Steady-state Steering/Cornering Issue

[JF1GG29]

I've searched and I can't find anything. In fact, I'm not even sure how to explain the issue in searchable terms. Hope someone can point me in the right direction.

 

2007 Legacy GT Spec.B, 88k miles, stock suspension except Whiteline LCA bushings, Continental DWS all-seasons w/ tire pressures 36/33, f/r.

 

When taking corner at a spirited pace, but well under traction limits, the steering wheel exhibits some strange behavior. Mid-turn, during steady-state turning/steering, the steering wheel will seem to 'loosen'. The car will hold the line, but if I want to turn in further, I'll have to turn the steering wheel a few degrees before the steering will respond. This is a repeatable problem that only manifests during higher-speed cornering, such as on-ramps, mountain roads, etc. There is no clicking, clunking, or other noise when this happens.

 

Anyone have any idea what this could be? Tie-rod ends?

[whitetiger]

its not mechanical. it has to do with the combination of your dynamic camber curve, tire grip limits and weight transfer and most likely will be the nature of the car with that particular combination. what you are experiencing is the beginning of mid corner under-steer. as the front grip levels change, the steering will become less responsive and more angle is needed to have the same affect of less angle at slower speeds/higher grip levels.

 

there are many ways to fix this, but the easiest way to do it is to get better tires.

[JF1GG29]

Thank you for the feedback, I really appreciate it.

 

there are many ways to fix this, but the easiest way to do it is to get better tires.

 

Wouldn't this problem persist, but at higher limits/higher speed? Should I be weighting the front (trailing it into the corner) to increase grip? Is increasing negative camber at the front wheels a reasonable solution?

 

Also, I'm a bit surprised that this is understeer. I have a GD WRX (though running more negative camber and larger sway bars) with similar tires and I had never experienced the issue.

[WRX USA]

You could be feeling the steering dampener. This will resolve it if it is: http://perrinperformance.com/i-22342620-steering-dampener-lockdown.html

[quick4dr]

You could be feeling the steering dampener. This will resolve it if it is: http://perrinperformance.com/i-22342620-steering-dampener-lockdown.html

 

CONFIRM THIS IS WHAT YOU ARE FEELING!!

 

I installed the dampener few weeks back and that sensation is gone. I have Tarmac 1 coils, hotchkis bars, whiteline bushings everywhere, avo subframe connectors, and 265/40/17s

[JF1GG29]

You could be feeling the steering dampener. This will resolve it if it is: http://perrinperformance.com/i-22342620-steering-dampener-lockdown.html

 

Interesting, but I don't think that's it. In their video, without the 'lockdown' part, the input and output shafts are still rotating together. What I'm noticing is a differential of a few degrees before the front wheels respond to what's happening at the steering wheel. And this is only when the suspension is loaded up, and only mid-corner.

 

My WRX is pretty 'hard' throughout. Almost too hard to live with day in and day out. It's a part of the reason that I got the Legacy, so I'm going to try very hard to prevent the Legacy from becoming like the WRX.

[JF1GG29]

CONFIRM THIS IS WHAT YOU ARE FEELING!!

 

I installed the dampener few weeks back and that sensation is gone. I have Tarmac 1 coils, hotchkis bars, whiteline bushings everywhere, avo subframe connectors, and 265/40/17s

 

Damn, really? I guess I'll have to look into this.

[KND]

I had my steering rack replaced and now mine is doing the same thing. Its a little unnerving if I'm driving a little aggressive. My mechanic says the rack needs time to break in. Not sure I believe that. It didn't do that before the rack change.

[whitetiger]

^thats BS. steering racks dont need break-in.

[quick4dr]

Bs. Might have air the system that needs to purge. But break in. Rofl.

[whitetiger]

Thank you for the feedback, I really appreciate it.

 

 

 

Wouldn't this problem persist, but at higher limits/higher speed?

