[Nailbender]

I ran the CSRP 1.5" drop spindles that MM was talking about for 2 autocross seasons before I swapped them out for CSRP stock hight big pin spindles. They weren't unstable or dangerous but I wanted to try the original geometry to see if it helped the car racing and it did a bit that I noticed. My friend Nick who is a much better driver than me didn't notice a difference. MM chopped up the steering arms on his spindles to shorten them as seen in the picture below.

I don't know what math he used when he shortened the arms?

I don't know how old the video in the original post is? Was it made before Shaun came out with his drop spindles, or is he taking a swipe at a direct competitors product that he has probably never tried? I hope not.

With my underwhelming experience with my first set of drop spindles I wasn't first in line for the new SoT spindles, but with the need of faster steering and more tire I bought a set a few weeks ago. I won't know how they work until April or May but I've bought a bunch of Shauns stuff and it has always been of excellent quality and works very well! Shaun didn't hack his spindles up in his garage they were designed on a computer using modern software by people who do that sort of thing for a living. I'm hoping that makes the difference.

 

[Nailbender]

Watching the MM video above and others I find it interesting what he considers a stock style fender. I believe old blue was running his fathers 2" flare fiberglass front fenders at the time, maybe more, and in the video above he makes it sound like you can run 275's with regular spindles and stock-ish fenders on a 65-66 and that is just not possible without a 20" wheel. I'm running 245/40/17's up front with negative 3 degrees camber and I don't think there is room for anything bigger. I assume most people don't want to cut up their cars for bigger tires and you can't do that up front without the tire/wheel going over the UCA and steering arm. MM seems to preach on the diminishing returns of moving the tire inboard and then you look at almost every modern car front or rear wheel drive and they all have a positive offset wheel. I realize the cars are designed for that offset. In a full on competition car like old blue the widest track available is going to be advantageous and the looks of the car secondary, not that it doesn't look cool for a race car! I guess what MM was trying to say was you don't need drop spindles to run big tires on your race or race type car with big flared fenders?
I'm always talking, texting, and sharing threads from VMF with much more experienced friends that I race with and appreciate their feedback, and that feedback has been important in my buying decisions.

 

[Nailbender]

A lot of terminology being thrown around! SAI is steering axis inclination. The angle between the upper and lower ball joints with the steering wheel straight. Does this angle change with camber, or is it a fixed angle of the spindle? The drawing below suggest to me that it might change with camber? I'm just curious and it has nothing to do with your average VMF member buying a few basic tools and aligning their car themselves. People throwing fancy terms around might confuse the rest of us and back in the day I aligned hundreds of cars without knowing most of this stuff. All I can say is that I am thankful for CAD and modeling programs but always curious. I could do rise run and diagonal calculations on multi pitched roofs before they had fancy calculators but arbitrary points I have trouble wrapping my head around.

I found a site with simple definitions! Definitions and Explanations of Suspension Alignment Terms

 

[Nailbender]

I can get 8° caster pretty easily.

View attachment 878153

How much total have you lowered you UCA from factory? Inquiring minds want to know. I can also easily get +7º caster with SoT's front end, but how much caster is too much? My friend Nick says thats not possible but it must be.

 

[Nailbender]

I currently run the upper arm with the standard one inch drop. But I also have it drilled for a two inch drop, which I've also used. It handles great at either location, but the two inch drop requires the steering tie rod to be mounted much lower at the spindle to reduce bump steer. I hate that term for our cars, straight axle cars have true bump steer, ours have bump toe.

How much caster is too much is the $64k question. The more caster you have, the lower the steering tie rod connection at the steering arm of the spindle will go, which affects bump steer, and will need to be adjusted.

You change one thing on these cars and it affects 3 more.

I have always thought of bump steer as toe steer as well because that is whats changing. There is obviously no perfect solution because all this has to fit underneath a car. The drivers side outer tie rod on 65-66 power steering cars is bent to clear the control valve. That has to jack up the steering geometry. With my longer "Shelby" idler and pitman arms and the significantly shorter SoT steering arms I hope to not need the goofy outer tie rod?

I find this kind of stuff fascinating, but in the end we are dealing with a quick and dirty suspension designed for the cheapest car Ford offered, the Falcon. The fact that Street or Track and others have been able to make improvements to where I can beat Corvettes on an autocross course is amazing! I don't want to cut up my car to where it is noticeable and yet still be competitive. There are only a few venders seriously into that option.