Suspension Review: Race Comp Yellow Springs

[Smudgeous]

Originally Posted by ATL BRZ

Yes, tightened them while using a spring compressor when reassembling while off the car, then double checked when they were on the car, then triple checked after driving on them.

Maybe they are too tight? Not enough clearance between the top mount and the black spring cap?? How are you guys judging torque on that top nut?

You should tighten them with 41 lb/ft of torque, as per the diagram.

[Smudgeous]

Originally Posted by mechaghost

Has Whiteline gotten back to you guys on what their action will be? I contacted them 2 weeks ago but they never called me back.

Try contacting Jan at WhitelineUSA (jan@whitelineus.com). My email to him was basically the issue I ran into after installing the mounts, along with the attachment of my sales order copy that my vendor provided me. For you personally, I would mention that you had previously mentioned the problem but nothing has progressed for the past 2 weeks.

[Racecomp Engineering]

Originally Posted by Smudgeous

Try contacting Jan at WhitelineUSA (jan@whitelineus.com). My email to him was basically the issue I ran into after installing the mounts, along with the attachment of my sales order copy that my vendor provided me. For you personally, I would mention that you had previously mentioned the problem but nothing has progressed for the past 2 weeks.

Yes exactly...Jan is the guy to talk to.

You can CC us on the email too if you like.

- Andrew

[mechaghost]

Jan just emailed me this morning, and has assured me they are working on the details on what to do with the defective top mounts.

[ATL BRZ]

Originally Posted by Draco-REX

Still no popping from my car so far.

I was just thinking about this. Of the two other cars in this thread, one at -0.8 camber and the other at -1.5, mine has the most neg camber at -2.0. If the tolerances are as tight as Myles thinks they are, maybe the more upright angle of my struts due to the max camber setting is providing enough clearance.

I know when un-installed there are no clearance issues. The tophats had no resistance to spinning freely. But when mounted to the car perhaps the strut is angled just enough for the upper perch to touch. I don't know, I didn't look too closely at the clearances after determining that the tophats spun freely.

Again to my suspicions... but I need to troubleshoot more!

Originally Posted by Draco-REX

While someone turns the wheel, check to make sure the nuts in the tophats are turning. Also, again while someone is turning the wheel, look at the upper spring perches and see if they are turning also.

Originally Posted by Draco-REX

I have top mounts and springs, no noise. A popping noise when turning the wheel usually means the upper spring perch is not moving with the wheels.

Originally Posted by Draco-REX

The top nut should rotate the same rate as your wheels. There should be no resistance at all. If it isn't rotating or not rotating with your wheels, then the tophat is binding up and your upper spring perch is not rotating the same amount as your spring. That would cause the spring to pop.

Also, make sure there is rubber between the spring and the upper perch.

Originally Posted by Racecomp Engineering

The issue I remember with assembly of the front struts is that unless you pay super close attention to the assembly of the noise isolator as you release the tension of the spring in the compressor its SUPER easy for the TOP rubber noise isolator to get deformed and this allows METAL ON METAL contact of the spring and the upper perch.......on PART of the front contact area. SO in other words part of the spring is resting on the rubber isolator and part is on the perch.

Quoting all this so I remember later this evening. I will be checking for proper movement/clearance of everything in the front strut assembly with the wheels off the car and see if I can isolate the noise. I will be driving home with the stock top mounts if I can't get everything including the Com-C's to stay quiet in one attempt reassembling everything and triple checking clearances.

It's also worth mentioning again that mine didn't pop or make any noises while turning when I had the camber bolts in. I swapped them for OEM bolts when I heard the rattling over bumps thinking wrongly that the camber bolts were loose and they were letting the assembly move around. THEN when running OEM bolts the popping while turning started. I think, as previously mentioned, that the amount (lack in my case) of negative camber has something to do with the popping from the Com-C bearings (PRESUMABLY, could be another part of the strut assy) while turning. The bearings still may be bad to begin with if they can't handle small deviations in camber. I think the rattling over bumps is bad clearances between the top mounts and the upper spring perch and rubber isolator, due to camber.

Originally Posted by Racecomp Engineering

Thats interesting as I ran this set up for a while with as much as -2.3 front and as little as -1.0.

Ok so this shifts the logic a bit over to clearance issues and improper movement of the upper spring perch/noise isolator/springs causing both the popping while turning AND the rattling over bumps, which MAY be improved or worsened by different camber specs, BUT may not ever be fixed with out a proper reassembly ensuring proper clearances and movement!!

