[Vid6639]

So who is trying this on a Verna? :-)

[Mpower]

Interesting mod! Should probably help with scraping bumps when loaded.

Originally Posted by GTO

What you'll like:

• The rear suspension doesn’t make “thud thud” noises when going over large bumps anymore.

• The rear end bounciness is 80 - 90% gone; the back feels a lot more planted. Nearly Octavia-like. The excessive vertical movement from the back (over imperfect patches of tarmac) is nearly eliminated.

• I was told that this mod would make the ride stiffer. However, after driving for 40 odd kms, I don't feel any deterioration in ride quality. Maybe it is additionally stiff, but the change is too slim to be noticed.

• One bloke on a UK forum said that the coil spring adjuster may "slip out" of the spring under hard conditions (I presume, when the spring is stretched out). However, I have yet to find a report of the same happening.

Noise, I guess its somehow acting as a noise damper.
I'm surprised that it hasn't made the ride stiffer at low speed. I would have expected that. Maybe its minimal.
Are you noticing lesser bodyroll in corners? It should also reduce understeer in theory.

Slip out: I would be more comfortable if it was molded in a cylindrical shape (without the cut)
If the rubber puck is sized correctly, it should'nt slip out. Unless you put daylight under the rear tires regularly, you're OK !

Tirewear: Actually you should see an improvement in tirewear because suspension wont be cambered so much under load.

Alignment: Dont see why its needed. I think they want to ensure that the poorly maintained car (out of alignment) dont blame it on the mod.

PS: Too late, but if you like how the post '09 civics ride, another option is to swap out your springs with theirs'

Originally Posted by SS-Traveller

Maybe, just maybe, turns at racing speed can wear out tyre shoulders a bit more because the treads don't remain as flat with the road when this gizmo is installed.

Good point, but I dont think they were thinking about that aspect.

Originally Posted by Sutripta

@Jaggu: One coil is not taken out of the equation, it is made 'stronger'. Or look at it another way. As if you cut of a coil, and replace it with a 'stronger' coil.

Assuming that the rubber is (almost) incompressible, at all times before full load (coilbound), one coil is deactivated.
Depends on the rubber durometer

Originally Posted by GTO

He's still recommending 1.5, but I'm happy with 1". The car is rarely loaded with 5 + luggage anyways.

Assuming that the 1" takes up the gap correctly (ie is fully deactivating one coil), the 1.5 should offer no additional benefit.

PS: does the Civic have a rear swaybar.

[SS-Traveller]

Originally Posted by Mpower

...Assuming that the rubber is incompressible, at all times before full load (coilbound), one coil is deactivated.
Assuming that the 1" is fully deactivating one coil, the 1.5 should offer no additional benefit.

Originally Posted by GTO

Claimed that it can compress to as little as 5 mm when required...

Nope, it seems the 'rubber' (or whatever polymeric material it is) is quite compressible - all the way from 25 mm down to 5 mm. My worry is, at that stage of compression, the rubber can pop out of the spring coil.

[Mpower]

Originally Posted by SS-Traveller

Nope, it seems the 'rubber' (or whatever polymeric material it is) is quite compressible - all the way from 25 mm down to 5 mm. My worry is, at that stage of compression, the rubber can pop out of the spring coil.

OK, but under what load does it go to 5 mm? If its designed right, the spring rate of the puck should be much much higher than the spring itself.
I agree that in real life there will some compression 'initially' because rubber's characteristic is to have a rising rate so the more you compress the stiffer it gets. But the initial compression could be used up by the preload used for installation and retention purposes.

Originally Posted by SS-Traveller

My worry is, at that stage of compression, the rubber can pop out of the spring coil.

At that stage of the compression, there is a v.high load on the spring (vehicle) and the coils will firmly sandwich the rubber.
The 'pop out' risk is really in the unloaded condition, (ie when GTO jumps the car rally style). But, if the preload in the rubber is sufficient, this should not be an issue.

