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tramp bars


d.p.n.s

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how much does a diff really twist the springs ive never really thought about that

(noobish to cars just moved over from bikes in the last 9mnths :rolleyes: )

Lots, and lots. Especially in lower powered cars that have been given big motors where the suspension was never designed for 3 times the power.

Sir Newton figured this out a loong time ago.

Every action has an equal and opposite reaction.

If you take this pic for example

1005139wr4.jpg

The wheel is turned anti clock wise if you are looking at the back.

There for the diff is forced clockwise and thats why the tramp bars there are fine.

If the bars were on the top they would still have to point forward.

The only way they can point backwards is if a, you do skids in reverse, or b, they are held some how to the body.

To quote Heinlein "I am only an egg"

I'm looking at the springs on a escort, and see that the front of the leaf the springs are linked directly to the body, whereas the rear is only loosely linked by a shackle. So, to me the rear part of the springs need controlling more than the front.

Like I say, I have absolutely no experience. Please let me know where I'm wrong... I see that there's a rotational component to the stresses, but still one end of the spring is more controlled than the other.

Cheers, Steve.

Well i have zero experience also. Noob school boy here, dont even think iv been in an escort.

However with a bid of mechanical knowledge and a fascination with anything that will do b-outs, its not hard to figure it out.

Someone up there said that they thought most tramp bars go to the back. And they do, but they are mounted to the body. These ones that point forward are not mounted to the body.

If i was going to do tramp bars i would use the front facing ones not mounted to the body. This is because you would have to be pretty good to get the fixed ones all the right length and aligned properly. While the ones above are extra un-sprung weight, they dont alter the geometry of the system. (fixed ones shouldnt, but arnt as easy to knock up in your garage. More chance of a stuff up). They can also be easily taken off leaving no trace of modification for MR WOF. And most the cars on this forum are not for going round corners fast and handling, so un-sprung weight = meh.

Thats how i see it anyway.

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Dan these are the ones i made for my wagon I made the rubber stoppers adjustable by drilling a hole & welding a nut on then brought some bump stops from canterbury transport spares just down the road for us .. I foun d it better to be touching but it pulled way better skids if you wound them of the spring a bit..

Nice work.

Did the bump stops come with a thread already in them? how much were they?

I'm keen on making some for my wagon now :)

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Filthy ones bars are placed correct for the small Fords.

The reason he got better skids when the stop was wound off a bit is it allows the pinion angle to change that little amount more sucking the car down at the rear and holding it there better.

If I remember correctly the best angle to set your diff to when it is fully under load is about 1-1.5degrees up from the horizon. (this is subjuct to the side of the pinion the crown wheel is mounted on, or as Mongol pointed out it will work the opposite therefore needing them on the rear side)

Any more will allow the spring to try and turn inside out and as already explained with Newtons Law travel just as fast in the opposite direction.

Hence the tramping affect comes into play.

Then add the tyre pressure increase and tyre bounce from before and we have affectively the tyre rotating then bouncing and catching traction, winding up the axle letting go and doing the whole thing over again.

NOTE: This is how most axles snap during skids and or spider or side gears get smashed.

If the bars are placed at the back the spring is traveling away from them which makes them of no use what so ever.

Also to add is the chance of getting hooked on judder bars with these (the judder bars now are like long fucken river banks!!) but they certainly do have there place and I will have them on my car if my new rear end doens't work to plan.

The other bars shown in the pics used to be called radius arms but are mostly called torque rods.

These stop the diff tipping down on the decelleration or power off as much as the accelleration.

Combined with a sway bar (not to large) they can be used to control bump steer at the rear by moving the sway bar forwards or backwards to alter the amount of pressure applied to the body hence stopping body roll and the bump steer by not allowing the spring to rebound the diff at such a fast rate (shock position/angle and pressure also come into this but its a lot more complicated). This is also possible to do with a double front sway bar set up and if the clearance allows for the engine running one inside the other has other benifits but is alot of setting up.

If angled the torque rod arrangement can also take away the need to fit a panhard rod, but they can also create weird things to happen at certain points of suspension travel that would never happen when they are inline with the springs.

I run ecentric bolts on my torque rods to allow the ability to alter the diff angle within a few minutes especially if using the same car for street, strip and track use.

I also move my rear sway bar alot and find where its best for all three applications then mark it perminently so I can move it to where I need it.

I hope this isn't to confusing for some and benificial to all.

Corey

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yeah if they are under the diff they should face backwards. If on top of diff they go forwards. Have you looked on turbosport there is a few good pics of tramp bars in escorts, they are all mounted on top of the diff and the other end to a bracket next to the front spring hanger.

Incorrect mate. Tramp bars are to control axle tramp (or hop) which is a result of spring deflection on the front half of the leaf. See pic below and it all makes sense

662zi8.jpg

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productscaltracsimg.jpg

w473.png

another option i will follow with my ute

link goes forward of the diff

Mate looks the goods similar to my 2 link set up just a note bro I see your in hamilton if you go to powerfarming hamilton they will have various tractor top links there wa cheaper then anything else you'll find

1004618xd3.jpg

1004622rg3.jpg

1004620vp5.jpg

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if you ever need some let me know will send some down freight free

im good like that

I'm keen im just worried about ripping my floor out, do you have to reinforce the floor where they weld on? any science to this or just weld to diff and weld to body?

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if you ever need some let me know will send some down freight free

im good like that

I'm keen im just worried about ripping my floor out, do you have to reinforce the floor where they weld on? any science to this or just weld to diff and weld to body?

i wudnt use tractor links. the tollerences arnt good and might rattel when driving. cheap and stront tho yes.

idealy you want links same lenght as the front part of leaf and mounted parrel, although this sometimes isnt possible.

mine are same lenght but not quite parrel. work mint tho. i actially used one of the links from the irs in a late model sti.

they are alloy and have rubber bushes in each end.

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i know some links can be got with a nice fine thread on them ,

caltracks don't hit the spring till you load the spring up on launch

so they won't affect everyday handling,

as long as heaps of grease is used they won't rattle and the rose joints can be retained,

attaching to the body on the other hand would need a little reinforcement

i would say even if it was some heavier steel beaten to fit on the inside of the car where

the welds are going to penetrate through to stop the links tearing out

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