Go Back OFN Forums > Fabrication > Offroad Fabrication

Offroad Fabrication Offroad Fabrication


Offroad Fabrication Offroad Fabrication

Reply
 
Thread Tools
  #1  
Old 02-29-2016, 03:31 AM
whawhat's Avatar
whawhat whawhat is offline
Fabricator
 
Join Date: Dec 2009
Location: Oppressed, California
Posts: 62
puzzled on my coilovers

Hi Everyone,

I've had these coilovers on my nissan titan 4x4. Com-10 on both ends. Fabricated LCA mounts and mod upper frame mounts keeping part of the coil buckets as part of the structure.

The coil bucket that remains started to come apart after the last mud fest. I completely cut out the coil bucket and started new. Fab'd up a new mount, welded and tested out. Full droop/comp is even on both sides, all numbers added up the same from drivers side to passenger side.

When I put the truck back on the ground. Driver side is sitting lower than passenger side. 0.50" on front and 1.0" on the rear.

When you view it from the front. You can see the passenger side LCA drops lower. Driver side LCA doesn't drop as low. Confirming the issue.

I measured everything again, numbers come up right for my mounting brackets, I swapped the coilover around no difference. SAW coilovers, 625 label on the coil, 6" stroke, 2" spring preload on both sides, I believe it's a 2:1 suspension ratio.

When I say, numbers added up. My bottom mount was my datum. I measured full coilover extension from the bottom LCA mount drooped to upper mount should be at frame. Then full compression measuring bot. LCA mount to my 1st mark I made at full droop. Also when I did the full droop I also took a point on the LCA and measured to the bottom of the bump stop so I can recreate my numbers, LCA position, upper mount placement.

When mocking up the upper frame mounts, I installed them on the coilovers, connected them to LCA bot mount. Measured from the point on LCA to bottom of bump stop.

Quad cab with both front seats and driver side rear passenger seat. Gas tank on driver side. Jerry can mounted on driver side. I didn't notice this issue before but I wasn't looking for it. It's a long shot posting this. Someone please point me in the right direction. I feel like I'm going in circles.
Reply With Quote
  #2  
Old 02-29-2016, 05:01 AM
350 Vortec's Avatar
350 Vortec 350 Vortec is offline
Master Fabricator
 
Join Date: Jun 2011
Location: Ireland
Posts: 482
Is it poss to weigh your corners ?? My nissan has side specific coils from factory due to extra drivers side weight(your pas side but it's also my driver side front prop)
Reply With Quote
  #3  
Old 02-29-2016, 10:00 PM
deaner's Avatar
deaner deaner is offline
Master Fabricator
 
Join Date: Jan 2013
Location: Northern Ohio
Posts: 435
Any chance your frame is off? It wouldn't take much.
Reply With Quote
  #4  
Old 03-01-2016, 12:51 AM
whawhat's Avatar
whawhat whawhat is offline
Fabricator
 
Join Date: Dec 2009
Location: Oppressed, California
Posts: 62
Quote:
Originally Posted by 350 Vortec View Post
Is it poss to weigh your corners ?? My nissan has side specific coils from factory due to extra drivers side weight(your pas side but it's also my driver side front prop)
- I suspected the weight issue since it didn't matter which coilover went where. I called the dealer and they said there was two different part numbers but wan't sure if there's a difference on springs. I hate calling the dealer. or any parts place... what vehicle is this for?

- We have scales to weight vehicles but they're for race cars and will not take the trucks weight.

- Now, since you mentioned different springs for each side... I measured the springs on a level surface... (passenger side, which sits taller, has the springs coils 1.125" center to center) (driver side, which sits lower, has the spings coils 1.25" center to center) Preload is 2" on both sides.

I'm gonna let out some pre-load on the taller side, get it aligned and go with what you said, different spring rates.

*** AS FOR THE FRAME BEING POSSIBLY BENT ***
I'd have to ask everyone out there, if you're still reading this thread...

I wheel but I don't mash and trash. It's pretty much controlled movements. I don't have high speed desert stuff out here.

Now, in the mud. Sometimes I try to carry speed to get through stuff and I'll hit pockets of some deep stuff and hit hard. Pockets seem deep enough to impact hard you hear it and feel it vibrate the whole vehicle.

Has anyone bent a frame mudding??????
Reply With Quote
  #5  
Old 03-01-2016, 10:15 AM
Graham08's Avatar
Graham08 Graham08 is offline
Master Fabricator
 
Join Date: May 2006
Location: Denver, NC
Posts: 1,700
Sounds like what you're seeing is due to the extra weight on the left side.

What type of springs do you have on the back? I'm guessing they're something not easily adjusted.

If you have access to scales, and have messed with this on a race car, I'm sure you understand heights and cross weight. The tough part is going to be if you can't adjust the back...and it would be tougher yet if you can't get corner weights to guide you in fixing it. Ideally you would be able to adjust all four corners to get the heights right, then make diagonal adjustments to make the cross weights equal (LF + RR = RF + LR).

