How's my numbers?

[Treefrog]

Treefrog- The trac bar and draglink are both 32.5" and within 1 degree of being parallel to each other (used a string between the mounting bolts for the tracbar, since it has a bend in it.)


Here is the Roll Slope and Roll Center that you requested. It doesn't swerve bad- fine for me. I just am trying to make it a little better, so my wife feels more comfortable driving it.
Appreciate you taking a look.

Hmm. Probably not steering then. Assuming bushings on the upper and lower links since it looks to be a 4 link. Front has oversteer tendencies. That could be part of it. But nothing really stands out that would cause darting. Does it dart more or less if its a left turn or a right turn? Does it dart more if the inside tire vs the outside tire hits the bump?

 

[Honky Lips]

ok. trying to figure the calculator out as its been 4-5 years since i used it. downloaded 5.4 and im trying to see if i should move my lower links on the axle.

what are the x y and z measurements for rear links?

 

[Treefrog]

ok. trying to figure the calculator out as its been 4-5 years since i used it. downloaded 5.4 and im trying to see if i should move my lower links on the axle.

what are the x y and z measurements for rear links?

Combining the response to this and your question on the calc thread about metric.

They are the end points of the links. Which axis is which is shown on the coordinates systems tab of the calc. Lots of other info on the Read Me tab.

By default it is in standard US Imperial units. Metric was added in version 6.0. All versions before that were based on imperial units.

 

[Joecova]

Thanks for updating the calculators. I was using v3 for a long time but not sure I ever really understood it. I'm rebuilding an old Jeep from scratch so working within some restrictions with a 4-link rear and radius arms up front. I wasn't sure how the radius arms would really calculate but this is the current rough estimates I have for front and rear, not realloy sure what I am looking at.

 

[Treefrog]

Thanks for updating the calculators. I was using v3 for a long time but not sure I ever really understood it. I'm rebuilding an old Jeep from scratch so working within some restrictions with a 4-link rear and radius arms up front. I wasn't sure how the radius arms would really calculate but this is the current rough estimates I have for front and rear, not realloy sure what I am looking at.

For radius arms the frame point needs to be the same. From a quick glance, the front roll slope is really high, but radius can cause that.

 

[Joecova]

For radius arms the frame point needs to be the same. From a quick glance, the front roll slope is really high, but radius can cause that.

Thanks! Made the adjustments and looks like the roll slope went up a couple of degrees, not sure how much I can really do to fix that. I have the suspension mocked up to the axles and frames so I feel the measurements are close to current. Thoughts on the rear?

 

[Treefrog]

Thanks! Made the adjustments and looks like the roll slope went up a couple of degrees, not sure how much I can really do to fix that. I have the suspension mocked up to the axles and frames so I feel the measurements are close to current. Thoughts on the rear?

Don't worry about it to much. It's not accurate for radius arms.

The antis are high. Trying to get those down to under 50 may be worth it.

 

[Joecova]

Don't worry about it to much. It's not accurate for radius arms.

The antis are high. Trying to get those down to under 50 may be worth it.

Awesome, thank you for the feedback. I'll see what I can do!

 

[ash]

Ok figured out compatibility on a Mac with 5.5...any thoughts on these numbers? This is on a Defender retaining the weird factory upper wishbone setup on the rear axle, but re-working the lowers, and starting from scratch on the front end. Doesn't incorporate real panhard numbers yet, since I haven't figured any of that out.

If I raise my lowers up to centerline on the axles the anti's drop into the 30's but I'm still not totally clear on what an ideal target is there.

 

[Treefrog]

Ok figured out compatibility on a Mac with 5.5...any thoughts on these numbers? This is on a Defender retaining the weird factory upper wishbone setup on the rear axle, but re-working the lowers, and starting from scratch on the front end. Doesn't incorporate real panhard numbers yet, since I haven't figured any of that out.

If I raise my lowers up to centerline on the axles the anti's drop into the 30's but I'm still not totally clear on what an ideal target is there.

30s would be fine. Probably a little better than what they are now.

Rear roll slope may be worth getting negative.

Front antis may be a tad high.

