If you mount them at a slight angle,they get slightly stiffer when the body rolls.Mounted straight up and down, they would get slightly softer as the body rolls. In real life,the difference is very small. Just do whatever looks good.
i always heard just the opposite. lay them over for a softer ride, stand them up for a firmer ride. but i dont know ****.
Thats what I've heard too... They get less effective, with more angle untill nearly Horizontal, when they might as well not be there. From what I've read and heard, it seems most Race Car Constructors want them absolutely vertical ( on a Beam or Solid Axle ), to about 10 Deg leaning in. Leaning a Shock that is too stiff for the car over to soften it up might not be the best sollution either, because that creates a dropping rate of dampening through the travel. ( the Shock leans more whith more compession of the spring ). Which is the opposite of what you want. ( I've been told a rising rate is better )
Same as springs, just simple trig.. 1" of vertical suspension travel nets <1" travel on a shock/spring mounted off vertical. The shock would be softer since the Inches Per Second travel rate of the shocks stem (thought I was gonna say "shaft" didn't ya) would be lower giving a "softer" shock.
I have my front tube shocks straight because that was the most convenient way to mount them using the original lever shock mount holes to mount my Bedframe "custom" mounts. Been fine, although I am on my second set of shocks on the front. they wear out when your hotrod is the car you drive. The rears are angled in about 10º-20º thru their range, when the rear end comes down the angle increases. I had to make an extra Xmember to carry them and that's just the way they fit best, and would utilize most of their range of motion. I used the same size shocks as on a '55-59 Chevy pickup so I'd know what to ask for when I needed to replace them and just made the brackets to fit them. The logic I can see for angling shocks in towards the center of the vehicle on a parallel leaf-sprung beam axle is to take up more shock on a one wheel bounce, by mounting both ends of the shock on the arc of that bounce, so I'd think the best angle would be one that placed both ends of the shock the same distance from where that axle is going to be pivoting in that kind of bump which would be somewhere between where the axle bolts to the opposite side leafspring and where the tread meets the ground. Some cars use staggered and angled fore and aft shocks on leaf spring suspended solid axles to control wheel hop. One in front of the axle angled forward and the other side behind the axle pointing back. Astro Vans with their fibergl*** rear springs use a lot of shock angle like that to keep the axle from wrapping up fast and cracking the plastic spring. Remember, shocks don't carry any vehicle weight and don't stop body roll. They just slow down fast bounces and slow down violent body roll or shake. I've been getting a lot of shaking in my truck on rough twisty roads in turns, like a few weeks ago on Pacific Coast Highway in Malibu and Sunset Blvd thru the hills. So I'm probably ready for some new rear shocks. (I already did the fronts, but dont remember how long go so they might be due again too. I was wondering about a little cracking on a sidewall on my front tire this morning and thought that can't be on a "new tire" so I checked the purchase reciept date, 4-30-98!)
When a shock is mounted at an angle, it will lower the dampening rate. The shock will travel less than the amount of axle travel at the wheel. I remember seeing a formula on the amount by deg. It is very little in 10-20deg range. In the range that is available on most cars it is not a huge issue. As you get closer to the wheel with the unsprung side, the shock will have more of an effect on dampening axle movement. Just think of it as a lever/fulcrum, and it should be a little easier to figure out. I would say straight up and down, unless it is an open wheeled car, and it just plain looks better at an angle. Just make sure with the shock strait up/down the wheel does not contact the shock as the suspension cycles.
I draw an arc from the centerline of the opposite tire where it contacts the ground and try to make my upper and lower shock mounting points fall as close as possible to that line. I also attempt to keep those mounting points as far outboard as is feasible in order to get full advantage of the shock's function.
The straighter the shock the stiffer it will be. It also requires a longer shock to compensate for axle travel. A shock straight up that has 6'' total travel gives you 6'', whereas the same shock laid over at 20 degrees will act as though it has 8''- 10'' of travel. This is not to be confused with the type of shock that you get when your daughter comes home with her first tatoo or purple hair.That will make you travel all the way to the closest bar.
With the tie rod ahead of the axle you will probably have more issues to deal with than how the shocks are performing..... Do a search for "Ackerman". This has been covered in detail here.
This could probably use it's own thread, but that's onother blanket statement that doen't always hold true. I was worried about that on my T, but apparently the only thing the guy who started the project did right was to flip the left and right spindles side to side when he made the axle. When I hooked up the tie rod with the arms in front, voila! Perfect ackerman (visually anyways) from a rod-in-front setup. Who knew?
I suggest turning your upper mounting holes 90deg from how they are in the mockup, that way the top shock mount can rotate around the pin. If you don't it will be in a bind under suspension travels and may break something.
