Quote:
Originally Posted by ckau
That thing really moves out now! I love the exhaust sound especially when it gets up on the pipe. I noticed you have substantial body roll in the sharp turns, enough to pick up the inside wheel. Is that characteristic of that type of IRS? Is that something you feel that may needs to be addressed or is it not worth being concerned about
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Short question long answer .
I knew the body roll was coming--looked forward to it;
Even with the swingarm, I was lifting the inside rear tire. Having body roll at the rear has actually lessened it and taken the torsional stress off the frame/then swingarm.
I also have a pretty high center of gravity and roll center--especially now with IRS. (going to calculate out the roll center and axis one of these days soon) This has more rear center and overall clearance than most of the vw woods rails--and needs it. Given the rocks i'll be running in, it's a major plus and outweighs flatland handling concerns.
i get very sharp initial turn-in response with the "negative" or "reverse" ackerman i built into it and the outside tire takes the bite and leads the turn.
(The decision as to which way is "correct" is a matter of heated debate for many)
For my design and application it works. "true" ackerman flat out does not work for me, just creates massive understeer.
I limited the amount of total steering input by using the rack/tie rod connection bolt/nut as a stop against the bulkhead. i could make this turn even sharper. but i'd be two-wheeling it a lot more. (Still plan on "dropping: the connection point as when i had to flip the rack, i created some bump steer)
I considered an anti-sway bar at the rear to cut the roll, as the donor did have one (i didn't get the bar with the trailing arms) but it would reduce its uneven terrain capabilities.
Right now it's mainly a matter of getting the feel for body roll, cornering grip/slip and front outside shock reaching full compression to know when the tire's going to come up. been forcing it into 3 and 2 wheel turns a lot to get used to what's going on.
I'd actually like the rear shocks to have more travel and softer spring rate to equalize front and rear a bit more. It'd roll more and more quickly, but it's kind of what i'm after. I need to be able to pile drive this thing through the rougher stuff without the back end kicking too much. It's better with the podiums/IRS, but not quite there yet.
vid "561" on my channel has a short clip at the end of it of forcing two wheels into the air.
So far i'm ultra happy with it overall, plush plush plush i've thought of going for a little more top end speed, but i think i'm too close to the limits of the centrifugal clutch ....