Anything roll related up front is not accurate until you have the panhard stuff in.

Watch your rear pinion angle; you may want more.

 

[BauerPower]

I'd love some feedback on a 4 link I am putting into a YJ. Front 3-link was built by an offroad shop in Florida with plans for a 4 link at some point.

Use case: Ultra 4 races, KOH, line mountain, and the like with some desire to get technical in the rocks. Not moon buggy level however.

Front is already built, so the calculator just represents current placement. Upper link has the only adjustment available and is set to the highest adjustment hole.
Rear is what I'm trying to either match or set better and then worry about modifying the front if needed.

Using the brackets that were pre ordered i made the first image and had a clearance issue for the lower frame side mount to tcase (0.25" - touching). I played around and made the second image. Is one better than the other? I like the second set better for fabbing, i think the Roll center height is better compliment to the front setup, and total triangulation is not at 80*.

Any opinions on the two, which i should focus on and what should i tweak? Open to suggestions and corrections.

Barnes 4wd kit- No Modification

Adjustment for Clearance and Triangulation:

YJ in question:

 

[Treefrog]

I'd love some feedback on a 4 link I am putting into a YJ. Front 3-link was built by an offroad shop in Florida with plans for a 4 link at some point.

Use case: Ultra 4 races, KOH, line mountain, and the like with some desire to get technical in the rocks. Not moon buggy level however.

Front is already built, so the calculator just represents current placement. Upper link has the only adjustment available and is set to the highest adjustment hole.
Rear is what I'm trying to either match or set better and then worry about modifying the front if needed.

Using the brackets that were pre ordered i made the first image and had a clearance issue for the lower frame side mount to tcase (0.25" - touching). I played around and made the second image. Is one better than the other? I like the second set better for fabbing, i think the Roll center height is better compliment to the front setup, and total triangulation is not at 80*.

Any opinions on the two, which i should focus on and what should i tweak? Open to suggestions and corrections.

Barnes 4wd kit- No Modification

Mind sharing which shop?

Assuming that pinion movement is good, The second one is probably better on antis, while the first one is better on roll center and slope at ride height. At risk of messing with the antis, try moving the upper axle down some.

If you are wanting to go faster, you should probably consider a wheelbase in the 110+ inch range.

 

[BauerPower]

Mind sharing which shop?

Assuming that pinion movement is good, The second one is probably better on antis, while the first one is better on roll center and slope at ride height. At risk of messing with the antis, try moving the upper axle down some.

If you are wanting to go faster, you should probably consider a wheelbase in the 110+ inch range.

Thanks Treefrog for the feedback.

Shop is Happy Trails 4x4 out of Atlantic Beach, FL. The work, welds, and so far design/setup look pretty good to me. Just a minor touch up needed for frame clearance on the drivers front. No fault of the shops, just improving gaps to get a min 6" up travel.

Didn't even notice i left off the Pinion movement, I've been staring at this for far too long.
Overall, both pinion change values didn't look scary or extreme.

1) Barnes 4wd kit- No Modification

2) Adjustment for Clearance and Triangulation:

I can play with the upper axle side and see what changes for the second option.

I agree on increasing the wheel base. The rear is already pushed as far back as allowed and the front will have issues since it needs to maintain a mechanical linkage, Ultra 4 4500 Class rule. Easiest seems be adding 10" of frame length right behind the atlas. With the current 2 options, a wheelbase increase was ~4-5% increase to A/S at full droop, negligible change at ride height or compression. I should be able to do that after i figure out the link locations as long as i leave some adjustment holes.

Thanks

 

[C4500towmater]

2006 C4500 4x4. The most offroad it will see is going on the beach. really trying to make it ride softer by air bagging it. making the lower links as level and as long as possible i know will help that also. should i lower the anti squat and front dive?

 

[Treefrog]

2006 C4500 4x4. The most offroad it will see is going on the beach. really trying to make it ride softer by air bagging it. making the lower links as level and as long as possible i know will help that also. should i lower the anti squat and front dive?

That's a big truck. Assuming you are aiming for a softer road ride. Change the drive bias from 0.5 to 1 for pavement. A lower antisquat will be softer when accelerating. I would suggest aiming for below 100%. The lower front dive is the smoother it will feel braking, but it will dive more.

