Can anyone chime with their experience on how effective this product is?

http://www.summitracing.com/parts/aco-907

I currently have no rear sway bar installed on this '73 coupe. It has a 383 engine and a composite Rear Leaf Spring installed with standard size G70R tires.

Much appreciated and Thanks in advance.
Steve

 

There are many threads on rear sway bars for C3 vettes. I suggest that you do a search since there are many opinions on this topic. Without knowing what you are trying to achieve (less understeer/more oversteer/balanced handling) and not knowing your current setup specifically what size front bar you currently have, it is difficult to make a comment regarding sway bars.

With that said, I would not use that type of rear sway bar although I have used addco bars (73 Nova SS, front/rear) on other cars I have owned in the past since that bar is NOT an OEM type rear sway bar with the endlinks vertically oriented, not horizontal like the front bar endlinks, which will restrict the movement of the IRS of a C3 adversely effecting handling in some situations. Whatever you decide, use an OEM type rear bar...stock GM rear sway bars were either 7/16 (Small block Sport suspension cars) or 9/16 (BB C3's). You need to match the rear bar to the front bar size...you should not just add a rear bar.

The OEM gymkhana SB C3's had either a 7/8 inch front bar coupled with a 7/16 inch rear bar OR in the late 70's a 1 1/8 inch front bar with a 7/16inch rear bar like on my 78. Either setup, the cars understeered from the factory (thank you Ralph Nader). My 78's suspension has been modified/improved across the board and I run a factory 1 1/8 inch front bar with all poly bushings (makes the bar act like BIGGER front bar) with an OEM FACTORY style rear 3/4 inch rear bar. My handling is very neutral now but every car is different.

Hope that helps!

 

Helps tremendously JB. Thanks.

I do have a 1.125" front sway bar. And I was concerned about the Addco bar's different mount from the factory type.

I confess, I was lazy in searching. Seems I always get too much info and nothing specific for a given item. But YOU came through JB, and I really do appreciate it.

Steve

 

The after market bars mount differently than the OEM bars. If you examine the two, you will see that the aftermarket bars are not much more than a cosmetic add-on.

 

If you or anyone else is interested I have a factory 9/16 rear with most of the mounting hardware and a bare 1-1/8 front bar...the rear bar isn`t cheap but it was designed for a Corvette and fits correctly

 

I agree. If you want to add a rear bar, use the stock set up. They are C3 specific and bolt on without any additional modifications.

 

I understand part of your theory. BB's came with sway bars at least with the 73's to keep the rear stable. But are you saying this hinders the IRS from moving ? But with a BB does the torque not need one?

 

No, I am saying that a NON OEM/factory rear sway bar will hinder movement of the IRS...the correct factory rear bar will not hinder movement. Also the BB cars were nose heavy (weight distribution 52-53% Front/Rear 47-48%) which means the cars would naturally understeer/plow more than a SB C3 (Front 48%:R 52%). The factory BB C3 had a rear sway bar to help dial out the front understeer and to make the car handle more neutral. The BB cars definitely needed a rear bar because of the understeer issues without one and the reason all BB cars came with a rear bar.

Hope that helps!

 

With apologies to those who have heard the following sermon before...

Although the General utilized a rear bar to do so, since anti-roll (and the resultant percentages acting front/rear) is provided by the combined effects of springs and bar(s), IMOE it is entirely possible to sort a BBC C3 w/o a rear bar. ...even preferable. Thing is, bigger springs don't carry the penalty of increased lateral weight transfer had by bigger bars; the latter of which by the way tires function as load increases actually serves to reduce overall available grip at a given axle (assuming roll is adequately controlled). This is why I always recommend first stiffening anti-roll with springs up to the practical limits of ride quality best suited to the roads in question and driver's preferences BEFORE adding more bar.

Thus, if the OP desires increasing rear anti-roll to better balance the car to his needs, assuming his backside will stand, I highly recommend opting for more rear spring and only after doing so to judge how much additional bar (if any) may be required for fine tuning. As for safely diagnosing the car's balance/drivability, a word of caution: Never assume that a car will necessarily react in the same manner once it reaches the limits as it may seem to do when not being pressed so hard. My $.02 on how to go about skinning this particular cat. PayPal accepted.


TSW

 

9/16 is the correct size in most cases. 5/8ths and 3/4 are the biggest

 

I put a 7/16'' OEM rear sway bar on my car and it made a huge improvement.