Stretched TJK (bigger rubber & extra inches)

[B00mb00m]

Here's where I need some help. My first question, Is too much down travel a bad thing?

I began playing with shock towers (Poly Performance) and a cardboard mock-up lower coilover mount. One side of the coilover mount will get welded to the axle tube, the other will straddle the control arm mount. As pictured, the tower sits within the engine bay with 2"+/- of height left over.

Current travel:
Bump: 22.75"
Ride height: 28.25"
Droop: 37" (disc on the ground).. I'm sure it can go more.

Poly's towers are short, compared to other manufacturers. Should I get a 2" taller tower & go with a 16" coilover?

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You start from ride height, and set up the top of your shock such that it is your bumpstop to get your max uptravel but give you a hard stop from keeping anything on the axle or tires from hitting something you don't want it to hit. If the poly towers dont give you the uptravel you need then modify the brackets. 14" CO's are more than enough. Max droop is wherever your shocks stop or your UJ's bind or the axle goes crashing into something (like driveline into exhaust). You have to ck your droop under articulation also not just straight droop. I added limit straps, which i believe are not necessary but i liked the idea and wanted to make it racer-y.

 

[sierradmax]

I would encourage you to not leave 1/2" of shaft at bump. In the front you need a hard bump that is the absolute limit of how far stuff can move. If you put a 1/2" of shaft showing and your upper joint is less than 1/2" from the AC compressor body, then a hard stuff of the front can result in damage to the compressor when the motor moves down on the rubber mounts to meet the axle coming up and the frame flexing.

Would air bumps help?

 

[starkey480]

You start from ride height, and set up the top of your shock such that it is your bumpstop to get your max uptravel but give you a hard stop from keeping anything on the axle or tires from hitting something you don't want it to hit. If the poly towers dont give you the uptravel you need then modify the brackets. 14" CO's are more than enough. Max droop is wherever your shocks stop or your UJ's bind or the axle goes crashing into something (like driveline into exhaust). You have to ck your droop under articulation also not just straight droop. I added limit straps, which i believe are not necessary but i liked the idea and wanted to make it racer-y.

Racer-y limit straps to prevent too much hangy downy. This forum speaks my language

 

[jjvw]

Would air bumps help?

If they create a hard stop before damage elsewhere happens.

 

[mrblaine]

Would air bumps help?

Doesn't matter. You need an absolute hard bump that limits how far the axle can move up and then stop before bad things happen. Accomplish that however you like but if you don't then you shouldn't be surprised when bad things happen.

 

[mrblaine]

You start from ride height, and set up the top of your shock such that it is your bumpstop to get your max uptravel but give you a hard stop from keeping anything on the axle or tires from hitting something you don't want it to hit. If the poly towers dont give you the uptravel you need then modify the brackets. 14" CO's are more than enough. Max droop is wherever your shocks stop or your UJ's bind or the axle goes crashing into something (like driveline into exhaust). You have to ck your droop under articulation also not just straight droop. I added limit straps, which i believe are not necessary but i liked the idea and wanted to make it racer-y.

You have control of ride height, you can set it wherever you like. The rig tells you where full stuff is, you can't arbitrarily change that once you get all it has. Ride height is set down from full hard bump.

 

[B00mb00m]

Racer-y limit straps to prevent too much hangy downy. This forum speaks my language

I think we could be friends.

 

[sierradmax]

A little more progress today.

Towers were tacked in place
Lower coilover mounts were cut
Suspension was cycled to make sure there was no interference. Dual rate slider runs up and down the shock body, freely.

Pulled the axle to finish welding the control arm & coilover mount. Machine was welding good until the wire just stopped. Not sure how but the liner developed a kink.. New liner ordered.

Any good, simple, & clean ideas for tower a brace/reservoir mount?

 

[sierradmax]

I need to start thinking about an air intake as it relates to the construction of my tower brace. @B00mb00m , any suggestions?

 

[B00mb00m]

I need to start thinking about an air intake as it relates to the construction of my tower brace. @B00mb00m , any suggestions?

