Handling Question

[04GT]

This spring I got panhard bar and bilsteins installed. I love the way the car handles, but sometimes it feels a little loose. In the rain, I'm fish-tailing all the time. I can only guess that it would be worse if I had done springs. It's kinda fun, but kinda scary sometimes, too.

I'm wondering what I can do about it, if anything. Wider rear tires? Adjustments? LCAs?

My tires still have pretty good tread...they are Pirelli PZero Nero M+S.

 

[squares98]

You need LCA's. i swear by them in the wet. Trust me on this one. Ive ran back to back comparison of global west, stock, and MM lcas. The aftermarket units were much noticably more planted in wet conditions, especially going around turns.

I'd get the MM Adj LCA's..

 

[5spd GT]

The panhard bar is most likely causing that, that could be a dangerous combo in wet weather with drag radials.

The panhard bar is, in a sense, locking up the rearend flex. It is acting as one unit now, instead of having such individual flex to "catch" the road on harder turns or those with smaller traction...

I'm sure in dry weather it is much better of course, and "slides" are more controllable...with less inconsistency...

LCA and UCA's will help nicely...help keep the tires planted...

 

[four.six]

is your car lowered? if so, maybe c/c plates, and a bumpsteer kit, and extended ball joint kit... thats what i did to fix my steering problem

 

[tomustang]

learn to adapt, best advice you can get, it's a solid axle and whenever you stiffen up the rear it will jolt more as one piece

 

[Thundermouse]

The panhard bar is, in a sense, locking up the rearend flex. It is acting as one unit now, instead of having such individual flex to "catch" the road on harder turns or those with smaller traction...

Could you explain what you mean by this comment a little further? It seems to me that if a laterally located rear is going to slide under certain road conditions, then there would be no reason to expect a loose rear that has greater bind in the suspension will keep its grip, all else held equal.

 

[DerekStangGT]

upper and lower control arms will help a lot. they center the axle and hold it there better, hence less movement in the back.

The panhard bar is, in a sense, locking up the rearend flex. It is acting as one unit now, instead of having such individual flex to "catch" the road on harder turns or those with smaller traction.

i too am perplexed by this statement. please explain.

 

[5spd GT]

A panhard bar keeps the rearend from moving from side to side.

Ever went around a corner and felt it "skip" and catch the road again...? That is do to flex...the panhard bar will keep it planted...or it will slide out (maybe controlled?)...but the "skipping" will minimize...

It is hard to explain "on paper" but easy to notice on the road...

It locates the rear as one. It acts very much like the lca/uca upgrade. It gets rid of flex in the rear.

It helps minimize that "stock bind" under real hard cornering. If that "stock bind" gives, that can cause that "skip" of traction I was talking about...

 

[04GT]

learn to adapt, best advice you can get, it's a solid axle and whenever you stiffen up the rear it will jolt more as one piece

That's pretty much what I thought. I love the way it handles on dry pavement. It's was just the wet conditions I'm wondering about. On dry pavement the rear grips is awesome.

 

[san~man]

Get a set of good LCA's, such as MM's. Unless you drag race and need the height adjustability, get the regular MM's. You can also take the last plunge and get the T/A, but that's up to you.

Fish-tailing really has more to do with your gearing and resulting torque multiplication more than the rear suspension. With H&R SS's, MM LCA's, MM PHB, and the Bilsteins, I still fishtail when it's wet.

Can also have a lot to do with your tires. But, no matter what, with 4.10's and torque, you're going to fishtail.

 

[5spd GT]

Get a set of good LCA's, such as MM's. Unless you drag race and need the height adjustability, get the regular MM's. You can also take the last plunge and get the T/A, but that's up to you.

Fish-tailing really has more to do with your gearing and resulting torque multiplication more than the rear suspension. With H&R SS's, MM LCA's, MM PHB, and the Bilsteins, I still fishtail when it's wet.

Can also have a lot to do with your tires. But, no matter what, with 4.10's and torque, you're going to fishtail.

Wet is the key word. If your into the gas around a curve, of course that will lead to "sliding"...

Tires have a lot to do with it. Also the locking or non-locking of the rear-end.

 

[Thundermouse]

A panhard bar keeps the rearend from moving from side to side.

Ever went around a corner and felt it "skip" and catch the road again...? That is do to flex...the panhard bar will keep it planted...or it will slide out (maybe controlled?)...but the "skipping" will minimize...

