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Old 10-09-2019, 04:35 PM
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Default Choosing/Optimizing Shock Length/Travel

First, I apologize for the lengthy initial post but I wanted to provide enough detail for better/specific responses. The necessary background info:

I've been researching coil-over options for a couple of vehicles I'm working on. The first is a C10 that's being retrofitted w/coil-overs from an air suspension (aftermarket front x-member w/R&P steering). The manufacturer of the suspension now offers a coil-over version but it's different vs. the older version I have installed. His recommendation was to pull the current air suspension based front cross-member & get one of his C/O set-ups. I built the rear suspension for the truck so I feel I can tweak what I have to install & use C/O's @ substantial savings. I know what he specs for his C/O set-up & it's the same as Ridetechs C/O offering for C10's. But the shock travel just seems short... as in OEM limitations short vs. what it 'could' have. I'm also wrenching on a G-body that I've already lowered using 2" spindles, stock steering, Hotchkis 600# 1" drop front coils + bump-stops, & Ridetech adjustable front shocks set to full 'stiff'. It needs a little more spring rate & I would like more adjustability that C/O's would allow.

So, these two different rides with two different set-ups got me researching C/O options. I seem to find most aftermarket systems list shock set-ups very close to what the OE shock travel specs were & oddly (or not?) both have the same recommended shock travel spec of 3.6" stroke length (using Ridetechs easily accessed guide/tech specs).

Since I'm building my own front upper mounts on the truck it seems I can build for more compression/rebound travel. Same w/the car... Seems one can open up the frame & mount the upper end of the shock higher (clearance permitting) which again would allow for increased travel. Speed-Tech & Global West do this w/their A-body kits.

I built my dually (a different truck vs. the one mentioned above) w/a 3" compression/3" extension goal on the suspension. I set my shocks & springs so they could travel up to those dimensions w/o bottoming out & it works as planned. It's low, doesn't bottom out, & rides good on real-world, pothole infested roadways. The 3.6" stroke recommendation is much less then 'my' spec but that's where I wonder just how much is 'better' or if I should just stick to my 3/3 goal & build accordingly.

Using Ridetechs 'universal' spec guide for their C/O shocks, they offer stroke listings beyond the 3.6 stroke spec'd for both vehicles (4,1, 5.2, 6.3, & 6.9). Obviously, with greater stroke dimension comes added shock length. Their spec'd 3.6 stroke travel yields ~2.1" of compression & ~1.5" of extension which seems too little to me. Using my 3/3 goal, the 5.2 stroke seems closer to real world (~3.27" comp; ~1.93" extension).

Thus my thread post.... How do you guys plan your builds? What is the minimal shock travel you use for optimum front suspension travel?
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Old 10-09-2019, 05:14 PM
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I will always take more travel if I can get it.

First, leave the shocks out of the equation. How much travel do you have before moving parts crash into not moving parts or something binds up......I'm looking at you ball joints. Now you know how much travel you can have, then you decide how much travel you need.

After that, how much room do you have to package the shock that gives you the desired travel? If it's wide open, hammer down. If not, decide where to compromise.

Don't forget motion ratio when calculating _wheel travel_ as it relates to shock travel. Ride Techs strong arms for your application have a .646 motion ratio so the 3.6" stroke shock yields 5.57" of travel. Any angle in the shock matters also, even in the rear, a 4.1" stroke shock at a mounting angle 25* from plumb gets you 5" of wheel travel.
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Old 10-09-2019, 05:45 PM
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^ What Donny said... First thing we did with my car was pull the coil springs, put new arms on the spindle and cycled it to see what hit first. Be sure to figure on increased caster which points the steering arms up (and on my case, put my tie rods right into my sway bar) Once we rearranged all we could, we measured max compression length between shock mounts and max extension, then where ride height would be. Then ordered shocks the correct length. I run 3.6" shock up front and they never bottom out and ride nice. You could put a longer shock in if you raised upper mount but that in itself isnt going to get you any more travel if lower arm still hits frame in same spot.
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Old 10-09-2019, 07:24 PM
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Good info to utilize.

The truck currently has the ability to plant the frame rails as is so the BJ's reach their binding point then. Inner wheel tubs are clearanced to allow increased travel & ~28" max future tire height.

No sway bar installed @ this point but it will get one w/the C/O swap. I have several C10 OE style bars I can try for mock-up. I also have a Ridetech C10 Muscle Bar set-up but it's on my dually & I didn't want to have to steal it if avoidable.

