Apexi N1 V Coilovers

[MacRS200]

Following on from last week I decided to have a go at finding out exactly what was going on with my coilovers.

Started with the rears, Measured the arch to wheel centre and then jacked the car up and measured again and found that the distance had increased by 10mm. Next I measured the spring length and then slackened off the spring seat fully and measured the spring “free” length. The spring was compressed by 20mm so the weight of the car compresses the spring 30mm and with that setting I only had 10mm of strut extension before the suspension “topped out”.

Next I measured the distance between the “bump stop” and the top of the damper cylinder (damper fully extended), this distance was 90mm, then I put a jack under the wishbone and lifted it till the wishbone was almost contacting the car body, total movement equalled 60mm.

Decided that I would then screw up the spring seat till it contacted the spring and compressed the spring slightly so that my figuring the car would then sit with 30mm of available upward travel before “topping out” instead of 10mm and 60mm downward before “bottoming out”. I also extended the entire strut by 20mm to compensate for the drop caused by the lowering of the spring seat to give the same ride height.

Put the wheel back on, off the jack and the car sat very nearly at the same height as it was when I started. Duplicated the settings on the other side e.g. spring length and strut length and off for a drive.

Result, knocking gone, plus I had a creak coming from the body at the rear which I reckoned was down to the chassis twisting, that’s gone too.

Sunday did the same routine on the fronts but found that the travel down was short so repeated the same set up routine to lift the car up on the spring and shorten the strut to compensate. Still got a very slight knock off the O/S/F but it is miles better than it was before.

Conclusion: The knocking from the back was the suspension “topping out”, also the lack of available downward travel for the wheel was causing the chassis to twist. The front was the suspension getting near to “bottoming out” again causing a knock.

[Mr Singh]

I don't understand why i have no knocking and some people do!

I must be dropped between 70-90mm, front tyre is tucked about 15mm, i get rubbing noise but no knocking.

Could u take a pic with all the above measurements so i can post my findings also?

Just some basic reference of mine..

Rear, when jacked up the spring is compressed, however before i put 100kilos of ICE in it was uncompressed by 15mm, so the weight meant i had to raise it. No knocking at all on the rear.

Front, passanger side spring is compressed, Driver side is uncompressed when jacked up by over 25mm. I have also installed bigger bumpstops to stop the damper from bottoming out - i did have violent knocking before that even on the original bumpstops supplied by Apexi with the coilovers.

I've picked up few packs of the PI Clip in bumpstops which i will be using to really fine tune the travel limits of the strut..

[Colin P]

interesting!

where did you get those from Am?

If I knew what I was doing i'd ***** about with mine but i'd probably break something!

my rears seems ok but front still bottoms out every now and again, plus it's not as low as I would like it to be!

i'd be happy to post my findings/measurements though so maybe between us all we can sort it out

I say we have a coilover meet at the weekend to sort it out :D

[Mr Singh]

http://www.rtecshop.com/index.php?p=browse&category=192

i need to get my lazy ***** out there and make some adjustments :o

[Colin P]

http://www.rtecshop.com/index.php?p=browse&category=192

i need to get my lazy ***** out there and make some adjustments :o

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it's too hot for anything energetic

ahh R-Tec, i'll go there at the weekend, right near my old Uni!

[Mr Singh]

Nice pleasant 20deg C here :D

[Mr Singh]

Okay made few adjustments, and installed clip on bumpstops.

The travel is good enough for me, little more bumpy but also nice a tight too.

On dual carrage-way or Motorway it feels very very comfy and no knocking what so ever

[MacRS200]

Okay made few adjustments, and installed clip on bumpstops.

The travel is good enough for me, little more bumpy but also nice a tight too.

On dual carrage-way or Motorway it feels very very comfy and no knocking what so ever

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What adjustments did you make Am?

Am I right in thinking that you have the damper adjusters screwed all the way out

[Mr Singh]

The Damping was on 5 clicks, i thought they were on softest! I turned them upto 8 clicks though. U have undo them then turn clockwise to stiffen

I need to experience this knocking everyones getting with Apex's... They all came from me as i did GB year ago.

[MacRS200]

I got mine 3 clicks out from hardest, the reason that I asked the question is I am going to "back them off" to the mid position which I think is 8 and see what happens now that I know that I have adequate suspension travel up and down. :D

[imi]

Let us know what happens, cos i hav still got my set, and if all is well, be looking forward to putting them back on....... (prefer the coils)

[Mr Singh]

I got mine 3 clicks out from hardest, the reason that I asked the question is I am going to "back them off" to the mid position which I think is 8 and see what happens now that I know that I have adequate suspension travel up and down. :D

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No wonder u have knocking then lol

If you have damping that high, maybe u want a firmer ride? slam it some more, or get some higher poundage springs.

[MacRS200]

I got mine 3 clicks out from hardest, the reason that I asked the question is I am going to "back them off" to the mid position which I think is 8 and see what happens now that I know that I have adequate suspension travel up and down. :D

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No wonder u have knocking then lol

If you have damping that high, maybe u want a firmer ride? slam it some more, or get some higher poundage springs.

