Front SLA, need help finalising design.

[BenE64]

Hi, I am in the final stages (hopefully) of designing my front SLA conversion for my truck. I have PT suspension analyser from a previous failed attempt at building a nice track car, so I have been using it to help with this new project. The truck is going to be built in pro touring "style" as it really has all the performance qualities of a large brick. It has a long wheel base and a high CG but I'm working with what I have got.

I am using a chevy C20 front sub frame which needs cutting to fit where I want it on the chassis. As a part of engineering to be able to register it on the road I am not allowed to have fabricated arms/ spindles etc so I am using all the standard componentry, this doesn't stop me from re-arranging them a bit to make it handle a little better.

After some fairly elaborate set up I got the subframe to sit in its factory position and measured it up to get the data points. I then made a jig to position the spindle in its correct location for my truck and re measured all the arms steering rack etc to the draw it in CAD. Once in CAD I can move it around while keeping the arm dimensions, spindle dimensions all the same but I can get the co ordinates to plug into the suspension program, make a small change, do it all again. Many weeks later and hours of forum and book reading I have narrowed my design to this




I have a few worries due to my lack of knowledge and real world experience! I am stuck with the spindle as it is, which leaves me with the following parameters to work around

SAI 8*
Scrub radius is 9.5cm

I have set Static Caster at 7.5* and camber at -.5*

With the arrangement of the links I have now I have .86* of caster gain and -.41 camber gain. 53% of anti dive. and a RCH of nearly 2in.

Can anybody give some pointers to where I may have gone wrong? It is a build once no real adjustability deal when finished so Id like to get it close to good as possible.

I have concerns on the following,

7.5* of caster and the high scrub radius, will this be a heavy steering pig or not really all that noticeable? the front tyres are only 225 wide will this reduce the effort anyway?

Is 53% anti dive to high? should I be in the high 30-low 40 range?

Being that it is a high centre of gravity land whale, would I benefit raising the FRCH a bit more, and with the current arrangement I have a fair bit of lateral RC movement in roll? at 3* it is nearly under the opposite tyre if that makes sense. will this cause excess jacking?

I have tried to arrange the arms differently but cant get the sort of figures Ron has talked about with out this lateral RC movement, is this a compromise I need to live with?



Sorry for the long winded post, If this isn't the right place for this style of truck let me know.

Thanks Ben