Swap Bar Decision, Safe Is Best

[cboney2000]

When I get around to upgrading sway bars, i've decided what I'm going to do. The safest suggestion for daily driving seems to be the 1le 32mm front and stock z28/transam 19mm rear. I will let you all know how it goes. (Going to be installing poly endlinks and bushings too). This is a 2mm upgrade in front and rear to keep the balance.

[ November 01, 2003: Message edited by: cboney2000 ]</p>

[V6Bob]

You will _not_ keep the balance with that change.

The front bar will increase in stiffness by 30%. The back bar will increase by 56%, almost twice as much. Plus, increasing the front bar doesn't change balance much, because of the improved camber curve. Increasing the rear does change balance directly, because the rear tires don't camber in a corner.

This is not a "safe choice", it is an agressive one. I can't say whether it is safe. I can say that it would be safer to leave the rear alone. The difference in roll will be trivial, because the rear bar contributes little to roll control.

See the thread "sway bars" below for more info. Bottom line is that sway bars are not as easy as "This is a 2mm upgrade in front and rear to keep the balance".

[ November 02, 2003: Message edited by: V6Bob ]</p>

[Wicked 3800 V6]

I'd go with a 35mm up front, and NOTHING ELSE. Start with that, see how you like it.

Then go with the 19 out back, and see how you like that. I'd say don't touch the 21 mm ...

Dude, it all depends on what your driving / racing goals are. If you want swaybars so that you can tell your friends you "got swaybars and it handles like a porsche", then give up on the mod. Swaybars are the most incorrectly used items on the car.

-Rob

[cboney2000]

I want the swaybars for road racing, not competitive but still do race and i want the better handling. I was under the impression that the stock sway bar setup was 30/17 for the v6, is that not the case, and if so wouldnt 32/19 be a balanced upgrade? If not, I will leave the rear alone and do 32 ile up front.

[V6Bob]

"I was under the impression that the stock sway bar setup was 30/17 for the v6, is that not the case,"

It is, for 93-97.

"and if so wouldnt 32/19 be a balanced upgrade?"

I _really_ don't mean to be obnoxious, but I explained exactly why it wasn't balanced. The increase in stiffness in the rear bar is twice as much as the increase in the front; and the front bar change doesn't affect the balance much, but the rear does a lot.

Seriously, what isn't clear to you?

[Wicked 3800 V6]

cb do you really Road Race or do you autocross? And do you really autocross or do you drive fast on the street?

I really autocross, and find the 32/21 a poor combo. I'd rather be in a 35 up front, and prolly lower out back. Actually, reminds me, front is disconnected right now. Gotta fix that.

Look at springs before you think about sway bars.

[DARK SDE '02]

Dude don't worry about going too thick in the back, seriously. I have 32/21 and I've never had any problems with oversteering. Unless you drive like a maniac on the road you'll never spin out anyways. With a toothpick of a bar in the back you're just keeping the stock feel of the V6 (massive understeer) which I personally found extremely obnoxious on a RWD car. I'll take oversteer over understeer ANY day, but I think I have the skills necessary to keep her on the road under normal circumstances, maybe you don't? In any case I'd say go ahead and get stiffer springs and shocks too, or else your car is gonna feel funky anyways.

[V6Bob]

"I'll take oversteer over understeer ANY day, but I think I have the skills necessary to keep her on the road"

The peculiar thing about oversteer is that it makes you feel like you're an ace driving really fast, but you're actually slow. From Carroll Smith, "Drive to Win":

"Corner exit oversteer thrills the spectators and makes the inexperienced (or ignorant) driver feel heroically fast. In some ways it's a pity it isn't the fast way around a race track."

"Unless you drive like a maniac on the road you'll never spin out anyways."

Unless it's slippery pavement and/or you have to swerve to avoid some idiot.

