Leaf Suspension Setup

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Hi guys, need some advice,

My experience is very limited when it comes to drag setups for cars. But i need traction, and lots of it.

I bought this ute as found here.

Now, i plan to raise the front of the car off its bumpstops as it is presently, an inch. And raise the rear possibly 2" after getting the stockos back.

Car is still to be street driven, so i can't go a full dedicated drag setup (90/10 shocks in the front... etc...)

My main question, is when i get the rear leafs reset, what kind of spring rate should i be looking at? considering the stocko's are designed to carry a load of 1 tonne. I will never have that kind of weight over it when im racing.

thoughts ideas?

[myne]

If you're concerned about take-off traction, look into tramp-bars.
Basically, they're just a plain steel bar bolted to the bottom of the shock plate (bit that the U-bolts go through) and they go from the shock plate to the front of the spring eyelet. They dont actually touch when the car is driving normally. They can have rubber pads on them too.
As the springs/diff housing twist on takeoff the solid bars make contact with the front eyelet and effectively kill further twisting.

eg :

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Useful information myne, but not quite what im after.

What i want to know, is how soft should i make the rear? To get some good weight transfer, and hopefully better traction. Since the hilux has basically no weight over the rear axle.

[oldcorollas]

are you looking to alter geometry as well? ie by changing the line of action between the diff and the front spring eye? (to help push the back of the car up or down.... etc)

i suppose you want to soften the springs and change geometry to make it squat much more, to get more rearwards transfer.... then again, some cars they do the opposite... (ie raise the rear of the car on launch to raise CG to give better rear tyre leverage)

hmm.... ther must be a lot of info for all the old american drag cars.... since they've been racing with leaves for yeeears

[thechuckster]

mayne spring works (at albion) can reset leaf springs - no ide about cost as the last time i dealt with them was the late 90's.

[30psi 4agte]

You will need to go to a spring place and get them to way the rear of the car they will then be able to provide you the info that will tell you what spring rates will do what .

Unless you can search the net and find someone with the same vehicle that has a different spring in it and find out what rate they are using.

Upper and lower control arms will make a MOJOR difference to the way the car bites in!

Also changing the pinion angle. I changed mine to -3deg ( pinion angled down) and it made a SHIT load of difference WAY less wheel spin.


To do this on a leaf spring i machined up some wedges to go in between the diff and the spring.
P.S you will need to measure your pinion angle first with the car on the ground so that you get an idea of what it is at and how much it needs to change.

They say -1-3 deg with a control arm setup and -3-7 deg with a leaf spring setup as the move alot more

[Ben Wilson]

These guys seem to be leaf spring gurus. I've never dealt with them, but their site seems to indicate they know a lot...

[millsi]

depends on if you want to carry a load anymore. if not, you can get all bar 2 leafs removed which will make it alot softer.

[WDE_BDY]

If you are not wanting to carry loads, look at mono leafs and putting in adjustable coilovers. Or you could go the whole hog and 4 link it since its full chassised, given its popularity for airbagging there are a few different kits floating around that would be suitable.

Callum

[Cameron_Datto]

http://www.sjperformance.com.au/Caltracs.html

The Bar With The Bite ,,Caltracs

[Mr DOHC]

dont use carrolls springs

talk to a racecar mob, like racecar engineering

FWIW, leafs are a bitch, expecially since u have no weight over the back, unless u put the well back on it

[oldcorollas]

get a "toolbox" bolted to the back of the tray and fill with concrete?

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get a "toolbox" bolted to the back of the tray and fill with concrete?

i was actually considering some lead plates.

[Ben Wilson]

There's a local XD 351 rally ute with two spare wheels bolted at the very back of the tray. Still doesn't seem to help much

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sorry to bump this up.

I was looking into tramp-bars (traction bars) and it seems that they arn't legal on the street? anyone wanna clarify that?