[Ryan19]

Hey guys so I have decided to RUF my 91 tin top.
Iv done much research and think Iv got it I just to confirm I'm 100% ready to go.

Okay so here we go.

I'm planning in using my stock rear Sierra springs they are not completely flat (yet)
Or should I just buy say OME 2lift rear?

Once that's sorted I chassis extend the front by 35mm,tack weld old shackle mount 30mm forward
Bold on the my shackle to check shackle angle ( my Shackles are 2" extended will the be okay to use?)

Full weld the extention and shackle mount
Mount up new springs and reft the diff thus moving the diff forward buy 20ish mm....

Extended brake lines by 4"

I'm already running hiace shocks up front

Is there anything elce I have missed??? Or anything I should keep in mind??

Thanks in advance Ryan

[2stroker]

Keep looking, you have missed a lot. Try this, measure the distance between the rear spring mounts on your chassis, that is the distance that you need to have between the front mounts in order to properly fit rear springs up front.

[mrgtt34]

dont do it . i did mine a few weeks ago and i putting it back.

[SierraDan]

if i ever bought a standard sierra again. the first things i would do are RUF and better gearing.

RUF made it so much better to drive.

[darcy]

mrgtt34 wrote:

dont do it . i did mine a few weeks ago and i putting it back.

Sounds like you did it wrong, you'd have to be the first person ever to be unhappy with a RUF.

Post pics/more info of you set up.

[ajsr]

mrgtt34 wrote:

dont do it . i did mine a few weeks ago and i putting it back.

whats the problem?? based of what info???
you must be the only person on this forum or maybe the world that would say a ruf sierra is less capable than a stock one.

[JrZook]

Probs did a FUR by mistake

[2stroker]

Hi mrgtt34's there must be some reasons that you were not happy with your attempt at a RUF.

Can you please explain what you did and why it didn't work, pics would be awesome.

Thanks

[tanshi]

mrgtt34 wrote:

dont do it . i did mine a few weeks ago and i putting it back.

bwhahahahahahahahahahahahahahahahahah, maybe the FUF is going to catch on!!!!

[neofitou]

How far you move the hangers is dependent on the shackles and springs you want to use in order to achive the correct shackle angle and ride height.

2" extended shackles are pretty long. Thats what I had. I moved my hanger 35mm and ran standard rears, but they were too short and the shackles sat up straight a bit much, I had intended on runnnig longer ones in the future, but didnt get that far before selling it.

Other things to consider,
Do you go to NT spacing at the same time.?
Do you want it engineerable you need to do ALOT more work, cutting the chassis, extending plating etc.
New longer shocks means taller shock towers or much longer bump stops.
Moving the diff forward means moving the bump stops and shock towers forward too and extending the steering column.
You can move the diff forward about 25mm before you run into steering issues, so you should be ok but keep an eye on the tie and drag rubbing together.

I installed Power Steering at the same time which is nice.

[matfan]

neofitou wrote:

How far you move the hangers is dependent on the shackles and springs you want to use in order to achive the correct shackle angle and ride height.

I'll jump in before 2Stroker does, I don't see why you would want to overcomplicate the process here. A variety of different after market rears fit in the rear of a sierra with no dramas so why wouldn't you just use the same perch spacing for the RUF as is standard in the rear??
If you springs are too long or too short with standard rear spacing perhaps it's just that you're springs are too long or too short.

Longer shackles are not the answer to any other question than "how do I make my car steer like a boat?"

GET RID OF THE EXTENDED SHACKLES!!!!!

[Zook_Fan]

Because the standard isn't designed for maximum articulation. By making it slightly shorter between mounting points it can give you a better shackle angle for articulation even if the steering isn't as tight. Depends entirely on the purpose of the vehicle and how much you intend on using it on the road.

[2stroker]

Sorry Zook_fan, your reasoning is a bit flawed mate. All springs original or aftermarket that are specifically made to suit the rear of a sierra will be made within a tolerance of lengths that suits the standard sierra chassis rear spacing so if that is where you start when doing your ruf you will be on the right track. The reason that people have varying success with ruf is that so much has been said on the topic by people who have little or no experience with it.