For driving along the road at constant speed, longer flatter links, less unsprung mass, the correct spring rate and shock tuning, and attention paid to keeping the body from pitching when hitting bumps.

Edit: more down travel will help with the ride. But may mean more uptravel is needed to keep it out of the bump stops.

 

[C4500towmater]

That's a big truck. Assuming you are aiming for a softer road ride. Change the drive bias from 0.5 to 1 for pavement. A lower antisquat will be softer when accelerating. I would suggest aiming for below 100%. The lower front dive is the smoother it will feel braking, but it will dive more.

For driving along the road at constant speed, longer flatter links, less unsprung mass, the correct spring rate and shock tuning, and attention paid to keeping the body from pitching when hitting bumps.

Edit: more down travel will help with the ride. But may mean more uptravel is needed to keep it out of the bump stops.

I'm planning on air springs at all corners, it currently has rear air ride but with a trailing arm set up. The weight of the truck is 13k but the calculator doesn't go higher than 9999. Ha Ha. From my reseach having a really high rear anti squat is good for traction but not for braking. Do you think it will be a problem? If i try to keep both rear anti squat and front dive in the 70s or 60s would that be the best comprimise?

 

[Treefrog]

I'm planning on air springs at all corners, it currently has rear air ride but with a trailing arm set up. The weight of the truck is 13k but the calculator doesn't go higher than 9999. Ha Ha. From my reseach having a really high rear anti squat is good for traction but not for braking. Do you think it will be a problem? If i try to keep both rear anti squat and front dive in the 70s or 60s would that be the best comprimise?

It should go above 9999. A 5 digit number may be to long for it to display so it may display ###### instead. Try widening the column to get it to show.

Your research is correct. But it should be noted that the increased traction is at launch. The front is similar but for braking. Higher AD results in more braking traction, but it will stiffen the vehicle against bumps in the road while braking.

But higher antis reduce vehicle pitch when starting and stopping. Passengers may find this to be more comfortable.

Theoretically antis shouldn't have much if any effect when at a constant speed.

I'm sure you know this, but you are going to need some beefy links especially with how long they are.

 

[C4500towmater]

It should go above 9999. A 5 digit number may be to long for it to display so it may display ###### instead. Try widening the column to get it to show.

Your research is correct. But it should be noted that the increased traction is at launch. The front is similar but for braking. Higher AD results in more braking traction, but it will stiffen the vehicle against bumps in the road while braking.

But higher antis reduce vehicle pitch when starting and stopping. Passengers may find this to be more comfortable.

Theoretically antis shouldn't have much if any effect when at a constant speed.

I'm sure you know this, but you are going to need some beefy links especially with how long they are.

ill try just inputting the weight and yes my links will be 2.5 inch .250 dom with 1.5 inch rod ends with 1 inch thu bolts. Thank you for the suggestions!

 

[Treefrog]

ill try just inputting the weight and yes my links will be 2.5 inch .250 dom with 1.5 inch rod ends with 1 inch thu bolts. Thank you for the suggestions!

If I may give another suggestion, try running those numbers on the link sizing page.

Edit: Just checked for any restrictions regarding weight inputs. It will show ##### for a 5 digit number. If you make the column wider it will show the full number correctly.

 

[C4500towmater]

If I may give another suggestion, try running those numbers on the link sizing page.

Edit: Just checked for any restrictions regarding weight inputs. It will show ##### for a 5 digit number. If you make the column wider it will show the full number correctly.

I did a search on here and nothing comes up for link sizing page. Am i missing something? link?

 

[Treefrog]

I did a search on here and nothing comes up for link sizing page. Am i missing something? link?

It's is one of the sheets of the 4 link calculator Excel file. Lower left corner of the screen. The tab labeled "Link Sizing".

 

[Felsenbeisser]

Just found this updated calculator and entered my numbers. I'd appreciate some feedback on them. It's an existing build and has worked so far but just like everything, there's always room for improvement and to learn for the next built.