[ November 03, 2003: Message edited by: V6Bob ]</p>

[PewterBird]

What if he changed rear springs to compensate for the higher increase of "stiffness" in the rear?

[V6Bob]

You're right - softer rear springs (relative to the front) can use a bigger rear bar. Unless you then bottom out the rear suspension over bumps :D . I think that's why GM went from a 17 to a 15 in 98; they stiffened the rear springs proportionally more than the front springs.

But how much softer? How much bigger? That's beyond my level of knowledge to say.

The whole issue of trading off roll control between springs and bars is debated endlessly. A lot of racecars use mostly springs and use just a small front bar and no rear bar. On the f-body Sam Strano prefers using bars to springs - see his stuff on 4th gens in the tech archives.

[ November 03, 2003: Message edited by: V6Bob ]</p>

[zlexiss]

I just talked to Sam a few weeks ago about an autocross setup for the V6. I'm currently bone stock on the suspension.

With the 400/150 LS1 prokit springs (and revalved shocks), he recommended the 32mm 1LE bar up front over the 35mm, and wasn't sure on the V6 whether the 19 or 21 rear is the best solution - I'm going to be trying each for at least a couple events, both on a looser surface and on sticky concrete tarmac.

The full setup won't be done till early next year (money). I'm putting on at least the front sway, and maybe testing the rears before the springs and shocks go on as a package. I'm getting killed on the tarmac when I hit the bump stops and the car jumps into bad understeer.

It's an interesting tradeoff on the rear bar. Going bigger you move toward neutral handling, which can give you more corner speed, but you'll need to take a lot more care with the pedals when you're in a turn - finish braking earlier, and hit the gas a bit later. It might come down to driving style more than proclaiming whether 19 or 21 is the best for any front bar.

V6bob: thanks for remembering to include springs in the discussion. I'm sure at least a few people were thinking "Why wouldn't 32/19 be balanced when it's stock on the V8, and even the 32/21 at times?" Of course, the answer lies more in the different springs than in the extra weight of the V8.

-Jeff

<blockquote>quote:</font><hr>Originally posted by V6Bob:
The whole issue of trading off roll control between springs and bars is debated endlessly. A lot of racecars use mostly springs and use just a small front bar and no rear bar. On the f-body Sam Strano prefers using bars to springs - see his stuff on 4th gens in the tech archives.
[ November 03, 2003: Message edited by: V6Bob ]<hr></blockquote>

[PewterBird]

For the sake of argument, if I was to put the complete 1LE sway bar and springs on my V6 would it be as effective as the 1le on the V8.

My point being: How much and what kind of impact does the increased weight of the V8 create?

[V6Bob]

"For the sake of argument, if I was to put the complete 1LE sway bar and springs on my V6 would it be as effective as the 1le on the V8."

The increased weight of the V8 is small (50 lbs?). There may be a bit more significance to the fact that the V8 weight is shifted forward, since the V6 is set _way_ back.

But, all in all, it's still less of an effect than whether or not you have a passenger. Or whether the gas tank is full or one-quarter. So I'm guessing the complete 1LE package would be as effective as it is on the V8.

Note that that some people call 32/21 bars 1LE when they were actually a failed experiment. They were only used by GM on a very few cars in 93, and changed when they proved to be not good. 1LE bars are 32/19.

[ November 04, 2003: Message edited by: V6Bob ]</p>

[DARK SDE '02]

There is no true 1LE rear swaybar after 95. But why does SLP sell the 21mm one as 1LE if its not? Wouldn't they get sued by GM if it wasn't a true 1LE part? The package doesn't include a rear swaybar though, you have to order it separate. Unless you're going pro I still think you'll have more fun with 32/21. But like I said before don't JUST change your swaybars, thats retarded, your suspension should all work together for the type of feel you want. I, of course prefer stiff as a board over slushy, what you really want is up to you.

And just a note, if you have to swerve around some idiot with wet traction, you're going to fast anyways. Drive safe guys.