[Zook_Fan]

When I set up my front end up exactly to the dimensions from the rear of the vehicle with a stock shackle in a very similar form to your method (flip rear mount and extend front) I was able to invert the shackle without much effort. To fix this I moved the front hanger back in 5mm to give a flatter angle and now it cannot invert. I then put longer shackles on it but this is irrelevant as they were aided for other reasons, nothing to do with ride or steering. I agree that it is a good starting point but you still need to make it work for the springs that you have got and your chosen shackle. There is no point giving people an exact measurement because there are too many variables in this set up.

[matfan]

Zook_Fan wrote:

I agree that it is a good starting point but you still need to make it work for the springs that you have got and your chosen shackle. There is no point giving people an exact measurement because there are too many variables in this set up.

I think perhaps there are too many variable is your setup.

By your logic, why not move the front hanger to immediately in front of the rear and use a metre long shackle? That'll give you more of that "maximum articulation" you spoke about earlier.

[JrZook]

matfan wrote:

A variety of different after market rears fit in the rear of a sierra with no dramas so why wouldn't you just use the same perch spacing for the RUF as is standard in the rear??
If you springs are too long or too short with standard rear spacing perhaps it's just that you're springs are too long or too short.

One major point that many fail to remember is how the chassis tapers down at the front of the vehicle with effectively give you more shackle angle per spring set than the rear.

On another note EFS 65mm rears are absolute borderline maximum main length for the rear spacing of a stock sierra. Problem doesn't seem to arise if you run the full 5 leaf pack (because it wont flex near enough) but occurs when you can actually get to the BS and have a loaded vehicle. I've seen 3 instances of this so far, mine also became a statistic as before I noticed this issue with spring length I used the EFS main length in my design of springs.

[2stroker]

JrZook what you are saying is that with good rear springs the original measurement is borderline too short which is what I am getting at as well. If he only extended the front by 30mm he is 45mm shorter than standard rear spring mount spacing. The standard rear spacing should be considered the minimum that the front needs to be and is a good starting place, you shouldn't need to go shorter spacing unless you have springs that are shorter than factory rears.

[JrZook]

That is correct

[SierraDan]

matfan wrote:

Zook_Fan wrote:

I agree that it is a good starting point but you still need to make it work for the springs that you have got and your chosen shackle. There is no point giving people an exact measurement because there are too many variables in this set up.

I think perhaps there are too many variable is your setup.

By your logic, why not move the front hanger to immediately in front of the rear and use a metre long shackle? That'll give you more of that "maximum articulation" you spoke about earlier.

That wont work.

[SierraDan]

x2 mine uses 1" extended shackles in the front. Performs very well and drives better than the stock setup on road.

[ajsr]

matfan wrote:

neofitou wrote:

How far you move the hangers is dependent on the shackles and springs you want to use in order to achive the correct shackle angle and ride height.

I'll jump in before 2Stroker does, I don't see why you would want to overcomplicate the process here. A variety of different after market rears fit in the rear of a sierra with no dramas so why wouldn't you just use the same perch spacing for the RUF as is standard in the rear??
If you springs are too long or too short with standard rear spacing perhaps it's just that you're springs are too long or too short.

Longer shackles are not the answer to any other question than "how do I make my car steer like a boat?"

GET RID OF THE EXTENDED SHACKLES!!!!!

mate this is rubbish, if you build the vehicle to use extended shackles it can handle just fine and have a massive amount of droop, but if all you want is rear springs in the front then yes I suppose you could just use the rear spacing (although I belive hanger its marginly too far apart for stock springs)

[ajsr]

2stroker wrote:

JrZook what you are saying is that with good rear springs the original measurement is borderline too short which is what I am getting at as well. If he only extended the front by 30mm he is 45mm shorter than standard rear spring mount spacing. The standard rear spacing should be considered the minimum that the front needs to be and is a good starting place, you shouldn't need to go shorter spacing unless you have springs that are shorter than factory rears.

my hangers were only moved 18mm and work on OME springs, again its all a case on knowing what you want the vehicle to do and the consequences of the change.
I dont expect it to drive like stock , but then if it did I'd be upset . It now does exactly what I built it for

[Gwagensteve]

'kn oath it does.

