aftermarket suspension = noise?

racerxj17

any one else have issues with "clunking" type noises? when the chassis flexes, there is an audible noise coming from the car, almost like a thud. all suspension points are tight, and the sway bars are well greased. i expect some noise, but its loud enough that it bothers me and raises questions from passengers.

i am running BC racing coilovers, and hotchis sways.

on a side note, the car feels VERY responsive, there is literally no body roll felt (it will literally pick the inside rear tire OFF the ground about 3" when entering a driveway at an angle, sometimes causing me to back out since the limited slip sucks and it just spins the tire....)

BUT i feel like the grip of the car has decreased. the car doesnt feel as planted, and seems easier to slide. it is very controlable, and its not just the rear, or front, better yet all around grip. i have a feeling that since my camber has not been adjusted and is still negative (around 2.5 front, 3.0 rear) perhaps the car cannot lean enough to put the contact patch of the tire on the ground.

any insight on the above would be appriciated.

Jon

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2009 PW Sport/Touring/Nav M6
Stillen Gen 3 Intake/CBE/Berk HFC/BC BR Coil over/Phillips 6500k/Hotchkis Sways/Stillen oil cooler/B&M SS

import111

The more you mod the more noise you get. Has happened with every car I have owned. Larger swaybars especially make more noise I have noticed with my last car.

Yea, you might have too much negative camber. Get that fixed. Also though, the stiffer you make a car, the line between grip and slip gets smaller and smaller. Ultimate grip may go up along with responsiveness, but the breakaway point happens more sudden.

Not sure if your swaybars are adjustable, but if they are you might try to put the rear on it's lower setting and see if that helps reduce oversteer. I also run BC coilovers on my Z and I keep the rear about 5 clicks softer than the front to help with that.

Modshack

I've modded a ton of car suspensions and never gotten more noise (clunking type anyway) . There's no reason to expect it really if the install done is carefully and correctly.

I think you have some sort of install error. Swaybar clunking is typically at the pick up points. Not tightened enough and they are moving in the holes. Make sure you use a wrench on the back side and the front side of the joint so it is tightened securely to the bar. This is the most common reason I've seen for noise, particularly after a sway bar install.

On the handling, you need an alignment. You most likely dropped the car and now a lot of your settings are off..Bad toe in the rear will cause the instability you seem to have. Depending on how radical the drop, you may need aftermarket parts to get it back in line..

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kenchan

+1 on the alignment. you need to get one if you lowered your car more than 1/2"

noise... ive had TEIN's in the past on my previous cars and they were pretty noisy.
especially the ones that have the pillow mounts. my current other cars sus are modded
and no noise. (prokit + dspecs and a set of endura-tech coilovers).

endlink noise usually occurs at low speeds going over uneven pavement... if that's
wat you're getting then your endlinks joints might be loose or worn out.

Z1Performance

-3 camber for the rear is a ridiculous amount, bordering on retarded. Your car needs a rear camber/toe kit given its slammed status.

bullitt5897

You got hotchis sways which are stiffer and keep the car from leaning therefore when you are cornering hard with your camber settings the contact patches cannot shift and cannot change for better traction. -3 is not alot of camber if you track the car but on a daily ride it is quite aggressive. You may want to take a little camber out if you can afford it.

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370zForever

Well, the thing about using racing coilovers is that they normally do lower the car and throw off the camber and position of your tires. I would recommend that you either buy a Eibach Alignment kit or check with a mechanic. It also depends on the stiffness of your sway bars. Sway bars can really help in body roll and in controlling your car, but sway bars that are too stiff will upset the car's suspension and ruin your handling. Try lowering the stiffness of your sway bars. I know that hotckis sway bars are adjustable. Also try adjusting the dampers or shocks on your coilovers. Too much pressure on the springs and shocks and cause problems in the suspension. Sorry that there isn't a simple way to fix this, but I hope this helps...

COD4

sorry to bring an old post from the grave but I have this question..