[SS-Traveller]

Originally Posted by Mpower

At that stage of the compression, there is a v.high load on the spring (vehicle) and the coils will firmly sandwich the rubber.

Not sure about that - at that kind of distortion under load, the rubber can slip out from between the coils ('pop out' may not be the right choice of words).

[Mpower]

Oh sure it all depends on the integrity of the design. I see that there is a U shaped channel that seats the spring.

But being the generic product, I wonder how well its matched to this particular spring. (imagine a generic dental crown!)

Like I said, it would be a lot better if it was cylindrical shaped without the break (cut) in the middle.

[alto99]

Originally Posted by Mpower

Like I said, it would be a lot better if it was cylindrical shaped without the break (cut) in the middle.

In that form it will have to be installed either above or below the spring. It wont be possible to install it in the way it is being done now.

[Mpower]

Originally Posted by alto99

In that form it will have to be installed either above or below the spring. It wont be possible to install it in the way it is being done now.

It can, you may have to compress (preload) the rubber some more.

Worst case, take the coil out...you'll get more clearance at free height and then reinstall spring.

[alto99]

Originally Posted by Mpower

It can, you may have to compress (preload) the rubber some more.

Worst case, take the coil out...you'll get more clearance at free height and then reinstall spring.

Geometrically speaking it is not possible to insert a cylinder in loops of a helix (helical spring). Similar to it being impossible to insert a circle in loops of a spiral.

[fordday]

Shouldn't there be forces acting in that one inch exposed arc of the coil between the ends of the Autorunner rubber? To me it seems rubber length should be more than the circumference of the coil so that no part of the coil is subjected to forces or rather torque.

Or it could be my idle brain playing games

[Mpower]

Cylindrical ie 'cylinder like' not shaped like a perfect cylinder. All I'm suggesting that it shouldn't have the cut in the middle..and be closed off in some way.

Not sure how it would look, I'd have to think about it.

[oxyzen]

Originally Posted by GTO

You can install coil-spring adjusters at the top of the spring (working at all times), in the middle (effective under mild to full load) or at the bottom (comes into play only under full load). I chose to install it at the top, as per Psycho's advice.

- First of all what I understand is the coil adjuster is just reducing the effective free length of the spring, thereby increasing the spring constant. However the overall length (or GC when empty) will slightly increase. So no matter where you install bottom, middle or top it will be working at all times.
- I think either top or bottom is fine. Keeping it at the middle can create the unwanted couple in the spring. (See fordday's Picture)
- If you are worried about it coming off you could have installed 1.5" instead of 1". Wouldn't that help?

I am no suspension expert. My opinions are purely based on basic physics.

[dot]

This thread has become very interesting between the enthusiast's posts, harried Civic owner's posts and how-it-works posts.

If it really works, I am in the queue to get these. Not that my car needs one (or a pair) but since this mod is reversible, why not try it out.

Originally Posted by oxyzen

- First of all what I understand is the coil adjuster is just reducing the effective free length of the spring, thereby increasing the spring constant. However the overall length (or GC when empty) will slightly increase. So no matter where you install bottom, middle or top it will be working at all times.
- I think either top or bottom is fine. Keeping it at the middle can create the unwanted couple in the spring. (See fordday's Picture)

True, agreed. However the rubber is not a elastic body, it is viscoelastic. So there will a loss of energy every time the spring flexes. Therefore the increase in spring constant is not expected to be linear. Placement (tip, middle, bottom) may matter. A dashpot analysis needs to be conducted to really find out the effects.

[1self]

The spring adjuster will NOT come off. Remember this is placed when the suspension is in full droop on the car lift. In any kind of driving your suspension will NEVER be in full droop position, unless you are in the air at WRC!

Also, the rear wheels will get a positive camber, that is reason for 5-10% more tyre wear. If the positive camber is dialled out completely during wheel alignment, there should be no reason for acclerated tyre wear.

[vasoo]

I think the setup is actually mimicking a stiffer set of springs by introducing a "damper" in between the coils. Not sure about the longevity of this solution, but looks effective on a short term.