It is hard to explain "on paper" but easy to notice on the road...

It locates the rear as one. It acts very much like the lca/uca upgrade. It gets rid of flex in the rear.

It helps minimize that "stock bind" under real hard cornering. If that "stock bind" gives, that can cause that "skip" of traction I was talking about...

I understand the experience of "skipping" of the rear of the stock suspension that you are describing. However, I believe that to think this skipping gives you more traction in wet conditions during mid-turn is a fallacy. Here's why I think this, but jump in and correct me where I am wrong:

We all know that without a PHB, the suspension is going to bind more in a turn. This causes a sudden increase in the wheel rate of the outside rear wheel. The increase in rear wheel rate is not matched by a sudden increase in outside front wheel rate. This is the imbalance that causes oversteer.

When the "skipping" happens, the tires have broken free of the pavement and as a result, the coefficient of lateral friction between the tire and the road is reduced. Because of the reduced friction, the suspension experiences reduced lateral force and gets a chance to readjust itself to a less binding position. This allows the outside rear wheel rate to return closer to is normal operating rate, and thus bringing back the front and rear balance which gives the tires the chance to "catch" again. All these reactions are why the stock rear is so unpredictable to drive at the limit.

With the addition of a PHB, the initial increase in wheel rate is reduced because the suspension does not experience as much bind in the lateral dimension. Consequently, the first loss of rear traction occurs at a greater lateral acceleration because the front to rear wheel rate balance can be held for longer.

I think we both agree that sliding with a PHB will be more predictable/controllable. What I don't understand is why you believe that a PHB hurts you in the rain. All of the above steps should still happen, and the point at which rear traction is lost should occur earlier for both due to the lower coeffecient of friction while on wet roads.

 

[BurningRubber]

My car has been lowered about an inch or an inch and a half, and in the wet it breaks loose whenever I want it to pretty much. Stiffness of the springs doesnt help at all, and as far as I can tell there arent any other aftermarket suspension parts aside from the springs... but I need to take a closer look. Anyway, I know what your saying about it being fun and scary. I can take off normal in first, shift into 2nd and blip the throttle when im letting out of the clutch and the tires will just spin, and I can point the car to the side and keep tracking straight basically. Its fun when you want to do it, but it has kicked out once or twice when I didnt want it to.

 

[5spd GT]

I think we both agree that sliding with a PHB will be more predictable/controllable. What I don't understand is why you believe that a PHB hurts you in the rain. All of the above steps should still happen, and the point at which rear traction is lost should occur earlier for both due to the lower coeffecient of friction while on wet roads.

I wasn't saying it would hurt you in the rain. Just it connects both rear tires more so. Less bind is also less flex in the rear. Less flex in the rear gets both tires to plant equally. Without the panhard bar it plants the tire on the turning side more. For whatever reason, the panhard bar doesn't hurt the car, just (from what I understand) makes the car more 'slideable'...

I was talking about in the posters case...because that is all he changed. It is more attributed to the panhard bar than the bilsteins.

 

[EPIK]

is your car lowered? if so, maybe c/c plates, and a bumpsteer kit, and extended ball joint kit... thats what i did to fix my steering problem

Do the bumpsteer kit & x2 balljoints make a noticeable difference? I was looking in to these, because ever since I lowered my car & installed the new wheels & tires my car seems to have a horrible bumpsteer problem, & it pulls into every seam & rut in the road. Is this due to the wider wheels & tires in the front, or my suspension, or both? Check my sig 4 mods. One good thing I can say is that the mm lca's definately grip the road alot better than the stockers did.....Oops, sorry my quote didnt come out right.

 

[04GT]

Mine's not lowered.

 

[billfisher]

your issue is rear spring rates/swaybar size balance front to rear. you can help it by using twist ins in the front springs. shortening the end links in the front swaybar and tightening the bushings will help more.

also higher tire pressures in the front and slightly lower in the rear will help. say 38 front 30 rear for example.


you need to let the front suspension take more of the cornering forces. soften the rear until it feels better. if you lift going hot into a corner you'll swap ends. it's a dangerous condition for average drivers. softening the rear shocks and hardening the front, etc. dial in more toe-in will help the front give way first. just a degree or two will help. you get the idea. loose is the fastest setup. but the fastest to the wall for some.