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Important Lowering Saftety Question

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Old Mar 28, 2006 | 01:15 PM
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Important Lowering Saftety Question

Okay........I have a slightly simple question..........when lowering your suspension with coilovers, is there a limit to how low you can go.........?

My gut instinct is that it would be dangerous to postion the lower spring perch at a position LOWER THAN THE BOTTOM OF THE UNCOMPRESSED SPRING (i.e. when the car is jacked up). My reasoning here is that if all of the weight comes off that wheel in a situation, then that spring has room to "move around", which seems bad for the suspension.

Will someone let me know if this is in fact true?

I would like to lower my front about 1/2 inch more, but I have positioned the lower spring perch at precisely this limiting position.

I know that for the rear, I have these "rubber bushes" that sit above and below the top tower mount.........I could always trim these down to make the total length shorter.

However, in the front, there are no "bushes", so is there any way to lower the front any more without touching the spring perch?

Last edited by jspaeth; Mar 28, 2006 at 01:27 PM.
Old Mar 28, 2006 | 02:47 PM
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Let me get this right, are you saying that it looks like the shock can extend farther than the spring when the wheel comes off the ground? Even with lowering springs on stock shocks I've never heard of that happening, this is besides the fact that if your wheels are leaving the ground while driving I suggest that you tear up your drivers liscense right now lol. The height of the uncompressed spring should always be greater than the height of the shock fully extended, this means the spring is always pressing against the top and bottom spring mounts, as long as everything stays bolted together that spring aint goin nowhere.

Last edited by soldierdude262; Mar 28, 2006 at 02:56 PM.
Old Mar 28, 2006 | 03:12 PM
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Perhaps my explanation needs clarification......

I have Tein SS coilovers..........

WITH the car jacked up, (i.e. spring bearing NO load, the spring sits flush against the top hat...okay fine.

Now, with the spring in that position, my question is, Is the "lower limit" on how far down you can safely set the bottom spring perch the point where it just touches the bottom of the spring? (i.e. on the brink of "no preload").

Like I said, because the springs are so stiff, if (hypothetically)

the weight were to come off of that one wheel, then having the lower perch any lower than this would allow the spring to be able to jiggle up and down.

In otherwords, for safe operation, is it necessary that the lower spring perch be set AT LEAST as high as the bottom of the spring when it is in its relaxed position?


If this is so, then with the Tein SS, I have achieved -1.75 inches rear and -2.65 inches front.
Old Mar 28, 2006 | 10:06 PM
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wouldnt that give it more travel? or bottom out the valve when pushed to the limit?
Old Mar 29, 2006 | 04:52 PM
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Ok, when the suspension is relaxed, the spring which is compressed between the upper and lower spring persches pushes the lower perch down (since the upper one can't move). At a certain point the suspension stops dropping, this is because the shock only extends so far, this occurs before the spring uncomporesses, in the end, you can use any spring/ shock combo sold for your car, and that spring will always be held in place, whether or not the suspension is under load or relaxed.

If it ever happend that the shock extended farther than the spring (meaning if the spring is too short), yes that could be unsafe, because the spring would become unseated when you jacked up the car. BUT, at least on the front suspension, this would be discovered during assembly. When the front suspenion is assembled there is of course no load on it, if the spring was too short it would be loose when the upper perch was installed.
Old Mar 29, 2006 | 07:24 PM
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i think we are in agreement........HOWEVER, i am using TEIN SS which are obviously spring and strut combo.....and i hate to brake it to you, but there is actually room to lower the spring perch and have the spring be LOOSE!!!!!


Nonetheless, you answered my question so thank you for your help.
Old Mar 30, 2006 | 03:46 PM
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ANSWER:

SS doesn't have shock length, only the lower spring perch to adjust ride height - therefore you're correct that you don't want your spring flopping around in there. That's a dangerous situation. That and since you're lowering the height at which the spring sits, you're also slowly compressing the shock already - which means you're shortening your stroke.

If you want to go lower you're kind of out of luck without going to a different coilover with shock length adjust, like Flex.
Old Mar 30, 2006 | 05:33 PM
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Thanks, that's kind of what i figured based upon trying to physically understand the situation....

Nonetheless, I have -2.65 front, -1.7 rear

Front is maxed out there, rear could go lower, but I don't want rear to be lower than front,

Right now, all 4 corners are within 1/16 inch of each other in terms of ground to apex of fender, so it's sitting pretty.....
Old Mar 30, 2006 | 10:07 PM
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itll rub when you have 3 fat friends with you!
Old Mar 31, 2006 | 03:34 AM
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Lol...three fatties in a 240...I think bottoming out is the least of the worries if you manage to get 3 fatties in.
Old Apr 2, 2006 | 09:22 PM
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Originally posted by Preston
Lol...three fatties in a 240...I think bottoming out is the least of the worries if you manage to get 3 fatties in.
LMAO

I should be the one to worry about that, when I get my suspension done, my body kit side skirts will set about .5-1" off the ground!

But I only weigh like 135 lbs, and 6'5" tall! D@mn I need to gain weight!!!
Old Apr 3, 2006 | 08:08 AM
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