This one is still yet undone for me. I did the old chop and cone filter. Has worked for 2 years. My final plan is for the Windstar into the cowl then a snorkel but it's a whole project. I got all the parts in my garage just got to quit starting new projects!

 

[sierradmax]

My goal this weekend is to fabricate a tower crossmember support. I've cut & bent some plate to bolt to the top of the towers and I have a 6' piece of 1.5" sch40 pipe. I'll have to put a bend at both ends and angled a bit towards the cab, in order to clear the A/C lines. Any tips to "birdsmouth" the ends so the crossmember fits nicely? Or should I buy more pipe for sure to happen mistakes?

 

[mrblaine]

My goal this weekend is to fabricate a tower crossmember support. I've cut & bent some plate to bolt to the top of the towers and I have a 6' piece of 1.5" sch40 pipe. I'll have to put a bend at both ends and angled a bit towards the cab, in order to clear the A/C lines. Any tips to "birdsmouth" the ends so the crossmember fits nicely? Or should I buy more pipe for sure to happen mistakes?

Sneak up on it like always.

 

[sierradmax]

Crossmember was easier than expected. I wanted to maintain at least 24" of horizontal length to mount the reservoirs in front. In order to do so and clear the crankcase vent, two 48 degree legs turned down to the towers where the pipes sat on the plates almost perpendicular. My Harbor Freight pipe kinker worked fairly well here. Like Blaine said, sneak up on it.. I shaved a 1/4" each time until it nested nicely.

 

[mrblaine]

Crossmember was easier than expected. I wanted to maintain at least 24" of horizontal length to mount the reservoirs in front. In order to do so and clear the crankcase vent, two 48 degree legs turned down to the towers where the pipes sat on the plates almost perpendicular. My Harbor Freight pipe kinker worked fairly well here. Like Blaine said, sneak up on it.. I shaved a 1/4" each time until it nested nicely.

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FYI, you could have mounted them even if it were considerably shorter. Nothing says the clamps have be at the ends of the reservoirs. You could have hung the opposing ends over several inches and put a pair of clamps a few inches apart on the remaining section of bar.

 

[sierradmax]

FYI, you could have mounted them even if it were considerably shorter. Nothing says the clamps have be at the ends of the reservoirs. You could have hung the opposing ends over several inches and put a pair of clamps a few inches apart on the remaining section of bar.

True.. My OCD had symmetry in mind. With that much of a bend, should I add a gusset at each side?

 

[mrblaine]

True.. My OCD had symmetry in mind. With that much of a bend, should I add a gusset at each side?

No and my OCD is just as bad. That means the clamps have to be the same distance in from each end, the screws have to line up with each other, and the amount each reservoir overhangs past the bend has to be the same.

 

[sierradmax]

Front is finally sitting on it's own weight... For now.

675# corner weight. 75 in/lb. combined rate..

On a stacker chart, a 150 primary, 150 secondary achieves 75 in/lb. Should I swap for a soft primary, firm secondary like a 130/175?

 

[B00mb00m]

Front is finally sitting on it's own weight... For now.

675# corner weight. 75 in/lb. combined rate..

On a stacker chart, a 150 primary, 150 secondary achieves 75 in/lb. Should I swap for a soft primary, firm secondary like a 130/175?

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I don't know anything about spring rates but accutune does have articles that explain their recommendations.n

How did you do for clearance to RCVs to the bj deletes?

 

[sierradmax]

I don't know anything about spring rates but accutune does have articles that explain their recommendations.n

How did you do for clearance to RCVs to the bj deletes?

The more I read into it, I think I'll wait until I get all wheels on the ground, sitting level @ ride height & trail weight before I go and order coils.

I think the front will net 5.5"-6" of shaft showing, depending on desired ride height and forward rake. That being said, I've read that figuring out stacked spring rate should consist of the amount of shaft compressed + 1"-2" to account for pre-load. This way there's 60lb.-100lb. of pressure at full droop.

As for the Deletes, no clearance was necessary. Josh said this amount of contact will "self clearance".

 

[mrblaine]

The more I read into it, I think I'll wait until I get all wheels on the ground, sitting level @ ride height & trail weight before I go and order coils.

Much better.