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Extebding stock toy A arms

sam_i

Well-Known Member
folks
this is my first post, so bear with me!

I am saving up for the Total Chaos kit, which will probably be another year or before i get there - but in the meantime am looking to extend the stock A arms so i can get more travel and better control when taking fast turns.

What i am looking to do (and this is just in the idea stage right now) is cutting the stock lower arm in half and welding a 2" extension to it(some sort of square tubing); after which i plan to gusset the hell out of that thing.
For the upper arms i am just looking to make my own - those shouldnt be too hard.

Questions are:
Has anyone done this with the stock arms before - any tips that may come in handy?
Also what would be the best way to handle to steering arm that connects to the wheel? I know i will have to extend that - can those be bought somewhere?

Sorry bout the lenght of this and thanks for any help / suggestions.

samir

"..... and Happy Scrappy Hero Pup"
 

BIG_FAT_LOSER

Well-Known Member
I am in the process of doing the same thing. I used two stock lowers per side. Cut, extended, then plated. For the tie rod adjusters, I cut them in half and found tubing of approiate size and slipped it over the rods to extend them. Still working on uppers. You might considder making a strut frame as to get the arm and strut rod on the same axis. An easy wat to make uppers is to find a used set of tubular ones and cut and extend also.

<font color=red>PAT KAPKO</font color=red>
 

sam_i

Well-Known Member
Pat - you are the man - excellent idea on the lower arms - i was still losing sleep over how i would get a square tube to match the dimesnions of the stocks lowers. I think i may use another set of lowers to extend those babies. (Actually i should make another post and check if anyones got some for sale)

Curious would you have any pictures of your finished lowers that you might be able to post?

Here's some more questions - if i understand right - the sole purpose of the strut bar is to prevent the wheel from going under the truck when it is off the ground (like in a jump) - i was thinking of getting rid of it and using limiting straps - sounds scary, but i'll excperiment with it before i finalize anything.

Also, are you refering to the 'tie rod' as the 'strut rod'? Cause if you are then i follow you.

thanks again
samir

"..... and Happy Scrappy Hero Pup"
 

BIG_FAT_LOSER

Well-Known Member
The strut rod is the rod that attaches to the bottom of the arm and goes toward the front of the truck. It prevents the forward and rearward movement of the arm. Is very neccesary. Arrow points to where stock arm ends. did not cut it. did shave some material to allow short section of other arm to slide over it. Plated on all four sides. I would only plate the rear if i was to do it again. gets thick and bolts will not fit through it. had to buy new ones.







<font color=red>PAT KAPKO</font color=red>
 

sam_i

Well-Known Member
Re: Extending stock toy A arms

pat
thanks for the pics - looks excellent. I am looking for a second set of lower arms now!
so how much extension did you gain? Looks like 2-3inches.
I'll keep you posted (thru this BBS) of my project.

samir

"..... and Happy Scrappy Hero Pup"
 

gary

Well-Known Member
Re: Extending stock toy A arms

are you gonna run coilovers, or stick with torsion bars??
 

gary

Well-Known Member
Re: Extending stock toy A arms

that question was for pat, by the way.....
 

BIG_FAT_LOSER

Well-Known Member
Re: Extending stock toy A arms

going to run tortions until??????..... if and when I do I will probrobly switch the strut arms to the rear, kind of like radius arms. have seen others done this way and looks clean and removes parts from the front lessening the chance of damage and more room for skid plate.

<font color=red>PAT KAPKO</font color=red>
 

Dylan

Well-Known Member
Re: Extending stock toy A arms

keep in mind that the spring rate will be much lower with longer arms on the same t-bars. To find the % change in your wheel rate take the old arm length devided by the new arm lenght and square that #. ie: old arm =14" new arm =20".....(14/20)^2=49%... you now have less than half the spring rate. sometimes its nice to have a softer rate but 6" will make it way soft. you can also get bigger t-bars to compensate for the added length, this could work very well you may never need a coilover, just run a single bypass. good luck with the longer arms, if you need help calculating a bar dia. based on your arm length let me know.
 

