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Don’t buy drop spindles?

2369 Views 51 Replies 21 Participants Last post by  Shaun @ Street or Track
Thoughts? I think someone else figured out the geometry.
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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.

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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.

View attachment 878347
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.
 

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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.
Thanks for that tidbit. Since I have front-steer theoretically the opposite would happen and the steering arm would rise instead, which might actually be helpful to me. It might just give me the push I need to go EPAS w/ a de-powered power rack.
 

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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?
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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.
 

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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?
It still is just two points connected in space, you can curve, twist, and bend everything between and the geometry won't care. It'll affect if that link will buckle under force, for sure lolol. In terms of the effectiveness of the geometry however, it doesn't matter. It's pretty common to see "bent" or non-straight links for OE geometry to provide chassis or axle clearance. Here's one from an e60 (mid/late 00's BMW) looks like (the one w/o the arrow):

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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.
Going into it, I thought the same thing but the geometry really isn't that bad. After plumb-bob measuring and then re-confirming with some simple 3d scans I was surprised to see the end result. There are some tradeoffs that were made but I'd chaulk that up to 60's era tech. Things were designed with narrower, bias ply tires in mind as well as safety. As an example, toe-in bumpsteer while cornering will give the car a tendency to steer-in, not wash-out. Also, again as I've mentioned, this was all done pre-CAD so it was all done in 2D perspectives and still is damn close.

RE: general design, people might be inclined to say the more "trailing arm" design (it you could call it that) of the front suspension in early mustangs is inferior to a "true double a-arm" style. Or that for newer cars, a McPhearson strut design is inferior to a "double a-arm" style suspension. The BMW e36 and porsche 911 from the G-body through the 964 used BOTH and they're heralded as some of the best handling cars in history.
 

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Nobody needs drop spindles, until you get into other necessary spindle design changes, dropped spindles are mainly a "looks" thing.
Track width is an important criteria in vehicle stability. The fenders get in the way on an early Mustang.
Here's the late Eddie Paul's method of getting around that problem.....

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Oh yeah, old enuf' to remember the original magazine article.
 

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1965 2+2 Vintage Burgundy A-code C4
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Oh yeah, old enuf' to remember the original magazine article.
I still think a “wide body” approach on a 65/66 looks better than just adding flares. More work but you don’t compromise that beautiful side scallop, especially up front. Too bad they don’t tool up fenders and quarters to accomplish this. Only flared Mustang ever really liked was the SN65.
 

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1967 Terlingua Racing Team Mustang Coupe recreation
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Here is a '67 Terlingua Racing Team Mustang I built. Running Global West upper & lower control arms, stock spindles,Koni Yellow shocks, Shelby 1" quick steer with a power steering box (Armstrong steering), Total control adjustable struts, 1" sway bar, 600 lbs springs stock tie rods. Now this car drove straight at 170 mph & cornered fantastic. I raced it in HSR West & won at Willow Springs Raceway. The thing about a early Mustang is Y'all steer the car with the throttle to get it bring the ass around & steer outta the corner. The steering wheel is for pointin & hanging on as Y'all roll into the throttle ta bring bring it outta the corner or hit Y'alls apex. If Y'all can master that in a early live axle Mustang driving a 2017 Shelby GT350 is like a go kart. It just sticks & turns with the steering wheel.
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In my stable: 1969 Mustang notchback, 1970 mustang notchback, 1970 sports roof.
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I got +7 caster on this one without really trying.

View attachment 878185
What year mustang did those wheels come off of? Did you have to use wheel spacers? They are different than the American muscle ones pictured on your website with the 315's on them. I like the rims in this photo better. Thanks.
 

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What year mustang did those wheels come off of? Did you have to use wheel spacers? They are different than the American muscle ones pictured on your website with the 315's on them. I like the rims in this photo better. Thanks.
I'm interested too, they're similar to these guys, but if there's an OE equivalent I'd rather use that. I've been shopping around for 18s for takeoffs and something this style would work well. CJ pony Parts VOXX
 
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