Bump steer spacers...

[heywier427]

Do they make them bigger than 1"?  I cannot find any.

 

My issues are two-fold.  I am running 300z shorter steering arms, and my cross member has been lowered by +/- 1/4" for my engine set up.

 

It was ok before I lowered the engine, but this needed to happen.

 

Worst case is I will machine up spacers for the 1" bump steer spacers I have.

 

Thanks.

[datzenmike]

I made mine in 1/4 aluminum and stacked them. Made enough for 1" per side but only needed 1/2", cost was $2 for the piece of scrap

[demo243]

T3 might be able to machine you a custom set? They seem to have the ability to do a fair amount of custom work.

[paradime]

If you lowered your cross member you also lowered your pickup points in relation to the rest of the suspension. Literally the opposite direction you want to go when lowering a 510. With shorter steering arms I'd imagine it amplifies bump steer from changes in steering geometry. I think you're headed in the right direction with taller spacers, but you may need a bit more massaging on the rest of the suspension. Aside from using spacers, Troy Earmish razes the pickup points at the X-member. He also uses a pitman arm with a 1/2" rise in it (I believe off a 79-82 210) to eliminate any binding. 

 

 

Pitman off my car

 

Pitman off a 210, part # 48502 U0100

Edited August 23, 2018 by paradime

[Icehouse]

Paradime is right!  You are playing with fire.  Moving suspension points is tricky business.  Even adding caster will mess with bump steer.  When me, Frank and Dillion had our little shop usually the cars that drove the worst had the most suspension "goodies".  Most aftermarket parts have "adjustment" which requires the installer to take care while installing them.   The adverage dude doesn't want to do a bump graph or study suspension.  Can't blame them.  Just remember everything you change will have an effect on the steering feel and handling.  

[heywier427]

Thank for all the info guys.  I had already been burned by the fire!!!

 

When I installed the rotary engine I bent the pitman arms down to get the draglink to clear the pan.  That and the fact that who ever flipped the crossmember welded in the studs crooked did help either.  The 1" spacers corrected this enough for comfort.  Only iffy when getting in the center lane truck ruts.

 

Now that I dropped everything even further, it really screwed it up.

 

I will measure the bump steer and add the 1/4" aluminum spacers as Mike suggested, till corrected out.

 

I just have to get motivated this winter and put the Sr in with the JB rack n pinion.  Life will be better with an Sr ?

 

Side note:  I ran into one of the owner of my car yesterday.  He was so excited to see it!!!  He had it when he was 17 and bought it for 500.00 in the eighty's.  He identified all the little quirks and cuts on the car.  Unfortunately he was not a billionaire and did not offer me a make me sell it price, but he was happy to see it in such good condition.  He still has grills and trim and random stuff in his basement for it!  Good day!

[paradime]

If you bent the pitman arm down to clear the pan, again that's the opposite direction you want to go to correct the steering geometry. Although I respect the mighty little B13, I will admit right up front I am an SR fanboy, so of course I highly recommend swapping to that platform. I can say the same thing for the JB R&P conversion. Not just better, but a seriouse life changer for an SR swapped 510. 

Edited August 25, 2018 by paradime

[thisismatt]

Maybe you should move the steering above the engine at this point :P

 

 

[datzenmike]

On 8/24/2018 at 5:35 AM, heywier427 said:

 

 

I will measure the bump steer and add the 1/4" aluminum spacers as Mike suggested, till corrected out.

 

 

 

 

 

 

I just made a template. One side, towards the wheel  is slightly thinner. All you need is a longer bolts, a drill and a hole saw, I forget the diameter but just go slow, the aluminum is soft enough. I used a carpenter's level...

 

   

 

As you can see the steering tie rod end at the wheel is higher than the lowered position of the steering box or idler arm on the body, which is causing the problem. I did a little figuring and decided to try 2 x1/4" and it was good enough.

 

As stated above EVERYTHING.... affects everything else. ANY height changes will push out, or pull in the wheels changing toe dramatically. When done you will need to adjust the toe again.

 

 

[G8KeaPoR]

I have a CNC mill for a side business.  No this is not a plug  or well it is and hopefully you will excuse that but if you need them made then PM me and I can make some.  I just need some basic dimensions though as admittedly I haven't bought them nor have I gotten to the suspension on my first ratsun.  I do have some nasty bump steer but after owning a 993 I'm used to it.  Rear engined cars just drive funky.

[datzenmike]

IRS probably? Over stiff front sway bars will also cause the car to 'duck walk'.

[G8KeaPoR]

12 hours ago, datzenmike said:

IRS probably? Over stiff front sway bars will also cause the car to 'duck walk'.

Do the bump steer plates make the car toe in or out?

[datzenmike]

Depends if you did an alignment after lowering. Basically when lowering the steering tie rods effectively are 'shortened' which pulls the rears of the tires into the car and toeing out the fronts. When you correct the steering knuckle by lowering it with spacers it will toe in and return it to it's proper alignment. I would suggest having it aligned anyway.

 

I do my own toe adjustments with some stakes and string.   

[G8KeaPoR]

Lol that’s how I align my 3500 since no one has a rack locally that can handle a crew cab with the long bed.  It works well just it doesn’t help if you need to make caster or camber adjustments but there are some wheel attachments with low movement levelers for that if you need it for about the same price as an alignment.

[datzenmike]

 For camber I use a torpedo level on the wheel rim. I have some old Moog camber plates that came on the car. With Maxima struts and home made lowering, they are maxed out but it works.