Moment Center?

[thinkstomuch]

I read about this in a certain magizine but I personally never make sense of what they say. On dirt modifieds is this important? Have builders figure this out in their designs? How can I find mine out without buying any software?

[RACEMAN]

You need to look in the Steve Smith books to get a good handle on moment centers. Important, whether they're dirt cars or asphalt. You can get the books here http://www.ssapubl.com/default.aspx

[Confused?]

It is important but no more important than camber gains/losses and bump steer. The M/C migration is more important, IMO, than the static location. It all has to work togethor to be fast and stable.

You don't have to have software, but good software helps you be able to map out the entire movement of the suspension. You can map out the static M/C(roll center) on paper, scaled down, or on your shop floor. Either way, take your time and be as precise as possible.

[HEAVY DUTY]

Most good chassis builders know where theirs are at. It really isn't anything the racer needs to worry about, if he is running a chassis brand that wins. There are roll centers on each side of the car, as well as moment arms on each side also. The guy who writes the articles in the magazine has renamed the front roll centers a moment center, which has allowed him to sell his software from a bully pulpit. Roll centers are somewhat important, but camber curves, caster gain, bump steer and ackerman are all more important. Roll centers are a by product of the a arm angles and lengths which also control the camber curve. It is way more important to have the tire patch flat on the ground during body roll than have the roll center in a little box. The front end is very complicated, and there isn't a good way of figuring it out without a 3 D software package that simulates roll and dive. You can find your static roll center by drawing it out, but where it goes after it moves is something you need the software for.

[thinkstomuch]

thanks for the good input, not going to mentioned my chassis builders name but the front end is the very popular metric clip, nova lowers, metric spindles setup. I might be wrong in saying that these types of setups are all very close from builder to builder? i assume this because of the lower control are point and style along with the spindle - three big standard things. I may be way off by thinking too. the builder wins some but not lots

[let-r-eat]

I wouldn't get real wrapped up in it unless your building your own stuff. I've seen lots of things on builders cars that I didn't think was appropriate but do away with it and it comprised something else more important. Lots of guys get themselves out in left field by not knowing how everything on the front and rear of car needs to work together. You can have the best front end geometry in the world but if the rear end doesn't let it work within the parameters it was designed for it ain't worth a hoot.

[Dirtrunner35]

Look at some data from a data acquisition, then you will think about if roll center are important. Anyone can find a static roll center and with the sofware ( and I have one ) you can find your dynamic roll center AT ONE HEIGHT, but hit a bump and it's all over the place. And like heavyduty said camber curves, caster gain, bump steer and ackerman are all more important

[jsf74]

And this is the reason I just bought a newer lightning!!!

[let-r-eat]

Here is something I crudely done up to show you how to find yours. Could be confusing so feel free to ask.http://i890.photobucket.com/albums/ac102/let-r-eat/rollcenter_zpsa17e6128.jpg (http://s890.photobucket.com/user/let-r-eat/media/rollcenter_zpsa17e6128.jpg.html)

[dirty white boy]

its one thing to know your moment an dynamic centers,..but there is no set right or wrong with it,..still comes back to driver preference after all the measurements an software work is done...