1LE vs Aftermarket Sway bar "front"

[01PewterDropTop]

ok how does a 1LE front sway bar stack up to an aftermarked bar for autocross not drag racing.

[Nikos95]

Re: 1LE vs Aftermarket Sway bar "front"

I had a 1LE in the front and replaced it with a Hotchkis of the same size, both have poly bushings, I didn't notice much difference, if anything my car seemed tighter, only reason I replaced it is because the old one literally broke!

I have not autocross'd mine yet, I have alot of work left.

[Hib Halverson]

Re: 1LE vs Aftermarket Sway bar "front"

ok how does a 1LE front sway bar stack up to an aftermarked bar for autocross not drag racing.

The 1LE bar is a good choice BUT....if you use it, you also need the rest of the 1LE suspension pieces to have the car balanced properly.

If you put on the 1LE bar but make no other changes the car is going to understeer (it will push or be "tight") pretty bad.

With the "Camaro Performers" magazine V6 project, we used the stock Z28 stabilizer bars, Eibach springs, Bilstein shocks and Goodyear Eagle F1 GS-D3s. That package made a huge improvement in the car's handling.

[01PewterDropTop]

Re: 1LE vs Aftermarket Sway bar "front"

What else was in the 1le package sway bars and bushings?

[V6Bob]

Re: 1LE vs Aftermarket Sway bar "front"

If you put on the 1LE bar but make no other changes the car is going to understeer (it will push or be "tight") pretty bad.

By simple swaybar theory, maybe. In practice on a 4th gen fbody, not so much.

The improved camber offsets some of the weight transfer effects, causing the increase in understeer to be smaller than might be expected. Maybe a lot smaller.

Swaybars in practice are _very_ complicated.

[memphis_raines]

Re: 1LE vs Aftermarket Sway bar "front"

From what I've gathered, changing the front swaybar won't affect things as much as changing the rear one. I don't think you have to have the entire 1LE package either. I have the 1LE front swaybar and springs, but my PHR, LCA's, subframes, and STB came from either SLP or BMR. And she'll hang a curve like nobody's business.........lol

[Hib Halverson]

Re: 1LE vs Aftermarket Sway bar "front"

By simple swaybar theory, maybe. In practice on a 4th gen fbody, not so much.

The improved camber offsets some of the weight transfer effects, causing the increase in understeer to be smaller than might be expected. Maybe a lot smaller.

Swaybars in practice are _very_ complicated.

I disagree.

Stabilizer bars are pretty darn simple. but you do need to look at the total suspension picture, ie: front and rear bars along with front and rear springs. It's a rediculous belief that you can simply bolt on a much larger front stabilizer bar then align yourself out of a gross understeer situation with negative camber.

Here's reality. Stabilizer bar rate increases with the square of the diameter. So. if you increase bar dia, say 20%, you're getting a 40% increase in stabilizer bar rate and a corresponding increase in roll stiffness.

If you add 40% front roll stiffness and make no other changes, it doesn't matter how much negative camber you might set, the car is going to understeer like a freakin' pig.

On a V6 car, unless your going road racing, a far more sensible upgrade is to upgrade both the front and rear bars to the base Z28 pieces, then go to a nice aftermarket street high-performance spring package such as what Eibach sells and finally add some Bilstein shocks.

This is the spring/bar package we installed on the "Camaro Performers" magazine project and, coupled with 265/40ZR17 Goodyear F1 Supercars on 9.5" Fikses, the car handles killer.

[Mr. Merk]

Re: 1LE vs Aftermarket Sway bar "front"

i was under the impression that a Z28 front bar was 30mm and the V6 front bar was 30mm, the only difference being the rear, V6-17mm, Z28 and some years 1LE were 19mm, some 1LE were 21mm

we've got the 19mm in the back right now and the 32mm front will follow shortly, we're also using energy bushings and endlinks

comments?

[V6Bob]

Re: 1LE vs Aftermarket Sway bar "front"

I disagree.