Johnnyfast rules....IMHO Just some thoughts.... With the shocks mounted so far in from the tire, wouldn't the axle be more likely to do the "funky chicken" (wheel tramp) at speed? The closer the shock mounts to the end of the axle the more control it offers at a given resistance. When I had my "Poorboy" V8 Datsun, I mounted the rear shocks to the lower bars of my 4 bar with additional holes spaced along the back half of the bars. Mounting the shock at the rearmost hole gave full shock effect, but moving it progressively forward gave effectively softer shock dampening...using the same shock! Poorboy tuning! It would be the same deal with mounting your shocks further inboard on a straight axle. In this case, less and less dampening of individual wheel events as the shocks move inward. Think about mounting the shocks right at the very middle...how much side roll or individual wheel dampening would they offer? NONE! The result...wheel tramp etc... My thoughts on shock angle follow along with Johnnyfast...vertical is too vertical...use the natural movement of the axle as it deflects on one side to determine the proper shock angle. That way, the angle of the lower shock mounting would remain constant to the axle. NOT a big factor for bushing wear or anything...just a good indication that the shock is getting maximum stroke per given movement, which will give optimum control for a given shock resistance. The "arc" Johnny mentions drawing seems to be an excellent, understandable plan! I'm liking your Willis more and more Mr Tingler! It's gonna be different AND cool.
Actually a blanket statement that ALWAYS holds true...unless additional mods are made to the steering arms... You didn't build the front end? Then you shouldn't make comments on how or why it works properly...if indeed it does...and it very well might! Your just causing confusion. Ackerman requires the lines drawn from the kingpin to the tierod end to converge towards the center of the rear axle. In a stock straight axle early Ford this is the case. Putting the tierod in front by swapping the spindles and making no additional mods to the steering arms, causes those lines to converge toward the front of the car. The result is your front wheels scrub badly in tight turns. It's a PITA... A front mounted tierod absolutely CAN be made to work, but might require some additional thought on wheel offset, tire diameter and KP inclination(not adjustable) to gain the needed clearance for the tierod ends as they move outward.
OK here is the old guys opinion, I think the lower shock mount should be mounted the same direction as the shackels. What I mean is your axle is going to move sideways when weight is applied on and off of it . The way the lower mount is designed on your axle the shock has to compress the rubber bushing or put a lot of strain on the mounting bolt. If the mounting bolt was running forward to back it would then easily move with the axle. A good example would be a dual spring like a econoline axle the lower mount would be great the way it is because the axle while running would move forward and back . Check all factory type suspensions and you will see what I am saying . This kind of backwards mounting is very common on modified rear suspensions also . The bottom mounting bolt has to run the same direction as the shackles.
My Model A in the 80s had a Total Performance frame. I-Beam front end and 55 Chev rear end with vertical springs. Four years ago we rebuilt it with a Paul Horton Frame. TCI Mustang II front end. Chevy S10 rear end with springs mounted at 12 or 17 degrees (I don't remember, I know it's written down at home). Before the car was scary to drive. After the rebuild four years ago I can cruise down the highway for hours at 140km/h with two fingers on the steering wheel. Part of the solution was independent front suspension, another was putting the rear springs on an angle. When springs are at an angle (I mean closer together at the frame than the rear end) they cancel each other out. So when you hit a bump they want to settle each other. When springs are mounted straight up and down they don't have the same effect and essentially bounce around.
On the angle/stiffness part, the guy who said ROLL shoulda said SWAY. Angling sideways softens shock in vertical travel, but gives it SOME lateral stiffness proportional to degree of tilt SIDEWAYS--so it resists sway. This is irrelevant in tightly controlled arm type suspensions, trivial probably with truck type springs, but potentially useful on cross springs. Cross springs can allow sway if sagging (or lowered..) so shackle angles are wrong--45 degree tube shocks useta was a traditional way of managing sway on custom Ford taildraggers.
Noooo...I'm not sure I should have said sway. I meant having the car LEAN to the outside of a hard turn, not shift sideways in relation to the axle...you know...the effect thats usually controlled by a SWAY bar. Hmmmmmm..... I see a problem! But I really think it's due to an improper use of the word SWAY. Cars don't have SWAY understeer/oversteer...it's ROLL understeer/oversteer. A ship rolls, an airplane rolls...a car rolls. You don't SWAY a car over if you turn too hard..you roll it. Thats the effect I mean and proper shock installation will lessen this effect in the initial stages of a turn, thus increasing response. But it won't limit the amount of total body roll if the vehicle remains in a turning state. How can it...a shock collapses under pressure. For that you need a SWAY bar!!! Hahahaha Ya know....everything is labeled totally WRONG anyway! A Panhard bar should be called a SWAY BAR... A Sway bar should be called a ROLL BAR... Shock absorbers should be called DAMPENERS(Go Brits!)...and a Roll bar should be...I DUNNO!...something else! thanks Bruce! Now I have a headache...LOL
I could be wrong, but I think the Brits talk about a Anti Roll Bar ( Sway Bar ), and a Roll Over Bar ( Roll Bar ). I'm not really sure about that, though...
I just added a "tech" post about a trick "sway bar" (roll stabilizer bar) that I'm using on my project.
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