You need to understand desired shackle length and angle, compression travel and spring rate. 35mm works for us, but we're running 100mm shackles and very limited compression travel. AJSR has more BS spacing than the norm, (75mm?) so 18mm worked for him.

IMHO the rear mount spacing is 50mm too long even for stck springs, so there's no way I'd replicate it on the front, but we're always spacing the bumpstops for shock/ tyre clearance.

Steve.

[matfan]

My point in all of this is and always has been that the longer the shackles, the less stable (for want of a better word) the front end is. Will anyone dispute that?

The one thing that really concerns me is that some of the advice given on this site is not suited for those who use their zooks as daily or even semi-regular drivers, mrgtt34's post earlier speaks volumes for what I'm getting at. He reckons RUF is shit and he's going to undo his, what's the bet his RUF is redrilled rear hanger and extended shackles?

Shackles are my issue!!!!! I'm more than happy to be wrong here but I feel as though my logic is sound.

[SierraDan]

A stupid long shackle will make it more loose on the road.

My 95mm shackle with chassis extension style RUF handles VERY well on road and performs well offroad.
How you set it up is crucial.

[jdk81]

Im working on RUF type calculations atm.
It's giving me the shits. There is no clear cut concise way people do it, and I fear I may need lots more work.
various spring packs front and rear camber, compressed lengths under standard load.
Also the angles, and effects of all the different shackles etc.

Trying to draw it and calculate it theoretically, when theres so many ways others have said they've done it. And many say it works for them.
How do they know? Unless you have an Oxford RT3100 shoved up your ass, the seat of the pants feelings do not really offer anything of real value.
I assume most people are just doing it without calculating, and its an option.

To people who have done a few RUFs, what equipment to you use? And how do you know you have maintained performance, and not made it worse?

[SierraDan]

The different ways will depend on the persons needs/wants and how they do things. Same reason one person needs 34's and another can make do with 205's.

I'd say the seat of your pants feeling is exactly what matters.. because thats where you work will show through.

If my car felt dangerous to drive on the road, "i'd think hmm something isnt right here."

If my car kept doing backflips and my diffs were falling out every step i climbed "i'd think hmm something isnt right here."

[ajsr]

the way Ive done it before, is to using only the main leaf tack the hanger in place and compress the spring to bumpstop position ,makeing sure it wont invert and has no nasty side effects. but you need to be using the main leaf of the springs your going to use and the shackles you will be using
it may take a couple of goes to get it exactly right but I belive its the best way to get a decent shackle angle and spring that wont invert. a few mm of movement on the hanger can make a massive difference.

[JrZook]

jdk81 wrote:

Im working on RUF type calculations atm.
It's giving me the shits. There is no clear cut concise way people do it, and I fear I may need lots more work.
various spring packs front and rear camber, compressed lengths under standard load.
Also the angles, and effects of all the different shackles etc.

Trying to draw it and calculate it theoretically, when theres so many ways others have said they've done it. And many say it works for them.
How do they know? Unless you have an Oxford RT3100 shoved up your ass, the seat of the pants feelings do not really offer anything of real value.
I assume most people are just doing it without calculating, and its an option.

To people who have done a few RUFs, what equipment to you use? And how do you know you have maintained performance, and not made it worse?

Dude search for a post from Highwaystar. There's a mathematical method in there and lots of info into how to set it up pretty darn close.
If you have a read through my build thread there is also a lot of tech in there regarding RUF setup and measurements.

Dan

[mrgtt34]

darcy wrote:

mrgtt34 wrote:

dont do it . i did mine a few weeks ago and i putting it back.

Sounds like you did it wrong, you'd have to be the first person ever to be unhappy with a RUF.

Post pics/more info of you set up.

There proble is some thing wrong but i feel for how much you have to change every thing i carn feel a gain, other than is drive like a pig to and from work. maybe the castor or something is up to shit , spring rate i dont no. For all the changers ive made over the years if feels like the worst one ive done.