Ball joint beam om link pin chassis...Possible?

[4agedub]

Is it possible to fit a ball joint front beam on a link pin chassis? From what I understood the ball joint beam's spacing is larger, so I would only have to manufacture the top support. We can then move the top backwards to get more caster as well.

[Dale M.]

Its possible.... There are several ways, somebody out in the world manufactures a adapter (you will have to search for manufacturer) .... You can cut main frame head and split it to accept wider beam, or just replace frame head for later model VW which accepts BJ beam.... All have been done with good success... All require a good degree of accuracy to maintain good handling and alignment...

Dale

[Steve Arndt]

Yes it is possible. Just make a new upper mount on the frame head. Retain the bottom mount on the frame head as that is a common dimension and location between the two systems.

[ONEBADBUG]

I welded in a whole new pan head, and installed it with a ~2-3 degree angle to get more caster.

[FJCamper]

Hi 4AgeDub,

Get yourself a ball joint axle with the increased travel or "lowered" ball joints. Take off the old link pin axle and just hold it up to the frame head. You'll see what you have to do.

It's not easy but it is also far from really hard if you have a good welder in the crew.

With ball joints and the ability to just twist an adjuster to get negative camber, you will get faster lap times. It will change the feel of the whole chassis.

FJC

[4agedub]

Thanks for the replies. Let me source a BJ front end first and see how it'll fit.

There is a couple of reasons for looking into this...
The link pins wear quickly and I need to tighten the bolts after almost every event
The link pin trailing arms bend even when supported, thus changing the camber under cornering conditions

[buildabiggerboxer]

Hi 4agedub, How's it going, my advice would be a pan swop and go IRS and b/j all in one go, it's inevitable, And I'm a big 'swing' fan and I would gladly take swing axle to a half dozen tracks we go to over IRS for that wonderful direction change ability, but only up to about 140 hp, I've noticed the busted spade axles happening to you, the cvs on IRS axles are great shock absorbers, we put 200 hp through 80mm stockers for years, altho the trans was toughened up, go up to bus 100 mm and they take 400 all day, build the pan up as you go, then do the pan swop next close season, you don't really want to be faffing around a major frame head swop working round the body and coolers/pipes etc. Regards BBB.

[Dale M.]

IF you want total handling go IRS rear and BJ front..... Not hard to change rear to IRS if you can locate donor parts (in US that would be 69 or later) and are not afraid to add brackets to torsion bar tube, everything else is bolt on....



Here is partial complete setup for adding IRS bracket on rear......



I had two fiberglass manx style buggies one was swing axle with K&L and other was later chassis with BJ and IRS there is a world of difference in handling with IRS, both cars were run on autocross circuits and invariable ( if driver did not screw up) IRS car was always faster then K&L/Swing axle car...

Even a long time driver (he usually set the pace for everyone to catch) with older chassis (same style) car thought IRS car handled better and his times were almost equal to his K&L/swing axle car, OBVIOUSLY he's a better driver then me....

Faster in corners means you get there sooner....

Dale

[Ol'fogasaurus]

viewtopic.php?f=51&t=143382&p=1170378&h ... p#p1170378

viewtopic.php?f=28&t=143224&p=1168470&h ... p#p1168470

There is some redundant information in the two URLs but some of it might be of some use to you. Off-road we go the opposite way front suspension wise but basically the information here is close enough to maybe be of some use to you.

If changing out the pan to a BJ/IRS is legal for the class you are running, that is probably the easiest way of solving the problem. In the first URL there is a pix to cutting off the whole frame head and welding a new one in place. It can be done but it is something I would not comfortable doing. The second URL is partly redundant but maybe there is some information that you might find usable there.


FJ is a very good source of info for bent circle racing (it isn't an oval or circle shaped track but eventually you end coming back at the same place you started... ).

(if class rules allow) If it were me I would also stiffen up the tunnel towards the outside of the pan where the body bolts to the pan. Add more connections from the rear torsion tube to the pan. Add stiffeners to the front beam, both lower and upper.

[buildabiggerboxer]

https://m.youtube.com/watch?feature=rel ... Xcksyuc0N8
Here's a myth buster, one of the very quickest Kaffer cup cars uses a ball joint axle beam, notice how well it turns in with no wheel lifting, and brakes dead straight without locking the fronts, it's the over rated 1303 strut cars that are struggling to keep up, the beam is less modified than my own increased width 4 SAW adjuster hybrid, but it uses a red9 through rod kit and no front ARB, I've sought out and driven both Beetles and buses with this kit, and find it a revelation in ride and handling, and the braking stability certainly is unbelievable, it's moved to the top of my must have list and Christmas is only 9 months away, check the vid link above.

