aftermarket suspension- clunk?

racerxj17 · 06-12-2009, 11:12 AM

just installed my BC coilovers set at about 1.2 F and 1.0 R drop. also have the front hotckis sway bar installed (ran out of time to do the rear). i havent had time to really push it, but i noticed today when i hit a few hard corners (90 degree) that there was a "clunk". i was able to reproduce it. it sounded and felt like it came from the rear end.

anyone share the clunk? i checked all bolts, nothing is loose. i did adjust the rear shocks to the OEM length (doesnt affect ride height), but thinking back i should have adjusted them an inch shorter to keep the shock stroke at the top.

the only think i can come up with is the spring is slightly lifting off the spring perch on the bottom when at full extension of the suspension (perhaps the inside tire around a hard corner?), since i do recall the rear spring being not as "compressed" as the stock springs at full extension.

or....possibly over tightened sway bar pivot points? i didnt use a TQ wrench since i was planing on replacing it very soon. ( i did take off all the bolts, but put it back on when i ran out of time)

anyways, ill dig into the problem more, but i figure since there are many with experience on a 370 id post up, or for those with similar issues.

lastly, anyone have rubbing in the rear with 1" drop? the outside edge of the rear tires have a very smooth, flat spot on the outer edge as if they were rubbing, but i cannot see where they would rub...

Jon

RCZ · 06-12-2009, 01:00 PM

swaybar walk, check your front sway... its moving side to side.

ChrisSlicks · 06-12-2009, 01:09 PM

Quote:

Originally Posted by RCZ

swaybar walk, check your front sway... its moving side to side.

Hmm, but he has Hotchkis which have a welded stop, really shouldn't be able to move far side to side.

Did you lube the inside of the rubber bushing up thoroughly when mounting? All I can think of is that you over tightened the bracket and had insufficient lubrication. That would load the sway bar like a spring until it developed enough tension to pop into place.

RCZ · 06-12-2009, 01:17 PM

My friend JUST installed his hotchkis with the welded stop and they are walking anyway. Just as in he installed them last week and started clunking the next day after install. They were installed by a very very reputable BMW tuner. (on his 335i, but the design is the same)

ChrisSlicks · 06-12-2009, 01:26 PM

Weird, I haven't experienced that and I drive the car pretty hard. The rear in particular would hit the exhaust pipe if allowed to move too far.

ChrisSlicks · 06-12-2009, 01:28 PM

Just a thought, there is considerable play in the bracket mounting holes so might want to adjust the bracket slightly to make a tighter fit against the stop.

racerxj17 · 06-12-2009, 09:19 PM

good input....ill check on the play in the brackets that might be allowing the sway bar to move side to side.

ill post up what the issue ends up being for others...

racerxj17 · 06-14-2009, 10:18 AM

brackets were fine. everything is well greased, and the clunk (more of a pop?) is still there, loud and clear. occasionally from the front now as well. frustrating to spend so much money and have it irritate you to drive

RCZ · 06-14-2009, 01:51 PM

sounds like a classic case of swaybar moving around..does the hotchkis come with adjustable endlines for our car?

travisjb · 06-14-2009, 02:52 PM

i have stillen sways and bc racing er series with a drop, and mine 'clunked' at the track yesterday on occassion... but i'm pretty certain it was bottoming out nothing to do with rub or sway bars

ChrisSlicks · 06-14-2009, 08:37 PM

Quote:

Originally Posted by RCZ

sounds like a classic case of swaybar moving around..does the hotchkis come with adjustable endlines for our car?

What are endlines? If you mean end links, the stock ones are reused. Adjustable ones would be a nice touch, but they are often as expensive as the sway bar itself.

Here's some for the 350.
Z-1 Performance Automotive Services Inc. - Powergrid Swaybar Endlinks 350Z/G35

Argos · 06-14-2009, 10:45 PM

u find out whats the issue yet? i was thinking about getting a sway bar

ChrisSlicks · 06-15-2009, 12:35 PM

Quote:

Originally Posted by Argos

u find out whats the issue yet? i was thinking about getting a sway bar

If you have the stock suspension, go for it. It appears as though the problem may be related to the new coilovers installed by the OP.

Argos · 06-15-2009, 10:49 PM

gotcha , so the sways were installed correctly then , i wasn't planning on changing up the suspension , the car is low enuf for me

racerxj17 · 06-16-2009, 01:19 AM

im pretty sure all the noise is from the sways. nothing makes noise unless there is a large load during turning on the sways. large bumps in a straight line do not cause any noise.

