I'd like to compare notes on how you are assembling your front end king pins and shim your axles. My setup is what I think is popular on the L4:

- Stock Aluminium IRS Caster blocks
- Stock sterring blocks
- Stock upper and lower a-arms
- aftermarket Wolfe 1/8" axles
- aftermarket IRS radical king pins (don't use e-clips)
- aftermarket Wolfe standard springs

CONTEXT: I'm in my first year of Pan car racing. I am still honing my skills as a driver. But start to notice the importance of an adjustment here or an adjustment there. So I would like to focus on the right ones.

What I'd really like to know is :

* do you really get a significant tuning aid out of the caster blocks locations? or is this a finer tuning aid?

* how / where do you shim the king pins? (i.e. below the nut, between the upper a-arm and the spindle, etc.) do you dampen it ? if so with what?

* how are you shimming your axles? (i.e. 2 brass washers inside, the wheel, the nylon spacer, a shim, then the nut)

* how do you set caster? at the caster block or by shimming below the a-arms?

* did you play with bump steer correction on the LF?

Thank you in advance,
I am sure many will find this of interest.
M.P.

comments?

[QUOTE=mproy]
What I'd really like to know is :

* do you really get a significant tuning aid out of the caster blocks locations? or is this a finer tuning aid?

* how / where do you shim the king pins? (i.e. below the nut, between the upper a-arm and the spindle, etc.) do you dampen it ? if so with what?

* how are you shimming your axles? (i.e. 2 brass washers inside, the wheel, the nylon spacer, a shim, then the nut)

* how do you set caster? at the caster block or by shimming below the a-arms?

* did you play with bump steer correction on the LF?
QUOTE]

No responses so I'll take a shot.

1) I don't mess with caster much. I've used 6* both sides (by mistake) and it worked very well. I usually run 2* left, 4* right. I've tried changing it to get the car to do what I wanted it to, but it didn't help much, I think your better off looking at other areas of the car for handling adjustments.

2) I use ksg caster blocks, long wolfe kingpins with e-clips and 1/8" wolfe axles. 2 .015" washers above steering block, 1 thick plastic black washer and 3 .015 washers on top. I run the top pivots upside down, less bind. Blue spring cups to center spring on bottom. Buds kingpin lube, good stuff.

3) Wheels shimmed. 2 washers inside wheel, 2 outside wheel.

4) Caster set at the block. 2 white spacers (with the kit) and a thin washer to take up the slop.

5) ksg toe corrector. not smart enough to figure out how to put right side steering block on the left and get the ride height correct.

Some use B3 kingpins, they are sweet.

-Tom

Just a general comment... I thought the IRS kingpins were a great idea, and bought them for my cars -- I've now started changing over to the Wolfe long kingpin setup... The reason was kind of sad -- I was attracted to the IRS kingpins because their threaded shaft/nut design meant no more e-clips, etc... However, I've also found that was a problem for me -- by their very nature, it is not easy to reassemble the kingpins the same way every time. I found that sometimes I'd not have enough "preload" on the spring and get 'sag' -- the next time I might get too much, making that corner of the car stiffer than I wanted... The e-clip designs are always the same length, time after time, and once I find the right shim stack size, I'm "golden"... I put one shim between the steering block and the upper pivot ball to ensure no rub/bind action, then the rest of the shims are on top to just remove sag... Probably just a matter of personal taste, and pretty frustrating, as the IRS kingpins really are a sweet idea -- I just never found a way to make them repeatable from one rebuild to the next...

Caster is normally 2* left, and 4* right... I played with reactive caster on the right, and it made the car more aggressive, but less consistent, so I went back to conventional caster...

I use Raceway Mfg. caster blocks (left side only), with the upper arm in the upper hole.

Left front tire is shimmed so the outer edge lines up with outer edge of LR tire. Right front tire is shimmed so the outer edge is about 1/4" inside of outer edge of RR tire...

any shims in top of the spindle will change roll center same as caster block holes, just be careful here. I assemble long king pins per instructions, then remove spring and
see if vertical travel is free..smooth. you may need to install upper pivot ball up side down. have just enough shim between spindle and upper arm so there is no bind.
as far as spring preload i start with spring guide washer flush with bottom of king pin
so you will have about an eclip width of preload. with car race ready rf should have no
droop- Sag and lf should have about .020"

lf tire in shims on oustide then nut. this will increase left side weight

rear axle spacing is based from lf position..lr out 2mm and total rear width 200mm. moving the axle to the left will tighten the car on entry.
hope this helps
TJ

tfrahm - you mention reactive caster... what is that?

toytowne - pivot ball upside down??

just the top one. it has a lip on it. it gives about .020 under the a arm instead of on top. when you compress the spring the spindle may bind on the upper a arm, that is why you may need a shim or two in there.
TJ

One area that wasn't covered is king pin dampning. Since Bolink's famed #3 is no longer available. What do you use?