Roll Center Adjusters?

http://www.meganracing.com/tech/faqs...er%20Adjusters

CSG and RCE tag-team suspension Q&A thread! Ask us anything!

http://www.ft86club.com/forums/showthread.php?t=45554

Developing a Proper Suspension Model

http://www.ft86club.com/forums/showthread.php?t=26661

MotoIQ: Tech Look at FR-S Underside - Suspension, Chassis, Brakes, Differential

http://www.ft86club.com/forums/showthread.php?t=3002

How to screw up your cars handling and ride - step by step!

http://www.ft86club.com/forums/showthread.php?t=67345

Sway bar option list

http://www.ft86club.com/forums/showthread.php?t=49659

sway bars? BEST choice?

http://www.ft86club.com/forums/showt...68#post1395368

Need for Roll Centre Adjuster

http://www.ft86club.com/forums/showthread.php?t=16373

Roll center location?

http://www.ft86club.com/forums/showthread.php?t=17961

Roll centre adjustment - options & benefits?

http://www.ft86club.com/forums/showthread.php?t=42493

TIA

[go_a_way1]

Originally Posted by cwpbrz-ji

What:

Front and Rear Sway (anti-roll) Bars _or_ Roll Center Adjusters _or_ Murphy’s Law (leave it alone)

Why:

OCD: Because sometimes I will spend over 8 hours on a 20 minute job ...attempting to seek tolerance/balance perfection.

Background:

I am not a stranger to suspension and am aware of slight differences between stock and modified when adding coils and LCA.

I am also aware that, sometimes less (parts) is better when considering adjustments.

During my last alignment I had the Ohlins and SuperPro LCAs set for “close to factory specs” and “grip”.

On a flat, smooth, blacktop surface they seem to work perfect.

On a road which is not flat or smooth, I am getting a little more roll than anticipated when cornering.

Although I am getting used to this roll, I would like to eliminate it, and have spent the past few months reading everything I can find on anti-roll/sway bars and roll center adjustment.

Update: The more I test this roll, the more I get used to it.

—————————————————————————————

Questions:

Re-adjust current alignment?

_or_

Install front and rear sway (anti-roll) bars? [I have selected 22mm front and 19mm rear]

_or_

Install Roll center adjustment?

_or_

Live with it?

—————————————————————————————

Modifications on my 2015 Subaru BRZ Limited:

Wheels:

Size 17” x 8.0” ~ Bolt 5 x 100mm ~ Offset +42mm ~ Hub 56.1mm

Tires:

BFGoodrich G-Force Comp II (245/40R17)

Suspension:

WORKS/Ohlins Stage III ~ SuperPro Rear LCA

Alignment:

Set for “close to factory specs” and “grip”.

Current Alignment Front:

Camber: Left Front -0.8° ~ Right Front -0.8°

Caster: Left Front 5.3° ~ Right Front 5.7°

Toe: Left Front 0.01° ~ Right Front 0.01°

Front: Total Toe 0.02° ~ Steer Ahead 0.00°

Current Alignment Rear:

Camber: Left Rear -1.8° ~ Right Rear -1.8°

Toe: Left Rear 0.01° ~ Right Rear 0.00°

Rear: Total Toe 0.02° ~ Thrust Angle 0.01°

—————————————————————————————

Partial Research:

Body roll

https://en.wikipedia.org/wiki/Body_roll

Roll center

https://en.wikipedia.org/wiki/Roll_center

Structural Performance Analysis of Formula SAE Car (PDF)

http://www.academia.edu/9654723/STRU...ORMULA_SAE_CAR

Design, Development and Analysis of the NCSHFH.09 Chassis (PDF)

http://www.mae.ncsu.edu/academics/du...pdfs/broad.pdf

Nonlinear Control of Roll Moment Distribution (PDF)

http://soliton.ae.gatech.edu/people/...l/00370716.pdf

Summary of Standard K&C Tests & Reported Results

http://www.morsemeasurements.com/tec...n-of-kc-tests/

Suspension: What are Roll Center Adjusters?

http://www.meganracing.com/tech/faqs...er%20Adjusters

CSG and RCE tag-team suspension Q&A thread! Ask us anything!

http://www.ft86club.com/forums/showthread.php?t=45554

Developing a Proper Suspension Model

http://www.ft86club.com/forums/showthread.php?t=26661

MotoIQ: Tech Look at FR-S Underside - Suspension, Chassis, Brakes, Differential

http://www.ft86club.com/forums/showthread.php?t=3002

How to screw up your cars handling and ride - step by step!

http://www.ft86club.com/forums/showthread.php?t=67345

Sway bar option list

http://www.ft86club.com/forums/showthread.php?t=49659

sway bars? BEST choice?

http://www.ft86club.com/forums/showt...68#post1395368

Need for Roll Centre Adjuster

http://www.ft86club.com/forums/showthread.php?t=16373

Roll center location?

http://www.ft86club.com/forums/showthread.php?t=17961

Roll centre adjustment - options & benefits?

http://www.ft86club.com/forums/showthread.php?t=42493

TIA

I would leave it alone a little roll is fine. Go to stiff and your suspension won't be able to work. I guess you could time a few laps at the track then install the bars and go back out and try again to see if it improved or hurt lap times.

[Racecomp Engineering]

Originally Posted by go_a_way1

a little roll is fine.

YES, thank you.

The end goal for every car isn't really "zero" body roll...it's a car that's fast and confidence inspiring.

For @cwpbrz-ji more overall roll resistance with the alignment he currently has...I'm betting will result in a slower car overall with a lot of understeer.

If the car feels sloppy and like the chassis isn't being controlled, that is indeed an issue. But a little roll isn't a bad thing. Isolate the problem and work from there. It's unlikely that your car is rolling more in a corner on a bumpy surface than it is on a smooth surface. What exactly are you feeling on bumpy surfaces?

Also bushing deflection is often a misinterpreted especially on cars with otherwise modified suspension. (Not saying that's the issue in this case, but a general observation).

- Andrew