Jump to content


Photo

short shocks for front


  • Please log in to reply
48 replies to this topic

#41 distributorguy

distributorguy

    Senior Member

  • Senior Member
  • PipPipPipPip
  • 1,101 posts
  • Location:Metropolis, MN
  • Cars:77 Datsun 620, 73 Datsun 620

Posted 07 December 2017 - 08:47 AM

Adding weight shifts vehicle height.  Its always been part of the argument.  Unless you run a rigid/fixed suspension???  Racers add ballast. Truckers add payload.  It all has to be accounted for.  



#42 Stoffregen Motorsports

Stoffregen Motorsports

    Datsun Mechanic

  • Senior Member
  • PipPipPipPipPip
  • 3,816 posts
  • Location:Cool, CA
  • Cars:http://www.4wdandsportutility.com/features/rover/0611_4wd_1957_range_rover/viewall.html

Posted 07 December 2017 - 08:52 AM

Well if Robert Duval says so....   :lol:

 

 

Well you can't change the parameters of the argument now.  It was on weight being added.... not changing vehicle height.

Good point. How did we get off subject anyway?

 

Find shocks that fit and that don't bottom or top out. If you like the ride, then your job is done.

 

Someone mentioned bumpstops. You can cut a hair off them so you're not constantly riding on them. But don't get rid of them.



#43 wayno

wayno

    Datsunahaulic

  • Senior Member
  • PipPipPipPipPipPipPipPipPipPip
  • 12,808 posts

Posted 07 December 2017 - 09:49 AM

This is an extreme example and not completely relevant to the shock argument. I agree with what you are saying, Wayno, but a load like this throws all baseline suspension characteristics out the window.

It took time to make this truck what it is and still be able to drive it empty comfortably, although it is much nicer with the trailer connected, empty I do have to slow down going over big speed bumps.

I thought we were talking about adding weight and how it effected the front end weight of the truck now, and my point was that it depended on the truck, I used my work truck as an example to show that adding weight on my flatbed was not lifting the front of the truck, my truck drops evenly when weight is added evenly on the bed, start at the bottom and work my way up, I don't load it that way, I plan ahead so that it is evenly distributed when finished.

My flatbed is also as low as I could build it and still clear the rear tires, any higher and it would act differently especially on freeway curves depending on how the curves were built.

I thought for a while about posting to this actual subject, in the end I could not keep quiet about the statement that any weight added to the box would lift the front end/take weight off the front end, it depends on the truck/vehicle and where the weight is put.

The only issue I have is when I put these kind of heavy weights on my truck, my rear coil over shocks have no effect, you cannot even tell there is a shock back there, there is zero dampening, that is why I mentioned crappy roads.


 

 


#44 Stoffregen Motorsports

Stoffregen Motorsports

    Datsun Mechanic

  • Senior Member
  • PipPipPipPipPip
  • 3,816 posts
  • Location:Cool, CA
  • Cars:http://www.4wdandsportutility.com/features/rover/0611_4wd_1957_range_rover/viewall.html

Posted 08 December 2017 - 10:23 AM

I was trying to bring the discussion back to the OP's original question of what were the right length of shock for a lowered truck.

 

Seems like we've been arguing about something he didn't even ask.



#45 wayno

wayno

    Datsunahaulic

  • Senior Member
  • PipPipPipPipPipPipPipPipPipPip
  • 12,808 posts

Posted 08 December 2017 - 03:48 PM

I was trying to bring the discussion back to the OP's original question of what were the right length of shock for a lowered truck.

 

Seems like we've been arguing about something he didn't even ask.

 

I jumped in after it started, but I will now put my 2 cents worth in on the front shocks for a lowered 620 that has disc brakes.

What I did was cut the lower shock mount out of the lower control arm, it's a bitch to do, then I bought a high quality set of 66-70 front Datsun Roadster shocks which are stud/stud, I mounted the lower shock stud in the sway bar connection hole, I drilled a hole for the sway bar connection in between the shock and ball joint and mounted it there, the Roadster shock is very short when compressed, I would then trim the bump stop to just before the shock bottomed out.

