88’ Raingutter Ranger

[MTSuarez]

Was able to do a bit more work on the truck with the info I've been given. With the 16/18 setup I'm getting around 30" of travel, and this is what the sway bar angles are looking like.

 

[FasterNU]

driveline gonna handle that much travel?

 

[MTSuarez]

driveline gonna handle that much travel?

Should be fine, guys are running 34-36" with minimal plunge. From ride height it's 13 degrees up, 16 degrees down. Travel still has to be restricted with limit straps and bumpstops/rubber stops on the shocks.

 

[FasterNU]

^^ I just looked back... your links are 60" long. Makes more sense now.

Either way... seems like too much travel!!!

 

[MTSuarez]

^^ I just looked back... your links are 60" long. Makes more sense now.

Either way... seems like too much travel!!!

I was considering trading my 18” coils for 20”s to get the 4” more inches

 

[MTSuarez]

Ended up making more alterations to the main cab for better tie in points to the backhalf (ignore some of the back wall tubes, need to go back and adjust them) Pretty happy in the direction its going, will start finalizing and prepping the tube work for laser. Indecisive on which option to do to tie the sway bar to the cab (straight shot or x pattern), included pics of both options to get some opinions.

 

[MTSuarez]

Hey all, looking for some insight. I've watched several videos and went through everything I could find on Race Desert but couldn't get anything definitive. Working around rear suspension numbers and trying to figure out my pinion change throughout the travel. Is it better to allow the pinion to swing up towards the transmission as it droops out? Or is it better to have it stay "parallel" with the transmission output? Seems like you place the U-Joints at a much harsher angle if you try to keep them parallel throughout the suspension travel. Trying to find a happy medium since changing between those two drastically changes my anti-squat numbers. Im also sitting with 2.6" of driveshaft plunge. Hard to get everything happy but I know that's everyone's case!

 

[FasterNU]

^^^ was just going to say.. that is all related to your squat/antisquat...

I'm sure people will argue with me... especially leaf springs...but I feel like 2.6" is a bit on high end for plunge... but you do have an ungodly amount of travel too.

Take this from a guy who has only bolted on kits really. hahah. I'm no expert for sure.

You are certainly asking all the good questions. This is the stuff it seems nobody really wants to answer. I couldn't get "squat" for info(pun intended) on this geometry question when I tried, nor on the sway bar rates like you were researching too.

Funny thing is... everyone seems to have an opinion when it comes to valving... but this other info is like KFC's secret recipe guarded in vaults. LOL

 

[the bodj]

Correct me if I'm wrong, but I believe a lot of this depends on driveshaft joint type.



For what it looks like you're doing (keeping trans output parallel with the pinion), there is a margin of about 1* in either direction that they can be out of alignment and not cause vibrations. You can mess with link and pivot geometry to induce a small amount of rock back on the pinion to help your angles at full droop.

 

[the bodj]

Here's the 4 link calculator I used. I know you're solid at CAD, but this spits out the numbers really fast

https://irate4x4.com/resources/4-link-calculator.4/updates#resource-update-133

Download button is in top right

 

[36Fan]

2.6" of plunge is too much, 1" or less is a number to shoot for. 34-36" of travel is not gonna happen without bad side effects, 30-33" and you'll be way better off. Most fight vibration at some point in the travel, droop is a common one. Try lowering your tailshaft pivot and check your plunge again. 13" of up travel is a fair amount, drooping 15"+ is going to cause binding. What are you horizontal/vertical pivot measurements at the frame?

 

[the bodj]

What motor is this thing going to get? 30" is a lot to push through

 

[MTSuarez]

Correct me if I'm wrong, but I believe a lot of this depends on driveshaft joint type.

View attachment 45751

For what it looks like you're doing (keeping trans output parallel with the pinion), there is a margin of about 1* in either direction that they can be out of alignment and not cause vibrations. You can mess with link and pivot geometry to induce a small amount of rock back on the pinion to help your angles at full droop.

