1" rear sway bar

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1" rear sway bar

Postby NixVegaGT » Mon Jan 15, 2007 11:33 am

Last year I bought a set of ADDCO sway bars. I thought, since I'd like to autocross a bit, I'd get the nastiest I could get. I bought the 1 1/4" front 1" rear. It took about a month and when they came HOLY CRAP they were a lot bigger! I don't think they offer the 1 1/4" anymore. I had the stock early GT package. I think that was 7/8" front and 1/2" rear... Might have been 1" front but I don't think so. I've been mulling over the rear sway bar. It might be over kill. I could always try it out since I've already spent the money and I will likely not get it back.

So my question is what kind of spring rate/ dampening to compensate for the larger swaybar? I'm assuming I'm going to need to increase these factors to stabilize the sway compensation of the larger bar so I don't get too much oversteer.

Incidentally, the new sway bar added like 7 lbs to the front! Way out front. I'm hoping to compensate with the Appleton rack (8lbs. total weight) and moving the battery to the rear (about 35lbs. rearward). Not sure how much more a standard battery weighs. I'll have to weigh one. The Wildcat should end up about 340ish lbs. Almost 50lbs more on the front.
- Nic '73 Vega GT "DogBoxx" Batwing LS1
http://www.cardomain.com/ride/2357894
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Postby cjbiagi » Mon Jan 15, 2007 3:05 pm

Every car and setup is going to be different. However, generally with huge sway bars you can get away with softer springs. If anyone remebers Herb Adams, he was a ex GM engineer who was big with Firebird heavy duty parts. His philosophy was basically soft springs and huge sway bars. Another philosophy was done by Dick Guldstrand, really heavy springs and soft sway bars. The two often were compared and both were very accomplished and sought after tuners of these and other GM cars. Both philosophy's worked, but I believe the softer springs/bigger sway bars were best for street driven vehicles. The important thing is to have a balanced system front to rear. A 1 1/4" front bar on a H-body is pretty big. It acts bigger on our cars because it is shorter in overall length compared to some other cars, so it's not a direct equal if the bar is longer or if the lengths of the arms is different than another 1 1/4" bar. Both bars that you have are pretty darn big, I would try them out and see how the car responds, especially in a high speed curve. Best to this away from traffic or light poles!! See if the car oversteers with this combo. It will also depend on tires and whether you are in the throttle on a curve. It's really a trial and error situation.
Clyde.........75 Monza 2+2
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Postby NixVegaGT » Mon Jan 15, 2007 11:04 pm

That's great input, Clyde. Thanks man. Maybe I can get some track time to try it out where I can run off safely.
- Nic '73 Vega GT "DogBoxx" Batwing LS1
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Postby cosvega76 » Tue Jan 16, 2007 10:36 am

I have the Addco 1-1/8" front and 1" rear bars on my Vega. I had no problem with oversteer. Turn 5 at Blackhawk Farms Raceway is a long, fast lefthand sweeper, and the Vega would begin to push if I came into it with too much speed. With the same 1" bar in the rear, a 1-1/4" bar would tend to push more. Of course, the Vega has an iron V8 in the front. If yours has a V6 or 4 cylinder in it, the push should be less pronounced since there is less weight on the front.

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Postby cjbiagi » Tue Jan 16, 2007 2:37 pm

Keep in mind that Chuck has some pretty big tires on his Vega as well as other mods. It all depends on the grip that your car has which can vary greatly between similiar cars. The bars are just one part of the total package.
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Postby NixVegaGT » Wed Jan 17, 2007 11:18 am

Chuck, Thanks for the input. I'm running an aluminum Rover stroker motor. 340 lbs. I'm likely going to have to go with wider wheels on the front from the sound of it. My rear wheels are 15/8.5" and I think they are too wide for the Vega. I'm still running stock wheel wells. I will probably get something smaller.

How wide are your front wheels? Wait... Your Vega is that hot blue one right? That's pretty cool. Did you change the rear wheel wells? Thanks for the help, guys.
- Nic '73 Vega GT "DogBoxx" Batwing LS1
http://www.cardomain.com/ride/2357894
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Postby cosvega76 » Wed Jan 17, 2007 11:57 am

Yes, the rear wheel openings have been flared about 1-1/2". I have 17x8 wheels on the back now, with 235/40-17 tires.

Thanks, guys, for the compliments. I turn more heads with the Vega than I do with the Corvette.

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