Help a nOOb set up his Coil-Overs in Winston

Dave, if you have the "right" spring rate i.e. - correct amount of pre load at ride height, there's no need for scales...tuning time will be all you need from there.

Matt
 
Spring rate is what I'm concerned about with the new added weight. It felt like it was bottoming out to easily in the rear at the flats this past weekend.
 
Oliver's said:
Spring rate is what I'm concerned about with the new added weight. It felt like it was bottoming out to easily in the rear at the flats this past weekend.
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But, if the ride height is where you want it and there is a proper amount of pre load, then you need to go in the shocks and start changing shims.

For instance if all these requirements are met, and I was bottoming out, I would add more compression damping, and nitrogen, possibly nitro in the bumps.

Do you know your shim stack rates currently?

Matt
 
Forgive my ignorance Matt, this is and has been a bit of a learning curve to me.

In my mind, I just assumed that adding more weight to back would have made my previous spring rates wrong.

Running 2" C/O's and 2.5" Bypasses front and rear. All the shocks, minus the front bypasses have been re-valved by me several times with help of Ryan at Accu-tune.

I can't quote the exact shim stack from memory at the moment. Maybe Ryan can chime in. @TRD
 
Oliver's said:
Forgive my ignorance Matt, this is and has been a bit of a learning curve to me.

In my mind, I just assumed that adding more weight to back would have made my previous spring rates wrong.

Running 2" C/O's and 2.5" Bypasses front and rear. All the shocks, minus the front bypasses have been re-valved by me several times with help of Ryan at Accu-tune.

I can't quote the exact shim stack from memory at the moment. Maybe Ryan can chime in. @TRD
Click to expand...

It's all good, we all learn all the time.

If that little bit of weight you added only change the pre load by a few fractions of an inch, you haven't hurt your spring rate...if it changed it by inches, then yes you need to swap springs.

The same thought above still applies.

Is the ride height where you want it?

Is there between 1-2" of pre load at ride height?

If both of these answers are yes...then you're springs are good, (99%of the time).

So if Ryan has guided you on shim changes and you have since added bypasses, you have more adjustments that you can/need to make; you can't just bolt on another $2500 of tunable shocks and expect them to fix it without tuning them. Keep in mind, when adding the bypasses- you also added more shims in the equation inside the bypass. But i would start with adjusting the tubes on the bypasses, possibly tighten up the bump zone of the rears to further slow down that last few inches of travel- without hindering low speed articulation. I don't know how many tubes you have on the bypass or their placement, you could also tighten up the mid travel area a smitten.

Ryan is a sharp guy, I'm sure he's steering you in the right direction, as long as you are able to verbally interpret the problems for him to make educated suggestions. Send him some video of the problems your feeling in action, that will help more than any "talk" of what's going on.

Get to a tuning session, somehow, somewhere. You'll learn more in two hours than 40 days reading here and listening to all us Internet jockeys! Lol.

In adding the bypasses you have essentially multiplied your adjustability by 10 at every corner! You now have an infinite set of tunability to get it where you want it.

Congrats on making the journey and trying to educate yourself on better performance...





Matt
 
Current pre-load on the rear. Needs to be a bit more for level ride height.
 
The rear bypasses have been re-valved twice now. The fronts were just installed over Christmas break and need to be addressed still.

2.5" Fox Triple by-passes on all four corners.

Thanks for your help and input Matt.
 
Oliver's said:
Current pre-load on the rear. Needs to be a bit more for level ride height.
Click to expand...

That's not exactly pre load Dave. Pre load is the distance from free length (where the nut is located once it barely touches the unloaded spring) to where it is turned to get to ride height.


Happy to help Dave.

Matt
 
Ok, yet another thing I was told and learned wrong. :shaking:

EDIT:

Define Pre-Load: Pre-Load is how much the springs have been pre-loaded with zero pre-load being the point at which the springs, slider, spring plate, and coil nut adjsuters are touching with no play. The amount of threads showing above the coil nut adjuster is NOT that same as pre-load.

^^^ for anyone else learning Coil Over speak like me.
 
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mcutler said:
That's not exactly pre load Dave. Pre load is the distance from free length (where the nut is located once it barely touches the unloaded spring) to where it is turned to get to ride height.


Happy to help Dave.

Matt
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I'll have to unload and put it on the lift tonight to answer that question properly.

Thanks.


