LSD control issue (v6bob please look)

[5_spd_pewter_v6]

well, here is my problem. right now i have bmr suspension stuff done (see sig) and when i was looking into the setup v6bob pointed out that the rear sway bar is wrong for our cars, and he is right, it is a little on the big side. now that makes it easy to get my car to fishtail around corners when i want to. so will putting in a LSD exagerate this problem, or maybe help it? i already have the SLP take off in the garage, so please help. thanks.

[V6Bob]

The LSD can hurt in some circumstances(with the open diff spinning the inside rear will reduce power to the overloaded outside rear), but mostly it will make no difference.

The easy/cheap cure is a smaller rear bar. It's a straight win.

[ November 01, 2003: Message edited by: V6Bob ]</p>

[SecretAgent420]

so v6bob does lsd produce oversteer or understeer. i ask because many racers like the t2r unit because its high bias and i was wondering why?

p.s. were do you live in colorado

[V6Bob]

"i ask because many racers like the t2r unit because its high bias and i was wondering why?"

Racers like LSD, because they have their cars set up properly, with the necessary (and it's absolutely necessary) amount of understeer.

If you car is set up badly and oversteers, LSD can make it worse, because it sends more power to the overloaded outside rear tire in certain circumstances.

I'm about 15 miles outside Denver.

[5_spd_pewter_v6]

thanks v6bob, i appreciate your input. one day i might go to a smaller rear bar, but for now i'm happy with the way my car handles. i took it to a big parking lot back when i installed the bars and you gave your first input and i didn't have any big control issues in high speed turning/jerking the wheel.

[SecretAgent420]

thank you v6bob.

[ November 02, 2003: Message edited by: SecretAgent420 ]</p>

[V6Bob]

"the rear sway bar is wrong for our cars,it is a little on the big side. now that makes it easy to get my car to fishtail around corners so will putting in a LSD exagerate this problem"

"one day i might go to a smaller rear bar, but for now i'm happy with the way my car handles"

I think you would still like the way your car handles with a smaller rear bar, and it will fix the problem. Fishtailing is slow. Your car will be both faster and safer with a smaller rear bar, can't beat that combination.

[5_spd_pewter_v6]

so v6bob, do you think that a 19mm 1LE bar would do the trick. i don't know of any smaller bar other then stock. i think i will do this later on, but right now i want to do the projects that i have planned.

[ November 11, 2003: Message edited by: 5_spd_pewter_v6 ]</p>

[V6Bob]

The problem is that picking swaybars is very tricky. It depends on a lot of things. It's a lot easier to say what's bad than what's good. A lot of advice on swaybars on the net is crap.

On stock V6 springs, I believe a 21 rear is too big. I believe stock is OK. In between (GM makes 15, 17, and 19 rear bars) - I just don't know.

What I can say with confidence is that if the rear is sliding, your rear bar is too big and is overloading the rear tires. In certain circumstances, it will be even worse with an LSD. By any standard your car will handle better with a smaller rear bar.

[ November 11, 2003: Message edited by: V6Bob ]

[ November 12, 2003: Message edited by: V6Bob ]</p>

[mrbako]

what about this rear bar

Addco 1" hollow rear anti-sway bar.

if my metric conversion is correct, then the bar is 25.4 mm.

however it is hollow....your thoughts.

[V6Bob]

You can't judge bars in isolation. They depend on the whole suspension, particularly the springs. All my comments above (I've edited one to be more clear) were based on the fact that the original poster reported fishtailing.

But, hollow generally only makes a small difference. The formula for relative stiffness is outer diameter to the fourth power - inner diameter to the fourth power. The fourth power deal makes the last term pretty small.

So that bar would be just a little less than twice as stiff as the solid 21. On a car where the 21 is causing fishtailing, the 25 would be a really bad idea.