SPF GT Front Sway Bar Clearance

[Lynn Miner]

The SPF GT40 (like all GT40s) suffers from very low ground clearance. This is especially true of the Heim Joints that connect the front sway bar to the lower A-arms. As delivered, the car has standard "off the shelf" Heim joints that are longer than they need to be. by performing this mod you can pick up another 3/4"+ in clearance at the front. As seen in the photos below, these joints are the first thing to get whacked if you hit something. Every fraction of an inch counts. The pictures are in chronological order and the entire process took about two hours.

A few cautions: Leave at least 5 threads on both the male and female portions of the joints. I did all the work on a lathe. A hack saw would work but you won't get as clean a job and cutting the nuts thinner would be difficult but not impossible.

One additional idea given by Rick Glover is to weld the arm to the sway bar shaft (last photo). The arm mounts to the shaft on splines. Rick did this because he hit something on the road stripping all the splines off the shaft. I elected to not do this because something has to give and I can always do this mod later if required (after I've stripped the splines off mine). Welding these parts together has no impact on assembly or disassembly because the entire sway bar drops out with 4 bolts.

 

[Jack Houpe]

Rick has some great mods! I will follow suit and do as you described Lynn, seems pretty easy and sensible.

I drilled my sway bar links and put a cold roll pin in mine just after I got the car,

 

[Seymour Snerd]

Before you go shortening your sway or anti-roll bar vertical links, you should probably check whether your ARB arms are parallel. It turns out on P2160 that the splines on each end of the bar don't quite align, meaning that when the chassis is set for equal ride height and the arms are clamped in the closest pair of positions, the end of one is about 3/16" higher than the other (that is, they are misaligned by a few degrees).

Now to be fair to the bar, this could be tolerance build up in the bar, the suspension, my precision in measuring ride height, etc., etc. I did not remove the bar in order to precisely measure its alignment. But in a way it doesn't matter: with equal ride height I want a neutral anti-roll bar and missed that by ~3/16.", and with maximally shortened vertical links would have no way to adjust out that 3/16" without one of the links getting very short on thread engagement. And this may all disappear, or get worse, when I go to corner weight the car but I thought I'd post the warning anyway.

IAE should you have an error like this of more than about 1-2 mm and you want to minimize vertical link length for ground clearance and maintain, say, 5-threads of engagement in the vertical links, you need to cut the links specifically for the side where each will be located. Alternatively, don't be so agressive with shortening the links, so you have at least a couple or three turns latitude before you run out of adequate thread engagement.

Finally, be sure your vertical link ball joints have the angular range needed; this is affected a little by the side-to-side motion available by re-positioning the arm on the splines, but the angular range problem is made worse by shortening the links. And as Kirby describes in another thread, if you shift the vertical link position back on the arm to stiffen ARB action, you may run out of angular range entirely, even with unmodified links. See: http://www.gt40s.com/forum/superformance-gt40s/36359-front-sway-bar-not.html

Upshot: tread carefully before you start cutting your vertical links.

 

[Rich E.]

I cut/modified mine about 4 years ago. No problems with it so far. I did mine because I didn't want that being the lowest point at the front of the car acting like a rudder if I ever had a blow-out. Especially running 15" rims.