Yes Sir; I have a Speed direct spreader bar. Yes, my alignment shop has to loosen the spreader bar in order to install or remove shims in the upper A-arms, then reset it when they are finished. As I have read some research on these bars, I've heard, that in order to work best, they need to be centered ( As close as possible ) between the two bolts holding the A-arms, or center of the Spring towers. Maybe VB&P or Speed direct could chime in & let us know if this is true or not??? Always wanting to learn more, Gene

 

I have mine set at "neutral" now, no preload either way, seems to work for my particular Vette

 

My bar is attached to the side of the shock tower. The two upper A arm bolts are not part of the install.

 

another one of the list of things to do

 

I installed a VB&P Spreader Bar on my 1973 convertible back in 1992. I was autocrossing the car at the time and was trying to do anything I could to remain competitive with the Porsche 911's I was running with. Since I was still utilizing the original clutch fan, I purchased the un-welded kit from VB&P.

Following their excellent instructions, I installed the mounting brackets to the upper control arm mounting points and then carefully marked the location for the mounting tabs that attach to the Heim joints of the spreader bar. I then removed everything and took them to a local machine shop to have the tabs welded to the mounting brackets. In my car the bar ended up being not quite centered between the upper control arm mounting bolts to clear the water pump and clutch fan.

Everything fit perfectly and I noticed a dramatic improvement in my ability to point the front end and have it react immediately when autocrossing.

One added point of interest I discovered a while later, was just how dramatically it did stiffen up the front suspension and it's something you can check very easily for yourself. Very often when reaching into the engine compartment of my '73 in the area around the water pump I would place my hand on the spreader bar. Once installed and tightened as directed I could quite easily rotate the bar about the Heim joints (as you might expect) by simply grasping the bar and rotating it.

At some point later I happened to utilize my floor jack under the front cross member to lift the front end off the ground to perform some routine maintenance, with appropriate support to prevent damaging the front cross member of course. While doing this, I happened to reach into the engine compartment and place my hand on the spreader bar. The first thing I realized was that the bar no longer would rotate with as much ease as it did with the wheels on the ground. Thinking that something may be amiss, I lowered the car to the ground and again grabbed the spreader bar. Just as before the bar once again rotated easily in my hand.

Needless-to-say I don't think I could have asked for any more dramatic proof of just how much tension there is on the front suspension and just how much movement results from normal suspension travel. I think I'll keep the bar in place!

Good luck... GUSTO

 

I installed my bar with the tires off the ground. When it's on the ground there is no way it can be turned. I don't know if the bar should be installed with the car on the ground or up. I could argue the point for both...anyone know?

 

68thumper,

The intent of the bar is to stiffen the front suspension to preserve the alignment settings better throughout suspension travel. The best way to do this is to lock the bar in place with the front end on the ground just as it was when the original alignment settings were made.

Having said that, I suspect it would be perfectly acceptable to make minor camber adjustments as TheSkunkWorks suggested above by adjusting the bar in and out should you want to do that.

I lock mine in place with the wheels on the ground, at normal ride height.

Good luck... GUSTO

 

Makes sense since the alignment was done with the wheels on the ground...I reset my bar...I figure there is less stress on the bolts and rod ends this way too...thanks.

 

I don't see how you'd get it centered with a long water pump; but then again, I've only seen a few things

Still, buy it, install it, it's completely worth it. I also hear it ends male pattern baldness.... okay, maybe I made up one of those attributes

 

Assuming the load on the shock/control arm tower is the same at each control arm bolt, then yes, the ideal position would be right in between the two bolts. However, this is not possible since the water pump pulley is in the way. I dont think the frame is weak enough to actually twist at the shock tower because of an off center spreader bar though.

Heres mine... I got the un-welded kit since I initially had a mechanical fan. This is as close as you can get to the center of the shock tower.

 

Your picture brings a question. What are the 2 arms going from the rear of the control arm to the ball joint called and what is their purpose. Can you notice a difference with these extra arms.

thanks
8valve

 

There are no extra arms. Those are the control arms... Instead of using shims to change the alignment, you can adjust the sleeves. Much more range of adjustment, extremely easy to change alignment (especially with a spreader bar), and quite a bit lighter than the VB&P box tube arms.

 

on my list

how well is the brake ducting working? got an under pic to see how you got it there and from where?

 

I am going to build my own spreader bar with what i think should be an improvement to anything on the market.
This will have 2x heim joint bars, the first positioned as close to the a arm centers as possible, the 2nd, at the outer position of the a arm.
This arrangement should also keep the arms parallel at all times.
Does anyone see a problem with this 2 bar set up? I m no suspension expert but it makes perfect sense to me,
Steve.

 

Overkill... If you get the bar in the center, it carries the total load of the control arm/shock tower. Say you have it as close to the center as I do... adding another crossbar to the front of the shock tower will do nothing but add weight and complexity since the one in the (almost) center is already carrying all of the flex. (OK, maybe not nothing but very little, if any gain) Unless you are racing the car with slicks, I doubt most people would be able to tell a difference between front or center mounted bars. There is just not alot of twisting going on with the shock towers

 

Last thread hi-jack
Brake ducts work great... I have a custom front splitter with openings for the ducts. Then they dump into the center of the rotors. Havent boiled fluid yet, but I have overheated some hawk hps pads a few times on 20+ minute track sessions. I have some hp plus pads that Im going to try next.
http://i176.photobucket.com/albums/w...n/DSCF1164.jpg

 

Point taken, and as its a strip only car, no slicks on the front.
Weight can only be a pound or so for the extra bar so that matters not.
When the wheels are lifted off the ground at the strip, would the a arms not tend to twist, depending on alignment settings, so 2x bars may keep them straight in free air before the wheels touch the ground again. Like i said im no expert, but, for a few dollars more, it might help.
Steve.

 

Most enthusiasts will never get near enough to the limits to matter that much.


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