 

It may, assuming you can approach the limit the same way and drive the same at higher speeds. (please dont try on public roads. we are talking theory here)

 

Should I be weighting the front (trailing it into the corner) to increase grip?

Yes, that is generally how these cars are driven. you can still overwhelm the front tires though this way. It will take practice to do it well. Just do it smoothly, too much brake will make the rear end light and make it step out if you are ham-fisted.

 

 

Is increasing negative camber at the front wheels a reasonable solution?

it really depends on what camber you have now and how much those AS tires can take. its much easier to just get tires with better compound. I really hate AS tires for their crappy compromises.

 

Also, I'm a bit surprised that this is under steer. I have a GD WRX (though running more negative camber and larger sway bars) with similar tires and I had never experienced the issue.

 

Bars will change the balance of the car, make the front end flatter and make both tires work better. remember as the car rolls and the outside shock compresses, it loses negative camber on a McStrut car. on your LGT, you have more caster than stock with the LCA bushings so turning the wheel more get you more camber(this is dynamic camber). this is partly why you are feeling what you are feeling. yo may want to just get a front bar for the LGT to keep the front end flatter and more predictable.

 

the steering shaft damper will makes the steering more numb, but wont require you to turn the wheel more to keep the car on line the way you described. its more about feedback and response.

[JF1GG29]

Yes, that is generally how these cars are driven. you can still overwhelm the front tires though this way. It will take practice to do it well. Just do it smoothly, too much brake will make the rear end light and make it step out if you are ham-fisted.

 

...

 

Bars will change the balance of the car, make the front end flatter and make both tires work better. remember as the car rolls and the outside shock compresses, it loses negative camber on a McStrut car. on your LGT, you have more caster than stock with the LCA bushings so turning the wheel more get you more camber(this is dynamic camber). this is partly why you are feeling what you are feeling. yo may want to just get a front bar for the LGT to keep the front end flatter and more predictable.

 

Ok, thank you for the discussion. I'll try a few changes in driving style and pay more attention to weight transfer to see how the car reacts at the front.

 

I also have a different set of tires I can try on the car. I will also keep in mind a stiffer front sway bar or a different alignment scheme. Just FYI, my last alignment (about two weeks ago) gave me -0.5 degrees of camber on both sides. Caster was at 7.1 degrees, which was much more than I expected to see. I was hoping to get to about -1.5 degrees of camber at the front, but I don't think I can get there without camber bolts.

 

 

the steering shaft damper will makes the steering more numb, but wont require you to turn the wheel more to keep the car on line the way you described. its more about feedback and response.

 

I really doubt the steering linkage dampener has anything to do with what I'm feeling. I'm not looking for 'more feedback', but to suss out what seems to be peculiar behavior at the front.

 

 

Again, thank you for the discussion. I had been speaking with my mechanic, who is an ex-stage rally driver, and his first thought was also understeer. I was a bit incredulous when he said that as I felt very far from the grip limits of the tire, but now I think I probably have to address it.

 

At the end of the day, I'm not tracking this car, but I do want to enjoy spirited driving and touring through the mountains. The mid-corner understeer absolutely robs confidence and I hope I can dial it out.

[Rhitter]

How new are your DWS's? I think the newer ones may be better. I have the 225/55/17 version of the tire and they understeer very predictably. It's obvious that's what's happening.

 

But my set-up is pretty different than yours so the tires might not be directly comparable. I have more camber, larger front bar, Bilsteins, steering dampened, lots of poly bushings.

 

Have you tried just adding more air into the tires.

[whitetiger]

The mid-corner understeer absolutely robs confidence and I hope I can dial it out.

 

then start with better tires. then a front bar or stiffer springs and as much camber as you can dial in.

 

think about running dedicated winter/summer tires for the seasons. nothing feels better than a sticky summer tire for spirited driving.

[Rhitter]

What do you recommend as a summer tire?