Correct depends on joint type. However from what I understand the 3° is for normal driving angles. You should not see the same forces on the driveline at full droop (in the air)

Check out short length builds and the driveline/pinion angles on them

https://www.instagram.com/reel/DD-HAqzJ_uL/?igsh=NTc4MTIwNjQ2YQ==

 

[MTSuarez]

2.6" of plunge is too much, 1" or less is a number to shoot for. 34-36" of travel is not gonna happen without bad side effects, 30-33" and you'll be way better off. Most fight vibration at some point in the travel, droop is a common one. Try lowering your tailshaft pivot and check your plunge again. 13" of up travel is a fair amount, drooping 15"+ is going to cause binding. What are you horizontal/vertical pivot measurements at the frame?

I’m reading on trucks with 4”, but that’s with larger travel numbers. I’m sitting at 30” metal to metal so it will be bumped and strapped short

This should be my most updated pivot locations.

 

[MTSuarez]

Guess my real concern is if I’m bumped and strapped less than 30”, how are trucks with 36” of travel having no issues. I’m basically running a back half mirrored after these trucks with 60” links.

 

[MTSuarez]

Here's the 4 link calculator I used. I know you're solid at CAD, but this spits out the numbers really fast

https://irate4x4.com/resources/4-link-calculator.4/updates#resource-update-133

Download button is in top right

What motor is this thing going to get? 30" is a lot to push through

This has been the calculator I’ve been working with. Big help but doesn’t answer all these more technical questions.

Running a 331 SBF with a Culhane C6 Race Tranny

 

[36Fan]

Don't go off what people say, go off what works for you. Keep the u joint angles at the trans happy and the plunge numbers as low as possible. If I read that correctly you have 6.35" vertical and 10" horizontal separation at the frame end? Whats your u joint centerline height at the trans from the lower link pivot at the frame? Guessing your shooting for a belly height of 19-20" from ground or do you have the lower link mounts beneath the belly?

 

[MTSuarez]

Don't go off what people say, go off what works for you. Keep the u joint angles at the trans happy and the plunge numbers as low as possible. If I read that correctly you have 6.35" vertical and 10" horizontal separation at the frame end? Whats your u joint centerline height at the trans from the lower link pivot at the frame? Guessing your shooting for a belly height of 19-20" from ground or do you have the lower link mounts beneath the belly?

The 6.35” vert is correct. Not sure about the 10” horizontal, that doesn’t make sense. The upper and lowers have about 38” horizontal at the frame. There’s ~11” vert at the axle end. If I start to raise the separation at the frame to “help” the pinion angle stay the same (parallel upper and lowers), the anti squat quickly drops into the 20-30%.

Lowers are raised 2” from the belly of the cab to help with the anti squat numbers at the ride height I want. They are 21” from the ground

 

[the bodj]

What antisquat numbers are you shooting for? I've got 2/3 your travel, but I'm in the 20-30% range and absolutely love it.

 

[36Fan]

The 6.35” vert is correct. Not sure about the 10” horizontal, that doesn’t make sense. The upper and lowers have about 38” horizontal at the frame. There’s ~11” vert at the axle end. If I start to raise the separation at the frame to “help” the pinion angle stay the same (parallel upper and lowers), the anti squat quickly drops into the 20-30%.

Lowers are raised 2” from the belly of the cab to help with the anti squat numbers at the ride height I want. They are 21” from the ground

You have a ride height of 19", lowers are at 21" and uppers 27.35". Your u joint CL at the trans needs to be lower in the chassis to achieve less plunge. Your lowers are 60" and your upper links are 49.75" long? The pinion will need to rotate up (some) at droop or you'll have binding at the diff u joint and bad angles at the trans. I would focus on making the driveline happy first and then shoot for your AS numbers. Your CG location will be a guess at this point, which will make you AS numbers a guess as well. Another thing is to pay attention to is your axle location at full bump, too far up and the horizontal separation of the chassis tube layout gets weak (too close together).

I have almost the exact set up on my chassis table right now. 60" lowers, 51" uppers with 7" vertical separation at the frame and a ride height of 19". 15" up travel puts the tire (40's) at the top of the bedsides without touching on F150 Raptor glass.