BIG_FAT_LOSER

Well-Known Member
Re: Extending stock toy A arms

I am presently using 26-27mm (not sure) sway-a-way tortions with steel body bilsteins vaulved extremely stiff. In the pic under my name it barley bottoms

<font color=red>PAT KAPKO</font color=red>
 

JasonHutter

Well-Known Member
Sam_i

I have some lower arms for the '86 Toy you are looking for. They are aftermarket ones from Fabtech (I think). I live in Colorado, but am racing at Primm. Will you be there, or someone you know? Let me know!

Jason
Fire Guys Racing
#730 for the Primm race

P.S. A half rack would probably suffice for the price of the two arms. They have the hiems on the end of the strut rods and are gusseted, but stock length.
 

Jkrell

Well-Known Member
Re: Extending stock toy A arms

Dylan,

Thanks for your spring rate change formula, I am in the process of doing a similar change as pat. Is there a formula to determine the spring rate of a torsion bar based on length, diameter, and material. I am widening my front end by approx. 3" (per arm) and I am upgradeing from a 25mm torsion to a 27mm torsion of the same length. I am considering moveing to an even larger torsion bar but I would like to figure out spring rate changes before makeing any decisions.

In the past the rear of this truck has worked excellent with 13-14" of travel, deavers, dual bilsteins, and hydro bumps. With my new front end configuration I should be getting around 13-14" of travel (I had 9-10 with the old setup). My question is: will tthe additional wheel travel in the front upset the rear setup, also, will a higher spring rate in the front affect the performance of the rear. Understandable the front end should work better though larger bumps, thus putting more load on the rear from larger bumps, but with regard to suspension engineering pricipals will one affect the other. Also, what is a good source (book or web) for automotive engineering formulas. Thanks.
Jon K.
 

sam_i

Well-Known Member
jason

thanks for the post - i have already picked up some stock lower arms of a toyota for $15 a pop. Thank god for live axels and rock-crawlers!

I posted on a 4x4 board and quiet a few poeple had 2wd parts trucks laying around that they had no use for the IFS on.

Unfortunately i'm in Wisconsin and its already string to get cold here, so no races for me till next summer, when i plan to go to Michigan and hit the dunes! Hopefully will have a decent rig by then.

peace
samir

"..... and Happy Scrappy Hero Pup"
 

sam_i

Well-Known Member
BTW: Does anyone have tubular upper A-arms for sale (pre 95 2wd toy). They can be any brand (Downey, dick cepek..etc) as long as they are tubular, i guess.

thanks

"..... and Happy Scrappy Hero Pup"
 

cleartoy

Well-Known Member
I have tubular upper Fabtech arms. Price is $200. Im in Oceanside,Ca.

Must be picked up.

Got Sand??
 

sam_i

Well-Known Member
cleartoy - i will pass on those - the price blows my budget out of the water.

thanks though
samir

"..... and Happy Scrappy Hero Pup"
 

sam_i

Well-Known Member
...also cleartoy, arent yours for a 4wd?
I shouldve mentioned but i need 2wd parts.

"..... and Happy Scrappy Hero Pup"
 

Dylan

Well-Known Member
Re: Extending stock toy A arms

Jon:
Good question. The equation for wheel rate of a torsion bar is a little more complicated but here it is.

Wheel rate = ((11.2E6)*(Pi)*(D^4)) / ((32)*(Lb)*(La^2))

were D= minor diameter of the bar. Lb= active length of the bar (overall length minus spline length on both ends minus half the taper down length from spline to minor diameter, La= length of the arm that the bar is attached to from inner pivot to outer ball joint. The rate will change with the angle of the arm throughout the travel, to get the rate at another position other than horizontal multiply by the COS of the arm angle or you can get close by using the horizontal distance from pivot to ball joint for La. 11.2E6 is the sheer modulus of elasticity for all steels (4340 end 300M have the same value)

As far as a book of equations I cant think of one that is directly related to automotive equations. The above equation is actually 3 different basic engineering equations that I combined for this configuration. There is a share ware program called “Dave’s spring calculator” that you may be able to down load. If I think of any good books I will post them.

Front and rear spring rate balance is way off in most off road cars I’ve seen. For a good starting place for spring rate versus weight and travel check out the tech tips section @ swayaway.com
 

cleartoy

Well-Known Member
I have Fabtech uppers, downey torsions, 2 front procomp shocks and lower profile bumpstops all for an 89-95 2wd Toyota. Arms will fit earlier, but torsions are for 89-95 i believe.

As a package i would take $300.



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