The problem you have right now is if you can only adjust the fronts, you can get the truck level by taking preload out of the RF and adding to the LF, but you're going to have more weight on the LF, which will make the truck turn left better than right. I'm not sure which problem would be worse...the "Detroit lean" you have now, or the handling change you would get by "fixing" it.

On edit: one more thought, if you have an anti-roll bar in the front, does disconnecting one side make the truck sit closer to level? That could be aggravating things.
Reply With Quote
  #6  
Old 03-01-2016, 12:28 PM
whawhat's Avatar
whawhat whawhat is offline
Fabricator
 
Join Date: Dec 2009
Location: Oppressed, California
Posts: 62
Hi Graham,

- No sway bar, front or rear.
- I'm moving what is possible to the passenger side... I guess unintentionally I had everything on the driver side as it's easy access for me.
- ADJ the passenger coil to equal out the height and aligning today to see what I get.
- Calling a couple of shops to see if they have scales that can take the weight. To dial it in further.
- ya, I understand cross weights... kinda the reason we are all on this forum, could you imagine this question on a nissan titan forum. Not trying to take away from them but there'd be so many replies of non-sense.
- I think the luck charms hit it right with the different spring rates. I think the best approach is to move the fuel tank to the center and all ancillaries evenly.

Thanks guys
Reply With Quote
  #7  
Old 03-01-2016, 01:21 PM
Graham08's Avatar
Graham08 Graham08 is offline
Master Fabricator
 
Join Date: May 2006
Location: Denver, NC
Posts: 1,700
Quote:
Originally Posted by whawhat View Post
- ya, I understand cross weights... kinda the reason we are all on this forum, could you imagine this question on a nissan titan forum. Not trying to take away from them but there'd be so many replies of non-sense.
Cool, I know what you're saying. You see some crazy stuff on forums with a more wider, more general audience.

I don't know how far you want to take this, but if you strike out on finding higher capacity scales you could make a lever setup to get close. A heavier version of the setup in the pic about halfway down this page:

https://grassrootsmotorsports.com/fo...s/26863/page1/

Reply With Quote
  #8  
Old 03-02-2016, 05:36 PM
350 Vortec's Avatar
350 Vortec 350 Vortec is offline
Master Fabricator
 
Join Date: Jun 2011
Location: Ireland
Posts: 482
Quote:
Originally Posted by whawhat View Post
- I suspected the weight issue since it didn't matter which coilover went where. I called the dealer and they said there was two different part numbers but wan't sure if there's a difference on springs. I hate calling the dealer. or any parts place... what vehicle is this for?

- We have scales to weight vehicles but they're for race cars and will not take the trucks weight.

- Now, since you mentioned different springs for each side... I measured the springs on a level surface... (passenger side, which sits taller, has the springs coils 1.125" center to center) (driver side, which sits lower, has the spings coils 1.25" center to center) Preload is 2" on both sides.

I'm gonna let out some pre-load on the taller side, get it aligned and go with what you said, different spring rates.

*** AS FOR THE FRAME BEING POSSIBLY BENT ***
I'd have to ask everyone out there, if you're still reading this thread...

I wheel but I don't mash and trash. It's pretty much controlled movements. I don't have high speed desert stuff out here.

Now, in the mud. Sometimes I try to carry speed to get through stuff and I'll hit pockets of some deep stuff and hit hard. Pockets seem deep enough to impact hard you hear it and feel it vibrate the whole vehicle.

Has anyone bent a frame mudding??????
Sorry im only getting back to you now,my nissan's are Y60 and Y61,coils on beam,most aftermarket coils are all same rate but genuine coils are side specific and colour coded
Reply With Quote
  #9  
Old 03-02-2016, 08:01 PM
whawhat's Avatar
whawhat whawhat is offline
Fabricator
 
Join Date: Dec 2009
Location: Oppressed, California
Posts: 62
Hi,
Thanks for the replies...

- Going to do the lever arm ratio on scales. Thanks for the idea.
- I reduced the pre-load and leveled the truck. Thinking of getting a different spring rates on one side so I can pre-load it evenly.

Unless this is splitting hairs at the this point?

The suspension does react differently between left and right hand turns. Still need to move things around in the cab and gas tank. Hopefully in a couple of weeks, get it all sorted out.
Reply With Quote
  #10  
Old 03-02-2016, 09:00 PM
deaner's Avatar
deaner deaner is offline
Master Fabricator
 
Join Date: Jan 2013
Location: Northern Ohio
Posts: 435
Glad to here you are going to weigh each corner. Let us know the results.
Reply With Quote
  #11  
Old 03-08-2016, 09:40 PM
whawhat's Avatar
whawhat whawhat is offline
Fabricator
 
Join Date: Dec 2009
Location: Oppressed, California
Posts: 62
Hi Everyone,

I got the race car scales out and ready to fab up the leverage arm. Last time I've seen my trucks weight was at a disposal yard. Going out you sit at a scale... I was at half tank of fuel weighting in at 5,600 lbs.

