Overslung Modified chasis questions

[SRXtripman]

What is the best way to figure out how long the left rear tie down chain should be ?

What is the recomended bar angles and lengths for the rear end ?

[dirttrackrocker]

You want the LR chained so as to not let the upper bar go past 45*. Bar lengths, you are gonna have to do some measuring if you can't get recommended lengths from the builder. IMCA rules say the axle centerline has to be at least 72" from the mid plate, but, wheel base can't be more than 112" . Most mods are built with axle centerline at just over 72" to allow for lead and trail of the rear. I'd say set your rear on stands and get it just over 72" from the mid plate and then measure what length rods you need.

[jurgens22]

Dirttrackrocker is correct..you don't want the LR upper bar going past the 44 to 45* point. Typically you can set it up so that the LR upper bar is at 38-40* when at full drop to begin the night (ie. when the track is typically tacky). As the track slicks off you can move your LR upper bar up a hole on the chassis which will then put you closer to the 44-45* mark with the same chain length. Anything beyond that mark will be counter productive and give you too much of an upward thrust angle instead of forward. Also, when close to those angles it should keep your LR spring loaded or close to loaded at all times. As far as bar lengths are concerned keep in mind a couple things: depending on the birdcages you run, you will typically have your bars bolted in at 4-1/2 inches above and below the centerline of the rearend housing. You will also want to make sure at ride height your birdcage is indexed correctly close to the 6 o'clock and 12 o'clock position. A lot of mod guys will typically run even up to 3/8" RR trail from what i've experienced, but like dirttrackrocker mentioned..keep the wheel base and 72" mark in mind.

[SRXtripman]

Thanks guys , makes sense , finishing touches are being made as we speak. Also sorry i posted this in the wrong section.