[roughzook]

Time to get some new suspension and considering asking for 2 rears from the 2inch lift kit. Would this be worth it?

Reasons for ruf?

1. Brings front axles forward so you can run bigger tires? However the one pic i have seen with ruf and 2 inch raised springs had the front wheel very forward, almost too forward.

2. Flex. now i get that flex is gained due to the shackle not sitting straight up and down. To really make use of this theory you would need extended shackles as with a longer shackle swinging to the same angle difference would result in more droop? i guess you also get a little more as the springs are longer.


ok now lets talk about ways to achieve the ruf.

half ruf...i assume this is just the standard rear top spring on say a 2 inch front spring lift pack? how far forward does this put the shackle? also would the curves of the springs match? this option means i can just get a normal 2" lift kit and use my stock rear later, but the front might droop. i am thinking of going 2-3 inch shackles 2 inch spring/shock and no bl? will be running 31's

another way i way thinking pushing the packs on say a 2 inch lift closer together then redrilling perches?

if you have done a ruf please post up how you went about it please? Or post up the best way to do it.

one other issue i have is you get the longer springs in the front....what about the flex in the back? this would not equal the same. The reason i ask this is i know a joint that can make me up custom springs easy enough if i give them measurements of spring etc. was considering this as i would then have perfect front and rear length and perches where i want. Could people post the perfect measurements up. I know it will be different for different tires, but lets say 31's but can run 33's

thanks for your help

[JrZook]

The extra flex is achieved through the longer leaves (std fronts are 3" shorter than std rears) as well as the shackle cycling through its whole effective range of movement. Here are some pics of mine that I just completed:





Have a read through my thread and it will give you a heap of info without me reposting it in this thread

http://www.auszookers.com/index.php?nam ... &start=120

I used custom leafs, 6mm thick roughly the same length as an EFS lifted rear all round. Stock shackles, rear mount flipped and moved back 30mm, front mount cut and moved forward 40mm. Yes you can get wayyy more flex (The way Gman likes) by leaving the rear mount where it is, just ,moving the front and run longer shackles but I wanted to keep my handling nice and tight. I run koni shocks all round with the fronts having 7.5" travel with a 10mm bumpstop spacer on 30" rubber. The shock now limits the down travel not the spring.

Dan

[Red89]

Half RUF commonly refers to people who have either redrilled the chassis mount or moved it back, which leaves the diff roughly in the stock position give or take. So they only get half the benefit of doing a RUF.

Full RUF commonly refers to people who have mounted the springs in the stock chassis mount hole and done a chassis extension in the front to mount the shackle mount on. So they get the benefit of the flexier springs and a slightly longer wheelbase.

Steve gets most of his extra flex from inboarding his springs and bumpstops at the same time, I would imagine.

[roughzook]

jrzook. nice rig i also like where your front wheel sits.

Why do you get more flex when you use the stock chassis mount? if the mounts moved back, the spring is still the same length, so why more flex when just modding the front mount?

Sorry for the questions, i just like to understand how things woek before modding the car

[2stroker]

I hate the term half RUF here is no such thing as half RUF it is a term used by people trying to explain the numerous ways it has been achieved, you either have Rear springs in the front or you don't. Those that maintain 1" more wheel base is what it is all about are kidding themselves. The advantage gained is in the longer spring regardless of how you achieve it, the second advantage is moving the tyre away from the firewall a little,

I have said this before and I will say it again for those of you who have not done the conversion, if the diff moves too far forward the drag link will bind with the track rod unless you also move the steering box forward. This may not be apparant when the springs have plenty of curve but as they settle and begin to flex well they will bind and you will start bending drag links or worse still have the wheel torn from your hands and crash.

Longer shackle use to achieve a RUF is poor practice and dangerous which is why it is illegal.

To do it properly you need to adjust the spring mounting points on the chassis to have them about 980mm apart, same as they are at the rear (fronts are 910mm apart so 70mm different from rear) and you need to ensure that the diff does not move too far forward so as not to cause steering bind. You can to do any one of the following things:

1. Move both mounts on the chassis and keep the diff in the same place
2. Move both mounts on the chassis and move the diff slightly forward
3. Drill the rear mount hole back and move the front mount forward
4. Leave the rear mount, move the front mount forward and redrill the perch

[roughzook]

2 stroker. you post makes a lot of sense to me. But why is running extended shackles dangerous? Or are you talking running stupid long shackles and keeping mounting points the same?

I see no issue with running 2inch longer shackles to get some of the benefit of ruf. Or is there some issues i am not aware of?

[JrZook]

2stroker wrote:

Longer shackle use to achieve a RUF is poor practice and dangerous which is why it is illegal.