[whitetiger]

well, if wear rate is no concern to you, then pretty much anything listed under tirerack.com's extreme performance summer category will do, with the bridgestone RE-71R being the current king. Nothing short of race tire level grip in a street tire. for the non-racer, expect any tire in this category to last you 2-3 years if you switch to a winter set in the colder months.

[JmP6889928]

If you are going to go larger on the rear bar, and even if you are just going to stay stock, you need the AVO rear sway bar supports. If you don't have them and you tear one of the stock supports off, you'll be in a much worse situation for cost and the ones I've seen that were repaired never seemed to be exactly right afterwards because of the twisting effect that caused the breakage.

[quick4dr]

Dude try the dampener lockdown. Trust me. I'll put my money where my mouth is buy it install it drive it if you don't think it transforms your steering before new tires which will ultimately help tons as well. But for you really don't think it was worth it I'll toss you $20 towards it which makes it then a bargain if a mod for you

[JmP6889928]

Dude try the dampener lockdown. Trust me. I'll put my money where my mouth is buy it install it drive it if you don't think it transforms your steering before new tires which will ultimately help tons as well. But for you really don't think it was worth it I'll toss you $20 towards it which makes it then a bargain if a mod for you

 

Same for me too?

[quick4dr]

You know what. Yes! Seeing as

That you have become a huge contributing member and your turbos are gold. I'll give you the same guarantee. I'll kick back $20. If you think it didn't make a difference

For you

[JF1GG29]

How new are your DWS's? I think the newer ones may be better. I have the 225/55/17 version of the tire and they understeer very predictably.

 

The DWS are fairly new, plenty of tread and about two years old. I am going to try some different pressures and see where that gets me.

 

 

then start with better tires. then a front bar or stiffer springs and as much camber as you can dial in.

 

think about running dedicated winter/summer tires for the seasons. nothing feels better than a sticky summer tire for spirited driving.

 

I do normally run dedicated summer/winter tires, but I got a deal on these tires that I couldn't pass up at the time. Now, I'm not so sure it was the deal I was looking for. I am putting winter tires on the car in a week or two, then I'll see if the car behaves any differently.

[JF1GG29]

Dude try the dampener lockdown. Trust me.

 

The idea has been percolating in my mind over the holidays. There are a couple of things I want to do to the car before I fiddle with the steering rack, but I'll give it consideration.

 

I just don't want to spend a lot of time and energy and money turning the car into my WRX.

[boxkita]

The DWS are fairly new, plenty of tread and about two years old. I am going to try some different pressures and see where that gets me.

 

I do normally run dedicated summer/winter tires, but I got a deal on these tires that I couldn't pass up at the time. Now, I'm not so sure it was the deal I was looking for. I am putting winter tires on the car in a week or two, then I'll see if the car behaves any differently.

 

"I got a deal on these tires" and now my car doesn't perform as well. Please help!

 

:spin:

 

If I had a dime for every time I read that line on this forum, I wouldn't need to play the powerball lottery.

 

You buy crap tires then go to your favorite road and try to go fast. The experience sucks. Well...what did you expect?

 

making an LGT handle like a sports car (its not) and not a grand touring car (it is), requires changes. Swaybars, suspension, high performance low profile tires, light wheels, and a bit of driving talent.

 

Handle better on your setup:

1. Look up the max cold pressure on your tires, then set all 4 tires to that

2. Crawl under the car and check all your suspension bits:

a. for leaking and/or damaged bushings

b: rusted parts (swaybars, struts)

c. any thing not tightened down

3. Get a gps/handling.video app for your phone - harry's lap timer or some such thing. Mount to your windshield on the passenger side of the mirror. You want it recording but not visible to you.

