Sportruk

I love the T-Bird IRS I put in mine. Now I just have to do something about the Twin I-beams up front.

Tim Skelton

That would present some challenges. As you can see from the image below (T/A girdle drilled for temp sender for gauge and pump switch, and fluid outlet), there's not much meat on the driver's side of the girdle. I'm sure that it's doable with the fabrication skills exhibited in this thread, but I was surprised how little material there is just over the ring gear.

Tim Skelton

Yes, I still recall your work. Equally stunning engineering!



It's a shame to have to put a bed over that!

race-rodz

i would say you are correct thinking that the threads in the case are the weakest link in sandwiched plate mount. ians idea of an offset top link hard mounted to the axle tube would cure any concern with this aspect.

im looking at the thickness of the flange, which will be better suited to help spread the "clamping" load from the bolts, compared to the stock stamped "tin" cover. one thought was to use longer preload studs to help hold the pivot mount, but im not sure if that may help or hurt the cast cover. im pretty sure the cast alum is not strong enough for the force needed keeping the rear laterally located if the pivot was directly attached.

after speaking with ian, i think we are going to check into a "newer technology" that allows infinate spring rate adjustablity..... something else that i was thinking about doin on my 1st gen.... if/when i get around to it.

btw... model T spec rear suspension would be a transverse mounted spring..... the parallel spring design dates back to ATLEAST the covered wagon era.

race-rodz

i have a design and a parts list...... still havent gotten any further on "that" project though

02silverbullet

i would spend more if needed but the only reason is i think scotts 4 link was around that price

djcobraman427

I just got home on the trial run of this set-up. This was 300 miles of freeway driving through Oregon mountain passes. I set the cruise control at 77 and ran through all of the 50 MPH corners without any difficulties. The truck was extremely stable, tracting was excellent, forward acceleration on freeway onramps at 135 MPH was also stable, unlike the old leaf spring setup. I was extremely pleased with the spring rates, firm but not not harsh.

It was raining during my drive home and the system didn't have any problems with standing water, unlike the old system that wanted to jirk the rear end around. The truck was running a Bellteck lowering kit before, 3/4, but the rear tended to bottom out, which was not a problem with the coil-overs. I had 200 lbs of sand, tools and spare in the bed, plus a Snugtop bed cover and the truck did not bottom once, even on the I-5 and I 205 bridges, which have some very annoying off camber joints which caused some unstable problems with the leaf springs. Reaction was controlled and very driver friendly. I definitely recommend this to anyone that uses their truck as daily drivers.

I think there was a question about my wheel sizes, they are 20X10s, Boyd Coddington billet aluminum with 5 3/4" back space, tires are Toyo Proxes, 295/40x20", siped for snow driving----like that's going to happen. The truck runs a Superchip controller, Bassani headers and Bassani catted mids and stainless Magnaflos, and 3" out and 4" stanless tips by RaceRodz.

mr12volt

To answer one of the questions about drag racing with a 3 link, the big issue is body roll. You will need one hell of a sway bar ( about 5"in diameter ) to even come close to controlling body roll in a drag application with slicks on.
It would probably slam the pass side rocker right into the ground.

The bind of the 4 link ( which is the nemesis of the road racer) is what helps control the body roll.
The other problem that I encountered with my setup with the 4 link was that with the load of the truck on 2 points, ( the shock mounts) instead of 4 points (like the leaf springs) is that the rear frame became rather flimsy. You can see this by looking in the mirror while driving and seeing the bed move around quite a bit. ( especially while going over any bumps. ) The bed has even hit the cab and left dents there.( with stock clearance gaps!)
As many may recall, I even boxed the entire rear frame in and still it moves around quite a bit. It really needs to be triangulated with a cage.

I was going to put a three link mount in as well to be able to switch back and forth, but I didn't think that crossmember would hang without some additional bracing, and I mainly drag race it so I left that part out.

If any of you remember the 69 pro touring Camaro we are building, it has both, a 4 link and a three link. Just remove the upper 4 link bars, and add the 3 link upper and you could go from drag race to road Atlanta in about 20 minutes.
Paul

Pitstain

Whoa this thread is becoming quite the gathering, I wonder where redfox is?

Hopefully between my own thoughts and the work done by others, plus the constant debating with my buddies, I will be able to produce something that will be nice enough as to get me banned from the site.....

Anybody want to sell me a nice used bandsaw?

brainbypass mod

i like it!

i would have offset the upper link, but it looks like a good first shot. with the offset 3rd link, body roll shouldn't be an issue as you are dynamically equally loading both rear tires.

i am building a '59 chevy truck that i am using a converging offset 3-link, to use as a test mule, then i will put one on the L. i will post pics of that once i get started with the fab work.

__________________
03 black turbo lightning - holset hx60 powered

"And another thing.....when I gun the motor, I want the whole world to think it's coming to an end"
-Homer Simpson

mr12volt

I don't care where you put the upper link, it will still body roll. That's the whole idea of a 3 link. ( a real 3 link that is and not a torque arm or a long ladder bar.)
Your rear sway bar is the only thing stopping the rear of the vehicle from body rolling.
If you start binding "it" ( the rear from rolling without the sway bar connected ), up in any fashion, you are defeating the purpose of the 3 link to begin with.

Pitstain

Body roll is also dictated by the roll center, and the lower it is set the less body roll will happen, there are 3-linked cars that have such low roll centers (watts or panhard mounted very low) that they often time need no rear swaybar to control the roll. Springrates also play a crucial roll in controlling the roll.

bluebolt

How about using the 2003 up Crown Vic front suspension with the aluminum crossmember and rack and pinion? It's getting real popular with the early Ford truck guys. Slick60s.org Go to Truck talk, there is a current post on the CV stuff.

bluebolt

It's also dictated by how far apart the springs are on the axle, the coilovers on this truck are spread farther apart which will lessen body roll. Drag cars with narrowed rear axles and ultra wide tires have the springs real close together which is going to aggravate the body roll and require a bigger sway bar.

race-rodz

you have a pm...

i feel everyone is entitled to their opinion, however, its not really factual information.

EDIT: real world testing is what the deal is all about, if the frame flex becomes and issue, i will address it.