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Old 10-28-2016, 06:07 AM   #21
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If you have the car sitting on the wheels, how high do you have to jack that side up to get the spring to unseat from the perch? If it seems really high, and unlikely that that wheel will get that much droop during normal driving, unless you go airborne or drop that wheel into a really deep pothole, maybe it will stay some level of compressed at all times?

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Old 10-28-2016, 05:05 PM   #22
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Nice report, cristian! Since you lowered the ride height and it found it helped with the "abruptness", it sounds like you were topping those shocks out as I suspected (not "bottoming out" as you report, as if you were bottoming out the shocks, lowering the ride height would make the problem worse.)

As for whether 1-2mm of "loose" spring travel when shock is at full extension would be a problem, really assuming you're not taking your car off jumps and getting it airborne, the most common/likely scenario where this could be a problem is when jacking up the front end and unloading both front tires at the same time. (Even in an extreme cornering situation with high-grip tires and in a competition situation, where you got one side of the car completely off the ground and the car into two wheels, the anti-sway bar would provide some compression to the unloaded side, so wouod unlikely allow the springs to become loose on the perches.) High-pressure monotube shocks have more nose pressure than low-pressure twin-tube. (Are these monotube or twin-tube shocks and can you find a nose pressure specification? This is the pressure the shock requires for compression to begin.)

If the upper spring perches have a tall enough spring-guiding sleeve such that the springs always reliably guides onto the perches, (and it's hard for me to imagine this being less than 1-2mm, usually they are more in the area of 1/4"-1/2") I'd say you probably would have no problem even if the springs do occasionally become loose.

Usually adjustable spring perches I've worked with have a locking feature of some sort, like a set screw or jam-nut - if yours do not, I'd suggest marking their orientation (like using a marker or paint), and monitoring them periodically (e.g. when you change tires) to make sure they stay put.

If loose springs were a problem, helper/tender springs could be a fix, or altering the strut tube or strut mount could be a fix. Or even zip-tieing the spring secured to the upper mount, although it's possible the spring could cut the zip ties if they compress enough.

You could also try raising the ride height slightly, (by, raising it back up by 1-2mm ) such that the springs become unloaded right as the shocks reach their travel limit. It doesn't seem like you'll need helper springs. They take up probably 1" or so. If you're looking to maximize performance, they are best to mount above the main spring (rather than below) so they're not unspring weight.

Nice work and good luck dialing in the rear also.
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Last edited by jakeru; 10-28-2016 at 05:07 PM.
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Old 10-29-2016, 06:55 AM   #23
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thanks for the input guys! as always very much appreciated!

i guess they are not topping out!! good to learn the correct term for it

it sounds like having a bit of play in the spring while suspension is not fully compressed should be fine. what i'll do is i'll lower the rear a bit, preload the suspension as if the car was sitting on it's wheels and then start taking that preload off and see how much the wheel would have to hang before the spring is a bit loose. i really dont think i can get into that situation on the street though, i dont rally the thing and wont be flying anytime soon so i will probably never be in that position.

I have monotube shocks and the perch has a locking nut so it wont move for sure.

i'm close to getting it where i want it and it's been a fun process, i've learned a lot and am grateful for it. more fun than just buying stock suspension



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Old 10-29-2016, 03:35 PM   #24
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Hello Cristian,

maybe helper springs could be a good idea in that case.

I would recommend that the springs are "pre-tensioned", because everything else will get you problems.

If you don't have pre-tension the spring can move in extreme driving conditions. And because your car is a sports car you can have them.

Also you can run into problems when you jack up the car and the spring can move, because the spring has to be in a defined position in the spring holder.

Worst case can be a broken spring or a damaged spring holder.

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Old 01-09-2017, 07:59 AM   #25
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i realize i never gave a final update on this. i did a lot of trial and error until i got the suspension setup to where i wanted it to be but it's a true road huger now.

to have enough spring travel/compression i simply had to make sure the ride height was within specs for the coilover set. using the instructions provided by the manufacturer (who was very helpful) also included in this thread somewhere by some of you i managed to set it up so that the front springs have sufficient travel to do their job. i'm also keeping the damping to all the way stiff then dial it back a quarter of a turn so it stays nice and tight, i dont like the bouncy bouncy of the softer setting and while stiff it's not jittery or anything. i was actually expecting the interior to have more squeaks and rattles but it really doesnt, guess these things are screwed on pretty well for convertibles. my S2000 was a RATLLE MONSTER and i never got that thing to be more civilized.. then again that wasnt the point of the car. but i digress

so lowering the car to keep it within specs and stiffer dampening did the trick and i never really have issues with it topping out unless i hit a pretty deep ditch in the road or a pretty big lip or something at high speed but i wouldnt hit those things hard even with stock suspension. admittedly it's lower than what i would like it to be but it's not impractical and i only have to be careful with the steepest ramps which can be negotiated by hitting them at a bit of an angle. all very manageable and it just demands a bit more attention while driving which is welcome, keeps the focus on the road ahead.

was it a pain in the ass to dial in? oh yes indeed! but i got on this path in an effort to learn more about suspension and settings which i have and to have a more customized drive, things that matter to me. i could have slapped on a sports suspension and call it a day but where's the fun in that?
another consequence of the lower ride is that i have a fairly aggressive alignment. 2.5 neg camber in the back (i couldnt get it any less due to the car being low) and 1.4 neg in the front with witch i'm happy.
i get no rub anywhere, fender liner is unscathed no matter what i do and the best part is this thing now rides very nice. very composed in the high speed turns, no body roll and it takes a heck of a lot more to get it to squeal its tires or get out of line.

things i would have done differently? buy a coilover set that has separate height adjustment independent of the spring compression which i might do in the future but for now i'm a happy camper. there's just something about being able to carve through a 90 degree turn not even considering touching the brakes and it makes the gt3 seats even more appreciated being busy holding you in place.

i'll post some pics when i get a chance.

thanks to all that helped out on this great forum! what a great community!



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Old 01-09-2017, 08:15 PM   #26
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Glad to hear you've gotten the suspension worked out, Cristian! Way to go getting it sorted. I think I've read in other posts that you've hit the autocross course - this is a great way to test out adjustments. I'm envious and hope to have the time myself to get back out there again soon. Cheers

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