06-12-2009, 11:12 AM	#1 (permalink)
racerxj17 Track Member Join Date: Apr 2009 Location: Socal Posts: 555 Drives: 09 370z Rep Power: 17	aftermarket suspension- clunk? just installed my BC coilovers set at about 1.2 F and 1.0 R drop. also have the front hotckis sway bar installed (ran out of time to do the rear). i havent had time to really push it, but i noticed today when i hit a few hard corners (90 degree) that there was a "clunk". i was able to reproduce it. it sounded and felt like it came from the rear end. anyone share the clunk? i checked all bolts, nothing is loose. i did adjust the rear shocks to the OEM length (doesnt affect ride height), but thinking back i should have adjusted them an inch shorter to keep the shock stroke at the top. the only think i can come up with is the spring is slightly lifting off the spring perch on the bottom when at full extension of the suspension (perhaps the inside tire around a hard corner?), since i do recall the rear spring being not as "compressed" as the stock springs at full extension. or....possibly over tightened sway bar pivot points? i didnt use a TQ wrench since i was planing on replacing it very soon. ( i did take off all the bolts, but put it back on when i ran out of time) anyways, ill dig into the problem more, but i figure since there are many with experience on a 370 id post up, or for those with similar issues. lastly, anyone have rubbing in the rear with 1" drop? the outside edge of the rear tires have a very smooth, flat spot on the outer edge as if they were rubbing, but i cannot see where they would rub... Jon Last edited by racerxj17; 06-12-2009 at 11:14 AM.

06-14-2009, 02:52 PM	#10 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 188	i have stillen sways and bc racing er series with a drop, and mine 'clunked' at the track yesterday on occassion... but i'm pretty certain it was bottoming out nothing to do with rub or sway bars __________________ 2009 370Z #104 For Sale

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06-12-2009, 01:00 PM	#2 (permalink)
RCZ A True Z Fanatic Join Date: Nov 2008 Location: Miami Posts: 6,403 Drives: '09 370Z Rep Power: 1118	swaybar walk, check your front sway... its moving side to side.

06-12-2009, 01:17 PM	#4 (permalink)
RCZ A True Z Fanatic Join Date: Nov 2008 Location: Miami Posts: 6,403 Drives: '09 370Z Rep Power: 1118	My friend JUST installed his hotchkis with the welded stop and they are walking anyway. Just as in he installed them last week and started clunking the next day after install. They were installed by a very very reputable BMW tuner. (on his 335i, but the design is the same)

06-12-2009, 01:26 PM	#5 (permalink)
ChrisSlicks A True Z Fanatic Join Date: Mar 2009 Location: North East Posts: 6,203 Drives: 09 370Z Sport M6 Rep Power: 653	Weird, I haven't experienced that and I drive the car pretty hard. The rear in particular would hit the exhaust pipe if allowed to move too far.

06-12-2009, 01:28 PM	#6 (permalink)
ChrisSlicks A True Z Fanatic Join Date: Mar 2009 Location: North East Posts: 6,203 Drives: 09 370Z Sport M6 Rep Power: 653	Just a thought, there is considerable play in the bracket mounting holes so might want to adjust the bracket slightly to make a tighter fit against the stop.

06-12-2009, 09:19 PM	#7 (permalink)
racerxj17 Track Member Join Date: Apr 2009 Location: Socal Posts: 555 Drives: 09 370z Rep Power: 17	good input....ill check on the play in the brackets that might be allowing the sway bar to move side to side. ill post up what the issue ends up being for others...

06-14-2009, 10:18 AM	#8 (permalink)
racerxj17 Track Member Join Date: Apr 2009 Location: Socal Posts: 555 Drives: 09 370z Rep Power: 17	brackets were fine. everything is well greased, and the clunk (more of a pop?) is still there, loud and clear. occasionally from the front now as well. frustrating to spend so much money and have it irritate you to drive

06-14-2009, 01:51 PM	#9 (permalink)
RCZ A True Z Fanatic Join Date: Nov 2008 Location: Miami Posts: 6,403 Drives: '09 370Z Rep Power: 1118	sounds like a classic case of swaybar moving around..does the hotchkis come with adjustable endlines for our car?

06-14-2009, 10:45 PM	#12 (permalink)
Argos Base Member Join Date: Jun 2009 Location: Miami Posts: 81 Drives: 09 nissan 370z Rep Power: 16	u find out whats the issue yet? i was thinking about getting a sway bar

06-15-2009, 10:49 PM	#14 (permalink)
Argos Base Member Join Date: Jun 2009 Location: Miami Posts: 81 Drives: 09 nissan 370z Rep Power: 16	gotcha , so the sways were installed correctly then , i wasn't planning on changing up the suspension , the car is low enuf for me

06-16-2009, 01:19 AM	#15 (permalink)
racerxj17 Track Member Join Date: Apr 2009 Location: Socal Posts: 555 Drives: 09 370z Rep Power: 17	im pretty sure all the noise is from the sways. nothing makes noise unless there is a large load during turning on the sways. large bumps in a straight line do not cause any noise.