coil over shocks on beam cars

[mlrailguy]

I have pretty much standard build sandrail with beam front end, with 10" travel Fox shocks. Thinking about going to coil over shocks. My front end, complete weighs in at 258 lbs when jacked a couple inches off floor and around 212 when let down to where tires are just touching ground. Any recommendations on springs?

[Ol'fogasaurus]

I thought I could post pix of rails having coil overs w/a front beam but looking at what I have, they were of different styles of IFS conversions; long travel, shorter travel, Ford style, etc. Then there is the long wheel base or short wheel base affect.

Also, the shock towers do make a difference. Stock towers are one thing but longer towers are something else. Opinion: don't use the "overload spring" style of stock length coil over on a stock tower beam. You defeat a lot of things that way by using them.

Based on some of the discussions I have been privy to the spring rate is often hard to figure out. For some reason a starting spring figure was chosen but then, after test driving using their style of driving they other spring rates often ended up being used.

I think the style of rail has a lot to do with it, e.g. do you sit forward or back almost over the trans in you rail design or is it a two seat or four seat, etc.

Lee

[PhillipM]

I'd run ~60-75lb/inch for light use and ~115lb/inch for fast/race use - as a starting point, if those weights are something close, if they're stock arm lengths.

[chuckput]

Unfortunately, I don't know the weight of my front end, but this is the front shock setup that I am running on my Baja Bug. I am running to different spring rates 150 / 250. The coil over shocks have been disabled and all the shock absorber work is being handled by the by-pass shocks.

2015-11-21 10.13.26.jpg

[Ol'fogasaurus]

Chuckput those are the figures I seem to remember but on rails or buggies with longer front travel potential.

Glass buggies take a bit different spring rates because of body weight (thick or thin glass build) and length or location of seating in the pan/frame. Glass buggies are normally in the 80" to 95" w/b range and rails run in the 95" to low 100" but also can range up to just under 120" w/b range before they graduate to the Sand Car category with much longer suspension travel range and beefier spring rates.

Lee

[mlrailguy]

I'd run ~60-75lb/inch for light use and ~115lb/inch for fast/race use - as a starting point, if those weights are something close, if they're stock arm lengths.

My rail weighs 1180 without me in it. Running Tweed's arms which are 1 1/2" longer and 100" wheelbase. I sit just in front of torsion tube, and I like driving hard and fast over the whoops. The shocks seem to do fairly well at keeping front from bouncing all over the place. I've noticed the front tends to sag lately, and really didn't want to mess with leaf pack again. Was thinking also I could get front dialed in better with the coil over shocks. Would I want to go dual coils or a single coil?

[Ol'fogasaurus]

MRG, I don't remember seeing "stacked" coils on the front w/o being fairly long travel but then I haven't seen everything. Part of the problem would be that each coil w/b fairly short which might limit the "wrap" spacing.

https://www.bing.com/images/search?q=du ... &FORM=IGRE

Lee

[PhillipM]

twin springs depends on what your main rate is and the ride height you want - mine has twin springs up front to get it low enough with a higher main rate.
If you're running longer arms those rates will be way out, as arm length makes a huge difference to rates even in small changes - same if you're still running the leaf spring pack up front. FWIW when I was running similar size Woods arms with the leaf pack I think I ran either 40lb or 60lb springs on the coilovers just to assist (but it's been a long time so I might not be remembering right)