• RME Gear & Apparel

Dirt Muscle Car

Greg

Greg

I run a tight ship... wreck
Admin
Location
Grand Junction, CO
Kinda basic, but a good explanation of how beams work...


They mention the steering sitting behind the beams factory... wonder if i can use my factory steering box and mount? Need to find a 2WD F150 to look at. 😁
 
Greg

Greg

I run a tight ship... wreck
Admin
Location
Grand Junction, CO
I found a set of early 80's F150 beams & arms with hubs and rotors for $250, apparently the beams are forged and more desirable. Seems reasonable, but after more reading, factory beam parts aren't strong for really beating on. But I don't know the limitations... if a Bonneville on 35's is too much for stock Ford parts...?

Then, I found this... https://www.diyoffroad.com/i-beam-suspension.html

You can buy the files to fabricate a completely custom beam suspension and have your favorite plasma table owner cut out your parts and DIY them! Looks like you can customize everything from the tabs to the frame crossmembers, beams, arms, swing steering, etc, etc. They even offer upright (knuckle) kits!

I'll have to take some measurements on the Bonneville and see. It would be bitchen to have custom fabbed beams on this car!
 
J

J-mobzz

Well-Known Member
Greg said:
I found a set of early 80's F150 beams & arms with hubs and rotors for $250, apparently the beams are forged and more desirable. Seems reasonable, but after more reading, factory beam parts aren't strong for really beating on. But I don't know the limitations... if a Bonneville on 35's is too much for stock Ford parts...?

Then, I found this... https://www.diyoffroad.com/i-beam-suspension.html

You can buy the files to fabricate a completely custom beam suspension and have your favorite plasma table owner cut out your parts and DIY them! Looks like you can customize everything from the tabs to the frame crossmembers, beams, arms, swing steering, etc, etc. They even offer upright (knuckle) kits!

I'll have to take some measurements on the Bonneville and see. It would be bitchen to have custom fabbed beams on this car!
Click to expand...

I think you would be fine on stock forged beams.
 
J

J-mobzz

Well-Known Member
+8 😳 hopefully that’s counting both sides a 4” over beam would be monster on the Pontiac. I personally think stock with a longer radius arm would be plenty.
 
Greg

Greg

I run a tight ship... wreck
Admin
Location
Grand Junction, CO
Have you ever seen a long-travel 1967 Pontiac Bonneville? Want to?? 😎 Yeah, me too!

I picked up a pair of I-beams and radius arms from a 1981 Ford F150 and will be deleting the IFS and adding beams to the Bonneville. It's going to be a massive project and take a ton of time getting it right, but it's going to be badass once done! I've never messed with beams or prerunners, so this will be a learning experience.

These F150 beams are forged with 1" kingpins, front steering knuckles.... probably the best possible option for factory parts. I'm planning to build longer radius arms and center mount them. I'll be building swing set steering, as well. I have a spare Saginaw steering box in the shop, I need to check it out and verify if it's a 4 bolt box. The swing set steering will quicken the steering ratio, which is fine with a standard ratio steering box.

Planning on 14" remote res coilovers with air bumps on all 4 corners. I plan to build the rear with trailing arms for massive droop. I don't remember if I mentioned it before, but I did pick up a perfect width Ford 9" awhile ago. It'll get a locker, gear change (5.13's?) and 31 spline shafts.

20240202_141018-X2.jpg

20240202_141025-X2.jpg

20240202_141032-X2.jpg
 
Greg

Greg

I run a tight ship... wreck
Admin
Location
Grand Junction, CO
J-mobzz said:
View attachment 169400

Pontiac on beams would probably be pretty fun in the sportsman class at the Grand Junction race this year.
Click to expand...

Funny that you posted this 20 min ago, I was working on the post about the new beams!! Having it done & ready by June is asking a LOT... I don't know that I can make that happen. Not saying I'm not going to try, but it may be next year. There is so much to do, fabbing the suspension F & R, building the cage, putting together the LQ4 engine, finding a trans, etc, etc.
 
Greg

Greg

I run a tight ship... wreck
Admin
Location
Grand Junction, CO
bryson said:
Beams are neat. Why is one beam longer than the other?
Click to expand...

Found this on Pirate, of all places...

"un = length beams came about in the early 80's when ford switched from = length king pin to un = length king pin then to un = lenghth balljoint beams.

The theory behind it is that one beam pivots infront of the other but the radius arms pivot in the same spot (opposite eachother). if you draw a triangle from spindle to rad arm pivot to beam pivot for drivers and pass side un = length setups triangles intercet in the center of the truck where as = length setups intercept of to the side of the center. somehow ford determined that un = length setups handled better for street driving, thus the change"

www.pirate4x4.com

Equal vs. Unequal Length Arms

www.pirate4x4.com www.pirate4x4.com

And...

"There are a few ways to look at this.

1) With un-equal length beams you will have equal length radius arms.
2) with equal length beams you will have un-equal length radius arms.

There is a give and take with each. We have found it really does not matter with equal length beams with the average setup. Unless you are going to spend the money to do it right with full hydraulic ram steering, correct steering geometry with all new spindles with correct ackerman etc... then go with un-equal length beams and when you get to it then ad a single swing steering to reduce the bumpsteer.

What is nice about a PROPERLY setup equal length system is you are in control of the complete setup. So yes you can reduce most of the bumpsteer to under 1/8" over 20+ inches of travel.

In most cases I see equal length beams are more of a buzz word then a need. I would also say that in most cases the people who have equal length beams should have stuck with un-equal length beams and spent their money on better parts through out there whole truck because they are on a limited budget."

www.race-dezert.com

Equal Length I-beams vs. Un-equal Length (equal geometry?) I-beams. . .

I'm sure there are advantages and disadvantages to each of these designs. . .I just don't know what they are. Would anyone be willing to post up the pro's and con's between these two I-beam set-ups? I'm new to I-beams and I'm trying to learn what I can. Thanks!
www.race-dezert.com www.race-dezert.com
 
bryson

bryson

RME Resident Ninja
Supporting Member
Location
West Jordan
Very interesting. I didn't know that was a thing, but it kinda makes sense. I wonder if the unequal length beams will play nice with your plans to run your radius arms to the center of the vehicle instead of mounts under each frame rail?
 
Greg

Greg

I run a tight ship... wreck
Admin
Location
Grand Junction, CO
bryson said:
Very interesting. I didn't know that was a thing, but it kinda makes sense. I wonder if the unequal length beams will play nice with your plans to run your radius arms to the center of the vehicle instead of mounts under each frame rail?
Click to expand...

I'm not sure, honestly. I have a ton of research to do, getting the steering sorted, camber figured out, etc.
 
You must log in or register to reply here.
Top