To do it properly you need to adjust the spring mounting points on the chassis to have them about 980mm apart, same as they are at the rear (fronts are 910mm apart so 70mm different from rear) and you need to ensure that the diff does not move too far forward so as not to cause steering bind. You can to do any one of the following things:

Agree with you there and that is how I decided to do mine. To be exact the rear fixed hanger spacing is 985, but I would convince people doing it to make it slightly shorter at 980. You will run in to less issues with the leaf flattening out and possibly inverting as I have found out. All these measurements are in my build thread if anybody wants further info. With repositioning the rear 30mm back and front 40mm forward to diff is effectively moved ~10mm forward with aftermarket spring center bolt spacings (OME, EFS)

roughzook:

The reason why I said you get more flex with just moving the front mount slightly forward as others have done is because you need a longer shackle to compensate for the extra length of the leaf and thus cycling through its full length of movement the extra length of the shackle accounts for more droop.

I wanted mine to still feel nice and tight on the road and not stand out with ext shackles so I kept them std. Yes I may have missed out on some extra flex but it is compensated by good handling and longer bush life.

Dan

[roughzook]

"The reason why I said you get more flex with just moving the front mount slightly forward as others have done is because you need a longer shackle to compensate for the extra length of the leaf and thus cycling through its full length of movement the extra length of the shackle accounts for more droop."

ok i see.

yeah i will make up some of my own shackles anyway. but i dont want to go stupid big with them. i am thinking 60mm extended. and as i said earlier you front wheel positioning looks good. I saw it done on another car with the front wheel very forward and did not want that.

[JrZook]

roughzook wrote:

"The reason why I said you get more flex with just moving the front mount slightly forward as others have done is because you need a longer shackle to compensate for the extra length of the leaf and thus cycling through its full length of movement the extra length of the shackle accounts for more droop."

ok i see.

yeah i will make up some of my own shackles anyway. but i dont want to go stupid big with them. i am thinking 60mm extended. and as i said earlier you front wheel positioning looks good. I saw it done on another car with the front wheel very forward and did not want that.

Yes I did this on purpose, I did not want to cut anymore off the front end. It looks quite out of place I believe with the smaller tires. But you will still need to at least more one of your mounts and increase the eye-eye separation otherwise you will have a unicorn like flat shackle angle and spear anything in its way. 60mm is nearly doubling the stock shackle length btw (stock is 70mm). The increased shackle length also puts a lot of side loads on the bushes/shackle plates and shackle pins.

Dan

[Gwagensteve]

All good , sound RUF advice in here.

However, I'm going to disagree a bit with 2stroker in regard to the effect of the wheelbase extension.

IMHO it has a pretty profound effect. Whilst it's only 40mm of added wheelbase or so, it does substantially change relationship between the motor and the front axle, so it moves more of the weight of the car between the axles.

As an example of the effect of small changes of wheelbase, Bruce Garland whilst building his Dakar Isuzu pickup pulled the cab back 50mm for the same reason (he pulled the motor back more, but engine setback isn't really feasible in a sierra)

In any case, in my experience, the wheelbase extension changes the balance point of the car, making it much more reluctant to weight transfer and hoist front wheels in the air.

I agree that it's a small part of a whole heap of improvements RUF nets, but I've not been impressed with RUF cars I've seen without the full wheelbase extension - they have the flex of RUF, but not the improved balance that's much more confidence inspiring.

Just my 2C.

Steve.

PS RUF with a wheelbase extension really is a "no turning back" modification. The shock mounts and bumpstop mounts need to come forward so it rapidly turns into a big job, even if the chassis extension is relatively quick.

[royce]

I would like to see the difference in corner weights pre and post RUF one day

[JrZook]

royce wrote:

I would like to see the difference in corner weights pre and post RUF one day

I would love corner weights in general. Where abouts could you get this measured in Briz and at what sort of price?

[royce]

JrZook wrote:

royce wrote:

I would like to see the difference in corner weights pre and post RUF one day

I would love corner weights in general. Where abouts could you get this measured in Briz and at what sort of price?

Decent (IE works on race cars) suspension shop should have scales, or some higher level weekender race teams

[ajsr]

JrZook wrote:

royce wrote:

I would like to see the difference in corner weights pre and post RUF one day

I would love corner weights in general. Where abouts could you get this measured in Briz and at what sort of price?

4 sets of fattie bathroom scales


most race car fabricators will be able to help

[roughzook]

JrZook wrote:

roughzook wrote:

"The reason why I said you get more flex with just moving the front mount slightly forward as others have done is because you need a longer shackle to compensate for the extra length of the leaf and thus cycling through its full length of movement the extra length of the shackle accounts for more droop."

ok i see.

yeah i will make up some of my own shackles anyway. but i dont want to go stupid big with them. i am thinking 60mm extended. and as i said earlier you front wheel positioning looks good. I saw it done on another car with the front wheel very forward and did not want that.