You will also have to flip the upper control arms from a 720 and put the right side on the left side and the left side on the right otherwise the upper ball joints will bind.

I went farther and made my lower control arms into drop arms, but the same thing can be achieved using late 720 drop spindles.

Another issue that will always rear its ugly head will be that you will start bottoming out the tension rod on the pittman arm/steering arm, this was a very big issue for me as I was really low, I was also always hitting the front tension rod mounts on the ground, everywhere I went they were hitting the ground or curbs, I finally had to relocate them to the rear and cut off the mounts on the front, I have had no issues since.

I have no advice for lowering a kingpin truck other than I found the 521 front shock to be the shortest shock of that type, but it appears that others have found shorter shocks recently.


 

 


#46 Stoffregen Motorsports

Stoffregen Motorsports

    Datsun Mechanic

  • Senior Member
  • PipPipPipPipPip
  • 3,816 posts
  • Location:Cool, CA
  • Cars:http://www.4wdandsportutility.com/features/rover/0611_4wd_1957_range_rover/viewall.html

Posted 09 December 2017 - 08:25 AM

What I did was cut the lower shock mount out of the lower control arm, it's a bitch to do...

 

You will also have to flip the upper control arms from a 720 and put the right side on the left side and the left side on the right otherwise the upper ball joints will bind.


I have no advice for lowering a kingpin truck other than I found the 521 front shock to be the shortest shock of that type, but it appears that others have found shorter shocks recently.

That's the right way to do it. Get the longest shock you think will fit and cut the brackets and make new ones.

 

Does swapping the upper control arms from side to side affect the caster?

 

Sometime in the recent past, there was a discussion about short shocks and someone gave part numbers.



#47 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 69,802 posts
  • Location:Vancouver Island
  • Cars:'74 710 sedan, '76 710. prevoius... '78 620, '71 521, '68 510 new '76 B-210

Posted 09 December 2017 - 08:52 AM

Has anyone even measured the stock shock to see if it even bottoms out at full suspension travel??? Just can't see a car maker having shocks that bottom out before the suspension does.

 

If riding on bump stops or cut bump stops the shock isn't doing any compressing when hitting, say, a speed bump. Only the air in the tire will and maybe some of the rubber bump stop, and it isn't damped at all. The stored energy will rebound undampened, throwing the vehicle upward harshly. On the other side of the bump the tire will extend down to follow the road surface and the shock will dampen this extension and then dampen the compression as the body weight comes down on it. This is why extreme lowered vehicles have a shitty harsh ride quality.  Best bet is to run as low a tire pressure as you can safely get away with or find a way to extend the suspension travel so the shock can actually do something. 


Posted Image

#48 Stoffregen Motorsports

Stoffregen Motorsports

    Datsun Mechanic

  • Senior Member
  • PipPipPipPipPip
  • 3,816 posts
  • Location:Cool, CA
  • Cars:http://www.4wdandsportutility.com/features/rover/0611_4wd_1957_range_rover/viewall.html

Posted 09 December 2017 - 09:05 AM

Good point.

 

I think you need to cut the bumpstops to get it as low as these guys like them, in which case, the shocks do bottom out.



#49 wayno

wayno

    Datsunahaulic

  • Senior Member
  • PipPipPipPipPipPipPipPipPipPip
  • 12,808 posts

Posted 09 December 2017 - 10:36 AM



 

 

Does swapping the upper control arms from side to side affect the caster?

 

 

 

If you don't flip them upside down it does, but we are talking about on a lowered disc brake frame in this circumstance, the offset of the arm needs to be forward on a disc brake frame and that is what I am talking about here.

Here is a upper control arm(UCA) in stock configuration lowered as far as it will go.

DSCN0616.jpg

Here it is flipped on the other side.

DSCN0612.jpg

See how close the tension rod is to the idler arm.

DSCN0614.jpg

Here is the steering arm.

DSCN0610.jpg

Doing all this using 620/720 parts on a 521 frame is the same but very different, way more is involved.