Issue that causes a lot of tradeoffs with the FJC when it comes to the rear end is the frame. The OEM suspension layout on the FJC tends to be mounted quite low to find a balance between uptravel and downtravel. We have all seen how far our lower links are mounted below the bottom of the axle and how far the bottom shock eyelets hang down. "Rock magnets" I call them and that what they are, otherwise folks wouldn't make a pretty penny selling the rear link and shock mount armor that we all know so well

.
Just look at how low these buggers hang down.
No big deal at all if you only do desert running or fire roads. But any significant offroading with ledges or rocks you can see those things can get you hung up all the time. Plus with them mounted lower it also causes your lower link to physically be lower on the axle. The lower it is the less ground clearence at that point meaning getting friendly with the rocks more often. For the desert runner or the soccer mom FJ owner these a non issues, but for playing in rocks the setup is less than desireable.
We eliminated this annoyance when we redid my rear suspension in 2011. As you can see below the link no longer mounts underneath and behind the axle
Shock mounts no longer hang 5" down below the axle
Talk about a significant improvement, eh? No longer had the need for shock armor and very rarely have I got caught up on the links even though they are significantly longer. Its a great solution for those who want to play in rocks or hill climbs with ledges. At the time that's where my head was for the most part and I didn't have the time, funds nor the affinity for cutting through body sheetmetal or frame :bigthumb: to improve upon it further. The setup was good for rock crawling, but lacked when it came to desert running or going fast offroad.
Why is that? Its due to the fact that you end up with limited uptravel on the suspension due to your lower links and frame layout. With the axle end of link mounted higher it brings the link into more of a horizontal orientation with the frame at your normal ride heights. With a long lower link from Heretic Fab, like I am running, you end up mounting the front of your link well past where the frame countours up. As such when your suspension cycles up there is limited room for the link to move upward. This effectively is the limiting factor in your uptravel (if you didn't run bump stops).
This setup resulted in a total travel of 15" of verticle travel. At ride height you'd have 5" of uptravel and 10" of downtravel. (For reference the OEM rear suspension has 9" and aftermarket long travel rears have ~12" if setup right)
As I mentioned previously I wasn't looking to chop the frame or make any compromises for additional uptravel at that point, due to time constraints. However, since getting more into the go fast stuff and wanting more uptravel its time to change that. Now have the time to do it right and resources to do so.
I'll talk about why more uptravel is desirable on the rear suspension in my next post