[Phaedrus29]

Ordered the Lite pack yesterday and received the springs today...credit to RCE for amazingly fast processing/shipping! I didn't get the bolts or bushings yet, but I'm assuming that comes in a separate package? (I think I remember folks mentioned receiving springs before the other goodies.)

I didn't get any info yet on RCE's recommended alignment specs...does that come with the bolts/bushings?

Now I'm really excited to throw the springs on...but my alignment (at a good shop nearby) isn't planned for another month. Would it be really bad to put the springs on and drive around for a month before an alignment (and before installing the bolts/bushings)? I don't really want to mess up my tires. I guess I can just install the springs a week before my alignment as planned, but it's gonna be tough letting them sit there in the box for three weeks.

[ATL BRZ]

So last night got my BRZ in the air and with the wheels on I turned the steering wheel left and right and my Dad could see the rubber surrounding the bearings and top nut in the Com-C's deforming, as the bearings did NOT want to rotate properly even when the suspension was unloaded. I wish I had gotten video of it.

I disassembled the front struts again and found no incorrect fitments or clearances:



The Com-C's did spin around freely when still assembled to the strut off the car, but a very faint noise could be heard inside them.

When taking them apart I found marks on the upper spring perches where they had been hitting the bottom of the Com-C's under compression over bumps WITH and WITHOUT the camber bolts:



I don't know why but it's got to be camber related IMO.

So I compared the Com-C's to the stock top mounts and sure enough, found the Com-C bearings to be notchy as hell and you could see and feel it when rotating the bearing with your finger. So again, under load, this is bad news.

[ame="http://www.youtube.com/watch?v=4QRSmwXSoks"]Whitline Com-C BRZ top mounts - YouTube[/ame]


Compared to the stockers, which were buttery smooth, and were completely silent when spinning around after tightening them back down onto the struts.
[ame="http://www.youtube.com/watch?v=Km4mleBXdrE"]Stock BRZ top mpunts - YouTube[/ame]

So now we have some good evidence that the Com-C's are shipping with BAD BEARINGS.


Now, the POPPING noise when turning did NOT go away when I drove around after reassembling the front struts with the stock top mounts. That turned out to be coming from the REAR strut assemblies (as determined by my Dad standing outside the car in the cul-de-sac as i turned around) so we disassembled the rears next. Turns out the rear springs were assembled incorrectly at first and the very end of the springs at the bottom were not lined up with the notch on the bottom spring perch; it was about 1.5 inches off. Correcting that and reassembling them made the popping noise go away.

So now I'm running stock top mounts and camber bolts, after reassembling both the front and rear struts, and I have no noises at all.

[mechaghost]

@ATL BRZ - my suspension shop has the same findings as yours

[BRZranger]

What companies make top mounts comparable to com-c's?

[ATL BRZ]

Originally Posted by brzranger

What companies make top mounts comparable to com-c's?

Good question!

[Racecomp Engineering]

Awesome, awesome post ATL BRZ. Thank you for that!

Really upset about the Com Cs. Some of us have been lucky but it's unacceptable that so many have had problems.

- Andrew

[JoeBoxer]

Originally Posted by ATL BRZ

Good question!

http://www.vorshlag.com/product_info...roducts_id=513

Pricey and i don't know if they are compatible or not maybe RCE could answer.

[Racecomp Engineering]

That specific kit is a no, but I believe they are working on something.

Gonna do some thinking on this topic....

- Andrew

[Phaedrus29]

Originally Posted by ATL BRZ

Yes, tightened them while using a spring compressor when reassembling while off the car, then double checked when they were on the car, then triple checked after driving on them.

Maybe they are too tight? Not enough clearance between the top mount and the black spring cap?? How are you guys judging torque on that top nut?

Originally Posted by Smudgeous

You should tighten them with 41 lb/ft of torque, as per the diagram.

OK sorry, I'm still confused about how to tighten the top nut. I can't use my torque wrench AND use an allen key to keep the strut from spinning. Would this work: use a go-thru socket (and allen key) to tighten the top nut down a bit...and then finish it off with just a torque wrench?? I just don't want to damage the strut by spinning/turning it.

------

Also, did RCE leave off the instruction and torque spec for attaching the swaybar endlink? I think the diagram says 34 ft-lb. Also, the RCE instructions say to torque the clevis bolts to 129 ft-lb, but I think the diagram says 114 ft-lb.

And does anyone know where I can find the torque specs required for the rear camber bushings install? Thanks.