[Marc]

IF the rules allow adding an extra link to the Super front end so there's something besides the swaybar to control the wheelbase, it can work well (so long as you don't do any chariot-racing with the `71-`74 steering box, which is far more fragile than a Standard's).
My most successful circletrack cars have all run tried-n-true balljoint beams (or some variation thereof). Yes, there are some compromises in its design, but it's hard to beat for overall robustness (of particular importance when you aren't the only car on the track)....last time I checked you still have to finish to win

If the rules allow it, a "ladder-beam" setup beats any other method of lowering, hands-down. Move the whole thing upwards in relation to the chassis by a few inches to achieve the desired ride height and all of the stock control arm/steering geometry is retained....

[Marc]

What are the Kafer Cup restrictions on front air dams? Watching that video, I gotta wonder why more isn't being done in that area - it seriously adds some much-needed front downforce to allow driving deeper into the corners without front brake lock-up.

[buildabiggerboxer]

What are the Kafer Cup restrictions on front air dams? Watching that video, I gotta wonder why more isn't being done in that area - it seriously adds some much-needed front downforce to allow driving deeper into the corners without front brake lock-up.

Hi Marc, I'm not 100% sure on the aero regs, it was probably limited to mass produced equipment on sale at the time, IE Kamie, it's now a defunct series unfortunately, just like our recent attempt to resuscitate the UK Series, our own rules banned any aero devices, which in hindsight was a good rule as the series was hugely successful for 7 years, staggering on for another 2 or 3 years, we managed to get a half dozen or so cars back on the grid two or three years ago but the rules demanded more cars, so it's dead again.
The trouble is folk like you and I, that think about our racing usually rise to the top lol, so the slow guys dictate how the class rules play out,,, you are right as usual, in that the Beetle needs more load on the front axle, it's the front that needs the work to go quick and a good air dam is a must, were rules ban these, there are still ways to control and turn the air out through the front wheels or wing gills to stop from generating lift, but you know that anyhow,,,
Were the through rods score is it enables front axle corner weighting,, this is THE biggest B/j weakness with the stock beam, corner weights are impossible and it shows up on the brakes, i blacksmithed my torsion arms in all directions and it was the scourge of the grid on the brakes, the heavy guys suffered more sat on the right, but not much could be done for them, unless you go split torsions and double SAW, but they banned that also in our series. As you mentioned, the beam allows all adjustments to steering angle and ride height in a jiffy, it's detached completely from castor, the same adjustment on a Mac strut means resetting castor, they were after all, only a packaging solution to allow a decent front luggage area for the 02/3 models. Regards BBB.

[Dale M.]

If the rules allow it, a "ladder-beam" setup beats any other method of lowering, hands-down. Move the whole thing upwards in relation to the chassis by a few inches to achieve the desired ride height and all of the stock control arm/steering geometry is retained....

This would be a real plus if possible.... by "lowering" you sacrifice front end travel and eventually exert added pressure/stress on ball joints as the reach max articulation...

Dale

[Marc]

Where the through rods score is it enables front axle corner weighting,, this is THE biggest B/j weakness with the stock beam, corner weights are impossible and it shows up on the brakes, i blacksmithed my torsion arms in all directions..

I built one beam for a mid-engine car that had a wider-than-stock track width, and since longer torsion leaves aren't exactly common I used four Sway-A-Way adjusters and chopped-up stock leaves - that left me another way to fiddle with corner weights (in addition to coil-overs). One could use that tactic on a stock-width beam too by shortening/redrilling the grubscrew divots.
Tweaking control arms to exaggerate camber has the undesirable side effect of also changing their effective length - that upsets the geometry of the control-arm "parallelogram" and introduces bump steer....something has to give when the control arm lengths don't match, so the steering knuckle is forced to steer as the suspension cycles. IMO you're better off leaving the arms untouched and fiddling with the spring-stack length - the needle bearings/bushings in the beam will easily accommodate a ~⅛" lateral shift of the control arms. I always carried a couple of "rebent" upper arms to the track for emergency corrections, but abandoned that as my primary method of camber tweaking long ago.