4. Get a radar detector and learn the normal sounds of your favorite road. Set the volume on high.

5. Turn off every other sound maker in your car (stereo, phone, extra long key chain, mirror balls, etc)

6. Now, drive your favorite road (best if it was a track) at slow speed then gradually increase until you feel something not right in the experience. Hopefully this occurs before you drive off the road

 

Now look at the data. The app should show what the car did the whole time. If its a good app, it will let you overlay the slower runs with the faster runs. What you'll find, typically, is you are changing where the car is on the road depending on speed. What you want to find is the car is in the same location regardless of speed.

 

On a highly camber'ed road (typical back road?), you should be using the full width of the road (hence why you do this on a track or use a radar detector). Look up apexing a turn. If you are not doing this, likely, your car is not setup optimally for getting thru the turn.

 

Before the apex, the typical LGT driver is hard on the throttle. At or beyond the apex, the typical LGT driver is hard on the brakes. Sometime later, the typical LGT driver is hard on the throttle. Sometime later, the typical LGT driver is posting on here about crap handling with their AS tires.

 

However, in your case, you have a bit more awareness. It's not how fast you enter the corner (before apex), it's how fast you exit the corner (apply throttle after apex). Look up "Miata passed high $ sports car" on Youtube. In the case of the LGT, applying throttle after the apex will cause the front end to get light (grand touring car. remember). When the front end gets light, steering will resemble under steer. At this point, you have 2 choices (assuming you don't want to spend money): lift slightly, or unwind the wheel a bit. Lifting the throttle (think flex your big toe) will bring the weight forward onto the front wheels more for more grip (the actual details are not important) which will decreasing turning circle and your pucker factor. Unwinding the wheel (slightly = 1/8 turn) will lower understeer and reduce side-load on front tires letting them grip more, however, your pucker factor will higher.

 

Depending on the tires you have, you'll hear different noises depending on the side loading. The first squeal is the tires starting to work. This should be a steady state not an occasional sound on the way to the second or third more tragic noises. Again, a track is better place to learn this. However, the practice runs at slower speeds with video/gps app will help you match sound to road position to cornering speed. As you work up in speed, you'll come to associate different tire noises with actual side loading not perceived.

 

A bit of looseness in the corner is expected. In mid-corner, you should not be turning the wheel at all as you're at apex. At apex, you should be worrying about how much throttle you can apply and still be on the road at track out. Given the AWD arrangement, you could even be allowing for beyond the edge of the road. Too far, and you get special mention on Youtube.

 

Case in point, a wagon with full Whiteline upgrades on corner-balanced cheap coilovers (yes it makes a difference) on race slicks on a decreasing radius sweeper can achieve 1.5 G laterally. This requires using the entire 40 foot wide track (3 lanes of a regular road) to complete the turn. After apex, the steering wheel is not turned until track out is reached. Mostly because it doesn't matter as you are steering with the throttle. Sgt.Gator does better in this section because front LSD & expensive coilovers.

 

However, on AS tires, you can still do alot. These were my AS tires with 1500 miles of track & spirited driving - http://legacygt.com/forums/showthread.php/fs-wa-michelin-pilot-sport-avs-plus-set-4-250-216181.html?t=216181 . On track, at speed, in steady state cornering, on stock suspension, they would howl alarmingly but still hold. There is video (can't find link) of the car riding on the bump stops making the turn easily. Apparently the view from trailing cars was unnerving.

 

Instead of spending $81 on the steering damper, spend 1/4 on one of these books - https://speedsecrets.com/ . On squishy AS tires, the damper is like the GS brake brace. All bling. Learning to corner properly will benefit far more.

[whitetiger]

yeah, bottom line is if you want more confidence and response in your car, its all about the tires first, or you will have to adapt to the slush that is AS tires.

 

Bridgestone RE-71Rs. Go buy 'em.

[sanchitosonria]

I had the Conti DWS on my 2.5i and the sidewall was mushy in turns at stock recommended PSI. The sweet spot for me was 40 in the front, 39 in the rear.

 

EDIT: : http://legacygt.com/forums/showthread.php/ultra-high-performance-all-season-tires-153785p30.html?highlight=41%2F40