TheSamba.com :: View topic

Fri Jan 16, 2009 5:53 pm

On the Rabbitt rack , you have to trim alittle on the tie rods.

Sat Jan 17, 2009 2:39 pm

how is the bump steer with that rabbit rack ?? And don't try to tell me it has none. I think a center mount rack would be way better.

RM

Sat Jan 17, 2009 3:36 pm

Yep, that is worse than the short side tie rod on a type 1.
That is why the offroad guys go with center mount racks.
Mike

Sat Jan 17, 2009 9:10 pm

the rabbit rack has equal length tie rods. the input shaft is just off to the left.

Sat Jan 17, 2009 9:20 pm

matt (wolfie) is right. The pinion is just on the left, the tie rods are still the same length as a center pinion rack.

Sat Jan 17, 2009 9:21 pm

I realize that they are the same , That's why we shortened both sides.And 57 Palms , I won't try to tell you anything , our work speaks for it self .We realize that the center steer would have been better that's why we have the Porche rack on our Manx.On my Singlecab we used the Rabbit Rack because that's what we had laying on the shop floor at the time.And to see how it would work.

Sat Jan 17, 2009 9:54 pm

OK Singlecabboy, so when are we gonna get a road report?

Sat Jan 17, 2009 10:49 pm

Keule/GAC wrote:

Here some stuff from Germany... The setup with a Porsche steering !!

Greetz
Andreas

Strange set of priorities. Slightly more precise steering, but NO HEAT

Sun Jan 18, 2009 8:55 am

We havn't driven it yet .we've been doing other things to the truck ,plus the cold.BOB not as young as he used to be either.TCB will be the place

Sun Jan 18, 2009 2:32 pm

right on! :D

Sun Jan 18, 2009 7:17 pm

The off road guys use the center rack because of the added wheel travel when they jump and stuff.

Wed Jan 21, 2009 2:57 pm

Drove the truck yesterday for the first time with the new Rabbit Rack and pinion dialed in.What a great ride ,We have the steering box in a straight line in front of the steering shaft.Maybe this elminates some of the issues spoken about ,I'm not sure .All I know is my steering box was wore out and this is the route we use to fix the issue.I invite any one to drive the truck to see what I'm talking about.Thanks for all the great input. It was invaluable in this project.I'm sue the Creative Engineering kit is ok for what your getting but with your help we accomplished our goal.

Wed Jan 21, 2009 3:14 pm

Here are the pics:
Sweet! 8) :twisted:

Wed Jan 21, 2009 3:31 pm

looks good! curious, is there a reason why you did not mount the vanagon steering box up higher? looks like it hangs down quite a bit which would be an issue for a low bus.

also, is the master cylinder in the way of doing a straight link between the steering box and rack? I Was thinking a U joint at the box then straight link to a U joint at the rack. looks like the master might be in the way.

Wed Jan 21, 2009 3:49 pm

not trying to upset anyone it is just that the stock tie rods mount to the center of the vehicle (swing lever) this makes for a nice long arm which equals a greater swing arc and less bump steer. The shorter the rod the greater change in length for a given suspension movement. It all has to do with the radius the arms are moving. By center mount I mean the rods mount in the center of the rack not the pinion. The location of the pinion has no effect on bump steer. it can all work just one more thing to think about. I did the same thing on a few cars and was always disappointed with the results. Not fun when the car gets all squirmy over bumps, especially in corners. For a wider mount to work properly it has to work with the design of the suspension. ie. suspension arm arc must offset steering arm arc.

RM

Wed Jan 21, 2009 4:04 pm

youre right, rack and pinion is generally used with an A arm style suspension where the spindles travel in an arc perpendicular to the travel of the vehicle, not parallel like with a torsion beam style suspension. There is pretty much no way to eliminate bump steer entirely on a beam suspension, having the tie rods as long as possible is our best bet.

if one wanted to, they could build somewhat of a cross steer utilizing a single side rack that actuated a rod with a pivot on the other end connected to the opposing frame rail...then mount two long tie rods that bolt to the center of the cross-steer rod.

Is all that engineering necessary? I dont think so, not many of us are driving our buses hard enough to experience life threatening handling characteristics of less-than-ideal bumpsteer.

Wed Jan 21, 2009 5:52 pm

had to chime in....I have many years of time with the rack setup in a bus! I build this first setup in 1998 on my 15 window! I recently removed it all in favor of the stock restoration plans..the things we hack when we are young! anyway, check out these pictures. I originally used a vanagon V box and a mazda GLC rack converted to center output. the point of this setup was to gain ground clearance more than anything. steering was nice and tight but the ratio is too slow with the GLC rack(like an extra turn lock to lock) that sucks. I did a few other installs on customer busses in later years and dicovered that "nascar" type circle track racks are your best bet. they are extremely strong, light weight and best of all you can order them to your specs with the proper travel(important for full steering radii)
and any number turns "lock to lock" try http://www.woodwardsteering.com they might even still have my specs on file? you still need to make a back crossmember to convert to center output but they can be ordered with the input on either side or center!

check out the crazy adjusters that I made! this was actually originally hydraulically height adjustable but that was scrapped. and the first ever set of 6" dropped spindles...yikes! I have so many hacks to fix on this bus and I did most of them myself...so think twice before hacking your bus you may too someday be sorry. by the way, this wacky bit of Volksfab history will be staying in my vault for posterity.

Wed Jan 21, 2009 7:18 pm

The steering box is kinda at a strange picture angle and is higher up the the original box ,and the Hurst bumper and the reg . bumper are way lower than the box.In the pic it does appear to be lower.

Wed Jan 21, 2009 10:01 pm

christ cameron its like confessions of a famous serial killer :)

Wed Jan 21, 2009 11:26 pm

That was a great idea on converting the rack to center mount!!

Looks like some very sound home fabrication to me.
Mike