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Crown victoria dirt car build

#21
Hey guys I'm back. I picked up a 97-03 f-150 to use as my frame for a solid starting point to this build. I like the narrow frame and long lower control arms. I guess it does about 9" of travel stock.
To start my build. I'm going to make custom longer A arms, upper and lower, 4.5" longer seems to be the norm for full long travel (17-20") I am very capable with a TIG, cutting and measuring, but still have some advanced questions.
Chromoly buckets/cups for uniballs are what are available from FK joints, but can the chromoly welded to mild steel without being heat treated? What are my other bucket options?
And my biggest question>
Is it beneficial travel wise to use a custom spindle? Or is the stock spindle the same, when a uniball is used and retains a horizontal spherical bearing?
Is it beneficial travel wise to use a lift spindle?
If I were to go custom spindle do i go Vertical or horizontal bearings/uniballs?
 
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Bro_Gill

Well-Known Member
#24
I don't think you are reading that picture correctly. The spherical bearing cut is not 1/8" mild plate, it is the machined piece for the spindle. The two other tube pieces that are probably 1/8" look like they are for bushing mounts at the frame end.
 

scottm

Well-Known Member
#27
It is no problem to weld mild to 4130, just pre heat the chromo to about 300F
 
#29
Good to know thanks. I suppose I can torch it for a minute. Or depending on where I do it. Maybe I can use an oven and run it over to my table...
Now how about the spindle design, anyone experienced with different designs? What makes the spindle itself capable of more travel. It would obviously save a lot of work to leave the stock spindle alone, and just do longer arms with uniballs. But if a custom spindle is the only thing that will allow 17"+ of travel I will need to make a plan for it.
 

scottm

Well-Known Member
#30
First decide what you really want it to do. Do you want to be competitive in 1450? Legal to a particular class? And what really is your budget? It will cost easily 2x more and take 2x longer than your best guess going in. Then spend some time in the shop section. Search words like camber, caster, spindle, scrub, etc. There are many threads over many years on this stuff. If you want to go fast, it will either take a lot of money or a well equipped machine/fab shop and a lot of knowledge.
 

vegasloki

Well-Known Member
#31
You don't need to pre or post heat < .120 wall 4130 even joining to mild steel though some do. I got the info from both the Lincoln class and the AWS cert class I took at the local CC some years back and have done it. In fact I'm doing roller spring perches on a classic Mustang right now. As in right now, I'm just in the house escaping the heat.
 

vegasloki

Well-Known Member
#32
i heard also cool as slow as possible, how?, good question, bury in sand?, like melted glass bottle??
The pre heat slows the cool rate as will a post or you can do it in an oven. It reduces the chance of a martensitic reaction in higher carbon steels like 4130. If it cools too fast it can't get out of a crystal state which can cause brittleness in the HAZ.
 
#34
Maybe one day I will build something to race in a class, but for now it's just for fun. I just want something to hit the jumps and do Hoodrat sh#t with my friends. I off road quite a bit in Mojave and Glamis and around California in my 05 Silverado 4x4 that I converted to coilover IFS. This time I would like a little more travel so I'm going with the Ford and longer arms and a 4 Link or the rear.
As for the front geometry I'm trying to keep it as stock as possible which is why I'm just lengthening the arms 4.5 in each and probably using a stock spindle. However if the stock spindle restricts the travel, I may have to build one. I dont see why the spindle would restrict travel if I use a 1" uniball upper and lower arm. But maybe I'm missing something.
Now for the money thing.. I will be cutting and TIG welding everything myself from .120 (1/8th") steel plate. So fairly cheap plus the cost of uniballs, bearings and rod ends from FK (Hopefully sub $600).
I will be caging the "truck" aswell with a custom body welded to that. Think trophy truck meets dukes of hazzard.
 
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