Four link numbers/measurements - advice?

[myjeepsbigger]

Hey guys, finally got my tentative numbers plugged into the calculator. The AS seemed a little low at first so I bumped my Axle-side upper mount about an inch higher than what I had planned....and here are the results. What do you all think? Acceptable starting point?

Screen shot:

 

[kubtastic]

3.5" difference in z between uppers and lowers - ~ equal to the height of the framerail. Are you keeping the floor and placing the lowers just aft of the t-case cross-member and below the rails?

 

[myjeepsbigger]

Sorry, guess I should have stated that the whole thing is tube from the rear of the console, back. There's very minimal floor remaining right now. The upper links on the frame side will be a few inches above the floor, the lowers will be tucked up...pretty much equal with the verticle center of the frame rail...they will not hang below.

 

[CRASH]

I think you have some really good numbers there. Liberating the sheet metal back there really helps with getting numbers in a good range. I always suggest a little adjustability in the upper mount at the frame side for tuning, and it should be very easily to implement with the body gone.

 

[BrettM]

your antisquat and roll-center numbers are almost identical to mine. I love the way it performs.

 

[myjeepsbigger]

Thanks guys. I thought the numbers looked ok, too. Finally got the links and such installed this weekend, so it's mobile now. I haven't gotten a chance to put it on the trail, but it sure seems to have a great deal of lift in the rear when I'm braking (on the road). I'm running Fox AirShox on it....so I figured maybe this was a normal quailty of them. I don't have a center limit strap yet, so maybe that'll make a difference. This is my first link build and my first experience with the AirShox.....Is this just a characteristic that I'm gonna have to deal with, or is it something I should address?

I know there are a million variables, so if there's anything else I need to state, please ask away.....All advice is welcome.

 

[FarmerMatt]

I'm running AS #'s close to your's with Rock Equipment air shocks. I haven't noticed the rear rising under breaking like you're describing. Are you sure it's the rear rising verses the nose diving (brake dive)?

 

[myjeepsbigger]

Well, not totally sure, I guess. But I don't really have anything to reference it to, since I've always run leaves in the rear (never had this issue with the leaf spring setup....I do realize that it would help counter the nose dive). Thing is, my rear is SUPER light in the rear right now since it's still in the construction phase. I guess I just need to build it out before I go making any drastic changes.

 

[cagedxj]

I have pretty much the same setup as you(rear gone and Fox AS), I just run an ATV winch for a limit strap/suspension control. It works great! It did tend to lift in the rear since the wheelbase CG is just under the A pillar hoop of my cage now.

 

[myjeepsbigger]

Actually got it out on the trail Saturday and was just completely blown away at how well this thing works. I changed my upper shock mounts before we went, and I really don't have the nose dive/rear lift issue anymore :weird:. It literally WALKED through some trails that I used to only be able to run with heavy throttle. I'm very impressed with the design now.

 

[NorCalXj1121]

Where do you guys get that nifty linkage calculator?

 

[myjeepsbigger]

Pirate4x4.com

http://www.pirate4x4.com/forum/showthread.php?t=204893&highlight=link+calculator

Links to all the calculators in Triaged's signature.

 

[NorCalXj1121]

Thank you, this program looks awesome, Im just not exactly sure what to enter for most of the variables. Can anyone help me out on this?