Stabilizer bars are pretty darn simple. but you do need to look at the total suspension picture, ie: front and rear bars along with front and rear springs. It's a rediculous belief that you can simply bolt on a much larger front stabilizer bar then align yourself out of a gross understeer situation with negative camber.

That's not what I said. The reduced understeer is due to less camber change, keeping the camber closer to optimal. I never suggested increasing static negative camber. Swaybars are not that simple at all. See below for one example.

Here's reality. Stabilizer bar rate increases with the square of the diameter. So. if you increase bar dia, say 20%, you're getting a 40% increase in stabilizer bar rate and a corresponding increase in roll stiffness.

Swaybar stiffness goes up as the fourth power of the diameter.

If you add 40% front roll stiffness and make no other changes, it doesn't matter how much negative camber you might set, the car is going to understeer like a freakin' pig.

Once again it's not about static negative camber. Camber change plays a crucial role. On FWD racers with McPherson struts they put huge front bars on to _reduce_ understeer. Swaybars are _not_ simple. If someone doesn't understand them well he can get in a lot of trouble following his instincts or random advice on the Net. For example:

"i am having rear traction issues, especially in the rain.
i just cant find a good deal on a 19mm or 21mm bar."

This guy didn't realize that, on an fbody, a bigger rear bar reduces rear traction, and would make his problem worse.

[V6Bob]

Re: 1LE vs Aftermarket Sway bar "front"

i was under the impression that a Z28 front bar was 30mm and the V6 front bar was 30mm, the only difference being the rear, V6-17mm, Z28 and some years 1LE were 19mm, some 1LE were 21mm

we've got the 19mm in the back right now and the 32mm front will follow shortly, we're also using energy bushings and endlinks

comments?

V6 bars are 30/17 97-back and 28/15 98 forward.

99.9% of 1LE bars are 32/19. GM built a very few original cars with 32/21 before changing them. My guess is that the racers told them the 21 rear was too big. Which is what most racers think today, for V8s. The 19 rear is too big for a V6 with stock springs.

[Den69RS96]

Re: 1LE vs Aftermarket Sway bar "front"

I don't think 32mm/19mm is too big for stock springs. My 96RS has plenty of traction with that combo. Everyones driving style is different and each person needs to tailor their suspension to there own driving style. What works for one, doesn't always work for the other. I doubt many nascar drivers use the same set up. If you like the way your car handles with a 32mm/19mm rear bar, then use it. If you don't take it off.

[Hib Halverson]

Re: 1LE vs Aftermarket Sway bar "front"

Swaybar stiffness goes up as the fourth power of the diameter.

You're right on that. I messed-up big time on my numbers but---with bar rate changing with the 4th power of the diameter, then going to a 1LE front bar on a V6 car with no other changes will make the problem even worse.

On FWD racers with McPherson struts they put huge front bars on to _reduce_ understeer. .

On that you're wrong. FWD racers may put huge front bars on their cars but if they do, they balance that with even greater roll stiffness at the rear and the reason they do that is to offset the significant front weight bias of a front wheel drive cars. I've built front-wheel drive performance cars. When they had big front bars and lots of static negative camber (to compensate for the lack of negative camber gain in strut front ends, they also had even bigger rear bars.

NO ONE increases front roll stiffness to *reduce* understeer. Given other suspension tuning remaining constant, increaseing front roll stiffness increases understeer.

If you want to decrease understeer by changing the roll stiffness, you either decrease front roll stiffness or increase rear roll stiffness.

[V6Bob]

Re: 1LE vs Aftermarket Sway bar "front"

FWD racers may put huge front bars on their cars but if they do, they balance that with even greater roll stiffness at the rear and the reason they do that is to offset the significant front weight bias of a front wheel drive cars. I've built front-wheel drive performance cars. When they had big front bars and lots of static negative camber (to compensate for the lack of negative camber gain in strut front ends, they also had even bigger rear bars.

NO ONE increases front roll stiffness to *reduce* understeer. Given other suspension tuning remaining constant, increaseing front roll stiffness increases understeer.

