Anti-sway bar (Page 2 of 3)

Reminds me of when I lowered my ITB Pinto (don't snigger, people raced them back in the day when I still had hair) so far that the rear axle bottomed out on the rubber snubbers.  When you went over the top of Turn 8 (Madness) at MidOhio the suspension would go full solid and you IMMEDIATELY were facing back the way you came.  It was fun for everyone but the guys following close behind you.  It's AMAZING how big some guys eyes get when your are suddenly looking at them windshield to windshield rather then nose to tail.  I still give thanks for the guys who managed to miss me, again and again.  I managed spin 4 or 5 laps in row before finally getting the message that that particular speed secret did not unlock any hidde path to glory.  Oh well. Live and learn.   These days I'm a HUGE fan of leaving the suspension well enough alone. Believe it or not the factory gets it right or right enough for Lemons racing 99% of the time.

Spud

The extra squareroot and squares for d1 and d2 are because I used the pythagorean theorum and photoshop to get the relative lengths of the pivots from the image of the lower control arm.  I was too lazy to crawl under the car.

Wheel Rate = Motion Ratio^2 * Spring Rate

I never understood this either until I found it explained like this:
"Squaring the ratio is because the ratio has two effects on the wheel rate. The ratio applies to both the force and distance traveled."

Of course while I was looking for that quote I found this:
http://buildafastercar.com/tech/Sway-Ba … Calculator

It correlates pretty well.  I think the difference is that they consider the bending stiffness of the arms.

The last two sentences of this post hit the nail on the head.  Just build it with a sufficient range of adjustability and tune it to your needs on the track. 

The calcs for the simple U-type with adjustable blades sway bar on our FSAE car were two pages long, and that was with a lot of assumptions and simplifications.  When we bench tested it, the "as-built" rate was different from the designed rate by about 35%.  Fortunately we had designed it with  +/- 50% adjustability so we still had plenty of room to tune with.

That we need a camera for.

ST_RAGE: I am very impressed in your innovation. Don't take what some of these guys have to say too much to heart. This is Lemons. Its a fun class to try ideas that you have in your brain. If it doesn't work the way you thought then that is part of the fun and you get to try something different for the next race. You have given this much more thought than we have. We also put a jeep sway bar on our car. Only ours was on the front of our E30. It worked great. If you take things too seriously you will miss the point of Lemons. Go out, try your creations, and modify from there. Keep up the good work. Im sure you will see more cars in the future with a sway bar mounted very similar to yours. I know you at least have my imagination going for our pinto and it may have a similar setup on it.

i've made that backwards trip (got tagged mid corner).... That was a major "OH SHIT" moment to have the whole pack catch up to me when I was facing the wrong way!

Civics are easy enough to get neutral via other means; we really don't need a sway bar on ours. A set of $20 eBay coilover sleeves, a selection of used springs (ended up using springs from a set of D2 coilovers off of a Nissan 240), and set the camber by lowering it (try -2 in front and -1.5 in the rear to start with). Minor adjustments to tire pressure or adjustable shocks (if you can get a cheap set) take care of fine tuning.

Nice.  Our limited shot at snaking the endlinks between the upper control arm and spring keeps us from copying that or else we'd do it.

Be quiet you.  His set-up will be perfect in the rain.

  you guys were indeed pretty quick.  i'm glad it worked out for you...well done!

Interestingly, your stiff rear bar was transferring weight to the outside front (and to the inside front to a lesser degree), keeping the front wheelspin and understeer down.  I think the notion that such a big rear bar could cause oversteer, especially in the wet, is absolutely true... but your wing provided either downforce or extra weight over the rear, which kept it planted!

Overall, a good combination.  Wish I could have seen it!

isn't cutting open the rear of the car somehow not going to pass tech?  Exhaust gasses?  Fuel tank / lines ?  I like the idea, but was not aware  you could have gaping hole in your trunk w/o some sort of bulkhead or firewall separating you driver from it.