 

[Treefrog]

Just found this updated calculator and entered my numbers. I'd appreciate some feedback on them. It's an existing build and has worked so far but just like everything, there's always room for improvement and to learn for the next built.

Any issues with wheel hop or over oddities when climbing? Probably a little rough when on the brakes. Roll stuff is decent for a crawler, a bit lower would probably be better for speed. Front pinion change could be sketchy at speed since camber likely inverts as the axle droops. As far as improvements, maybe flatter links, and a little lower antis.

 

[Felsenbeisser]

Any issues with wheel hop or over oddities when climbing? Probably a little rough when on the brakes. Roll stuff is decent for a crawler, a bit lower would probably be better for speed. Front pinion change could be sketchy at speed since camber likely inverts as the axle droops. As far as improvements, maybe flatter links, and a little lower antis.

Treefrog, thanks for your prompt response!
It used to have some wheel hop at steep climbs but I guess running water masked that with more unsprung weight on the ground. Not to worried about speed since it's, as you noticed, a pure crawler.
How would I go about lowering the antis? Don't really have a grab on flattening the links without reducing belly height, which with that wheelbase might end up causing more problems on the brake over angle. Except for maybe the uppers, which are mounted with 3 hole brackets using the center one.

 

[Treefrog]

Treefrog, thanks for your prompt response!
It used to have some wheel hop at steep climbs but I guess running water masked that with more unsprung weight on the ground. Not to worried about speed since it's, as you noticed, a pure crawler.
How would I go about lowering the antis? Don't really have a grab on flattening the links without reducing belly height, which with that wheelbase might end up causing more problems on the brake over angle. Except for maybe the uppers, which are mounted with 3 hole brackets using the center one.

Did you add water to just the front tires? Did you change anything else related to suspension or weight distribution? Did both axles hop or just one? Getting a better grasp on wheel hop causes and solutions has been on my to do list for some time.

Moving to the upper hole should help lower the antis some. Flat links are more important for speed than for crawling.

 

[Felsenbeisser]

Did you add water to just the front tires? Did you change anything else related to suspension or weight distribution? Did both axles hop or just one? Getting a better grasp on wheel hop causes and solutions has been on my to do list for some time.

Moving to the upper hole should help lower the antis some. Flat links are more important for speed than for crawling.

Yes, front only. The hop was dominant in the front but once it started, it eventually made it's way to the rear as well. With the water and its added traction/downforce, It eliminated the hopping almost completely. I also just changed the front main coils from 250 to 200 but haven't really run them yet and they therefore haven't settled at all.
Thanks for the advise on the upper. Haven't even thought about that! I can see the difference in the calculator after entering that change.

 

[j.mcconnell]

I'm going to throw mine in here before I weld everything out.
Basic TJ on 60s. TMR single triangulated frame brackets and Barnes stuff on the axle end. About a 2" stretch once I moved the coil buckets and lined everything up. Frame brackets are tight against the factory skidplate nutserts and all joints are in a neutral position. I added some math to the spreadsheet to play with belly heights. Front 3link is an estimate until I get the factory stuff cut off and mock up the new.

 

[Treefrog]

I'm going to throw mine in here before I weld everything out.
Basic TJ on 60s. TMR single triangulated frame brackets and Barnes stuff on the axle end. About a 2" stretch once I moved the coil buckets and lined everything up. Frame brackets are tight against the factory skidplate nutserts and all joints are in a neutral position. I added some math to the spreadsheet to play with belly heights. Front 3link is an estimate until I get the factory stuff cut off and mock up the new.

Antis are a bit high. It may be worth looking into lowering the upper axle points some.

 

[chaplinfj60]

i was just looking at the sheet , mine and yours, why do we have to put numbers in the rear pan hard bar section if we dont have a pan hard bar

 

[j.mcconnell]

Antis are a bit high. It may be worth looking into lowering the upper axle points some.

This leads to a question I've had, but never asked. I feel like the consensus is to get the AD down in the 30-50% range and go toward the lower end of that if you're anticipating faster dez stuff. Are those numbers based on a drive bias of 0% or 50%? 50% drive bias halves the AD so I figured I was good. I'll be doing east coast trail wheeling with some limited street time.