Definition of my plan...
- If I estimate my corner weights to be 1,400 lbs
- I plan to make the leverage arm a 3:1 ratio
- Tire is 12'' wide

Question I have...
- In order for this to be a ratio.
- Datum would be 0" at fulcrum point, then 18" out center of my contact patch, then 48" out contact patch to scale.
- To re-word this; fulcrum point to 1' out would be the start of my contact patch (12" tire), other end of the tire contact patch would be 2' from the fulcrum point, then 4' out from the fulcrum point would be the contact to the scale.
- Without leading anyone on in my question, will this obtain what I want or this will give me a higher ratio.

Last question...
- I don't know what options I have in Square tube. I don't buy square tube often. I'm thinking 1018 mild, 1"x1" with 0.188" wall. Will that support my corner weight?

I'm asking you guys because if I ask my suppliers any questions on fab work they just give me this blank stare, put antlers on their heads then it wouldn't be so creepy.
Reply With Quote
  #12  
Old 03-09-2016, 10:50 AM
Asm109's Avatar
Asm109 Asm109 is offline
Fabricator
 
Join Date: May 2010
Location: Poway Ca
Posts: 50
I would put a bump or piece of tubing on the lever where the center of the tire sits.
This will concentrate the tire load onto the lever at the proper point. That way you know that reality matches your simple math model. You want to avoid a situation where the tire load gets concentrated on the inner or outer edge of the tire. That would give you wrong results.

1 inch 3/16 wall tubing is NOT strong enough for the lever.

2 inch 1/8 wall will do the job. this is assuming steel with a yield of 35,000 psi.
Reply With Quote
  #13  
Old 03-09-2016, 11:56 AM
Graham08's Avatar
Graham08 Graham08 is offline
Master Fabricator
 
Join Date: May 2006
Location: Denver, NC
Posts: 1,700
Quote:
Originally Posted by whawhat View Post
Hi Everyone,

I got the race car scales out and ready to fab up the leverage arm. Last time I've seen my trucks weight was at a disposal yard. Going out you sit at a scale... I was at half tank of fuel weighting in at 5,600 lbs.

Definition of my plan...
- If I estimate my corner weights to be 1,400 lbs
- I plan to make the leverage arm a 3:1 ratio
- Tire is 12'' wide

Question I have...
- In order for this to be a ratio.
- Datum would be 0" at fulcrum point, then 18" out center of my contact patch, then 48" out contact patch to scale.
- To re-word this; fulcrum point to 1' out would be the start of my contact patch (12" tire), other end of the tire contact patch would be 2' from the fulcrum point, then 4' out from the fulcrum point would be the contact to the scale.
- Without leading anyone on in my question, will this obtain what I want or this will give me a higher ratio.

Last question...
- I don't know what options I have in Square tube. I don't buy square tube often. I'm thinking 1018 mild, 1"x1" with 0.188" wall. Will that support my corner weight?

I'm asking you guys because if I ask my suppliers any questions on fab work they just give me this blank stare, put antlers on their heads then it wouldn't be so creepy.
Your math is close, if your levers are 48" long, the center of the tire being at 16" from the point where the lever is on the ground and 32" from the point the lever touches the scales, the force at the scale will be 1/3 of the force at the wheel (3:1 ratio). ASM109 makes a very valid point about the location of the tire contact patch on the ground. We normally don't know for sure where that point is. As long as you're close to zero camber, it will be reasonably close the the center of the tire. The larger the camber angle, the further away from center this point is, and it becomes really dependent on the tire construction and mold shape to say how far it moves.

Why a 3:1 ratio? I think my Intercomp scales have 1500 lb capacity pads. With your ballpark of 1400 lb per corner, 2:1 would get you well within the capacity of the load cells. I'm assuming your truck is probably nose heavy, so you'll be over that 1400 on the front and under on the rear...but still pretty far away from hurting anything with a 2:1 lever. The lower the lever ratio, the more precise the numbers off the scales will be (in this case 2 lb increments at the wheel instead of 3 lb), and the less sensitive it will be to slight error in centering the tire on the lever.

I would be looking at 1" x 2" x 0.120" rectangular tube, or 1.5" x 3" x 0.120". The height is what is going to help in this situation. The stiffer you can make the levers the better, because flex in the levers is going to allow cross weight to "disappear" in the same way a flexible chassis will.
Reply With Quote
  #14  
Old 05-13-2016, 04:53 PM
whawhat's Avatar
whawhat whawhat is offline
Fabricator
 
Join Date: Dec 2009
Location: Oppressed, California
Posts: 62
Hi,
Just wanted to update this posting.
The Com10-T or heim joints on the coilovers were blown out. So decided to fix that and any other issues. Alignment and so on...

With the new heim joints installed, it resolved most of the issue. As well adding preload on the LF coil sping.

The LR left spring pack is definitely worn out and causing the truck to lean a little left. I swapped the left springs around and the problem changed sides.

I was not able to build the leverage ratio arm as I'm not working and trying to conserve my money right now. As soon as I get back on my feet. I do want to check the cross weight and will post it. Hopefully in a month I'll be back working again.
Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 08:11 PM.

Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Template-Modifications by TMS
Copyright 2012, Offroad Fabrication Network