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On a "steep learning curve" here mate, but think that I'm getting there.

The springs are off Fargo's IS3 so I am assuming they are stiffer than required for the feather light Tezza. Take too much damping off and the back end will bounce up and down like a rabbit procreating :o

[Mr Singh]

There same as mine, bought 5 sets over from the States and sold them on LOC ;)

so your back end is bouncing up and down? When i had damping on say 13-15 clicks, there rear made the car bounce ALOT, like a rabbit :P

I've got rears on no clicks at all, and its fine even with boost!

[Fargo]

yep springs are the same as Am's

[MacRS200]

I've got rears on no clicks at all, and its fine even with boost!

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Yeh but you got half a ton of ICE in the back, I just got a set of golf clubs

yep springs are the same as Am's

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Thanks mate

[MacRS200]

OK now got the damping set at 12 "clicks" (not kilometres) from the softest damping setting. Can't honestly say that the knocking has completely gone but it is so much better and is more of a rattle than a knock now :D

Now the poxy chassis twist "creaking" is back

[Mr Singh]

Put it all the way down.

Drive it about so it settles then turn it up till your happy, i've turned mine back down to 5 clicks, 8 wasn't to my liking..

[MacRS200]

Now got the rears set to 8 clicks and the fronts at 6. Tracked the "creak" down to the O/S/R top mount rubbing on the body "socket", checked the nuts were tight but that did not cure it so resorted to a little WD40 and viola. Nice quiet drive into work today :D

For Am. Decided to do a little drawing to try to illustrate what I was "rabbiting" on about on Monday with all the dimensions

Each of these will give exactly the same ride height assuming that the car has compressed the spring. The settings on the left will not allow any downward movement of the wheel, the suspension has "topped out", the middle settings will allow equal movement up and down and the settings on the right will not allow upward movement of the wheel, the suspension has "bottomed out".

What I was saying was that the maximum travel of the damper rod is 90mm and that the weight of the car compresses the spring 30mm. So winding the spring seat up to compress the spring 5mm with no load makes it look like the diagram on the right. Then when the weight of the car goes on the spring it compresses by another 25mm and looks like the diagram in the middle except that I have 25mm of downward wheel travel and 65mm of upward wheel travel.

[Mr Singh]

Wait for a minite before i try and get my head round it, lol

Well done on the pics its very clear now. After i adjusted my bottom lock, the ride is firm and lost its smoothness. I adjusted the entire body further down so i could raise the spring height which meant the spring was acutally compressed...

So as a result i have topped out?

[MacRS200]

Wait for a minite before i try and get my head round it, lol

Well done on the pics its very clear now. After i adjusted my bottom lock, the ride is firm and lost its smoothness. I adjusted the entire body further down so i could raise the spring height which meant the spring was acutally compressed...

So as a result i have topped out?

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Depends on how much you compressed the spring.

What I would do is measure the wheel arch to wheel centre with the car sitting on the ground. Then jack it up and measure wheel arch to centre again, the difference between the two measurements is the amount of downward wheel travel you have before the suspension tops out.

Then take the wheel off and measure the spring length from the top mount to spring seat, take the load off the spring by winding the seat down and measure the "free" spring length. Take the difference in spring length and add on the amount of wheel movement measured when you jacked the car up and that is the amount the cars weight compresses the spring. It will be different to mine as you have more weight in the boot.

Say you want to leave 20mm of travel before topping out. Subtract 20 from the amount the cars weight compresses the spring and this is the amount you want to "pre-compress" the spring with the spring seat, the cars weight will add another 20mm to leave 20mm before topping out. This will affect the ride height so you need adjust the bottom mount to compensate.

If you take the new length of the compressed spring and compare that with the old compressed length this is the amount that you need to adjust the bottom mount by. So if the old length was 200mm and the new length is 210mm the car will sit 10mm lower so you need to screw the bottom mount out by 10mm to give the same ride height.

Make sense?

[Mr Singh]

Okay will take measurements.

By looking at your diagram, if you lower the bottom mount don't you get more travel? but you need to compress the spring alot more otherwise the car would be more than just slammed lol

The of the pic on the above diagram would be the perfect compromise.

Boy these coilovers are good :D

[MacRS200]

By looking at your diagram, if you lower the bottom mount don't you get more travel?

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Not quite mate the bottom mount is just a cup that supports the damper cylinder, its the spring that controls the position of damper rod and hence the travel.

but you need to compress the spring alot more otherwise the car would be more than just slammed lol

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If you screw the bottom mount up you need to lift the spring seat up to compensate.

The of the pic on the above diagram would be the perfect compromise.

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The diagram shows a set ride height and effectively what it shows is the damper cylinder moving up and down relative to the top and bottom mounts. The distance between the spring seat and the bottom mount stays the same.

[Colin P]

this is all too much for me, I need to lay down :iraqi-info-minister:

[Adie]

this is all too much for me, I need to lay down    :iraqi-info-minister:

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Me too

Was the knocking noise cured