Ride Tech a-arms (their OG versions). I also have their adapter brackets for the bottom of the C/O mounting (the C4 adapter brackets). My plan is to replicate the upper bag mount (*make a separate mounting plate), clearance the current upper spring bracket as needed for the C/O, & build the upper C/O mount from there. The truck is currently set-up @ 4.5" ride height (~27" front tires) @ the front cab mount which puts the lowest part of the x-member around 5" (frame rails are the lowest part of the truck/lower than the x-member).

*The replicated upper spring/bag bracket is solely to allow swapping back to bags @ a later time if desired.*

Quote:
Originally Posted by dontlifttoshift
Don't forget motion ratio when calculating _wheel travel_ as it relates to shock travel. Ride Techs strong arms for your application have a .646 motion ratio so the 3.6" stroke shock yields 5.57" of travel. Any angle in the shock matters also, even in the rear, a 4.1" stroke shock at a mounting angle 25* from plumb gets you 5" of wheel travel.
My set-up is about 2" lower than what the Ridetech C10 kit could provide. I can tweak the shock angle as well within limitations but w/that being said, maybe I'm fine @ the 3.6" stroke.
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Old 10-09-2019, 07:29 PM
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Quote:
Originally Posted by SSLance View Post
^ What Donny said... First thing we did with my car was pull the coil springs, put new arms on the spindle and cycled it to see what hit first. Be sure to figure on increased caster which points the steering arms up (and on my case, put my tie rods right into my sway bar) Once we rearranged all we could, we measured max compression length between shock mounts and max extension, then where ride height would be. Then ordered shocks the correct length. I run 3.6" shock up front and they never bottom out and ride nice. You could put a longer shock in if you raised upper mount but that in itself isnt going to get you any more travel if lower arm still hits frame in same spot.
As for the G-body portion of my quest, what spindles are you utilizing for your car? I'm lower than you in the front but that's an "Is What It Is" thing for now until the upgraded parts are decided upon & sourced.
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Old 10-09-2019, 11:23 PM
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I ran factory metric spindles circa long time and about 2 years ago upgraded to the ATS spindle. I had to rearrange things bit to optimize my setup for the new spindle, but it was well worth it.
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Old 10-10-2019, 08:53 AM
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Quote:
Originally Posted by SSLance View Post
I ran factory metric spindles circa long time and about 2 years ago upgraded to the ATS spindle. I had to rearrange things bit to optimize my setup for the new spindle, but it was well worth it.
Care to share the details on this statement?
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Old 10-10-2019, 12:09 PM
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So the ATS is a 1" drop spindle and it along with the new brake package moved my wheel out about a .25". These two changes created tire into fender issues with the same ride height as before.

I tried about 6 different ways of alleviating the tire rubs but the ones that kept the fender off the tire, also made it push like a dump truck. I finally put a real nice set of adjustable bump stops on the coil overs that let me set the geometry and ride height exactly as I had it before, but stopped the shock before the tire hit the fender.

The tire rub was one of those things that was fine on the street, but once driven in anger on course, became quite the issue. Was super happy to finally get it dialed back in, I hate driving a car that pushes...
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Old 10-10-2019, 02:34 PM
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Quote:
Originally Posted by SSLance View Post
So the ATS is a 1" drop spindle and it along with the new brake package moved my wheel out about a .25". These two changes created tire into fender issues with the same ride height as before.

I tried about 6 different ways of alleviating the tire rubs but the ones that kept the fender off the tire, also made it push like a dump truck. I finally put a real nice set of adjustable bump stops on the coil overs that let me set the geometry and ride height exactly as I had it before, but stopped the shock before the tire hit the fender.

The tire rub was one of those things that was fine on the street, but once driven in anger on course, became quite the issue. Was super happy to finally get it dialed back in, I hate driving a car that pushes...
Always wondered if yours rubbed. The G-body I'm working on has 25" tall fronts that are currently relatively narrow. They don't rub the fender lip but do buzz the top of the inner well. I know these cars face limitations when low & wanting them to stick (w/wider wheels/tires) hence my previous questions on your thread about back-spacing. It is currently a little lower than I feel it should be because of the spindles.

I've had the ATS/X spindle on my radar for a while now but that buy-in is a tough one for a car that's strictly for spirited public driving. There's a new option coming down the pipeline that's similar yet different (much improved camber curve, various drop options, & cheaper but heavier than the ATS). That easier buy in allows $$ for adding the C/O's.
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