Im hearing those clunking type noises on my rear passenger side everytime I go over a bump or hole... I took the car for an alignment after the installation but the car still feels weird... feels like the grip of the car has decreased specially at high speeds and its not like im superdropped cuz I still have like two fingers of clearance all around... could this be installation or alignment error??

jmlenz

what are you dropped on? Coilovers or springs?

SE

If you have coilovers, it's the spring binding and/or spinning. Did you adjust the preload? This may be the cause of the popping sound. If it's coming from the front while you're turning it's definitely a binding issue.

Also, why does everyone feel the need to just slap on suspension parts and expect to be a handling god? You need to tune your setup to get the right feel.

To the OP- does the rear feel like it's sliding out during cornering? Adjust the dampening on the rear coilovers or take off your rear sway bar. The camber amount you are running is rediculous unless you're running that much just to fit crazy wheels. If not, adjust your camber because there's too little contact patch with the road except under heavy cornering. Reduce it to -2.0 or less and you should be fine.

azn370z

I have bc br too. The rear passanger makes a clunk sound when going over bumps. The driver side makes noise too but it has to be a big bump. From what I've read coilovers can make noise because it's mostly metal to metal contact. Some people with coilovers have noise and some don't, some people are bothered by the noise and some aren't.

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2010 k23
H&R sport springs / Spc rear camber arms / SSR SP1 / Berk cbe / Varis cf lip / Nismo S-Tune side skirts

SE

Again, thats because you either didn't set any preload or if you don't have enough dialed in.

azn370z

I don't think you have seen the bottom of the car where the perch sits on, it's not completly flat. I do have preload, and the right amount as the spring does not wiggle when the wheels are off the ground. I actually took my z to speedware which specializes in making race cars and Installing kw coilovers. They're one of the biggest garages here and drivers that love their z, vette, Porsche, viper, etc take their cars there. They took my suspension apart to see if I installed correctly and the preload was right. As I said before some times coilovers make some noise and some times it doesn't. And because it makes noise doesn't mean it's installed incorrectly. Search in the g and z forums about noise issues, there are many.

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2010 k23
H&R sport springs / Spc rear camber arms / SSR SP1 / Berk cbe / Varis cf lip / Nismo S-Tune side skirts

jmlenz

Man tell me about it! I have the Megan coilovers and am experiencing the same noises from the rear. Over large bumps, dividers, etc the rear will make a loud 'clunk' or 'boom' on impact. Sometimes loud enough to startle passengers lol...they always ask WTH was that? I thought I could ignore it but it is just pissing me off now. Oddly it ONLY comes from the rear. I have fiddled with the springs/perches and even had them taking out and reinspected to be sure everything is installed correctly...it is. What the hell causes this?

Also, how do you adjust preload on the rear springs? The instructions dont mention anything about this and this was never brought up by the installer. My only thoughts are that the rubber isolator (on top of rear spring perch) is not thick or robust enough to dampen these noises. Did you notice how big the OEM rear spring isolator is?

azn370z

For the rears what you need to do is remove the stock strut and spring
Take the spring seat collars and set them at the same level not tightening them yet
Put the springs on, put the tires back on and bring the car to the floor
See if the height of the car is the desired height, if not then raise it back up doing the prev steps
(be sure to keep the height about 1/4" higher than what you want as you still need to set preload)
Once you have achieved the height you want, raise the car back up, take out the springs and spring seats
tighten the collars on the spring seat and reinstall (if you try to tighten them while on the car there is a possibility you can strip them)
You should have a bolt that goes through the factory lower arm and bolts to our spring seat, at this point tighten that too
Take your spare jack and place under the hub raise the hub so that the spring sits snug but not compressed

Now install the strut, tightening the top only
Measure the distance from the center of the hub to the fender
Raise jack 1/4" creating the preload on the spring
Scroll the lower mount of the strut up so that its level with its mounting bolt, slide the bolt through it and tighten
At this point you should have the spring preloaded 1/4" and the ride height at your desired level.

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2010 k23
H&R sport springs / Spc rear camber arms / SSR SP1 / Berk cbe / Varis cf lip / Nismo S-Tune side skirts