Front End Alignment - Caster

[11Budlite]

I'm going to be installing a wide-track kit and new springs/dampers as soon as my garage warms up a bit. I have recommended starting points for camber, caster, and toe. The recommended caster setting is "as much as possible".

 

The following are the washer combinations that I found from this build thread: https://caterham420detailedbuildblog.co.uk/2019/11/03/front-lower-wishbone/

 

There are five possible combinations listed from most caster to the least caster. 

• 4-0-4 More steering effort, more self centering / straight line stability
• 3-1-3
• 2-2-2
• 1-3-1
• 0-4-0 Less steering effort, less self centering / straight line stability

 

I'm presently running the recommended 2-2-2 from the Ikea assy guide. So going to the max caster setting of 4-0-4 will increase steering effort, stability, and will also gain neg camber on the outside wheel during cornering. I've never felt that the steering effort was excessive even with the 260mm leather steering wheel that came stock, and I'm presently running a 280mm suede wheel.

 

My question is, are there any other negative consequences to going to the 4-0-4 caster setting other than increased steering effort?

 

 

[MV8]

I can't think of any definite negatives. The toe link moves up and forward with front steer uprights but not much, so ackermann increases slightly and bumpsteer changes slightly. Not necessarily bad changes.

 

washers out of the same bin can vary significantly in thickness, so have enough to stack to the same overall thickness for each side and position. Measure with a dial caliper. Cars are not precise either. If it pulls, try less caster on that side or more on the other.

[11Budlite]

Thanks MV8. Didn't even consider the washer thickness being a potential issue. I will definitely measure them upon dissy and when I'm doing the install. It tracked straight before so I shouldn't have to worry but I'll be aware of the possibility. I had planned on checking bump steer as well as corner-weighting too.  

[CarlB]

All of what both of you are saying is correct. I might suggest measuring the caster before you take it apart. There is enough variation that assuming the washers will get you what you want might not be accurate. Caster changes camber gain and steering geometry, but the affects a slight. If you haven't bumped steered your car before, you will find it is not close. After all that, Caster is really a feel kind of thing. Adjust it to make the car feel good to you. 

[11Budlite]

Thanks for your input CarlB. I did some research and found this thread which has some good info and links for eliminating bumpsteer: 

 

Edited 8 hours ago by 11Budlite