Yes I did this on purpose, I did not want to cut anymore off the front end. It looks quite out of place I believe with the smaller tires. But you will still need to at least more one of your mounts and increase the eye-eye separation otherwise you will have a unicorn like flat shackle angle and spear anything in its way. 60mm is nearly doubling the stock shackle length btw (stock is 70mm). The increased shackle length also puts a lot of side loads on the bushes/shackle plates and shackle pins.

Dan

yeah the extra load dont bother me, ill run thick re-enforced metal and pins. ill be putting in new bushes all round and if they wear quicker, meh they are like $50. The way i see it flex in general will put a lot of sideloading on your bushes extended shackles or not.

I need to do something soon though, i just bought the car with plans to change the suspension anyway, but had a look under today and the drivers side is inverted at resting stance........ i want to take it out this weekend just for a small run in, but afraid i my snap a leaf!

[roughzook]

Gwagensteve wrote:

All good , sound RUF advice in here.

However, I'm going to disagree a bit with 2stroker in regard to the effect of the wheelbase extension.

IMHO it has a pretty profound effect. Whilst it's only 40mm of added wheelbase or so, it does substantially change relationship between the motor and the front axle, so it moves more of the weight of the car between the axles.

As an example of the effect of small changes of wheelbase, Bruce Garland whilst building his Dakar Isuzu pickup pulled the cab back 50mm for the same reason (he pulled the motor back more, but engine setback isn't really feasible in a sierra)

In any case, in my experience, the wheelbase extension changes the balance point of the car, making it much more reluctant to weight transfer and hoist front wheels in the air.

I agree that it's a small part of a whole heap of improvements RUF nets, but I've not been impressed with RUF cars I've seen without the full wheelbase extension - they have the flex of RUF, but not the improved balance that's much more confidence inspiring.

Just my 2C.

Steve.

PS RUF with a wheelbase extension really is a "no turning back" modification. The shock mounts and bumpstop mounts need to come forward so it rapidly turns into a big job, even if the chassis extension is relatively quick.

Now this makes all kinds of sense to me. I come from the import world, so weight over front wheels and weight distribution has always been very important to me, and i know the difference it makes.

[shakes]

royce wrote:

I would like to see the difference in corner weights pre and post RUF one day

I'll post this up roughly xmas time if I remember.

[Fatzook]

JrZook wrote:

royce wrote:

I would like to see the difference in corner weights pre and post RUF one day

I would love corner weights in general. Where abouts could you get this measured in Briz and at what sort of price?

I'm looking at buying some scales to aid in the coilover setup for the ute, and eventually cammo. I'll let you know If i shell out the $2500 or not

[2stroker]

Gwagensteve - mate I can't argue with what you have found with your own cars improvements but I just can't imagine 40mm making a noticeable difference, if it does then standard front springs with the diff forward 40mm would be viable.

Mate with respect you have done a RUF and noticed a great improvement I think the 40mm forward may asist in the overall package but that the added spring length is really what has made all the difference.

I am aware of moving the engine weight back for balance in my blue LJ80 the engine is moved back 20CM yes that is not a typo 200mm, now that is significant and makes a profound difference.

roughzook, lots of advice has been given by people who have been there and done RUF, we may not agree on every aspect but we do agree on most, it seems that you will just have to learn from your mistakes.


This is a standard WT with standard front springs, see how close the arms are, this is why you get steering arms binding when diff is moved too far forward

[got_bar_work]

I've never owned a leaf car but woulnt the chassis extention be best if done behind the steering box so that all the steering geometry stays the same and so to for the bull bar mounts etc. Would also need to make new body mounts or better yet ad a few in down the center of the front clip making more room for larger tires . My mate has 6 in added to his front to clear the 37 on his dd but it's on coil overs and 80 diffs but same principle

[Gwagensteve]

We're doing a club tech night in a month or so and it's at a workshop where we can do corner weights, but unless it's done pre and post RUF on the same car it will be pretty hard to draw any meaningful conclusions.

PS my front axle is 30mm forward on stock front springs. It does have a noticeable effect on the cars balance point. Not as effective as RUF, but it does isolate the effect to the COG change only. Obviously, I'm LWB it's a lot less noticeable than in a SWB, but since I did the 7" WB stretch after a did the 30mm front stretch, I can vouch that the effect of the 30mm is far more noticeable than you'd think even compared to the 7" out the back.

2stroker - I think I've RUF'ed about 10 cars or something over the years... I dunno, I forget.

Steve.