Nissan 4 link

Crashbig

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I'm toying with the idea of going 4 link on my nissan, I read thru the whole lower links section and got tons of info, but I need to now what the length of the lower link should be. Right now the drive shaft is 2 piece with center support bearing, should I replace and go one piece with slip yoke or stay 2 piece. Should Lower link be the length of the drive shaft from UJ to UJ, or something like 90%-80% of DS length. I just need something to get started so I can toy around with it, I'm going to have to figure it out on paper wish I had solidworks or something close to it.

The higher you jump the harder you crash so crashbig
 

rdc

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There is also a guy who races a white Nissan in Whiplash, I can't remember if it had a 3 or 4 link though.
 

Kritter

Krittro Campbell
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A guy with a 4 linked Nissan works at Balboa Tattoo I think thats the name...it is right across the street from Hooters in Newport.

Kris
"Buy American before it's too late"
 

Crashbig

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Yeah read thru the is everyone a fabricator now post. Took it as a case of what not to do, Iv'e been fabbin since high school so I have the confidence in my work so it won't be a death trap, and I figure about a year to complete the truck so theres no rush, just want to take it up a notch so keep the info comin.

The higher you jump the harder you crash so crashbig
 

SpareChangeRacng

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I'm pretty sure it's Balboa Tatoo Kris, BUT I'm not sure if the guy still has it. I know it was for sale for a while, and I drive down there every day for work and haven't seen it recently so I'm not sure it's still his - could be though. I looked at it for a second on day when I walked by and I seem to remeber his shocks being offset of his lower trailing arms like the one in the bent 4-link post. Steve
 

John Bitting

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Peter the reason no one has wrote on here to give you an answer is because this is someones business and paycheck. If people handed out exact numbers, dimensions, and specs who would take there truck to a shop, they could do it with a buddy. There are a lot of things I would love to know so I could save a ton of cash but the reality is that if you are not paying someone they are not going to provide you with exact answers. Take what you can from the other threads and then talking to different shops and by looking at trucks that are linked properly that might give you an idea of where the pivots should be in relation to the driveshaft. Its tough and I wish you all the luck I wish it was as easy as posting it on a board. Maybe someday it will be.

"faster than it looks"
 

ntsqd

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Here's a trick that, while slower than some high powered CAD package, will get you there if you have the patience to stick with it. Buy a Tabloid sized graph papaer pad and get a cheap drafting board, a 45* and a 60-30* triangle, and a T-square. Lay out, to a set scale, where the engine, trans, and rear axle are relative to the frame and the ground.
Using a hard pencil do the IC layout we talked about in LCA 101, bearing in mind Fabricator's comments that the CG is likely to be further back than my original estimate. That will get you close anyway.
There is a way to measure where the actual CG is, but you will need to find someone with some scales and a free part day. I have a qwik corner weight checking tool that uses a beam type torque wrench that would work for this.

Now for the trick part: Get some single thickness cardboard or really thick construction paper and some thumb tacks. Layout the LCA, UCA, and axle in the heavy paper. You don't need an exact scale creation of these, just where the important points are. Thumb tack the fixed ends to the board and use more tacks upside down as pivot points. I would carefully Xacto a slot in the 'axle' that represents the pinion gear centerline with the forward end of the slot being the UJ CL. Now you can move the assembly and mark the travel path. If you make the 'arms' long enough (past their fixed pivot points) then you can easily extract where the IC has moved to. If the pinion 'slot' is to scale then you can extract what the pinion angle is at any point and you can figure out how much change (Delta) there is in the driveshaft length.

Buy the Herb Adams book. Buy Carrol Smith's books. Buy Van Valkenburg's book. Read them, digest them.

TS

I used swerve around my halucinations, now I drive right thru them.
 

Kritter

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Here is an easy formulae I use to calculate CG of a vehicle
1. The front wheels are set on scales and the rear wheels are set at the same height using a spacer.
2. A reading of the weight is taken from the scales
3. The rear axle is raised lifting the vehicle to an exact height
4. A new reading is taken from the scales and the weight difference is calculated

Centre of gravity height = HCOG

Wheelbase distance = dWB

Weight difference = WDIFF

Weight total = WTOTAL




Kris
"Buy American before it's too late"
 

Kritter

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for some reason the formula switches between a banner ad and a formula so I hosted it on my server instead




Kris
"Buy American before it's too late"
 

Kritter

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Horizontal? Do you mean fore aft location? You can do that by using a piece of tubing and jacking the car up until you get it to somewaht balance for a rough estimate or you can interpolate from the front and rear weights...both are estimates but should be close.

Kris
"Buy American before it's too late"
 

ntsqd

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What Kris said worded another way:

Percent of total weight on front wheels is the percent of wheelbase where the CG is located fore/aft.

Example:
1000 lbs vehicle with a 100 inch WB.
600 lbs on front axle, 400 lbs on rear axle.
60% of weight on front axle, CG is @ the 60% of WB point. Start at the light axle and go towards the heavy axle 60% of the WB, in this case 60 inches. This is the fore/aft location of the CG.

TS

I used swerve around my halucinations, now I drive right thru them.
 

Tom_Willis

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Solo Motorsports in Azusa had an ex-shortcourse 4 link Nissan a while ago. It might still be there. 626.815.1430

I live my life one paycheck at a time
 

SpareChangeRacng

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Yeah the Nissan is still there. I drove by it the night after I posted that. Steve
 

Crashbig

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Guess I'll have to make my way over their and take a look at it, thanks guys

The higher you jump the harder you crash so crashbig
 
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