Addco Sway Bars

[Paul]

A rear bar only = BIG OVERSTEER = UNSAFE

Can't comment specifically on the different front bars on the GT.

But I can give an example of what different bar combinations can do for another vehicle.

The NEON ACR and R/Ts came with a 22mm ft bar and a 16 mm rear. The trick set up for SCCA stock class was to use the SMALLER 19mm front bar from the base Neon. The greatly helped to reduce Understeer. This was our only option since no changes were allowed to the rear. If that had been allowed then the trick would have been to increase both. For example, I currently run 22 mm on both the front and back for very neutral handling on the street.

Its all a matter of proportion and front to rear balance.

"On the surface" it would appear the larger 1" ft bar coupled with a common sized and designed rear bar would yield more understeer than the 3/4" front bar. Now, all bets are off it the two different rear bars are either of different diameters or have different length lever arms.

Sorry, just throwing out a little info... HTH

[opeldean]

the brackets were welded in today.

it rained today , too slick to really test it out.

but I can tell, the rear bar helps the front bar. Car seems flatter in a turn and back end isnt as switchy.

[Old Hippie]

opeldean,
look for a brass bushing material that has a 1/16" wall. This will fill the gap and you can get it to length. Check at a bearing house or machine shop in your area. (3/4") 6/8" - 5/8" = 1/8". Devide by 2 = 1/6". Just grease the inside of the bushing so that the slide bolt will rotate in there easily, which would reduce the ware on the bushing. If any of the fulltime machineist see something wrong with my idea, please fell free to chime in. I can take criticism, honest! :o
OPPS! Seems I answered a question from the wrong page! Silly me! :o

[kwilford]

To answer the mix and match question, you should never run different diameter bars front to back for a lot of reasons.

As GTJIM has said, different sized bars front to back will provide different results. As will different mounting arrangements (stiffer bushings, longer lever arms, etc). Addco and OGTS provide a matched set, for what they perceive will provide the best overall balance. But "balance" can be affected by more than sway bar size. Spring rates, shock settings, roll centre lowering, tire size (especially when the tires are different front to back) all affect balance. So it is a bit too simplistic to state "don't mix and match". But only do so with the knowledge that you might get unintended results.

As for which is easier to install, the Addco bars are somewhat simpler. No welding on the differential, and they don't require the motor mount be dropped (which the OGTS, and stock, bars do).

Which provides the best handling? Normally, thicker is "better", but harsher. But a thicker bar with different mountings can actually provide a softer result. Bushings play a key role. Mounting points play a factor. I haven't compared the Addco bars with the OGTS bars (I have the Addco's front and back), but because they mount differently, I suspect that the lever arms are of different lengths. A different lever arm length will provide a different ride for a given amount of suspension deflection. This also affected by where the bar mounts. A short lever arm, mounted closer to the centreline of the suspension, will give a stiffer ride than a longer lever arm, mounted only part way along the suspension arm. So a direct comparison of both types of bars has to compare all these factors.

Finally, as I understood it, a stiffer rear bar will cause more under-steer, while a stiffer front bar, will induce more over-steer, which is the opposite of what Paul described. But I might have that mixed up. But neither in the extreme is desirable. But a bit of under-steer is generally "safer" (at least more predictable) to the average driver in typical conditions. So be careful of too much front bar (or rear bar, if I have the results switched).

JM2CW

[nobody]

To be completely honest I was repeating what I was told by both of those sway bar sellers. I got involved in a sway bar deal that included 3 people 2 companys and two areas of the world so while getting everything situated I had alot of time to ask these same questions. I understand why they both said it was a no no. Liability if you go out and spin it into oncoming traffic or something. I know it could be done and was thinking of mixing to do a bit of tweaking myself. I chose not too as I am not that brave I guess.

I have both of the OGTS bars and I sent the Addco south, way south. First I did get a good look at it and all the hardware of course.

[GTJIM]

And that Addco front bar is very, very much appreciated!

I have two Impulse rear bars - one 16mm the other 19mm to play with - and minimal liability issues here in NZ. So, being brave/stupid, I shall have a wee play with them.

[Gordy]

An old thread but a goodie. Seeing the pics takes all of the "mystery" out of the job before hand. Excellent photos that document the installation of the sway bars!

[Anonymous D]

The ADDCO rear sway bar, has a potentially-serious design defect.

It requires a straight end link, to be bolted to the side of the rounded lower coil spring seat.

That improper fitment, increases the likelihood that the nut on the attaching bolt will "walk" itself loose (and with added cornering pressure over time, it may pop off or snap).

[opelnut10]

The ADDCO rear sway bar, has a potentially-serious design defect.

It requires a straight end link, to be bolted to the side of the rounded lower coil spring seat.

That improper fitment, increases the likelihood that the nut on the attaching bolt will "walk" itself loose (and with added cornering pressure over time, it may pop off or snap).

That is one of the reasons for using high grade bolt and elastic nuts, to prevent that from becoming a problem. Addco has been making suspension parts for a very long time and have a sterling reputation in the industry. I have ran their sway bars on Opels, Chevrolets, Buicks and Oldsmobiles and never had or heard of a failure like you are talking about.

[P.J. Romano]

The ADDCO rear sway bar, has a potentially-serious design defect.

It requires a straight end link, to be bolted to the side of the rounded lower coil spring seat.

That improper fitment, increases the likelihood that the nut on the attaching bolt will "walk" itself loose (and with added cornering pressure over time, it may pop off or snap).

I agree. Noticed that during the installation. I will likely reinforce the setup by spotwelding the L-shaped bracket to the spring bucket.