4-link

[Picone]

I am looking for design info on a 4-link. I have a few books but they are mostly for road cars.

I am building a long-travel rear suspension for a newer Supercrew. In particular, I am looking for maximum u-joint angles and amount of anti-dive others have worked with. I want the back to drop pretty hard when I get on the gas. I think I want to shoot for about 50% a-d, but not sure.

ALSO, has anyone ever cut into a cab to mount shocks before? The shocks look they will have to go right thru the back of the cab to get the kind of travel I want (maybe 25", up to 29" if I can).

Thanks,
Dominic

 

[Slowzuki]

Through the cab? What are you talking about? Look at desert trophy trucks to get some ideas.

 

[Picone]

It's not a trophy truck, it's a pre-runner. The bed is shorter on the supercrew than on a supercab with a short bed, however the wheelbase is the same. To add to the difficulty, the transfer case takes another 18" out of the drive shaft length from a 2wd. Most of what you will see are supercab's with 2wd. It's a totally different setup here.

To get the thing to travel like I want, a dual shock system won't work on the trailing arm unless I start cutting into the cab (to move them forward) or get some custom length shocks made (about 20"-21&quot. One way costs more, and the other takes more time. If there was a way to cut into the cab and make it look real clean I might do it, but I don't really want to spend a couple weeks to do it.

When the trophy trucks run into this problem, they run the reverse linkage and I really don't know how that works too well. CST tried to do it for last years SEMA show and it didn't work at all...they just didn't have time to fix it before it got painted and finished. i won't have the time to fix it if build it completely wrong either.

 

[GregLocock]

Why not lean the shock over? That will reduce its stroke for a given wheel travel. Or use a bellcrank,

Cheers

Greg Locock

 

[Picone]

Lean it where? into the cab? Can't lean it backwards, need longer shocks for that.
What do you mean by a bell crank? Can you explain or show a picture?

 

[Slowzuki]

http://www.swayaway.com/shock.htm

18 inches of travel, and you have some room to lean, the axle is not under the cab. Connect shock to axle and lean the top near the cab.

Ken

 

[Picone]

If you do that, the shock will be leaning over too far at the top of the stroke (about 75 degrees). Usually you don't want the shock to lean past 30 degrees to remain effective, and consistent through the stroke. That's why you mount them on the trailing arm.

 

[TBFab]

I understand the problem your having. Check out this web site there is almost an identical project to yours where they also used a supercrew and it had 25 to 30 inches of wheel travel. Hope this will help

http://prerunners.com/features/features.htm

Once at this address go to special features and Dave winters prerunner