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NEED SHOCK AND SUSPENSION HELP ASAP!!


620dude

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So, I should start by saying that I bought this truck off a guy who was on his was to turning a 1975 datsun PL620 into a rat rod..  

 

Things he modified were:

Nissan Silvia Engine: SR20 non turbo direct 

Brembo Disc brakes 

and 5 speed transmission

 

he also took out the torsion bars and replaced it with double adjustable coil over shocks.  

 

Here's where I need help.  

 

He cut the springs on the shocks (why?  I don't know, cause these shocks should be adjustable to get whatever ride height you want!)

they were nearly ruined when I got the truck.  

 

I replaced the front tires and afterwards realized that the passenger side shock snapped at the base where it bolts in.  

 

NOW I AM IN NEED OF NEW SHOCKS AND AM THINKING I SHOULD STICK WITH THE DOUBLE ADJUSTABLE COIL OVERS, UNLESS THERE IS ANOTHER AND MORE AFFORDABLE OPTION.  

 

WHICH BRINGS ME HERE.  

 

DOES ANYONE HAVE ANY TIPS?  OR HAS ANYONE CONVERTED THEIR DATSUN TO SHOCKS AND HOW WAS THE BEST WAY TO GET A RIDE HEIGHT THAT MATCHES THE ORIGINAL RIDE HEIGHT OF THE 620?

 

any help appreciated!! thanks!!

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Cutting a coil; spring increases the stiffness or spring rate. If the spring was too weak for the weight of the truck front end, cutting them could be one way to go. Cutting should never be done to adjust the ride height. The chances of getting the ride height AND the stiffness right where you like it is very remote.

 

Type 620 coil spring into the search engine top right of every page and start your research. 

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"TO GET A RIDE HEIGHT THAT MATCHES THE ORIGINAL RIDE HEIGHT OF THE 620?"

 

Make it original again.  Very few people and I do mean a smaller than you think are as smart as the Nissan engineers who designed the truck in the first place.   A stock Datsun is a reliable and safe Datsun.

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If the coil over has snapped chances are it is not mounted correctly and is in a binding state. Just replacing it may not address the root issue. 

 

 

Pics would help a lot with troubleshooting your setup. 

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ok I'm looking at the QA1 coilovers...pretty sure they will work.  does anyone know what the front end weight of the truck is?  I know the whole thing weighs about 2300 but I'm trying to decide a good spring rate... 400-450 sounds about right but I'm not sure

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Also sprung weight vs unsprung weight should be taken into account. 

 

 

A 620 Kingcab weighs about 2650lbs, about 60% of which is over the front end. Of course part of that is the tires and control arms (unsprung weight) 

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My earlier reply was incomplete, and really, you're not going to get all the information you need here, especially if you're not familiar with suspension setup. 

 

Springs are measured in the amount of force required to compress it 1 inch. Other than leverage ratio I mentioned above, you also need to take shock stroke length into consideration. For example, if you're running a 3" stroke shock, you may want the static ride height to have 30% sag - or 1". However, if you're running a longer stroke shock,  you might want more than 1" of sag.

 

In short, without having the slightest bit of information on the suspension on your truck, there's no point in even guessing what spring you need.  

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