That's always the case in these Bulletin Boards. So that being said, how would you suspension change if the arms were longer? I have read through all of the discussions recommended and haven't found the answer to my question. I suppose that it really doesn't matter because I'll end up doing what I do based on my research but I really do like Savvy products and engineering and if there is something there that has already been figured out, I would love to know what it is.
You cannot get the link separation desired at the frame with longer links without modifying the tub or having lower links that hang down too far. Lower link separation does not allow for the best control of the instant center especially when your center of gravity starts moving like in a climb. If the link separation is too low then you might as well run a radius arm. The net effect is the same.
Well seeing as folks are just responding with pictures and not data/words, what's the difference? A picture of a stuck jeep tells me nothing. A picture of a jeep that is not stuck tells me the same. Not trying to be a dick here but we are on page two and nobody has responded to a single question that I have asked . Now I already know that Savvy is the best and that long arms suck but I can't find out what everyone considers a "long-arm" and why a 27" rear LCA is the best.
Did you go read the other threads I put links to? Typically when "long arm" is being mentioned it is referring to bolt on kits like RE, Tera, Skyjacker and the like. Bolt on kits are about ease of install first and good suspension geometry second. The common trait is that the lower arms usually hover around the 3 foot mark because that is what the Warn XCL used and people just considered that the standard. Ironically Warn had a "long arm" developed for the rear of a TJ that only used what we now call a mid arm. Warn sold the Black Diamond line off before the kit made it out of prototype.
Short arms and tall tires don't work well together. Your starting point is a pretty vertical upper and lower control arm that wants to wants to fight obstacles instead of riding over them. And on the road.....well, a rough ride. But I'm not researching front suspensions at the moment. I am looking for answers about the rear suspension and most specifically, about why Savvy designed the length of their arms at around 27"s. I am NOT attacking them and I am not pretending to know more that you or anyone else on here. Just answer some of my questions. Or don't. But whatever you do, please don't answer my questions with more questions. Seems to be a thing around here..
Unless you are running more than 4-4.5 inches of lift control arm angles have little to do with ride quality. Springs and shocks do.
Savvy put the arms at the length they are because it gave them the amount of link separation, roll center and instant center they wanted. Not moving the lower arm mount on the axle was part of those considerations.
I am actually coming at it from a different direction altogether. I am working the 4-link calculator and trying to get the anti-squat to be as close to 100% as possible. I know that this is a single metric and perhaps not the holy grail but I am focused on it the most because it appears to be the metric that I can change the easiest. That being said, my axle mounting points are fixed. I have committed myself to 37" tires and I have 4.5" springs. The CG Height is what it is (assuming around 34" for my TJ) and that leaves placement of the frame side mounts as the only variables. So the longer the arms, the closer I get to 100%. Shorter arms yield me a higher percentage. So in a nutshell, that's why I'm advocating for longer arms. But I'm definitely not a suspension expert and am trying to get an answer as to why I might prefer a shorter arm. For example, I could see that have shorter lowers keeps the links out of the rocks and shorter uppers might triangulate the axle a little better and prevent it from wandering at higher speeds?
Why the fixation of 100 percent? How much higher of a percentage if the links are shorter? Where is your instant center location? Since you say your axle points are fixed is the link separation at least 9.25 inches? Did you move the lower control arm mount on the axle from the stock location and if you did is it above the axle center line? Too many people fixate on antisquat and keep forgetting that there certain rules that need to be adhered to and that in the end packaging is everything. Stuff is going to go where stuff is going to go.