Dave
 
Hi Dave, based on your picture it seems like Matt is correct. Your springs are probably ok.

If you're running stock valving in the front bypasses that's likely part of the problem.

I can calculate sprung weight from preload, spring rates, shaft showing at ride height and motion ratio (shock mounting angles). If you post up your new specs I can run the numbers.
 
Oliver's said:
Ok, yet another thing I was told and learned wrong. :shaking:
Click to expand...

You can measure preload like that, but only as a reference point. For example, you'd need to know what that measurement was (from the top of the shock to the spring perch or wherever you're measuring from) at zero preload, and then you can measure from the same points after adding preload and subtract. It doesn't matter what part of the shock you're measuring from, as long as you use that point consistently so you know what the difference in length is.

Basically that picture isn't particularly showing anything by itself, without another picture at zero preload for a measurement delta. Preload is just a delta, starting with the perch at zero spring load before adjustment.
 
You know, it's really too bad that most coilovers don't have any inpendent adjustment of preload and ride height.

For example, the one from the article posted above. There's no way to decouple the ride height adjustment from the spring preload adjustment, because they're the same thing. This just means that spring rate is the most important part of setup, and you're just using preload adjustment to bias the damper shaft travel to a certain range, and to set ride height by doing that.
How-To-Set-Preload-Sq-300x300.jpg
 
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Fabrik8 said:
You know, it's really too bad that most coilovers don't have any inpendent adjustment of preload and ride height.

For example, the one from the article posted above. There's no way to decouple the ride height adjustment from the spring preload adjustment, because they're the same thing. This just means that spring rate is the most important part of setup, and you're just using preload adjustment to bias the damper shaft travel to a certain range, and to set ride height by doing that.
How-To-Set-Preload-Sq-300x300.jpg
Click to expand...



You are correct and that's why springs are so hard to get right (and why we offer unlimited springs swapping).

Totally off topic, but some circle track shocks have adjustable height rod ends so they can separate the preload and ride height. Downside is the collapsed/extended shock lengths change with adjustment.
 
TRD said:
You are correct and that's why springs are so hard to get right (and why we offer unlimited springs swapping).

Totally off topic, but some circle track shocks have adjustable height rod ends so they can separate the preload and ride height. Downside is the collapsed/extended shock lengths change with adjustment.
Click to expand...

A lot of struts are like that too, they're especially easy to do because they mounting lugs are offset from the shock body. Much easier than doing something that's got sphericals that are coaxial to the body. And of course the easiest of all to decouple, pushrods with a bellcrank!
 
So after a getting the buggy on the lift, my pic above was only off by 1/2" on the pre-load. Ended up with 2" of pre-load front and rear, with in .125" +/-.

Springs: Rears are 80/100 with 200 psi. Fronts are 110/200 with 200 psi.

@mcutler you were right about the springs being ok, I had a lengthy discussion with Ryan at Accu-Tune @TRD last night. He did his "magic" calculations and determined some changes in the valving were defiantly needed, front and rear.

Thanks again for the info and expertise.


Dave
 
Oliver's said:
So after a getting the buggy on the lift, my pic above was only off by 1/2" on the pre-load. Ended up with 2" of pre-load front and rear, with in .125" +/-.

Springs: Rears are 80/100 with 200 psi. Fronts are 110/200 with 200 psi.

@mcutler you were right about the springs being ok, I had a lengthy discussion with Ryan at Accu-Tune @TRD last night. He did his "magic" calculations and determined some changes in the valving were defiantly needed, front and rear.

Thanks again for the info and expertise.


Dave
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That's great Dave. Happy to help, but Ryan is the real expert, I'm just a metal monkey that studies shock theory.

I would be very interested in the shim stacks/bleed/ shock & bump pressures/ bypass settings that Ryan recommended for all 8 shocks on such a light buggy- especially the shim split (on a single corner) between the c/o and bp, just for study's sake. I'm quite interested in tuning shocks, as my experience grows.

Matt
 
Mac5005 said:
Keep us posted On the progress Dave.

Is there still valving in the coilovers?

Got any video from last weekend?
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Yes please keep posting your progress.

I feel like your going to need a rear sway bar, if you don't already have one. A stiff one. The front is really going to put that light ass to work, (rear always does more work than the front anyway) no weight back there for the shocks to work from.

Keep posting, we're paying attention...[emoji106]

Matt
 
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