If you want to decrease understeer by changing the roll stiffness, you either decrease front roll stiffness or increase rear roll stiffness.

That's the simplistic view. But it's more complicated than that. Some racers DO put huge front bars on to reduce understeer. Two examples:

"Before anyone flames me for possibly running a big front bar in stock class in a car that understeers, the reason for doing so is that sometimes a big bar alone can reduce understeer! It can do it by reducing roll which reduces negative camber loss under roll, which in turn will keep the wheels flatter on the road giving the tires more grip. "

http://www.se-r.net/car_info/suspension_tuning.html

"Big front bars help BMWs because the camber curve up fron tis so lame, it is better to keep the front from rolling much at all. Most BMW race cars run very large front bars and little to NO rear sway bar. Check out pictures of any BMW race car (productio car based) at th eapex of the corner and you will see the inside front wheel off the ground, which indicates lots of front roll stiffness and little rear roll stiffness.

Nick autocrosses, tracks, and races BMW cars. I autocross and track BMW cars. We both have found (and yes we tried other setups) that lots of front bar, little rear bar is best. Last I talked to him, he was looking for a NN-sort stock rear bar for his race car, to go with the HUGE aftermarket front bar.

Adding a big front bar will reduce understeer in a BMW, which is backwards from what you would expect. But that is the way it is. General charts and knowledge is fine, but not all cars follow the pattern."

http://www.bimmerfest.com/forums/sho...d.php?t=148730

Etc. How many of these do you want? :D

This works especially well on McPherson strut cars. Struts do not have _any_ negative camber gain. They have serious positive camber gain, which seriously reduces front traction. Stop the front from rolling and you gain enough traction potentially lost thru unfavorable camber change to more than offset the traction lost due to increased weight transfer. Increasing rear roll stiffness isn't the answer for these cars. Once you have enough rear roll stiffness enough to lift the inside rear wheel, increasing it further will do absolutely nothing. In many FWD cars (VW Rabbit/Golf) that point is reached with _stock_ rear roll stiffness.

Note that I am _not_ advocating excessive static negative camber, which you seem to be hung up on.

Swaybars are simple on cars with well designed independent suspensions front and rear, like Corvettes or purpose built race cars. Otherwise, not so much. Sometimes, as in the cases described above, they're downright counterintuitive.

In the case of an fbody, the situation regarding camber change is not as extreme, and increasing the front bar does increase understeer, but by no means as much as the simplistic analysis would indicate. Many serious fbody autocrossers run large front bars and stock rear bars, without excessive understeer. If you don't believe me (and there's no reason you should) talk to Sam Strano.

Swar bars ain't simple. The simple rules of thumb don't always work. People who don't understand the complexities can do do seriously wrong things.

[Chaotic Firebird]

Re: 1LE vs Aftermarket Sway bar "front"

The 21mm rear swaybar was only used on 1993 1LE cars. Only because GM used softer rear springs, so they compensated with a 21mm swaybar. In 1994 through 2002, GM changed the rear springs to stiffer ones and used the regular 19mm V8 rear swaybar.

Starting in 1997, a lot of the upper models got a 32mm frontsway bar standard. 1LE, SS, WS6, and Firehawk. A very few Non-WS6's and Z28 got a 32mm front bar.

[Hib Halverson]

Re: 1LE vs Aftermarket Sway bar "front"

The 21mm rear swaybar was only used on 1993 1LE cars. Only because GM used softer rear springs, so they compensated with a 21mm swaybar. In 1994 through 2002, GM changed the rear springs to stiffer ones and used the regular 19mm V8 rear swaybar.

Starting in 1997, a lot of the upper models got a 32mm frontsway bar standard. 1LE, SS, WS6, and Firehawk. A very few Non-WS6's and Z28 got a 32mm front bar.

You seem to know spring rate information and I've been looking for that. Do you happen to have or know where to get the spring rate info for all the various, O.E. suspension levels?